Why sprue plate down on hot plate?

I have read several times that the way to heat up a mold is by placing it on a hot plate with the sprue down on the burner. Why is that better than just setting the mould down on it's bottom?

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I put the mold bottom down on the hot plate because it also heats the hp pins that way. (MP molds) NOE hp molds have all that apparatus on the bottom to the don't sit well that way and I can see sprue plate down being a good option.

I set the bottom of the mould on the hotplate and put a 1 pound ingot on top to maintain firm contact. I only have one hollowpoint mould and it is a Lyman single cav., so I just leave the pin out to heat.

I use a propane torch to preheat my mould. Heating all sides with hot flame, but not too hot.

Yap bottom of the mold on the hot plate

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The idea of the sprue plate down is to heat the sprue plate. Place the mold bottom down for a while then turn it over & heat the plate. A mold oven helps a bunch.

Rick

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"Let us remember that if we suffer tamely a lawless attack on our liberty, we encourage it." Samuel Adams

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Whichever gives it the most surface area contact is the way I go.

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The idea of the sprue plate down is to heat the sprue plate. Place the mold bottom down for a while then turn it over & heat the plate. A mold oven helps a bunch.

Rick

Rick, how long you talking on keeping it sprue plate down for?
I use a big old green bean can for a mold oven, but never tried the turning the sprue plate down. Always relied on my sprue puddle to get it up to temp.

Didn't say I do it, only that it is done (by some) to heat the sprue plate. I think Glen suggested it in his book as one method of getting the plate up to temp.

I've had very good luck getting mine up to temp with the hot plate & electric box oven. Miha & NOE plates take a bit longer to get up to temp because they are much thicker.

Rick

"The people never give up their freedom . . . Except under some delusion." Edmund Burke

"Let us remember that if we suffer tamely a lawless attack on our liberty, we encourage it." Samuel Adams

One side is for Liberty and the Constitution and they are called domestic terrorist, anti-American, nazi's and mobsters. Just what is the side using these terms for?

NRA Benefactor Life Member
CRPA Life Member

Didn't say I do it, only that it is done (by some) to heat the sprue plate. I think Glen suggested it in his book as one method of getting the plate up to temp.

I've had very good luck getting mine up to temp with the hot plate & electric box oven. Miha & NOE plates take a bit longer to get up to temp because they are much thicker.

Rick

Sorry Rick, I must've misread your post. I was thinking you'd tried it or used that method also.
Same with me though, i use the green bean mold oven, get my molds up to heat while my melt is melting in the furnace. Takes about 3 pours for my sprue to be up to temp.

I might have to try it as an experiment though just to see, next time I do some casting. Be an interesting thread on here perhaps.

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