Metal Casting Zone

I am thinking about building a burnout oven for small casting jobs. I am having trouble trying to figure out weather to use 16gauge nichrome wire. I need to know the length to achieve 12ohm. coiled of course I'm thinking 1/4' inside? anybody tackle this type of project and any wiring help? Thanks, Plow

hi and welcome to the forum. i too am asking the same question. i hope someone can help us.

I do have some schematics I downloaded from a popular brand name burnout oven. Seems pretty simple, but figuring out the heating coil element ohm is bogging me down. I have some 18ga. nichrome wire I coiled around a 3/8" rod and measured the ohms on it. In that gauge I would need approx. 25' of wire to reach 12ohm. I was wanting to use 16ga. as it would last much longer. Also hoping to find a cheap supplier of 12" square firebrick. contact me at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

This is my next project also, i was thinking of sacraficing a toaster oven. any thoughts?

my thoughts are to make an oven that goes on top of the furnace. i have plenty of firebricks and if i could float some over to the usa i would to help out.

Go to the nearest appliance store and pick up a used electric stove trade in, that maybe has issues with the top burners, but the oven still works. Usually they are free for the taking.

The heating element usually is around the outside of the oven area. Remove all trays etc. from the bottom. Drill a 1" hole in the bottom of the oven and put a catch pan under the hole in the lower drawer that is used to store pans.

Put a rack as close to the top of the oven as possuble, to get your molds in the hottest section of the oven.

Run the oven @ 400 F and the molds will dewax very well. Then put them in a gas fired cabinet to burn them clean.

I found a site like this with the way to make a great burn out oven for lost wax and total cost is 250.00 or so sounds great I am starting to build it hear is the link and a 5.00 book on amazon tells you more if this does not do it
cs.artjewelrymag.com/artcs/forums/t/20315.aspx
This log will encourage all as it did me, as I was looking at ovens, ya, like I need a new car first LOL.
Cheers
Dan Abaldo

www.heatersplus.com/nichrome.htm

Hope this helps.

First off, if you are using hard bricks, why? The use of lightweight materials like Fiberfrax and carvable Bricks have cut the weight of process ovens, and one of the issues is fallout of insulation. Low temperature ovens often use a highway mesh to hold the insulation above it. I am unsure of higher heat treat ovens as the heat exceeds the steels yield point.

You should consider, for small scale a rendering oven, that will capture the bulk of the wax for reuse. The temp is driven up to 5-600 degrees to 'dry out' the molds, evaporating the remaining wax.

I should be mentioned that molding wax burns like Diesel fuel at any heated stage, and the vapors can condense and cause problems in the shop, smoking everything up, or catching fire in the last stages of heating.


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