Worn Out Furnace Preheats Moulds

[Silver Jack Hammer]

My casting furnace gave out, it only got up to 550 degrees. Now it serves great as an oven that preheats moulds. Using the worn out furnace as an oven makes it so that by the time my new furnace has heated up the alloy, the old furnace has pre-heated mould. The first boolit drops perfectly and the preheating phase is no longer necessary.

And to think that I almost threw the worm out furnace away.

[D Crockett]

you have thought of a way to make casting easer for you that is great D Crockett

[Walter Laich]

do you leave it on the whole time or turn it off once the mold comes up to temp?

[bangerjim]

You are using the old one just like most of us use an electric hotplate. I have been pre-heating all my molds on a lab grade electric hotplat for years. And I use it to preheat feed ingots also, shortening the recovery time of the pot.

Preheating your molds to FULL casting temp saves a lot of time rejecting bad boolits at first start of session.

[Silver Jack Hammer]

When my alloy is up to full temperature I grab my mould out of the old furnace, the timing seems to be just right.

[Hardcast416taylor]

Just curious. What brand is the old furnace?Robert

[Silver Jack Hammer]

Lyman Mag 20. I loved this furnace, hated to see it give out. Now I really appreciate it.

[Mike W1]

Long ago I added a shelf on both my Lee 10# pots to preheat my moulds and they definitely did help do that. But in the last couple years after adding several types of K type TC's to my collection and doing a lot of measuring I've concluded that those shelves don't get quite as hot as one would think. Highest I ever read on one of them was 300°. The one mold I've used the most casts best at around 320-340° and the shelf will not get them quite that hot. Usually 290° or so at best. Running my hot plate at 390° will get the mold 310-320° while the pots are heating up. Possibly the warming shelves on the RCBS & Lyman will do better than the little Lee but I don't own either of them so can't say.

[crandall crank]

That's a great use for the "old" furnace. I just place the mold on top of the pot as the lead is heating up. That works well enough, until I want to change molds for a different bullet. This is when I usually refill the pot with smelted ingots, place the new mold on top of the pot and wait for everything to get hot/melt. Once the lead melted, the mold is hot and ready...ymmv