How much clearance is needed?

[JeffL]

I am in the planning stages of building my oven.Is there a certain clearance needed between the parts & the oven walls? How much room should I give between the parts & burners? Due to severe space limitations I plan on making the oven to also support my welding table.Would this present any problems?I also plan on using the cement board for the walls along with that foam board insulation & will sheet over that. The reason for this is I have kids, & don't want them accidently getting in the shop & touching the thing if it's hot.I would only think this will further help insulate & help the process.

[mikekozura]

On big parts I have only about 2 inches on the sides. Watch getting the part to close to the elements I kinda burned the base coat on the first frame I did. Now I but a piece of tin on top of the elements as a deflector when I do frames. You can see what I mean from the pics on the other thread.I got all my ideas from this site. There's a lot of threads on oven building on here. Grab a beer and start reading (if your 21 that is). Like I've heard on here the best way is what works for you. Good luck again.
http://www.powdercoatoven.4t.com/Index.html

[JeffL]

I read on one thread about inner & outer walls.Do I need to have air space between the cement board & my insulation board?Or can I simply attach the foam board to the cement board, then sheet the foam?

[mikekozura]

I don't belive you need a air space. But hopefully some of the big boys will start to chime in on this. My self I don't like the foam board. I used 2" ridge fiberglass Owens Corning #703 it's rated for 450 degrees.

[planebuilder]

I used 3" or 4" of regular fiberglass "pink" house insulation It works great, the outside of the oven will be close to room temperature and no danger of toxic fumes from melting foam.
Just my preference.

[mikekozura]

Yea I would definitely go with some kind of fiberglass or wool. I used the ridge because it stood up by itself. I high temp siliconed it to the cabinet and it stayed there will I tinned it.

[JeffL]

Now if I go with home insulation(nonbatted) I will have to make the frame 4 or so inches thick to accomodate the insulation correct?

[mikekozura]

Well not necessarily that stuff will compress. But that maybe a pain to put in. Thats why I liked that Owens Corning 700 series stuff And you can cut it with a hand saw. The problem is you just don't buy it at Lowes. I found a commercial insulation place in Pittsburgh that sold COD to the public. Sorry to keep harping on the insulation I used but it was so easy to work with.