Homemade ovens

hmm…can’t see how it could be good for a part, but yeah, as long as it is sealed in the bag, it SHOULD be protected.

i have been looking for some affordable fans for my oven.anyone know what to use?need to withstand 250 degrees.i have searched on mcmaster.not sure what to search for

convection ovens have fans that can withstand that. Check your local kitchen appliance dealer. They should have some trashed units with the fan still intact. They will give them up for beer money.

might try a long shaft. Motor on the outside, bearings on the walls, and shaft going inside with the fan.

alright.thanks for the advice.i will look and see what i can find.my friend had the idea to use car fans.run them off a pc power supply.i dont think they would take that high of heat though.

One of the teams here ripped a fan out of a convection oven. It seems to work alright although the oven itself is not very good.

I also found got this quote from Wikipedia. Hopefully someone will find it useful.

“The fan motor is in a separate enclosure, to protect it from overheating and melting any plastic components including wire insulation”

i searched for restaurant convection fans.didnt find anything.is there a home convection oven?i would think that would be easier to find.thanks for the info canyon.

A search on google product shows both convection ovens and convection oven fans. Maybe you’ll be able to find something you’re looking for in there

http://www.google.com/products?q=convection+oven+fan&aq=f

Also a quick craigslist search in my area shows a number of both home and professional convection ovens for sale.

thanks.i did see a few fans on ebay.craigs list is hard to weed out all the crap you get in searches.i get tired of it real fast.i went back and searched for convection ovens.after weeding through several travel trailer and motor home adds.i found a few.

Ok, i found the old thread on oven building… maybe we can revive it again. I seriously need to build two small ovens now that i have the space for them.

I’m thinking 2ft high x 3ft depth x 8ft width.

I saw this 13" Crossflow Blower fan i like for low temp oven. Says it’s good up to 140f.
http://www.mcmaster.com/#exhaust-fans/=93rsx2

For a heat source i was thinking infrared lamps with sheetmetal under them so i get an even cure across the inside of oven. Mount the blower up high blowing across 3 of these heat lamps. My heat lamps are wired to a rheostat for range of controll.

I like the rockwool idea of lining the oven for insulation, energy saving, and fire protection. The lamps and fan i can put on a timer. for a thermostat just insert a hand held metal thermometer into the oven… possibly drill a small hole thru the oven side and have just the dial portion of the thermometer on the outside of the oven for viewing.

This would make a decent curing oven… not very controllable or high temp but works for one of my oven needs i think. If you have ideas to improve this and not add costs lemme know.

Why go to all the trouble and expense of rockwool for a low temp oven? EPS foam(blue foam insulation) will take 150d F. and it has a R value of either 5 or 10 per inch. that plus the convienence of buying it at your local Home Depot make it a great option.

Regarding the fan, I know there are good ones out there for higer temps I just need to look them up again.

i built my oven from the silver lined insulation foam.its sold at home depot.1/2 inch thick.my heat and fan comes from 2 heat guns.it turns out i only needed 1 heat gun.the oven size is 33x33x65 inches.with one heat gun running on low it gets to around 180 f.i use a thermometer that has a cord on the probe.its a cooking gadget found at bed bath and beyond.i lay the probe right on the part so i know the exact temp the part is seeing.this setup has worked perfect for me.i have ran it for over a year with no issues.

First of all… I haven’t got a chance to read through this whole thread, but here is something I might point out…

Actually, depending on how familiar you guys are with heat transfer (:eek:) you might could put in say two layers with the high temp stuff on the inside and the lower temp stuff on the outside to minimize cost and maximize allowable inside temperature. Not necessarily saying that this will be a better option. It will depend on the costs of various thicknesses of layers, conduction coefficients, allowable temperature range and such, but I think it would be something to look into. I can help out with the number crunching for this if there is interest.

After today’s lecture I might be able to help you out too :D. Funny how I come back from heat transfer, glad that I want to be a materials scientist, only to come back to read this!

I second Flesich’s suggestion though. Putting whatever insulation you choose in the right order can greatly improve the performance of an oven with a greatly reduced cost.

Reducing energy costs wouldn’t be effective if using a heat gun in the oven though as it constantly runs.

What type of heating element can i use that will be safe and cheap to source? I should go to Apache Surplus in Phoenix… they sell all this stuff and maybe even the rock wool. I’m not going to be stuck on rock wool now that i understand foam will be good to 180f. I may build an oven later on that can reach 350F. For now my molds are polyester/vinylester frp so heating them much over 120 results in the mold overheating. Unless i can find a surface coat that is high temp for molds that i can lay up with vinyl ester? That is another topic.

Foam sounds good from HomeDepot and cheap. I think a 1.5" thick sheet runs about $55.

I’m liking my infrared heat light idea. Just need a fan for air circulation.

I don’t understand… You are going to have an insulated system and a heating element inside of it running all of the time? Surely you are you going to care what temperature you are running…

Or motor with long shaft and just fan blade on inside…no problems abt heating the motor

i run one heat gun on low.its like 600 watts.so energy usage is low.i use the silver lined insulation foam.i have read that its good to around 250 f.a friend built a larger oven and he ran it at 250 several times.the foam board held up fine.its still being used.another reason i went with a heat gun is it has a fan built in.so killing 2 birds with one stone.the thing works great.i use it just about every day.

You can not beat this guys price for what you get and you could not make one for much less.He has made many
http://www.tedsfabrication.com/powder_coating_ovens.htm
check this out if you want to do it all yoour self
http://www.powdercoatoven.4t.com/

that is actually the first decent site that I have seen anywhere on then net that gives any real details on how to build an oven that is capable of real hot temperatures. Very good find there Jaxon.

The tedsfabrication ovens look like good value also. Nothing that im sure most of the people on this forum couldnt do, its just a question of time and money! oh and space!!!