# Mako Burner



## bmac2 (Nov 15, 2014)

Hum. Looks like I have to find something to keep me amused for the next 5 or 6 months. Good thing winter doesnt start until Dec 21/22.


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## bmac2 (Nov 15, 2014)

Ive been thinking about getting into metal casting (aluminum) for some time now and recently discovered that my wife is not totally against the idea. As in, when she saw I was looking over a web site on making a small (paint can) foundry said oh. Werent you going to make one of those? Im going to take that as a green light to start tooling up. Thm:
Its going to be too cold and way to wet outside to get right into pouring metal but I figure I can start by trying a couple of burner types. 
I stumbled onto the Gypsy Tinker (https://sites.google.com/site/gypsytinker2012/info/foundry) and thought the low pressure Mako Burner (https://sites.google.com/site/gypsytinker2012/rantings/blog/makopropaneburnerdesign) looked interesting and gave it a go. Only took about an hour or so to scrounge/make up the parts and put it tougher.


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## bmac2 (Nov 15, 2014)

The flare looks like crap because I heated it up thinking it would make forming the bell easier and in the process had the tube crush down a bit. Now Im thinking quality not quantity here but to me the flame looks pretty good. I dont think it would melt anything but I just used a spare BBQ regulator so thats what, 6 - 8 ounces? I have to get some proper hose and fittings before I can test it out with my adjustable regulator.


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## Brian Rupnow (Nov 15, 2014)

Bmac--You haven't got the market cornered on snowfall----it snowed 8" at my place yesterday in about 3 hours. Good luck with your casting.---Brian


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## jasonh (Nov 15, 2014)

You might find the following interesting:

http://youtu.be/l697pB9X5TI

Lot's of people use naturally aspirated burners- I made one, but I had trouble getting enough heat out of it. I've since gone to forced air (with a hair dryer) and while it might not be as clever- it gets the job done and gives the possibility of cranking up the heat by cranking up the air and fuel.


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## bmac2 (Nov 15, 2014)

;D





Brian Rupnow said:


> Bmac--You haven't got the market cornered on snowfall----it snowed 8" at my place yesterday in about 3 hours. Good luck with your casting.---Brian



Thanks Brian
I think youve followed enough of my builds to know that if Im working from castings Id better be able to make a second one. :fan:
On average we dont really get a lot of snow our here, its too dry. We do say strange things like its not going to snow, it has to warm up first. Youve got that Great Lakes effect thing going and Ill take my colder but dry over your cold but damp any time. Hell I bought my first snow blower last year (used it twice) and thats only because Im getting lazy.


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## bmac2 (Nov 15, 2014)

Hi Jason thanks for the link.  
I was reading Myfordboy site (again) the other day and see that he has added a blower to his furnace and it sure looks impressive.
[ame]https://www.youtube.com/watch?feature=player_embedded&v=ZjGT8ZAVnts[/ame]


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## bmac2 (Nov 21, 2014)

Got the Mako paired up with an adjustable regulator today and gave it a try. Played with the position of the bell a bit and to me the flame looks good at about 4 lbs. pressure.


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## bmac2 (Nov 21, 2014)

I couldnt see most of the flame with the lights on and turning them off helped but only a bit. Im assuming thats a good thing, clean burn?


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## bmac2 (Jan 4, 2015)

Well I woke up this morning to Environment Canada issuing a weather warning of *Extreme Cold*. Its January. Its always cold in January. 
Todays forecast: _Sunny. Wind up to 15 km/h. High minus 17. Wind chill minus 41 in the morning and minus 29 in the afternoon._ 
Oh. . . . . Looks like a good day to start on my Coffee Can Foundry.


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## bmac2 (Jan 4, 2015)

Please keep in mind I don&#8217;t expect this to last forever it&#8217;s more of a test bed or proof of concept than anything else. If I get into casting I&#8217;ll have to make something more substantial. My game plan for now is just casting ingots from some scrap aluminum I&#8217;ve started hording. Then I have a couple of ideas I&#8217;d like to try using lost foam. If that works out then I want to try making some simple patterns and sand casting. 

But before I can do anything I need something to melt stuff in.

This is going to be my 49th parallel Foundry. The outside is a Kirkland coffee can from Costco (USA) and the inner liner is good ol Canuck Tim Hortons. This should let me use a 3&#8221; by 6&#8221; high crucible. The burner support pipe/ tuyere is an old plumbing fixture and a nice fit for the Mako Burner. I cleaned it up and cut it to intersect the inner can on the tangent.


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## bmac2 (Jan 4, 2015)

Playing around with this setup Ive rediscovered that I cant juggle. I just couldnt keep the 3 pieces lined up so I tack soldered them in place. The solder is going to survive the first light up but it will hold everything in place while I ram up the refractory.


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## bmac2 (Jan 4, 2015)

The refractory mix is 1 part Fire Cement to 4 parts Perlite straight off the Myfordboy blog. Ive seen web pages swearing that Portland cement/ Perlite/Fire Clay as the way to go but Ive also seen too many pictures of catastrophic failures of that mix to want to try it.  I figure if anyone knows *how not* to blowup a furnace its Myfordboy.


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## bmac2 (Jan 4, 2015)

I read somewhere that the vent hole in the lid should be the same size as the crucible so I made it 3 but it looks too big somehow?


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## bmac2 (Jan 4, 2015)

So far all I have invested in this other than time (and I dont care much about that on a day like today) is $12.99 for a tub of Imperial Hi-Temp Cement. . . . Oh. . . . and someone just might owe my wife a bag of Perlite from her gardening supplies.:hDe:


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## bmac2 (Jan 11, 2015)

Wow. Is that home page ever out of date _August Project of the Month_ 
Anyhow.
While reading yet another page on metal casting they once again pointed out that _soup cans should never be used as a crucible_. This started me thinking about the Tims can I left in the furnace. Isnt that a bit like using a food tin as a crucible? I had leftover Hi-Temp Cement so I gave the interior a good skim coat. This should protect the tin from all the direct nastiness of the burner so all it has to contend with is the heat. Im thinking of asking my wife to hide this somewhere so I can stop itching to light it up . Im confident that the Mako burner will get it up to a temperatures hot enough to fire it, but with winter temps in the garage (-20 to -9C) I dont think the last step in firing a new furnace IE letting it cool slowly to avoid cracking would work out very well.


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## bmac2 (Jan 11, 2015)

Stopped by Metal Supermarket on the way home from work Friday and dropped $4.50 on a foot of 3 pipe, this will give me enough for 2 crucibles. The walls a tad over 3/16 and I have some 1/4 plate for the bottom. Ive got a small wire feed unit but my welding skills are second only to my sewing and basket weaving (gob on lots and break out the angle grinder) so I might just get everything cut to size and cleaned up then phone a friend.


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## RichD (Jan 12, 2015)

I'm watching the progress.
Looks good so far. You could use it to heat your shop now.
Someday I hope to make a home foundry as well.
What's Perlite? I'm not familiar with that term.

Rich


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## bmac2 (Jan 12, 2015)

Hi Rich
According to Wikipedia : http://en.wikipedia.org/wiki/Perlite
Perlite is an amorphous volcanic glass.
According to my wife: Its used instead of soil to start plants from cuttings and in the garden to prevent soil compaction.
For a home foundry it gives a cheap (9L bag for $3.19 at Lowes), lightweight insulation that can take high temperatures.
From everything Ive read a monkey with a book of matches should be able to melt aluminum. Maybe not well but melted. I think judging temperature will be my first challenges. For now Ill be happy if I can take all the aluminum parts I mess up and cast them back into a usable shape. :fan:


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## bmac2 (Jan 16, 2015)

The weather looked like we were heading into a warm spell (this is Alberta, -20 Monday. +10 Wednesday) so I thought I would get a chance to fire up the furnace. I started by hanging a 60w bulb in it for a day then used a heat lamp on and off for a couple of days (didnt want to leave it on unsupervised) then out to the garage.

Switched out the adjustable regulator for the old BBQ one I first tried the burner with and lit it up. Sorry no pictures. After about 10 minutes I started getting smoke coming out the holes in the pop rivets that are holding the wire running around the inside supporting the refractory. There was no smell coming off it (a hint of hot dirt maybe?) so with the overhead door open a bit I let it run. This got boring after about half an hour so I decided to put the adjustable regulator back on and give it some heat.

So the things I have learned. Dont use Imperial Hi-Temp Cement. From one of the Yahoo forums I read.
_There are several different binder systems used for refractory cements. The least expensive, and the lowest temperature rated, is sodium silicate. Unfortunately, the sodium silicate will bubble considerably if heat is applied to it. Unless, you go through and add vent holes about every few inches._

Im thinking that the Imperial Cement contains sodium silicate. Ive started calling my furnace the Troll Forge. Lots of warts . Shortly after I hit it with the Mako burner the skin started to blister. 
On the up side I think its still serviceable, the outside wasnt getting hot, and  it didnt take long to get the inside glowing a nice soft red. With the garage warmed up nicely and the foundry glowing I put a 6 length of the pipe Im going to make my crucibles out of in it and it started popping. I remembered reading about this, backpressure. It looks like with the size of the furnace and the amount of air space I have around the crucible I can only run the burner at 2 or 3 pounds pressure. At this pressure it still has a full flame wrapping around the crucible and coming out the top.

Next up. . . Finish the crucibles and see if I can melt something.


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## bmac2 (Jan 17, 2015)

Last night my wife told me that she wanted a different shelf setup for one corner of her quilting room. She then proceeded to show me some shed found on the internet ranging around the $100.00 mark but none of them where quite the right size. Looking at what she wanted, top, bottom, 1 fixed shelf and 4 adjustable. I knew I could knock it out in a few hours for less than $50. So this morning I was off to the lumber yard then into the garage. Happy wife, happy life. Quick tip for spacing pin for adjustable shelves. I just use a piece of peg board and bit for centering screw holes for hinges. This wouldnt be good enough for displaying your prized marble collection but it will do for cloth.


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## bmac2 (Jan 17, 2015)

So 4 hours later my wife is happy and I think I just built up some more shop time credits. Thm:


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## bmac2 (Jan 17, 2015)

Oh ya oh:, there is supposed to be an interesting part. This also looked like a good time to play with the Troll. After all Rich said I could use it as a heater. The Troll was smoking again so the garage didnt warm up with the doors open. It was +1C in the garage so this was definitely a COLD start. The little Mako got the Troll up to red in just over 10 minutes with the regulator set at about 3 lbs. I didnt dare melt anything. Ive got a foot of snow outside and the pad inside is wet from all the crap that melts off the cars. 
Yep. I think Sam and Frodo could have saved a lot of time and effort if they had just built one of these.*knuppel2*


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## RichD (Jan 17, 2015)

good idea on making the shelves for shop credits.
Rich


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## bmac2 (Jan 18, 2015)

The weather is still cooperating so I decided to work on my crucibles.  The plate I have is a little over 3/16 so hopefully it will hold up. Marked out the 2 bottoms and Ill cut them out on the band saw.


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## bmac2 (Jan 18, 2015)

This is a pattern I made up once when I needed to form up a belt guard. I came close to tossing it more than once thinking Id never use it again but it makes a great seat when using the 4x6 vertically. I use a couple of bungee cords and clamps when using it like this, my _Gentlemans bits_ dont like staring at a running blade.


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## bmac2 (Jan 18, 2015)

The band saw wasnt going to be able to handle the radius so I made relief cuts down to the cut line.


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## bmac2 (Jan 18, 2015)

Every thing's cut and cleaned up so I guess its time to attempt to weld two pieces of metal together.


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## bmac2 (Jan 18, 2015)

Well once again I have proven that _owning a welder_ and _being a welder_ is not the same thing. When I first bought the welder I could get a weld that wasn&#8217;t horribly embracing. But after the 6 ft. real of wire that came with it ran out I haven&#8217;t been able to get the same results. Agggg. That&#8217;s enough ranting. I don&#8217;t think the bottoms will fall off and with the viscosity of molten aluminum they shouldn&#8217;t leek so I&#8217;m going to go with them for now :fan:. If anyone thinks this is a BAD IDEA, please speak up now :hDe:. 
One day the local college should offer a course on welding that isn&#8217;t for people working on a Pressure &#8220;B&#8221; ticket. They could call it &#8220;Farmer Welding 101&#8221; for us total hacks.


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## vederstein (Jan 19, 2015)

Don't skimp, stick with a good quality wire.  If you have the ability to TIG, you can smooth out some of that porosity without adding any filler metal.

I was welding up a manifold to gang run my steam engines yesterday.  I could have used another method (like a single block), but I wanted to TIG it for the practice.  I proved what you said is true:   "_owning a welder_ and _being a welder_ is not the same thing".  After five ports, my skill was definitely improving.  Too bad I'll lose that skill after awhile.

I used the be the engineer at a welding shop.  Professional welders tend to have a bit of a complex.  They all think they're the best welder!


...Ved.


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## bmac2 (Jan 19, 2015)

vederstein said:


> Don't skimp, stick with a good quality wire. If you have the ability to TIG, you can smooth out some of that porosity without adding any filler metal.
> 
> I was welding up a manifold to gang run my steam engines yesterday. I could have used another method (like a single block), but I wanted to TIG it for the practice. I proved what you said is true: "_owning a welder_ and _being a welder_ is not the same thing". After five ports, my skill was definitely improving. Too bad I'll lose that skill after awhile.
> 
> ...


 
Hi Ved
Isnt it great when by the time you finally get the technique down just right youre on the last hole?
 I think that complex comes from breathing in the fumes. I like to wear a respirator when Im welding, maybe thats why I cant get it.
I have is a Lincoln Handy Core so no shield gas. According to the book of words that came with it, most of which states how important it is *NOT* to lick any part of the welder and to never place welding wire in your ear, the spool was NR-211-MP flux-cored wire. I have several Lincoln dealers in my area but none (that sell retail) carry it. Ive had them tell me _this stuff is the same thing_ but I just cant get the same results as I did with that original spool. Id like to get another just to see if its me or just some slight difference in the wire composition. It still shows up on the Lincoln web site but I find it frustrating that Id have to order the wire from the US and pay the shipping when every kid and his dog around here sell the welder.:rant:


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## bmac2 (Jan 25, 2015)

I got to use up some of my shop time credits and fire up the troll to see if I could melt something. Its 10C in the garage today, weird weather for Alberta in January but Ill take it. Started it up at 3 psi and got the crucible up to red in 5 minutes.


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## bmac2 (Jan 25, 2015)

The muffin tin my wife gave me (always ask) had a coating on it so I burnt it off while I got to work cutting down some more of my scrap into bite sized pieces. Whatever that coating is (dont think its Teflon) it stinks a bit.


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## bmac2 (Jan 25, 2015)

When we replaced our furnace a couple of years ago I kept the fan assembly and it makes one killer exhaust fan. It comes in handy for times like this.


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## bmac2 (Jan 25, 2015)

After some pre heat I started loading the crucible and increased the pressure to 7psi. Once the troll gets hot is seems to deal with higher pressure better and 15 minutes later it was ready to pour. The next 3 melts where done with the regulator set to 10 psi and it took about 10 minutes from load to pouring.


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## bmac2 (Jan 25, 2015)

I can read all the information on metal casting available on the net and look at hundreds of charts on melting temperatures but until I did my first pour its hard to really grasp just what the numbers mean. I didnt see this until I watched the video. In the video my pliers are in contact with the crucible for a grand total of 34 seconds and they got hot enough to scorch the cardboard when I put them down.

[ame]https://www.youtube.com/watch?v=JNLaCiv1Kwk&feature=youtu.be[/ame]


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## bmac2 (Jan 25, 2015)

I only melted the extruded scrap and didnt do any of the cast scrap I have. I cut one of the pucks in half and it looks pretty gummy, I dont think it would machine very well. It might be Ok for an engine base or something. Looks like Im going to have to do some reading on improving alloys.


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## bmac2 (Jan 25, 2015)

Well that was fun and educational. Despite my dodgy setup I only burnt myself once and that was on a piece Id pre heated and put back onto the pile of cold scrap. Needless to say I forgot about it until I tried to move it while setting up for the next melt. Lesson learned; keep the hot stuff and the cold stuff separate.  The crucible looks like it held up Ok with only light scaling. It stood up better than the muffin tin, I had one stick :fan:.


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## TorontoBuilder (Jan 25, 2015)

bmac2 said:


> I can read all the information on metal casting available on the net and look at hundreds of charts on melting temperatures but until I did my first pour its hard to really grasp just what the numbers mean. I didnt see this until I watched the video. In the video my pliers are in contact with the crucible for a grand total of 34 seconds and they got hot enough to scorch the cardboard when I put them down.
> 
> https://www.youtube.com/watch?v=JNLaCiv1Kwk&feature=youtu.be



Please dont take this the wrong way...  but  my wife used to be a workplace safety trainer for commercial electricians and she'd freak if she saw this. No leather apron working on your knees offers zero protection. Then on the last bit of your pour you gave a sort of jerk to get the last drop out of the crucible. That could result in a blob of molten metal being flung onto your unprotected legs.

I know a guy who gave himself 3rd degree burns by spilling molten lead on his leg while casting fishing sinkers from tire weights. Please consider proper long handle tongs for lifting your crucible and pouring so you can stand up and gain some much needed distance from the molten stuff.


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## Cogsy (Jan 25, 2015)

I have to agree it was a little dangerous. Having worked as a hot dip galvaniser, I can tell you that even a small drop of molten metal on the skin causes a major jerking reaction/reflex. If you happen to be holding something molten at the time, it will end up splattered all over the immediate area. So the idea is to not be in the immediate area - less chance of getting a splash and less chance of getting covered if an event happens.

We didn't wear aprons in galvanising (just too cumbersome to run in, and I have literally run for my life on occasion) but we did get some 'fireproof' (so they said) shirts. I once had a fireproof shirt catch fire and I could not put it out. Ended up pulling it over my head, still buttoned, while it went up in flames. At least it did offer some thermal protection and I wasn't badly burnt. 

I would never go into galvanising these days, but I am slowly getting set up to melt and pour aluminium. Be safe and don't take chances.


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## bmac2 (Jan 25, 2015)

Torontobuilder, Cogsy. 
Take it the wrong way? How? I agree with both of you. In review I wont be doing it again until I get my hands on some PPE, something to lift the crucible with, and a proper sand setup to pour in. I have a much better understanding now of just what 1500 degrees really is.


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## RichD (Jan 26, 2015)

Good attitude towards the safety advice.

One small thing I noticed was when pouring, you started on the hole closest to you, then you had to reach across the just poured items to pour further out. Another exposure!
Rich


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## RichD (Jan 26, 2015)

Last year I was given a brief tour of a small aluminum/brass foundry nearby. The top edge of the pot (as big as a garbage can) with the molten aluminum was ~chest high. There was a sturdy stone ledge all the way around the pot for protection and the ledge was used as a fulcrum for the dipping ladle handles. That added a lot of security for the workers since they only had to dip and rotate the handle using the ledge to support the ladle.

The ladles had handles about 36" (or more) long. The "spoon" end was just a section of pipe butt-welded to the end of the handle near the top edge of the pipe. The pipe was about 1-1/12" in diameter and about 5 or 6 " deep.

Your crucible is about twice a big as the ladles I've described, but you might be able to fashion a permanent handle to the top edge for pouring. They also had a pouring lip formed into the top edge like a regular measuring cup has.

Oh, and the most important part...the guy pointed to the ceiling about 30ft above and said...sometimes moisture in the pot makes it "spit". There was spattered aluminum stuck to the ceiling. It was a good tour, and my wife got to see how the custom bed frames were made in the factory.

Rich


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## canadianhorsepower (Jan 26, 2015)

bmac2 said:


> and see that he has added a blower to his furnace and it sure looks impressive.
> https://www.youtube.com/watch?feature=player_embedded&v=ZjGT8ZAVnts


 
Nice build interesting
I dont know if you notice but he's using 220 volts source
If you plan to do the same thing youll go with out adaptor

cheers


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## bmac2 (Jan 26, 2015)

Hi Luc
Myfordboys in the UK so yep 220v. It sure looks to improve the performance of the furnace but I dont think Ill be looking at anything like that for a while. The Troll is made from a couple of coffee cans and I honestly feel that the Mako is almost too much burner for this small a furnace already. If I keep with this Ill want a solider setup. Ive seen a few rigs made from 20lb propane tanks and the size seems a good fit for hobby casting. I was talking to a local propane supplier about a new tank with no valve and he wasnt sure (no one has ever asked for one before) but he figured it would be under $20.00.  The idea of cutting into a USED propane tank just doesnt appeal to me at all.


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## Cogsy (Jan 26, 2015)

bmac2 said:


> The idea of cutting into a USED propane tank just doesnt appeal to me at all.


 
I have an out-of-date tank in my backyard that I'm going to attempt to cut open. It seems you can unscrew the valve reasonably easily and safely, then I'll flush it thoroughly and it should just be an inert metal cylinder.

It's on my to-do list for the near future so if I suddenly stop posting you'll know it went badly...


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## bmac2 (Jan 26, 2015)

Cogsy said:


> I have an out-of-date tank in my backyard that I'm going to attempt to cut open. It seems you can unscrew the valve reasonably easily and safely, then I'll flush it thoroughly and it should just be an inert metal cylinder.
> 
> It's on my to-do list for the near future so if I suddenly stop posting you'll know it went badly...



I saw one where the guy cut the tank with an angle grinder while it was full of water. 
I just thought _Great wouldnt blow up, I just get electrocuted_:fan:
I had thought of using a nitrogen bottle after washing out and continuously flood the tank but I just dont know if it would do anything except waste the nitrogen bottle.


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## RichD (Jan 27, 2015)

Bob,
I retired after 42 years in the oil refining business. One thing I've done a lot of is prepare equipment for maintenance during process shutdowns. We would typically water wash the systems and related piping, drain, then steam until the towers were above 200 degrees F, then turn off the steam and follow with nitrogen until all the steam was expelled. You could then safely cut and weld once the equipment was properly isolated opened and aspirated with air blowers and eductors.

Equipment that was in LPG service such as propane/butane was typically just steamed out since there would be no traces left once all the hydrocarbons were boiled away by the steam.

In your case if you depressure the bottle, fill it with water, drill a small hole somewhere in the dome so the water has somewhere to go, then flood it for awhile, you'll be safe.

If you're still worried you can then purge it with  with air for 30 minutes via the small hole used as a vent.

Rich


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## Swifty (Jan 27, 2015)

Propane tanks are no problem, plenty of people make small wood burning camping stoves etc. out of them. But drums that have had petrol in them are another story, I wanted to solder a tap on to an old drum years ago, it had been used to store petrol. I washed it out several times with hot water and detergent, well as soon as I put a flame near the tap it soon cleared out any remaining fumes, the resulting WOOMP as the fumes burnt could be heard for quite a distance, the blast of air out the filler hole was quite something. Lesson learnt!!!!!

Paul


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## bmac2 (Jan 27, 2015)

Rich . . Paul . . . Im getting tempted.
So what youre saying is this is doable? scratch.gif
With no Kaboom?


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## Swifty (Jan 27, 2015)

Yes, very doable. I've seen pictures of furnaces made out of propane bottles.

Paul.


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## RichD (Jan 28, 2015)

If you follow all the advice points posted you shouldn't have any problems.

Bear in mind that the local fire department probably has the same "sniffers" we used in the refinery to determine "LEL" (lower explosive limit) and "VOC"(volatile organic combustibles) prior to welding. You could ask them what they think. Maybe they'll check it for you...or throw you straight in jail for just thinking about it.
Rich


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## bmac2 (Jan 28, 2015)

*Holly paradigm shift Batman!* :wall:
Funny how you can see something every day but after 3:30 its out of sight out of mind. We use gas detectors all the time, I just never thought to sign one out for the weekend. It must be just that Id dismissed a _used_ tank thinking that cutting it was too sketchy.


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## bmac2 (Feb 1, 2015)

Well I dropped some coin and topped up my PPE. Not much choice when I know my wife reads these threads. *AND I do not want to be these guys*. Torontobuilder DONT LET YOUR WIFE LOOK!


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## bmac2 (Feb 1, 2015)

I know I screwed up on my first pour but . . . . OMG. 
Anyhow, armed with my new sleeves, split leather apron and chaps (feel nervous wearing backless chaps in the province they made the movie &#8220;Brokeback Mountain&#8221; in) and my old face shield, gloves, Kevlar boots (trust me, you don&#8217;t want steel toed where it can hit -30) my wife will let me go outside to play. Also made a lifting fork and hook for the crucible. 

The ingots from my first melt are pretty soft but it was extruded to begin with so I wasn&#8217;t expecting much from it. I&#8217;ve been reading about ways to improve the quality of cast aluminum this past week and it looks like the best bets are adding silicon, magnesium, zinc or copper. 

Silicon hummm nope, don&#8217;t have any.  
Magnesium, that&#8217;s not going to happen, I&#8217;ve seen a magnesium fire, so no. 
Copper, I can do that. 

So my game plan is to try four melts pouring two ingots of each. Three with copper at 1, 2, and 3% respectively. And one with zinc, ok I&#8217;m going to toss in a couple of pennies so technically it will be Al-Zn-Cu. Canada doesn&#8217;t use pennies any more so I shouldn&#8217;t get arrested. ;D
The 1% melt was already in the Troll before I thought to take a picture. Sorry no vids, I forgot to put the chip back in the camera and the internal memory is _very_ limited.


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## bmac2 (Feb 1, 2015)

The three pictures below are: 
Raw extruded aluminum, very soft and gummy
1% copper, better grain and not as gummy
2% copper looks and cuts much better.


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## bmac2 (Feb 1, 2015)

Unfortunately this is as far as I got with my experimenting with alloys. On the third melt something went very wrong. I fed the Troll the first ingot and was waiting for it to melt before adding the copper and the second one. When the first one looked ready I went to give it a stir and as soon as I touched it with the rod it froze. The whole thing turned to 244 grams of thick sludge. I know Ive read something about this happening but I cant remember. Im not sure if the crucible is salvageable. I might try putting it in the Troll upside down and see if I can melt it out. It must be the kid in me but I was really looking forward to tossing in those pennies.


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## Swifty (Feb 1, 2015)

The third picture looks like you were almost there, would you be better using aluminium from old mower crankcases or similar instead of extruded. I have no idea what happens in the casting process to the additives in the parent material, are certain elements burnt out or do they remain. If you started off with a good grade of aluminium, do successive melts and repours lose some of the elements in there, like copper or zinc.

Paul.


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## bmac2 (Feb 2, 2015)

Swifty said:


> The third picture looks like you were almost there, would you be better using aluminium from old mower crankcases or similar instead of extruded. I have no idea what happens in the casting process to the additives in the parent material, are certain elements burnt out or do they remain. If you started off with a good grade of aluminium, do successive melts and repours lose some of the elements in there, like copper or zinc.
> 
> Paul.


 
Hi Paul
Ya I really wish I got the last 2 melts done. I think the 3% copper would have been a keeper. And Im still going to run them I just have to solve that happened with that last melt first.
I think it says in the Backyard Foundry Bible somewhere _thou shalt cast upon thy molds that which has already been cast_. Ive got a small stash of good cast scrap but Im saving it for when I know what Im doing. Ive found that you dont have to even look for extruded aluminum it will find you. As soon as word gets out that your building/have built a foundry suddenly all your family, friends and neighbours remember the old aluminum screen door they replaced thats been sitting in the corner of the garage for 5 years. Ok. First they think youre crazy, and then they remember the door, bent ladder etc. We are literally surrounded by the stuff and if youre willing to clean it up . . . . .
Ive got a couple of good sources (auto industry) for cast scrap but I havent asked them for more than a couple of pieces yet for fear they will come by one night and fill my back yard.
Im no expert on metallurgy (I read a book once *club*) but I do know that one of the ways to purify an alloy is to burn out the impurities. Zinc I think would cook out pretty quickly if the melt was over heated. A lot of the stuff Ive been reading lately on improving alloys is still all _Black Cats and Pointy Hats_ to me but with one session open to the article and another on Wikipedia Im stumbling forward.


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## bmac2 (Feb 3, 2015)

Winters back. With highs chasing -20 over the past couple of days Ive had lots of time to think about my crucible freeze. Looking over my notes (yes I take notes) and comparing them to my first melt I think with a little help from Alloy Avenue, Ive come up with what went wrong. At no time in my second melt did the Troll look like this.


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## bmac2 (Feb 3, 2015)

During the first melt I was having problems with backpressure and was compensating by adjusting the regulator starting at 3 psi to preheat, going to 7 for the first melt and then 10 psi for the rest. At the time Id thought Once the troll gets hot it seems to deal with higher pressure better. Now Im thinking that once it gets hot it _needs _the higher pressure. 
This time when the Troll started to surge I was adjusting the burner position in the tuyere until it stopped and leaving the regulator set at 5 psi. I know that just into the last melt the Troll was surging and I moved the burner to get it under control. Thinking back now I remember seeing a small amount of blue flame around the top of the crucible. I think what happened was the gas was only burning in the top half of the furnace and the bottom was basically just getting cold air.


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## bmac2 (Feb 3, 2015)

The aluminum _looked_ melted in the crucible, as in shiny and smooth. When I went to stir the melt I think the rod acted like a heatsink taking it over the edge and the burner wasnt butting out enough to recover. As soon as it warms up a bit Im going to see if I can melt the gunk out, or use my spare crucible to get the 3% mix and toss in those pennies. 

For now, its cold outside but driving around today, Im still living in a Christmas card.


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## bmac2 (Feb 8, 2015)

Well with the weather this past week and nothing on TV except another Duck Dynasty marathon on A&E I decided to go play in the shop. ;D
 The one thing that comes up on a lot of the web-pages Ive seen is the Reil burner. This is the burner I had originally thought to build before I made the Mako. Looking through my junk I had an 8 piece of ½ black iron pipe and a 1 reducer but didnt have all the stuff so I faked one up out of what I had at hand. Going to give it a try, if it works out Ill have to pick up some parts to do a proper job.


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## bmac2 (Feb 8, 2015)

Set up the Mako burner in the Troll with the regulator set to 15 lbs. and 25 minutes later the gunk in the bottom or the crucible was looking a lot more like molten aluminum and poured out easily. It doesnt look bad so Ill toss it back in with the extruded ingots.


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## bmac2 (Feb 8, 2015)

The crucible is cleaned out so I now have a green light to carry on experimenting with the aluminum/ copper alloys. I weighed out the copper for a 3% and 4% alloy as well as one for .75% zinc. What do you do when Apple wont let you update your old I-pod? Keep all your threading/machining apps and a spreadsheet on it and let it live on in the shop.


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## bmac2 (Feb 8, 2015)

I was having back pressure trouble with the Troll starting to surge when I put the crucible in and again when I put the lid on so I decided to try the Reil. Ive got to say I dont think Ill be going back. Had the regulator set at 7 lbs. and it just runs. Each melt was around 400g and start to pouring was a constant 10 minutes. The way I was getting the copper into the aluminum was to melt the heavier of the 2 ingots first, drop in the copper and submerge it with the second ingot to try and keep the oxidation down but I still got a fair bit of dross. The stuff is light as a feather.


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## bmac2 (Feb 8, 2015)

My results.
In the following pictures, on the left is an raw ingot poured from the extruded aluminum and on the right is one with the copper added. 
The 1% is soft but not as gummy as the raw ingot.


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## bmac2 (Feb 8, 2015)

The 2% is still soft but getting there.


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## bmac2 (Feb 8, 2015)

This is the one I was looking forward to last week when my melt went south. The 3% copper cuts much better than the first two and does have a better look to it.


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## bmac2 (Feb 8, 2015)

I am glad I decided to try 4%. Id almost pay money for this stuff. I think I may have overheated it a bit wanting to make sure the copper tubing was melted. It was red hot going into the muffin tin. Looks like I have a lot of reading to do on degasing but it cuts very nicely and has a good look to it.


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## bmac2 (Feb 8, 2015)

Cant see much difference with the zinc but it did cut well in the band saw. And I got to melt some pennies, well half of one.


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## bmac2 (Feb 8, 2015)

When I made the alloys I did two pours of each so I could cut one in the band saw to see a cross section and another to put in the lathe. All of the muffins machined, well like aluminum. But I have to say Im quite happy with the look of the 4%.


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## bmac2 (Feb 15, 2015)

I made a stop at Princess Auto on the way home the other day and after getting the parts I needed to finish the Reil burner I took a walk through the surplus section (you know you gotta). Found this little 4 squirrel cage fan for $4.99. (http://www.princessauto.com/en/detail/sony-brushless-blower-fan/A-p8586604e) and just had to buy one.


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## bmac2 (Feb 15, 2015)

My original thought was that I might use it to replace the fan on my mini-mill thats starting to make some noise but I already have a couple of salvaged 12vdc muffin fans that would drop right in so why reinvent the wheel. 

I have to wait for spring before I can try sand casting to see if Im able to actually cast anything other than ingots. But *IF* I can, and I build a larger furnace I might use it as a blower for forced air. Hooked up to my bench supply it will run down to around 1.5v with no problem so all Id need to do is make up a quick and dirty variable 12v supply. At 500ma it could easily just run off a couple or rechargeable batteries, one less thing to trip on around the furnace. 
[ame]https://www.youtube.com/watch?v=3hf-qR_m55w[/ame]


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## gus (May 13, 2015)

Did some gravity casting with Cast Iron Molds. Was casting Automatic Condensate Traps and getting pin holes and leaks.
Bought some degassing agent that looked more like muffins and you need a inverted cup to push it down to the bottom to enable the degasser to produce mini bubbles to bring crap. A refining agent is added on to make the machine surface look good. I used extruded bars and scrap pistons to improve machineabilty.
Foto show aluminum auto trap on the left hand side. Build a steel plate clad furnace with high temperature firebricks and custom cast C.I. crucible. Crucibles made with steel pipe did not last look long. After a few casting sessions the aluminum ate thru the steel pipe.

Casting Temperature. Too high pouring temperature cause excessive shrinkage.Too low and you get cold runs. Pouring temperature has to be figured out. Silicon additives make pouring and metal flow into mold smoother.

Have fun casting aluminum but take extreme precaution and well protected. 1400 degrees Fahrenheit burns very badly. No busy body on-lookers. No visitors. I had zero accidents. Gus was Operations Manager,Ingersoll-Rand,Singapore Small Air Compressor Plant for 20 years till laid off.


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## darwenguy (Dec 10, 2015)

Hi well done on the furnace experiments. I too learnt to cast recently. I made my furnace from an old lpg tank just drain fill with water then cut no prob. I fire mine with coal and a hair dryer. I  also added about 6 prcent copper to the mix makes a massive difference when machining tapping. I must thank myfordboy and tubal cain for there videos are more educational then any book. For degassing i use soda crytals and for flux low salt both available anywhere. Good look with sand casting and dont give up you will learn the most from your mistakes (i did). Ive just got myself a ceramic crucible and some scrap cast iron since my furnace melted my steel crucible!!


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## Beachside_Hank (Dec 16, 2015)

I've been gearing up for a home foundry capability and posted my results thus far up on Instructables:
http://www.instructables.com/id/Benchtop-Foundry-And-Forge/

I recently used the lower section from a barbecue cart as the mobile stand for my works after melting down the upper ally firebox 

I'm at the stage of "clarification", that is to say making dross- free ingots in muffin tins, ready for the day when I am ready to cast- right now I'm thinking hotwire foam molds to begin with.

I have a propane tank foundry ready for refractory, but so far this little forge has done all I ask, so the big brother is on hold.

My fuel is free, simply hardwood furniture picked up from my neighbors during "asset recovery sweeps" of my 'hood. My main source of ally is 
Sears Craftsman radial arm saws, a very- high quality set of castings. Emerson Electric has a recall event going on these saws built 1958- 1992, and pay a $100 bounty for the motor, so all the rest of the metal I get to keep anyway, so I'm kinda swimming in ally right now, have about 50 pounds of clarified ingots in a bucket, probably twice that amount in raw parts to process.

It is unbelievable fun to do this, trouble is it now cuts into my lathe time.


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