How to attach sheet metal to insualtion?

[twistedneck]

Hi everyone!

I'm new here and I found this forum by chance after i started to build my locker oven.

I have a 12"x12"x60" locker, 2 finned 1000W 240V elements, PID control, 25A SSR, Mcmaster 9356K11 1" insulation Q=0.26.

I need to cover the oven interrior insulation with sheet metal lining.

What thickness and type of sheet metal? How do i attach? Also, how do i 'stick' the insulation to the inside of locker in the first place.. aint no glue gonna work i presume?

I also picked up a 13' of 1/2" dia fiberglass tadpole door seal - not sure if that's even useful on this locker door or not, or how to attach - a waste of money?

I'm happily surprised there is a message board for paint curing ovens! awesome.

[TurboRoadster]

hhm, I dunno, why not get longer screws and screw through the insulation to the metal frame? Its hard to say w/o seeing pictures of what ya have.
Welcome to the forum BTW and be sure to keep us updated.

[jrow]

twistedneck,

If the locker is metal, which I assume it is? i would put the insulation on the outside, so that you don't make the inside smaller. Your oven is going to be awful small as it is. I would suggest that you put a shelf in it so you don't have to heat it all at once. That would require you double your equipment so you can heat the top or bottom independently! Of course you could make a disconnect for one unit and accomplish the same thing.

John

[twistedneck]

Turboroadser, thanks for the welcome! How about screwing down the sheet metal shielding to the locker, and then fasten the insulation to sheet metal with smaller screws.. That way the screws don't stick out of the locker (except the few sheet metal mounting screws). Also, that would eliminate any compression of the insulation.


jrow, its a metal locker. I need something tall and skinny to cure long knives, sword blades, gun bbls and full gun frames. Space inside is not a worry except it must be tall. i want insulation on the inside so i can mount a box with the PID, and SSR box on the outside surface on the oven..

I'm using a rediculous moly based coating called 'molyresin' from John Norrell. Have you heard of it? I do coating stuff at work sometimes so i have nice samples of good stuff to paint with like a rediculous caustic sand blased parts cleaner (MI-Clean 100 from Hubbard hall http://www.hubbardhall.com/files/2002019.pdf ), PPG Zinc Phosphate, PPG chrome free conditioner, etc..

I will provide updates as this gets built! Any thing wrong with mounting SSR and PID to the oven?

Thanks again, twistedneck.

[TurboRoadster]

Originally Posted by twistedneck

Turboroadser, thanks for the welcome! How about screwing down the sheet metal shielding to the locker, and then fasten the insulation to sheet metal with smaller screws.. That way the screws don't stick out of the locker (except the few sheet metal mounting screws). Also, that would eliminate any compression of the insulation.


jrow, its a metal locker. I need something tall and skinny to cure long knives, sword blades, gun bbls and full gun frames. Space inside is not a worry except it must be tall. i want insulation on the inside so i can mount a box with the PID, and SSR box on the outside surface on the oven..

I'm using a rediculous moly based coating called 'molyresin' from John Norrell. Have you heard of it? I do coating stuff at work sometimes so i have nice samples of good stuff to paint with like a rediculous caustic sand blased parts cleaner (MI-Clean 100 from Hubbard hall http://www.hubbardhall.com/files/2002019.pdf ), PPG Zinc Phosphate, PPG chrome free conditioner, etc..

I will provide updates as this gets built! Any thing wrong with mounting SSR and PID to the oven?

Thanks again, twistedneck.

I wouldnt think so, just insulate accordingly.

[chromeitout]

Just a thought, I might consider laying the locker on it's back and put the insulation inside without any screws. It will stay in place temporarily, fairly well. Measure th inside dimensions after the insulation (if it's 1" insu. then the dimensions are 10x10x58 ). Now have a sheet metal fab shop bend your sheet metal to fit the inside leaving a 1 1/2" flange all the way around each piece so that you can screw or pop rivet the pieces together once they are inside the locker. Once assembled you can run 1" sheet metal screws in the corners of each panel to space the inside from the outside of the locker. There you have it, with no exposed screw points. Sorry, a little long winded.

[twistedneck]

Originally Posted by chromeitout

Just a thought, I might consider laying the locker on it's back and put the insulation inside without any screws. It will stay in place temporarily, fairly well. Measure th inside dimensions after the insulation (if it's 1" insu. then the dimensions are 10x10x58 ). Now have a sheet metal fab shop bend your sheet metal to fit the inside leaving a 1 1/2" flange all the way around each piece so that you can screw or pop rivet the pieces together once they are inside the locker. Once assembled you can run 1" sheet metal screws in the corners of each panel to space the inside from the outside of the locker. There you have it, with no exposed screw points. Sorry, a little long winded.

That is a great idea. Any recommendations on sheet metal thickness and type (galvanized?)..

One more thing, should I use a small fan at the top pointing down, or just put a small vent in there to keep the temp even top to bottom?

[chromeitout]

Galvanized will be fine. 20 ga. minimum. 18 would be better. You will need a vent if the oven is sealed good, but it won't control temperature evenness, it's just to give the expanding hot air somewhere to go and also exhaust the fumes (best to pipe outside). I've seen some people on here put just a fan in for circulation, but I don't know how it worked for them. I actually built an exterior ducting system that takes hot air from the top of the oven and pipes it back into the bottom (of course mine's a bit bigger than yours). Anyway, if you don't circulate the air somehow, the top of your oven will be much hotter than the bottom.

[twistedneck]

Thanks chrome, I will look for 18ga stainless (worried about the evil galvanized fumage if i get too hot).. and i'm going to put a 'through wall' fan in there, mount to ouside of locker at the top, pointing downward, just high enough to clean the part hangar hooks, will that keep temp even? any lewer an it will hit the parts.

[chromeitout]

I wish I could say that it would keep it even, but I don't know for sure. It should help anyway. Just don't create a tornado in there as it will disturb your powder and stir up trash.