Pre-Heating Ingots

[Kenneth L. Walters]

I've used a bottom draining 20 pound furnace for years.  I tried most of the furnaces and finally decided that the RCBS was the best.  I've got three, one for each major alloy that I use.

I wondered if adding ingots to the furnace during a casting session made any difference.  To study this I picked several single cavity moulds that yielded bullets of pretty uniform weight, cast for a couple of hours and saved the bullets in their as cast order.

Then I weighed them and did visual inspections.  By noting where ingots had been added I could see if adding those ingots made any difference either to bullet weight or to defects that could be spotted by visual inspections.  Made no difference whatsoever.  Adding ingots during a casting session doesn't make any measurable difference.  Doesn't with linotype, wheelweights, 30 to 1 alloy or pure lead.

One thing, however, does matter.  Breaking your casting rhythm.  Flux for any noticeable amount of time and bullet weights and visual inspections do suffer, at least for a little while.  Go get a cup of coffee.  Same result.  Establishing a regular rhythm matters.  Not much else does.

[Cat Whisperer]

Ken -
 Good observations!  Thanks for posting these.  I know that it took more than just an evening to fire up that pot for 4 different alloys and several moulds to be used with each one.

[Kenneth L. Walters]

Obviously I meant this as a response to another post.  Why it didn't show up that way I don't know.

[LAH]

I cast using bottom pour 40 pound Magma Pots. I try to add ingots as soon as there's room for them in the pot. Our ingots weigh 8 pounds each. I normally lay one of these on the ledge of the pot to pre heat before adding it to the melt. I notice no difference in the bullets.

I can see no difference when fluxing which is done each 1/2 hour. A cup of coffee though makes a big difference.