Toaster ovens and their accuracy

[RobS]

I will caution though should you have a convection oven. The fan being constantly turned on and off by the PID unit will result in a burnout eventually. Since my fan was a 12V fan that was hooked up from the factory through a circuit board I simply snipped those wires and took the cord from an old 12V cell phone charger and direct wired the fan. Yeah I have two wires that I have to plug in and now have to remember to unplug but the fan will not burn out.

[shickf3]

Yard sale oven,never checked but just keeps turning out good boolits.

[Motor]

I voted no but I will check it. I've just started powder coating I'm using a barely used 20 year old B&D toaster oven. I set the control to 400, pre-heat, add tray of boolits start 20 minute timer. I've noticed the boolits are wet looking before the timer reaches 15 minutes to go. I bake until the 20 minutes are up. So far so good.

I do allow 2 more minutes in some situations like oven open a little longer between trays or for a full tray of bigger heavier boolits like 440gr 500's.

Motor

[Motor]

Today I checked it. Since banger jim pre-heats his boolits I decided to check it at both 200 and 400 degrees. As it turns out the 200 setting is ok for pre-heats. It's like 185 degrees.

It also turns out that I cured my first few hundred boolits at about 370 degrees. I found a setting that holds very close to 400 degrees (on the "F" in 400 F). Then baked another 300 boolits.

Motor

[6bg6ga]

Good Thread that brings out the problems associated with any toaster oven or oven for that matter. Consider yourself fortunate if your oven is within about 20% of the dial setting. Some here especially the thread starter were smart enough to test the temp. Never rely on ANY oven setting always verify and adjust if needed.

[AZPaul]

My first batch I tried with a new oven, melted some of my bullets when set to 450. I put a thermometer in there and it was really reaching 650 when set at at that temp. So my advice is either get a thermometer or only try a few bullets at a time.

[6bg6ga]

My first batch I tried with a new oven, melted some of my bullets when set to 450. I put a thermometer in there and it was really reaching 650 when set at at that temp. So my advice is either get a thermometer or only try a few bullets at a time.

There is no toaster oven out there that is going to be accurate cycle after cycle. Part of the circuit in some of the ovens contains a timer circuit for the heating element. Some simply turn on and off at intervals and this is supposed to corrispond to temp on the dial. Install a PID and you will be fine.

[Dragonheart]

I have a 30" convection wall oven with the elements controlled with a PID that I use for larger PC projects. I also have two Hamilton Beach Countertop Convection ovens for bullets, which come up to and hold the temp as well as one needs, monitored with a $10 glass Taylor Oven Guide Thermometer. I have been powder coating since "Sandy Hook", which I believe was in 2012 and have now cast and cooked tens of thousands of bullets, with no problems. In my opinion installing a PID is a lot of work, not to mention an unnecessary expense if you start out with a good oven and a simple thermometer. There is no reason to make the process more complicated than it needs to be as it is a simple process to get great bullets.

[6bg6ga]

I have a 30" convection wall oven with the elements controlled with a PID that I use for larger PC projects. I also have two Hamilton Beach Countertop Convection ovens for bullets, which come up to and hold the temp as well as one needs, monitored with a $10 glass Taylor Oven Guide Thermometer. I have been powder coating since "Sandy Hook", which I believe was in 2012 and have now cast and cooked tens of thousands of bullets, with no problems. In my opinion installing a PID is a lot of work, not to mention an unnecessary expense if you start out with a good oven and a simple thermometer. There is no reason to make the process more complicated than it needs to be as it is a simple process to get great bullets.

There are some out there that wish to use a toaster oven they have owned for years and don't want the expense of purchasing a higher priced unit when a cheap toaster oven with a cheap PID will work fine. Not making the process more complicated just possibly using what one already has. Anyway, PID's aren't expensive when purchased correctly.

[308Jeff]

Just checked mine ($5.00 Rival yard sale pickup). It was hot by 40 degrees. Once I found the right spot on the dial, it did a good job of maintaining 400.

[SonnyW]

This is my first post so be nice...

I used my Lyman lead thermometer to check my Black and Decker toaster oven. The thermocouple probe will just go between the glass and the frame if the little plastic part is gone, (mine was anyway from the lead pot) and the door will still close. I used a little timer and a notepad and recorded the time and temp every single time the element clicked on or off. I put all that into a spreadsheet and made a chart of it. I ran a preheat test and then another bake cycle test with about 1 pound of bullets in the tray. (55 each 130 grain) What I found out was that the oven really overshoots during preheat but after about 15 minutes it settles down and will control within maybe +/- 20F. I already knew that my oven runs a little high so I set the dial just under 400. I set the timer for 20 minutes plus a little. The temp dropped a lot when I opened the door and it took about 6 minutes to get back to 400, but after that it controlled pretty good, though still set a little high. I could set it a little lower next time. I've used this setting before with no problems with HF red and several Eastwood colors. Here are some photos and the chart.

[Dragonheart]

Hi SonnyW and welcome. I would suggest getting a Taylor Oven Guide Thermometer and setting is where you can read it through the glass door. Once your bullets are loaded in either a cold or hot oven all you have to do is bring the temp to 400, which you can see as the glass thermometers react quickly, and start timing. The problem I had with my B&D oven was the temp was all over the place and never settled, so I abandoned the oven, but since I had found it new at Goodwill for $10 it wasn't much of a loss.

[SonnyW]

Thanks Dragonheart, glad to be here.

Yes, I'm not intending to use the Lyman thermometer all the time, I just used it for this study, and this oven works fine for me. The Taylor oven thermometer is a good idea and I will probably add that. I've got one somewhere. Mainly I did this study for my own benefit, but just thought other people with the BD ovens might be interested in the chart. Maybe the chart is too small. It's much easier to read if you click on it and make it bigger. I took about 70 data points and spent a couple of hours between taking data and analyzing it with this study. I even calibrated the Lyman thermometer against another one I have that is certified and traceable to NIST, and it is within about 2 degrees F up to about 200 degrees which is as far as I checked it.

I think the chart shows quite a bit about how these ovens react over time. I haven't been having any problems with the powder coat passing the smash test or melting bullets or anything like that, this particular oven works perfectly fine for me as is. The control knob is about 20 - 30 degrees off to the high side but once you know that it's easy to compensate. What surprised me was how much overshoot there was with a cold oven. Proves to me that at least 15 minutes of preheat is needed. I guess the thermostat is far enough inside the unit that the whole thing has to warm up before it is halfway accurate. I haven't seen any evidence so far that it is necessary to control any closer than within about +/- 20 degrees anyhow.

By the way I have had other bi-metal thermostats like on space heaters that didn't work worth a flip, sometimes work, but sometimes on the same model or even on the exact same heater they just stick and either stay on, or don't come on at all, when they worked fine the last time. So I know what you mean about the one from Goodwill. I have put a PID on a crockpot I use for melting wax for my guitar pickup work so I know how to do that, but don't think I will need to do it for this oven.

Moderators, if I put this in the wrong thread just let me know...

[Dragonheart]

I first started with a Hamilton Beach Countertop convection Oven. It comes to temp much slower than the B&D, but doesn't overshoot it just stabilizes and stays there. I have used it since 2012 and it is still performing fine. I guess I just assumed all the convection ovens would work and when I saw the B&D I took it home. It wasn't until I did a trial heat up I found it just was not the reliable oven I was used to, so now it sits on a shelf as I really have no use for it. I did find a newer model Hamilton Beach for $20 that looks new and like my old oven it works just the same. I wanted a backup oven and maybe will run both this winter when I start casting & coating. At the present the daily temperature here is running 95 degrees with jungle like humidity, which does not make a pleasant day sitting in front of a casting pot.

[Westtrapper]

My wife picked a used oven for me 8 .00. Good deal my first powder coat , turned it to 400 ,20 min put bullets in. Cool came back to check them a red puddle dripping to the bottom of oven ,400 must mean 650 on my oven. 275 setting works good ,must be metric ha ha

[Markbo]

[Dragonheart]

My wife picked a used oven for me 8 .00. Good deal my first powder coat , turned it to 400 ,20 min put bullets in. Cool came back to check them a red puddle dripping to the bottom of oven ,400 must mean 650 on my oven. 275 setting works good ,must be metric ha ha

The temperature dials on many of these ovens do not mean anything, my Black & Decker oven purchase confirmed that. When you think about it most of the kitchen ovens dials are off also and these ovens cost way more than toaster ovens. The main thing is finding an oven that will come to temp and stabilize there without wild fluctuations. If an oven won't do that then save yourself a lot of work and frustration and toss the oven. When you find one that works a $10 Taylor Oven Guide thermometer you keep in the oven where you can monitor it will allow you to get perfectly cured bullets every time.

[Smoke4320]

yes 90% plus of the problems we see in DT coating is .....NOT shaking hard enough or oven temps not correct

funny thing is they will argue with you forever that their oven is correct or just don't care/don't get it but continue to have problems and blame it on the coating

[Dragonheart]

Agreed. I guess the remaining 10% of the problems is poor choice of powder, but if you start out with smoke's powder you will be 10% ahead of the game.

[RP]

yes 90% plus of the problems we see in DT coating is .....NOT shaking hard enough or oven temps not correct

funny thing is they will argue with you forever that their oven is correct or just don't care/don't get it but continue to have problems and blame it on the coating

Do you have any facts to back this up ? This sounds like some people I have dealt with. Sad but true and there is no cure know to man that is legal