so how hard do those little 110v toaster over elements have to run to get a gun cabinet sized oven up to temp to cure Cerakote on a barreled action? This thread has piqued my interest in doing Cerakote myself again. Used to do it at a former place of employment but they had nice commercial built ovens. I don't have that kind of budget so this might work out better.
Interesting you should ask.
I just finished my oven yesterday. I WISH I'd found these threads before I started the project. Having looked over several of the threads in these pages I see examples of very professional looking projects. Mine's kinda butt-ugly but functionally much like the ovens represented here. I used:
* A WELL used, 2-door, metal storage cabinet that I got off Craigslist for $20
* A used convection oven that the wife picked up for about $30 from a thrift shop.
* Ebay pid/ssr like
PID Digital Temperature Control Controller Rex C100 K Sensor 25DA SSR | eBay
* Roxul insulation from Lowes.com
Shop Roxul 12-Pack 47-in L x 15-1/4-in W x 3-1/2-in D 15-R Stone Wool Insulation Batts at Lowes.com
* 6' of gutter down spout
* 3 rolls of pipe hanger tape
Shop AMERICAN VALVE 4-in dia. x 25-ft L Galvanized Hanger Iron at Lowes.com
* 1/2" x 1/8"
nomex high temp BBQ gasket tape
The cabinet had a metal piece that ran top to bottom and held the magnets that kept the doors closed. It also had one shelf near the top. I removed the metal piece as I figured that would just be in the way and removed the shelf from the top. I gutted the convection oven and mounted the elements in the bottom of the cabinet. Drilled a bunch of holes in the metal shelf, reinforced the sides with some aluminum angle (because it was quite flimsy) and used that as a diffuser. I cut some holes in the top of the cabinet, mounted the fan from the convection oven and routed that into the metal downspout which runs down to the bottom of the cabinet. Drilled a hole through the very middle of the cabinet/downspout to mount the thermocouple and run the wire. I used the bracket from the convection oven for the thermocouple. Whatever gaps were created where I had to drill or snip are sealed with Permatex Hi-temp RTV silicone gasket maker. Door gaps were sealed with the nomex gasket tape.
The most expensive component was the Roxul insulation. I used one "bundle" and had some left over but as I'm also finishing out the inside of the garage/shop, that didn't go to waste. While it is stiffer than standard insulation batting it's not rigid enough to just pop into the cabinet and hold itself there. I couldn't think of an elegant way to hold it in place so I just threw up my hands and used the metal pipe hanger. (Like I said, it isn't pretty.) But it seems to work. The outside doesn't get over 116 deg. where the insulation was the most difficult and in most places it's hardly even warm to the touch. I also used aluminum angle to fashion a mechanism to hold the doors shut because, frankly, I just didn't want to go back to the hardware/home store yet again.
Now, to finally answer your question... As I said, I'm using the heating elements from the counter-top convection oven. From my tests yesterday, the oven topped out at about 270 deg. but it takes quite a while to get there. It took 30 min. to get to 235 deg. 60min. = 264 deg. and 90min = 270 deg. I wasn't really happy with that after reading through some of the threads here I'm REALLy not happy with it. I will run another test today without the diffuser to see what that gets me. If it's still unsatisfactory I'll try a different heating element like something out of a smoker. I don't have 240v power in the shop yet so I have to stay with a 120v system for now and my options are somewhat limited in that respect.
Hope that helps. I'll post pictures if anyone's interested.