Cooking up an oven project...

[dagobert]

Hey, 11111111- are you still thinking of selling an oven setup? And if so, what specs and how much? I'm looking at trying to get something working that I can powdercoat motorcycle frames and wheels in, and that is reasonably priced. OK, CHEAP, even. If you would, give me an e-mail at dagobert@ix.netcom.com and let's discuss it further.
Thanks,
Jay

[11111111]

it has taken me the better part of wo years to develop a low cost high quality oven system just for myself. thier are a lot of different people doing quite a few types of ovens. I've seen really cool stuff to some scary stuff (and most of it turns out pretty decent product. the problem i have found is that it takes about 20 plus hours to build a oven and about $400 for material for a basic 3ft by 5ft by 3ft oven. by the way this size is with out question the most feasible to build to for the size of the average parts you will do. i have oven an myself that will do entire car at one time as well.
I would only build a oven that had the ability to add modules to the end side or top so that if the need arises you can just un bolt the side and bolt on the module. this was harder to devolep than i had ever guesed. you can not run anything through the areas that will come off (wiring sensors elements) and you need to be able to circulate air at different rates depending on cubic ft. i came up with a formula that seems to be spot on for every size so far.
to start with lets look at what the average person is doing. you start with a toaster oven and or a cooking oven depending on what your up to (free to maybe $50.00. lets stick with the cooking oven here. people using toaster ovens or the likes simply dont need a bigger oven. the basic cooking oven is 18in by 18in. by the time you build hangars and give yourself alittle room around your project with placing inside your biggest part is most likly a wheel for a car, and were not talking about a 17in wheel. remember the oven is just 18 inches at the max.
i have taken ovens and simply cut out the back sides etc and built sheet metal boxes and added them with great success. the problem i started running into is saturation (heet) of the part. this was not obivoius to me for quite a while. all you first time oven builders pay attention to this mistake i made and save yourself the time and headache of trying to correct it. if you add on to the oven with sheet metal boxes ( double walled and insulated) you must put burners in the new boxes or create a circulation system to maintain even saturation points and cure times throught the oven.
the point i'm am trying to make or maybe the question i am asking is how many people need to upgrade to a better sytem or would actually take the time to build a oven. I fabricate for a living and know how much is involved to build a topp notch unit that is not hacked together.
at harbor frieght you can buy a powder coat oven 400? it is exactly 18 by 18 inches but with a fan and timers. not a bad system if your looking for something the same size as a oven with these options but i can get as good or better quality product from a free oven thats been sitting in the rain out back for a year.
always remember that good product comes from great prep.

how about everybody that reads this chime in on what they use for a oven if the are currently (actually) coating at this time. or if your thinking of getting started what were you planning on using. also what would you pay for a oven that is of the size i described (1200 to 1500 to be seriuos). one more thing if i made up a set of drawings for a oven and they were free do you think you could actually build them. welding , wiring, sheet metal work etc.

i think it would be intresting to put together a network of peolpe in different areas that would help others to fabricate what they could not build themselves. just food for thought. I would have been pcing a long time ago if i would not have needed a bigger oven than a cooking oven for almost everything i have ever done.

take the time to answer these questions i think if we can compile a little info we could really get a idea of what and where we need to be going. i will be disappointed if this does'nt become the largest thread on this forum, it certainly would give everybody some answers to a lot of questions on ovens and how esay or hard it is for them to get started.

[remotestartdepot]

I have the ability and equipment to fabricate an oven. If you were to make plans, I would definitely be interested. What are you using for insulation? What about heating elements? What gauge sheet metal is used? These are the questions I have.

Kris

[dagobert]

What I've been doing so far is using an IR propane burner, with its obvious limitations. As far as what part can I do; my dad was an electrical contracter, and I spent most of my summers in high school doing commercial wiring along with also working with some HVAC equipment, so that part shouldn't be a problem. My next door neighbor has a mig welder, and while I don't make the prettiest welds in the world, the metal stays together.

What I don't have is a brake to bend the metal with properly, and I could pick up some air shears to cut it with. I was hoping to find something perhaps as a kit- or maybe find someone who was good at and knew how to make the panels, and then I could buy and install the electrical myself. That might help keep the cost down?

[11111111]

heres a trick i learned from hvac guys. on site they used a two by four to make bends. i wathced these guys bend around wood for everything.

cheap and clean with a little pactice.

[11111111]

just pick up a oven used and take out the upper and lower elements the internal temp probe and the control unit on the top of the range. i have just removed the the oven control panel right off the topp of the oven and install it right to the new fabricated oven. it looks clean and very functional. go to the local exhaust shop and pick up two inch exhaust pipe. you should not have to pay more than 8 to 10 dollars per ten ft stick. just get enough to build a box the size of the oven you want. call around to your hvac suppliers and find out where thier getting thier sheet metal (thinest stuff they have ) about 10 to 13$ a sheet. the pipe should be aluminized, it may not even be an option to get it not aluminized. (wont rust). the sheet metal will be galvanized (wont rust).
go to the home depot and get a bag of insulation that is for blowing into the attic it is none flamable and it easily stuffs in betwwen the sheet metal walls. when you build the inner box and outer box use a two by four to bend the sheet metal if you dont have a brake. use self tapping screws to put the outer sheet metal on so that if need be you can access the wiring and such. just use rivits on the inside (thier flush and easy). take pictures of the wiring if this will be a problem. the only difference will be that the oven has broil and bake, bake is the lower element and broil is the upper. in a cooking oven they dont come on together unless you have a self cleaing unit i believe. you do not have temp control on self clean mode so dont use this option.
what you will be doing is wiring both elements together so that they work on bake or broil it does'nt matter which. mount them on the sides of the oven box and build a sheetmetal shield and place it over the side of the elements so that the infrared light waves can not reach the parts and that the heat is not directly reaching the part. the shield should be open all the way around so that the heat can rise straight up (if you dont leave the sides of the shield open especially on top it wiil get too hot and make it hard to heat evenly).
you need to build a fan system that moves the air around inside, this can be the toughest part by far. i like an electric motor from a ceiling fan on a re astat. lowes has them as cheap as 30$. the trick here is the re a stat, air flow control is paramount.
by a small fairly well pitched steel blade you can mount on your ceiling fan motor. you will need to make a mount to hold the fan to the top or back depending on where the door will be. top loaders work very nicely. step the bracket back 8inches or so and extend the shaft to reach into the oven leaving an inch or two of space from the oven wall to the back of the blade. i mount them as close to the bottom as possible. the cool thing about these fans are the have reverse switches built right into them (helps with finding the best circulation to keep temps even).
important to keep the shaft long enough to disipate the heat that is being pulled down the shaft from the enternal temps. doesnt take much but it is important, if the shaft does'nt get to hot the motor will last a very long time. thier is no load on it and you will never use it as much as if it were running in your home.
run the wiring against the outer wall and attach it with metal tape and the outer sheetmetal becomes a heat sink and will take the hassle of the wiring being damaged from heat. where the elements plug in use the stock oven wire and plugs, makes it easy.
cut the window out of the oven with a few iches around the edge and rivit it in place where ever you want (easy way to go) or build the sheet metal up and install the glass like the oven depending on your skill level (this is tough if your not really good with sheet metal).
if you want you can put in multiple windows and also dont forget to install the oven light inside a couple if they dont get in the way.
do yourself a favor and weld some heavy duty casters to the bottom so you can roll it around in the shop. knot to just put it away but this really helps to get stuff in it if you can move it a bit exspecially if you are lowering stuff into the top of it. (top loader style).
it would be wrong to bring your groceries home in a shopping cart and modify it hold your oven, this would be wrong. but it would give you a super nice handle to move it around or push it outside for cooling it down after the baking is done.
this oven worked pretty well for me, i sold it to a local shop or i would send some picts.
if i missed anything or any of this is confusing just e mail me and i will clarify. jeff

[11111111]

dogaburt i was just emailing custom about my new big oven. 9ft by 15ft or so. i was thinking of installing ir to heat the room. the walls are going to be sheet metal so what i have been thinking of is chroming all the sheet metal before it is installed. like having mirrors on the floor roof and walls.

[11111111]

i just posted some pics of my new building

[kchotboat]

Originally Posted by 11111111

i just posted some pics of my new building

any info on ovens?

[tinbender722]

I have been doing HVAC sheetmetal and architectural sheetmetal fabrication and installation since 1969, and have owned my own sheetmetal business since 1996. I will be glad to give any of you tips or my ideas on what I feel will be the easiest and most economical way to build your oven shell. I think that the simplest way to build an oven - for someone who doesn't have easy access to fabrication equipment - would be with metal studs, flat sheetmetal and metal stud floor track. I just finished building a 4' x 6' x 6' oven, but I wouldn't recommend the method I used on it. In fact, I won't build my next one the same way. I hope to get caught up enough with my other work in the next week so that I can hook up my propane torpedo heater and see if it will work for a heat source instead of electric elements. I will also try to take some pictures and get them posted.

Leo