Mould Warmer

[Mike W1]

Need this about as much as a hole in the head but I'm pretty sure you're supposed to have fun in retirement and these goofy projects keep me entertained. I don't know what the basic closure was made for. Looks like it could have been a mounting bracket for an electric trolling motor. So I added a back piece, a bottom and hinged a cover for the front out of scrap aluminum. Bottom is only 1/8" aluminum so may have to go heavier on that later on. Seems to be OK on initial tryout with a cheap 1/8" TC inserted into the side. Also made a couple different gizmos so the mould's sit flat on the bottom.

Next step is to use one of those little threaded TC's and tap the bottom plate for it. Can watch the temperatures on the other probe with the multimeter and keep an eye on the PID while it's tuning. Did seem like the AT went a long time getting done on the first go round. That picture ain't great but believe I shot 30 of em' to get this. Flashes or bare light bulbs don't seem to be compatible with brushed aluminum!
http://i171.photobucket.com/albums/u310/Mike4245/Mould%20Oven_zpskzxzfroc.jpg

[lobowolf761]

Looks great.

[Pee Wee]

OK Mike, you have way to much time on your hands, oh that's right it gets really cold where you live.

[rush1886]

Are you planning on a production run, anytime soon?

[Mike W1]

Are you planning on a production run, anytime soon?

Between mowing a LOT of grass and trying to organize my bench in the garage I've managed to play with things a bit. So far it appears that the idea of controlling the temperature is better served with a TC monitoring the air and not the surface of the warmer bottom. What I'd like to find is some sort of insulating material to put in the warmer. In days of old my choice would have been asbestos board that we used to call cement board. Gray stuff that was smooth on one side and a rougher texture on the other. But not available now of course. I imagine there's something along those lines out there but don't know what and sure ain't gonna buy a 4x8 sheet of it for this little toy. Lot of heat escapes that thing. Surface TC showed the bottom at about 466°, cabinet side a 343° and the top at 394°. Not any big deal of course but remember I'm "playing" here. Getting familiar with the Mypin settings and like the unit though I prefer the Auber.

[LAKEMASTER]

This is neat !
I heat my mold with lead in the pot buy this is a neat way

[montana_charlie]

You are heating a lot of volume, and it's all surrounded by large radiating surfaces.
Reducing the size should be more efficient (I think) and this is one idea.

http://castboolits.gunloads.com/attachment.php?attachmentid=50219&d=1238431668

[dragon813gt]

I use a metal coffee can cut in half. Isn't fancy and doesn't look pretty. But it works.

[montana_charlie]

I use a metal coffee can cut in half. Isn't fancy and doesn't look pretty. But it works.
I also use a simple tin can. The image I posted is something that I 'saved' years ago, but have never built.

The can I use is rectangular (for Spam, or something) and fits quite closely to the dimensions of my mould(s).

[Spruce]

Nice, like to see more pics of what casters are using. Have not come up with one yet, but I had better get on the ball as cooler casting weather is near.

[JakeBlanton]

OK Mike, you have way to much time on your hands, oh that's right it gets really cold where you live.

For Florida, our mold warmers consist of just leaving the mold out in the sun for a bit.

[JakeBlanton]

Nice flat surface on the top to double as a coffee cup warmer. Great idea. :)

[bangerjim]

I just lay my molds right on top of the flat-top 1.5KW aluminum lab hotplate I have. Also pre-heat feed ingots on there also. No need for a surround. Molds can get to 500-550F real fast. (I do not just warm them! I take them to full casting temps). I get perfect drops from the 1st one.

This time of year here in AZ, if I just lay a mold on our swimming pool deck, the sun will get it to almost 200F! Guess Obummer would call that "green" energy?!?!?!?!

banger

[edctexas]

Here is an interesting thought. I have measured the surface temp of my mold heating hot plate and the temp of the mold. Now the two TC's are not the same exact type. The other thing is the Surface sensing TC is attached to a small block of AL placed next to the mold with it's TC. I get a fairly constant differential in temp when I control the surface TC with a PID. There must be a Temp difference if the Mold loses heat to the air. Does anyone think I could do any better getting a good starting temp by regulating on the mold TC or do any better by adding a heat shielding cover?

Ed C

[bangerjim]

To get good thermal transfer, you need an tight intimate contact of the mold with the surface of the hot plate. Mine is flat with excellent contact. I still put a 1# lead ingot on top of the mold to keep that contact. Contact is the key. That is why semiconductors use heat sink grease on the heat sink.

Worrying about mold temp is pushing the envelope! I never measure it. I know if I put my mold on the plate with the dial set at 5, it will get to casting temp in about 11 minutes.....while the 4-20 is heating. And get perfect boolits from the 1st drop. That's all I need. Works every time for me. If I ever need a mold temp, I will shoot it with my $150 IR gun aimed at a black spot on the mold. Close enough for gubmint werk.

[Walter Laich]

I got one of those RCBS lids advertised on this site. I just sit the mold on top of it and mold is ready when lead is up to temp.
.
Do put an ingot on top of mold as they tend to tip towards the handle end.

[edctexas]

Have been disappointed with trying to measure mold temp with an IR gun. I try to read the sprue cutter but the temp never seems to agree with mold I have with hole to insert a TC for a reading.

Once you have a method for determining the mold is hot enough. It is time to start molding and getting good boolits.

Ed C

[jonp]

I use a flat, round cast iron pancake pan that was hanging on the wall when we bought the house. Mold's sit flat on them and heat pretty good.

[Dale53]

I'm not knocking anyone's idea. However, I have a two burner electric hotplate next to my casting station. It is the solid metal burner type (not a calrod unit). I sit the mould on top at a pre-determined setting when I turn my my RCBS Pro-Melt on. When the metal is up to temp, so is the mould. I actually set the mould temp just under final casting temp so one or two moulds full bring it up to speed (that way I will never overheat my mould and possibly warp it). I also use the second burner to pre-heat ingots when needed.

FWIW
Dale53