Electric furnace

[kadora]

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]

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]

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]

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]

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]

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]

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]

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]

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€ for 4 resistors with shipping cost included.

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

(sorry for my english language)

 

[kadora]

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 .

 

[///]

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]

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

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

 

[kadora]

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]

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]

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

 

[chucketn]

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]

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

 

[kadora]

hello my kiln is finished.

 

[dnalot]

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]

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