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View Full Version : Using a Kiln to heat-up/keep molds hot.....



Butcher45
02-25-2021, 10:32 PM
Did a search, and could not find any info.

I intend to heat up, and maintain the heat of my molds via "garaging" using a kiln.

Anyone doing this? Is there anything I should know before I do it?

Thinking I'll set ceramic tiles set in the kiln to keep the molds clean.

FYI: There is a small door on the kiln for the handles to stick out of.....so no worries regarding the overheating of handles.

Mal Paso
02-25-2021, 10:41 PM
Most of us use a covered hotplate to do that but if your kiln will work around 400F you could use it. One fellow here uses a precision lab hotplate.

Butcher45
02-25-2021, 10:47 PM
Most of us use a covered hotplate to do that but if your kiln will work around 400F you could use it. One fellow here uses a precision lab hotplate.

It will hold 400 degrees pretty-much on the nose no problem. It's at my ventilated workbench already, so no reason I can see not to use it.

I suppose molds could be set on top of the kiln as well, for a different level of heat than inside the kiln.

samari46
02-26-2021, 01:23 AM
I bought one of the lab style hot plates. Numbers 1-10 but does not have temptures in degrees. Before I start casting later this year, going to get one of the infrared gizmos from Harbor Freight. Frank

GregLaROCHE
02-26-2021, 02:00 AM
Not sure if you could keep the handles from getting too hot. Even if they are not damaged, you would surly need to use gloves to handle them.

Butcher45
02-26-2021, 02:06 AM
I am using an AIM 99LS/D kiln that has a triple door. Handles of my work with glass that hang out the door the same as an Iron mold's handles would, do not get hot. I realize iron is different than glass, but I am not foreseeing a problem with the handles getting hot from the kiln itself.....only from the mold. There is great ventilation in this area.

mehavey
02-26-2021, 08:05 AM
How big a gang mould are you anticipating having to accommodate ?

https://s15.postimg.cc/n7t2rmxtn/Hotplate.jpg

Wayne Smith
02-26-2021, 10:19 AM
I have a hotplate and put aluminum foil over it for the first time a couple days ago - had the brass mold so hot that it took minutes for the lead to go from molten to hard in the mold! I now leave it at 50% - my only concern for the kiln would be overkill, too hot.

farmbif
02-26-2021, 10:47 AM
I guess I'm going to have to try this hot plate mold preheating thing. seems y'all have crafted it to a fine art.

Stewbaby
02-26-2021, 12:37 PM
...imagine the mold is in the paint can (didn’t have a pic with it that way for whatever reason, I think I was done for the day)

https://uploads.tapatalk-cdn.com/20210226/a8f1f18b865ecf9eb6b747f91b24a186.jpg

GregLaROCHE
02-26-2021, 04:26 PM
I am using an AIM 99LS/D kiln that has a triple door. Handles of my work with glass that hang out the door the same as an Iron mold's handles would, do not get hot. I realize iron is different than glass, but I am not foreseeing a problem with the handles getting hot from the kiln itself.....only from the mold. There is great ventilation in this area.

In that case, I don’t see why it shouldn’t work well.

oley55
02-26-2021, 06:37 PM
another hotplate mold oven option. Rotate the coffee can to accept one, two, or zero molds. The clad pan seemed like it was transferring too much burner heat so I have a (cupped/warped) cut to size circular saw blade laying in the bottom to provide a little heat cushion.

If you select a photo they will become right side up.

crackers
02-26-2021, 06:44 PM
"I have a hotplate and put aluminum foil over it ..."

That foil's only gonna last three or four years before it has to be replaced.

Wayne Smith
02-27-2021, 09:56 AM
"I have a hotplate and put aluminum foil over it ..."

That foil's only gonna last three or four years before it has to be replaced.

I'll be glad if I can keep it around that long!

mvintx
02-27-2021, 10:09 AM
I bought one of the lab style hot plates. Numbers 1-10 but does not have temptures in degrees. Before I start casting later this year, going to get one of the infrared gizmos from Harbor Freight. Frank

I've got one of those infrared gizmos...trying to get an idea of what temp the mold liked during casting. I preheated the mold on a coil-type hotplate set at halfway on the dial - no cover of any kind over the mold. The bottom of the mold read somewhere in the 275-300 range and the top was much cooler...180-225. After a few casts and getting good fillout I checked the temp again and it was lower than what I started with, under 250. My pot temp is 750.

I was surprised at the low temp of the mold and learned they dissipate heat very quickly, but as far as determining that ideal temp for starting to cast, I did not. Simply preheating the mold is enough for me.

nvbirdman
02-28-2021, 12:52 AM
Is starting out with a hot mould really that important? I start out pouring and dropping as fast as possible, dump the first half-dozen drops back in the pot, and my mould is heated up.

mehavey
02-28-2021, 08:14 AM
Pre-heated as on Post#7 (http://castboolits.gunloads.com/showthread.php?420111-Using-a-Kiln-to-heat-up-keep-molds-hot&p=5128995&viewfull=1#post5128995), my moulds drop first-bullet/perfect-bullet.
And as Pre-heat/Pot-heat are simultaneous - very efficient use of life (time)
[smilie=6:

Mal Paso
02-28-2021, 10:24 AM
I've got one of those infrared gizmos...trying to get an idea of what temp the mold liked during casting. I preheated the mold on a coil-type hotplate set at halfway on the dial - no cover of any kind over the mold. The bottom of the mold read somewhere in the 275-300 range and the top was much cooler...180-225. After a few casts and getting good fillout I checked the temp again and it was lower than what I started with, under 250. My pot temp is 750.

I was surprised at the low temp of the mold and learned they dissipate heat very quickly, but as far as determining that ideal temp for starting to cast, I did not. Simply preheating the mold is enough for me.

Infrared thermometers are Not accurate on shiny surfaces. One member blackens areas of his molds to get an accurate read. Birchwood Casy has aluminum and brass black. NOE has a wired thermocouple system too.