Looking for a way to controllably heat an aluminum bar to 320f

[DavidScott]

I am looking for a way to controllably heat a minimum 1"x2"x7" aluminum bar to 320f for a 10 minute cycle to cure a resin. I am thinking of a controller with a sensor driving a cartridge heater or two. This is outside of my realm so I am asking for help picking it out. Once picked out I can figure out the rest. This is a Harry Homeshop adventure in some ways so cosmetics don't matter, but it is professional so no Ebay or Amazon cheap. I want to leave some headroom on size so any info would be appreciated. I am thinking of about 5 minutes from shop to full temp. I am guessing a 250 watt cartridge heater but that is just a guess. I don't know enough about this to know if I have given enough info or not so please let me know what I am missing.

Thanks in advance for all your responses.

 

[kustomizer]

countertop oven?

wife's oven?

 

[52 Ford]

countertop oven?

wife's oven?

Come on now... it's 2022.

Husband's oven?

 

[kustomizer]

Come on now... it's 2022.

Husband's oven?

Not here, ya ought to hear how I was threatened the moment I finished installing "her new oven in her house"

 

[Garwood]

I have several aluminum top lab grade hot plates for melting the wax used in lost wax casting cores. I don't know if they go to 320, but I'd bet they do or use a different temp controller. If you could use one or 3 you're welcome to them if you want to pick up.

 

[52 Ford]

Not here, ya ought to hear how I was threatened the moment I finished installing "her new oven in her house"
View attachment 343647

LOL.

I'm still waiting to find someone getting rid of a propane range.

I'm not allowed to dry low hydrogen rods inside.

Oven does get hot enough, anyway. Lincoln Electric says hold at 800 degrees for something like a few hours to dry 7018s.

 

[Milland]

I'd go with a quality toaster oven. I've used a Cuisinart for post-HT tempering (~500F).

 

[TDegenhart]

I think you need to give us a few more details. How important is it to heat quickly, what type of resin, powder coat, temperature variation, effect to too high or too low a temperature, radiant heat, convected heat, temperature control, box oven, flow through oven, part temperature sensed or open loop among others.

Tom

 

[DavidScott]

I am trying to figure out a shortcut way of molding phenolic resin, without the big press. I was originally thinking of a toaster oven but want the versatility of cartridge heaters for ramp control as well as other reasons. I may want to clamp my molds between two heated plates, or ???

 

[boslab]

Band heaters, type k thermocouple to each, PID controller to each PC interface so it’s easier to tweak heat up, soak, cool down
Mark

 

[Conrad Hoffman]

I'd look for a surplus small Blue-M convection oven or similar. I wouldn't expect cartridge heater solutions to give even heating. 5 minutes heating time is probably way optimistic.

 

[Scottl]

Nowadays there are temperature controllers available very cheaply and if you combine one with a "dumb" (non-digital) toaster oven set for a higher temperature it should work fine. Modern controllers have auto tune so just put some scrap of approximately equal mass in the oven while letting it auto tune and you should be good to go.

 

[CITIZEN F16]

Why not just use your oven in the kitchen and use a laser thermometer to check the temperature of the piece. Most ovens aren't that accurate on temp, the older ones seem to have wide open tolerances.

 

[CITIZEN F16]

Nowadays there are temperature controllers available very cheaply and if you combine one with a "dumb" (non-digital) toaster oven set for a higher temperature it should work fine. Modern controllers have auto tune so just put some scrap of approximately equal mass in the oven while letting it auto tune and you should be good to go.

You could probably get a toaster oven at a garage sale for $5 and use that if worried about smell or spillage.

 

[atex57]

You could probably get a toaster oven at a garage sale for $5 and use that if worried about smell or spillage.

Hook the controller to a toaster oven or an electric frypan.

Ed.

 

[Joe Gwinn]

... and use a laser thermometer to check the temperature of the piece.

Be aware that those pistol-shaped IR thermometers (with pointing laser), are not at all accurate on shiny objects, and are often wildly off. This can be demonstrated by trying to measure the temperature of a mirror-polished bit of metal. You'll get some mix of mirror temperature and the temp of what is seen in that mirror. Nor does it work correctly through most kinds of glass.

Stick to direct-contact thermocouples.

 

[technocrat]

try an electric clothes iron upside down in a vice. Use a temp controller if you want tight control.

 

[Conrad Hoffman]

IR thermometers are fine if you can control the emissivity of the surface. For anything where I want an accurate temperature, I just paint the area with some flat black paint, hi-temp if necessary.

 

[CITIZEN F16]

Be aware that those pistol-shaped IR thermometers (with pointing laser), are not at all accurate on shiny objects, and are often wildly off. This can be demonstrated by trying to measure the temperature of a mirror-polished bit of metal. You'll get some mix of mirror temperature and the temp of what is seen in that mirror. Nor does it work correctly through most kinds of glass.

Stick to direct-contact thermocouples.

I wasn't aware of that. Fortunately what I used it for had a margin of error. Checking temp on a passivating tank,
dry film lube parts, and experimenting with bluing and black oxide.

 

[CITIZEN F16]

IR thermometers are fine if you can control the emissivity of the surface. For anything where I want an accurate temperature, I just paint the area with some flat black paint, hi-temp if necessary.

I had to look that word up, I am still fighting concussion symptoms, reading the definition gave me a headache.