# Electric furnace



## kadora (May 29, 2013)

Hello friends
I would like to start to cast my own engine parts but i am bigginer
and i need a lot of  help .
First i need an furnace . In my city is banned back yard open fire
so i have decided to buy electric furnace.
Please have a look on this ebay address if is worth to buy this furnace ?
http://www.ebay.co.uk/itm/330761134776?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
I want to cast only small engine parts but i am not sure if this mini furnace
can serve me or it is absolutely useles for engine parts casting.
Thanks for your advice.
Kadora


----------



## kadora (May 29, 2013)

I forgot to say i want to melt aluminium 
take my apology.


----------



## aarggh (May 29, 2013)

NOOOOOO!

Sorry, I bought one and can say it's definitely not suitable for anything that approaches any real use for casting, smelting, or high temperature. The heating elements are quite thin and are not designed for many cycles. And at higher temperatures the wire actually breaks due to corrosion with the heating/cooling cycles. Doing brass with mine just kills it, and even for aluminium I have to get it to at least 800-900 celcius to melt due to the heat losses. Mine is now sulking in the garage after the second coil disintegrated, I will get it fixed as it's good for occasional small stuff, but I don't know if doing even just one melt each month, if the element would last in between long enough to get good usage out of it before it corrodes and breaks. The other problem is the 3kg crucible sounds good, but it very, very quickly becomes too small for most stuff.

For the money, your better off getting an old electric top loading kiln that is designed to routinely go up to 1200 celcius, and that should last quite well.

cheers, Ian


----------



## /// (May 29, 2013)

kadora said:


> ...
> In my city is banned back yard open fire
> ...



A furnace is a _contained_ fire.
Some firebricks or castable refractory, propane burner, go for it.


----------



## dnalot (May 29, 2013)

This is a furnace made from and old gas cylinder. It holds a number 10 crucible. I have been using it for two years now and it still looks like new inside. It will melt aluminum quickly and bronze but slowly. I plan on adding an inch and a half of ceramic insulation this year to improve its performance, and some wheels because its to heavy to lift with my old back. I keep on old crucible in the lower compartment to catch any spills. 

The photos are from its first fire. I do my foundry work out in the driveway as you don't want to spill any metal on the concrete as it will cause a steam explosion.

Aluminum is the most economical metal to recycle, needing only 1 percent of the energy needed to produce it in the first place.  I prefer salvaged outboard motor castings as they flow quiet nicely. Extruded salvage is not very good but you can mix a little in.

Mark T


----------



## jwcnc1911 (May 29, 2013)

dnalot...  That is fantastic!  I'm very curios about this... I've been considering a dive into home foundry for a few years now.  Would you provide details on the burner?  How you "coated" the inside of the old cylinder with what ever that is (it looks like Quik-crete)?  Specific curiosity because my time is already so limited... how long does it take to melt "1 batch" of aluminum? brass/bronze?  Have you ever done iron or steel?

Is that burner ceramic?  Do you use forced air in any way?

So many questions...


----------



## dnalot (May 29, 2013)

> That is fantastic! I'm very curios about this... I've been considering a dive into home foundry for a few years now. Would you provide details on the burner? How you "coated" the inside of the old cylinder with what ever that is (it looks like Quik-crete)? Specific curiosity because my time is already so limited... how long does it take to melt "1 batch" of aluminum? brass/bronze? Have you ever done iron or steel?



Wow, it would take a book to answer all of that. Lucky for you there is (Gas Burners for forges, furnaces by Michael Porter) Step by step instructions. 

The book gives details for several size burners, a number of furnace and a forge. The liner is 3000 degree refractory that I bought from a pottery supply house. No blower is needed ( yet it sounds like a jet )and it can melt 10 pounds of aluminum from a cold start in about 45 min. and the second load takes about 20 min. Double that and then some for bronze. Note that there are different types of bronze with a wide range of melting temps. Cast iron is beyond my reach. 

Mark T


----------



## aonemarine (May 29, 2013)

Heres my propane furnace melting iron...[ame]http://www.youtube.com/watch?v=CbLBiCdgRi4&feature=share&list=UUSrlSdQ3dLlHlahmmmYbb2A[/ame]


----------



## jwcnc1911 (May 29, 2013)

Wow!  You make that look so easy.


----------



## enfieldbullet (May 29, 2013)

i think the OP wants something low profile.

an electric furnace would do well there. perhaps an induction furnace.


----------



## dnalot (May 29, 2013)

That is great. Does your furnace have a blower? 

Mark T


----------



## cfellows (May 29, 2013)

I've built several electric furnaces that work fine for melting aluminum.  You can buy heating elements which are nichrome or kanthal wire coiled into a long spring shape.  For insulation, you can use insulating fire bricks which are about about 11.5 x 23 x  6.5 cm and are very soft.  They can be cut with common hand tools like a hacksaw and file.  You can also use Kaowool which is a thick fabric type of insulation.  For a container, you can use large popcorn cans or spaghetti cooker.  

Chuck


----------



## aonemarine (May 29, 2013)

dnalot said:


> That is great. Does your furnace have a blower?
> 
> Mark T


 
  When I cast Iron I use a blower (hair dryer) but for anything else I dont need it.


----------



## Mike N (May 29, 2013)

I bought one of these:

http://www.foundry101.com/Furnaces.htm

http://www.foundry101.com/search.htm

Works Great for Aluminum & Brass!


----------



## Jon (May 29, 2013)

If you want to build an electric furnace, check out Dan's Workshop Blog. Specifically, the page about his electric furnace. I think I first saw it on the Backyard Metalcasting forum. He sells plans for it on his site for $3.95US. I thought enough of it that I actually bought the plans. I haven't gotten around to actually building it yet though.

 For the heating elements, see Budget Casting Supply. They pretty much have everything you will need. If you really want to get serious about your furnace, they even have programmable furnace control boxes. With that, you can even use your furnace as a heat treat oven. 

I hope that helps.

Jon


----------



## kadora (May 30, 2013)

Thank you guys .
Kadora


----------



## gocy (May 30, 2013)

All the comments and links are very helpfull.
thanks


----------



## kadora (Jun 1, 2013)

why are electric kilns so expensive? 
Good quality SMALL hobby kiln costs 1500 EUR here compare to 
100 kg Optimum bf 20 milling machine it cost the same price - strange

I have found vendor of electric heating chamber with kanthal wire 2,6kW
1200 C for 280 EUR.
Probably i will build my own kiln but i am not brave enough to start.
Best wishes Kadora


----------



## Wizard69 (Jun 1, 2013)

kadora said:


> why are electric kilns so expensive?
> Good quality SMALL hobby kiln costs 1500 EUR here compare to
> 100 kg Optimum bf 20 milling machine it cost the same price - strange
> 
> ...



I was going to say it is the European disease then I realized that you are talking about kilns which are exactly cheap on this side of the pond.     Around here I would look for used or business close outs / going out of business auctions.  

As to building your own, you will never get anywhere if you don't try.  This is a serious AC power project though so if you don't have experience there, I'd highly recommend getting help with the build.   Oh by the way controls can be a big part of your cost depending upon how compliant you won't to be and how fancy with that control you are.   I must reiterate though get help if you aren't familiar with high power AC systems, the wiring can be lethal.


----------



## mecanotrain (Jun 1, 2013)

Hello guys,

Kadora, I built an electric furnace for brazing. I also used to melt aluminum. 




Here the construction of the oven; the total cost is 200&#8364; max.
https://picasaweb.google.com/109200417126637456771/FOUR1100C#

Regards


----------



## kadora (Jun 2, 2013)

Thank you guys .
mecanotrain what kind of insulation material did you used for your kiln ?
If i want to reach 1200 C inside chamber is OK to use bricks for 1500C? 
And could you tell me inside and outside dimensions of your kiln please?
Thank you


----------



## mecanotrain (Jun 3, 2013)

Hello guys, hello kadora,
Here are the dimensions of the oven; Outside: 285x285x370mm (mailbox of french postal service ) , Inside: 140x140x200mm.
Bricks are used for maximum temperature of 1350 ° C.


----------



## kadora (Jun 4, 2013)

Hello Roger
Thank you for dimensions I will build very similar kiln.
One question  more - did you use Kanthal wire for heating coil?
and how high is electricity consuption i plan to feed kiln 
with 2000 W maybe not enough.
Thank you a lot.


----------



## mecanotrain (Jun 4, 2013)

Hi kadora,
Yes, 2000W is fine.
My oven is manufactured with 4 dual resistors wired in series: Kanthal A1, max temp 1450°C 
The total power is 2200 W.


----------



## aarggh (Jun 4, 2013)

I can't seem to find those ones on ebay Roger, only the tight loop or plain wire Kanthal. Most of the sellers don't list a temp rating either I noticed, just the wattage. Where did you source yours?

cheers, Ian


----------



## hi speed scrap (Jun 4, 2013)

Hi Ian,

I can get a price for local manufacture of those elements for you if you want.
Theres a local bloke here that makes all that sort of stuff.
In Boronia.  Might make one myself.

Need physical dimensions and wattage/voltage etc

Dave.


----------



## kadora (Jun 5, 2013)

hello 
Ian try on ebay.UK- HEATING ELEMENT- i have found a lot of them
already coiled from Kanthal A1 and power up to 3000W 
China production.
Kadora


----------



## aarggh (Jun 5, 2013)

I found a lot of cheap Chinese ones that are just long coils with no straight ends, but also very thin, I don't know if I'd trust them for any substantial work? Especially as they look identical to the ones in my little furnace, and I've already had two sets self-destruct. Pic attached. I did find some really great ( Duralite) ones from the US, 14GA, but as usual the insane postage just kills any value. I could just about buy a new kiln for what enough of these would cost:

http://www.ebay.com.au/itm/261223874139?ru=http%3A%2F%2Fwww.ebay.com.au%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D261223874139%26_rdc%3D1

cheers, Ian


----------



## mecanotrain (Jun 5, 2013)

Hello all,
I have not bought my resistors on ebay, I contacted a French manufacturer that has wound according to my request.
http://www.adampyrometrie.com/boutique/view.php?cid=489&i_id=979
see "descriptif" ==> description:
Manufacturing coil resistors are custom made and on all brands of oven: 
The price depends on:
- The diameter of the wire
- The number of turns
- The number of strands
Do not hesitate to contact us - FREE QUOTE

Here's manufacturer, that coil resistance according to your wishes and the price is not expensive. I paid 150&#8364; for 4 resistors with shipping cost included.

It is the same work that Dave offers in Australia Thm:

(sorry for my english language)


----------



## kadora (Jun 6, 2013)

I won small wankel engine on ebay com 
price 250USD
post  40 USD
when i clic pay now on paypal invoice appeared
import charge +78USD fortunately seller was able to delete
this "hidden" charge. 
Be careful with this new Global Posting Program .


----------



## /// (Jun 6, 2013)

kadora said:


> I won small wankel engine on ebay com



Sorry to go slightly off-topic, but, nice work!
I've been trying to purchase one of these engines for a reasonable price for years.


----------



## mecanotrain (Jun 6, 2013)

kadora, If you want to make an oven, you should consider ALL equipment purchases:
4 resistors: 150 &#8364; (local supplier)
15 Bricks: 60 &#8364; (local supplier)
1 PID controller temp: 40 &#8364; (ebay)
(http://www.ebay.fr/sch/i.html?_nkw=pid+temperature&_sacat=0&_odkw=r%C3%A9gulateurs+PID)
Miscellaneous: cables, box, hardware, .... 50&#8364; (local store DIY)
The total cost is 300&#8364;.

Is this feasible in comparison to commercial equipment? That is the question !


----------



## kadora (Jun 6, 2013)

mecanotrain
thank you for the costs sumary.
I have found on internet the cheapest furnace  /miniature one/ for 500 euros
I think that for this price i can  build bigger furnace.
However what kind of brick did you use for your oven.
Thank you


----------



## mecanotrain (Jun 7, 2013)

Hello kadora,
I bought my bricks from a supplier in my city:
http://www.ceradel.fr/ceradel/Famille/CATALOGUE/IDZ.aspx?   >>>> #JM23 60 or #JM26 60 
the bricks (1350 ° C) that I used are no longer in the catalog, only 1260 ° and 1450 °.


----------



## kadora (Jun 9, 2013)

Thank you Mecanotrain
These bricks are not on the market in my country.
Probably i will try YTONG bricks.


----------



## chucketn (Aug 26, 2013)

dnalot, did you make your furnace from plans or is it your own design?
I have 3 tanks "airing out" under a tree in the back yard. They've been trere for 2-3 years with the valves removed. What precautions did you take when cutting the tank?
I also have Mikey's burner book. Which burner did you build?

Chuck


----------



## Forestgnome (Aug 30, 2013)

I didn't know you could melt iron using propane. I thought you needed a cupola furnace. Details please!


----------



## kadora (Sep 6, 2013)

hello my kiln is finished.


----------



## dnalot (Sep 6, 2013)

> dnalot, did you make your furnace from plans or is it your own design?
> I have 3 tanks "airing out" under a tree in the back yard. They've been trere for 2-3 years with the valves removed. What precautions did you take when cutting the tank?
> I also have Mikey's burner book. Which burner did you build?
> 
> Chuck



I made a few modifications from the furnace described in "Michael Porter's book Gas Burners" Mine is a little taller so the flame doesn't strike the crucible first, The nozzle shape is cast into the refractory. I also welded a second tank to the bottom of the first for a pedestal stand. I keep an old crucible in there to catch a spill if one ever occurs. And my latest improvement was to add 1" of ceramic insulation with a sheet metal cover and some wheels. I can now melt cast iron if I crank up the gas pressure to 25 PSI and shoot a little air into the burner at about the same pressure as the gas, For aluminum I use 12 PSI of gas pressure.

The furnace has held up very well and is very efficient. Last week I fired it up in the morning and melted all my aluminum scraps. After 11 loads I had 85 pounds of ingots and used less than 25 pounds of propane. 

My burner is the one made with 3/4" gas pipe. I use a .035 welding tip for the jet.

Mark T


----------



## dnalot (Sep 6, 2013)

> hello my kiln is finished.



You have a fine looking piece of equipment there. Please post an update on how it works and what you can use it for

Mark T


----------



## kadora (Sep 8, 2013)

Hello 
I am testing my kiln right now.
Four flat heaters.
Power 3200 W , kiln reaches temperature 900 celsius within 20 minutes /empty chamber/
Control box
 Fuse switch , PID controller , Timer , Power adjusting potentiometer /800W-
3200W / 4  switches to turn on heaters separately.


----------



## mecanotrain (Sep 18, 2013)

Hi all,
NICE furnace Kadora Thm:


----------



## tractionengine42 (Sep 18, 2013)

Hi Kadora
Very nice, looks very well made.
I am interested in building a similar furnace.
May I ask you the details of your heating elements. I have seen some on ebay from china but from memory they are 0.2 ins dia., i am not sure if they would be suitable. 
I am in the UK, not found any suppliers here.

Thanks

Nigel


----------



## kadora (Sep 19, 2013)

Hi tractionengine42
I have heaters from UK supplayer.I will try to find his E shop address
for you .
Or go to ebay UK , find this seller  /sophiacollector/   hi sells
small electric kilns produced by company where i bought heaters.
sophiacollector may give you instant answer.


----------



## tractionengine42 (Sep 19, 2013)

Hi Kadora
I have found the seller, thanks for your info. 
Lots of interesting stuff there.

Cheers
Nigel


----------



## kadora (Sep 19, 2013)

Promised address http://www.technicalsupermarket.com/
a lot of things for our hobby.


----------



## nevadablue (Oct 19, 2013)

Excellent choice I think. I have a small Paragon glass kiln that serves for all kinds of work from heat treating to melting. The kilns are very versatile.


----------

