Another new oven build...

[Subternal]

First off hello to everyone. Im new, and Ive been following this forum for quite a while, but first time posting. This is where I got my inspiration to build my own oven!! Anyway so here's my deal:

I am in the process of putting together a 3'X4'X7' oven for atv and bike frames and maybe an occasional rear end diff. So of course I have a few questions...first off I am using 3 5/8" metal studs for the frame work and for the most part I have most of the walls done. I know where to get most of my supplies (McMaster, Ebay,..ect) from. My question is since this oven will have a rough volume of 84 cubic ft, and from the excel spreadsheet I calculated that I would need about 13500 watts and 4 3300watt burners to achieve decent heat up. Is this correct? If so I have an adaquete power supply in my garage to use a 70amp breaker for an oven of this power requirement. That was supposed to be more of a question....Another question is that if I use these metal studs (25ga Lowes) how much weight can they support? I mean if I needed to hang somethign heavy in there like and engine block or a rear diff, do I need to make some other kinda steel tube support or something??


Can anyone possibly walk me through of what I'd need exactly or at least tell me if Im missing anythign:

PID
Elements
SSR or Contactor
High temp wire
insulation (mineral wool)
Thermocouple



Im sure I'll have more questions as I go along, such as exact wiring but Im more in the begining stages and want to know if I am on the right track before I get to far ahead of myself...any help is much appreciated.

[jeeplogic]

I am new also but have been walked through the whole thing, as far a strength, I would brace up the celing some if you want to hang a diff but for smaller stuff you should be fine.
search for schematics or go through every post to find the schematic that will work for your design or ask Ed for help with the schematic. (he's awesome)
just my $.02

[ed_denu]

Welcome to the forum. It looks like you have a good start on your oven. To answer a few of your questions, 13.5k watts should be fine for an oven this size.

A lot of people double up the studs in the oven roof for additional support to hang items. If you are doing very heavy items it might be best to look to build some sort of rolling cart or trolley system to move these into the oven versus attempting to move and hang them by hand.

As for parts since your oven is tall look for some sort of fan or air recirculation system. You might also add a few switches for the lights, pid, fan etc.

A 70 amp circuit would be correct and is going to need #4 wire which is rather large and somewhat difficult to work with. An alternative might be to install (2) 40 amp circuits and run (2) ssr's or contactors. This approach was discussed in a recent thread.

[Subternal]

Welcome to the forum. It looks like you have a good start on your oven. To answer a few of your questions, 13.5k watts should be fine for an oven this size.

A lot of people double up the studs in the oven roof for additional support to hang items. If you are doing very heavy items it might be best to look to build some sort of rolling cart or trolley system to move these into the oven versus attempting to move and hang them by hand.

As for parts since your oven is tall look for some sort of fan or air recirculation system. You might also add a few switches for the lights, pid, fan etc.

A 70 amp circuit would be correct and is going to need #4 wire which is rather large and somewhat difficult to work with. An alternative might be to install (2) 40 amp circuits and run (2) ssr's or contactors. This approach was discussed in a recent thread.

Ewww...good thinkin! Just the kinda advice I was lookin for. As for being tall, I was actually going to lay at in its side so if you were looking at from the front it would be 4' tall 7' wide and 3' deep. With that being said would I still need a fan?? Or do think a better use of space would be to have it vertical?

So if I used to 40 amp breakers, is it best to use 8awg or can I get awayh with 10?

So if I made a cart or kinda rolling frame of sorts, wouldn't I still have to contend with the whole weight support issue? except of course it would be resting on the bottom of the oven instead of hanging from the top. Can it support more weight on the bottom if I double up on the studs?

Is there any opinions on whether to go with SSR's or Contactors?? recomendations?

Last question...Is there a specification on which element(s) I should get? or can I just get any 3300-3500 watt 240v?

[ed_denu]

Ewww...good thinkin! Just the kinda advice I was lookin for. As for being tall, I was actually going to lay at in its side so if you were looking at from the front it would be 4' tall 7' wide and 3' deep. With that being said would I still need a fan?? Or do think a better use of space would be to have it vertical? Vertical is usually more practical and easier to load parts

So if I used to 40 amp breakers, is it best to use 8awg or can I get awayh with 10? #8

So if I made a cart or kinda rolling frame of sorts, wouldn't I still have to contend with the whole weight support issue? except of course it would be resting on the bottom of the oven instead of hanging from the top. Can it support more weight on the bottom if I double up on the studs? Double up the studs and/or use a thicker plate on the oven bottom.

Is there any opinions on whether to go with SSR's or Contactors?? recomendations? Kind of a personal choice. See the sticky at the top of the page for recommendations.

Last question...Is there a specification on which element(s) I should get? or can I just get any 3300-3500 watt 240v?Any at this rating(240-250 volts) would work fine.

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