Powder coat oven: user error?

[Lloyd Smale]

Ive got a small apartment sized gas range in the garage I use. What I did was some experimenting with different alloys to find the lowest temp bullets slumped at (lineotype). I then turned it down 2o degrees (which turned out to be 460 on the dial) and that's what I use for all of them.

[popper]

The other problem with PID controlled (or any control) is the overshoot in temp. PID learning will overshoot, then learn from repeated runs. Problem is when you change the load (amount of boolits), learned heating curve isn't correct. Yes, using a metal pan/sheet for baking will allow the pan to conductivity bake the boolits. One reason others use fire brick, etc. is to preload the oven so the PID doesn't overshoot when loading the empty oven - PID has learned a large mass heating so added boolits are just a smaller % of load. Actually my toaster oven has elements above and below, I wired the upper set to the PID and the other always on - can't get too hot and SSR only controls a smaller load so SSR can be smaller rated or smaller heat sink.
I mostly ESPC 30 cal. rifle boolits and the hot plate is much faster. I load a flat glossy ceramic tile with ~ 90, place on H.P and 10 min (from cold), done. I could make a sheet metal plate with handles to place under the tile so I could change loads when hot but I don't do that many at a time anyway. No need for NSAF or parchment paper, just let them air cool and pop them off. Any PC that stays is removed with acetone. DON'T WD the tile!! When I WD, I just use hemos to pick and drop. Actually I've done HiTek the same way but acetone doesn't cut the stuff so use parchment paper or clean residue with a single edge razer blade. I don't even PID the hot plate - it won't get hot enough to melt IF the tile is used.

[Smoke4320]

I have to agree with bangerjim the fan needs to run all the time you are cooking bullets not just when the elements cycle on

[fgabriel]

I was having the same problem with my el cheapo toaster oven. Turned out I had the rack in upside down and it was too close to the bottom element. Turned it over. Same temp and time settings no more melted bullets. Boy did I feel like a dummy.

[ichthyo]

I've only melted bullets one time. Used the same oven, temperature, and time. Never happened again. Maybe ambient temperature messes with us?

[Bama]

My original oven died and replacement did not have convection (cheap replacement). Used thermocouple about 2" above plate trying to set temp at 400'F. The thermocouple never read over 300'F but bullets slumped at base. Unless it is a convection over the actual temperature of bullet can vary depending on surface (top and bottom) of support plate due to the radiant energy heat transfer. Actual surface temp of plate spiked passed over 500' F + when thermocouple was placed on plate. Just a heads up on what can happen. New convection oven works great!

[DerekP Houston]

Mine melted the first few times, there's a hot spot in my oven directly under the radiant heaters. Moving my tray down and adding a PID solved my issues (PID was double use, just another TC). My oven dial was off by more than 50f.