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View Full Version : Heating or preheating molds



Tom-ADC
07-05-2010, 09:48 AM
Do you preheat your molds and if so how? Aluminum & steel?

qajaq59
07-05-2010, 10:00 AM
I put both iron and aluminum on the lead in the pot until the lead melts. Then I keep them on the rim until I'm ready to pour. Seems to work ok for me.

BoolitSchuuter
07-05-2010, 10:05 AM
I have an old Lee 10lb pot. I set it on the lowest setting and stand my mould in it. I only have three moulds so it is a simple matter to rotate them during a casting session.

winelover
07-05-2010, 10:47 AM
Propane torch.

Winelover

mooman76
07-05-2010, 11:16 AM
The aluminum moulds I dip in the lead melt and the steel I set on the edge of the pot while it heats up but I don't have many steel moulds.

chboats
07-05-2010, 11:17 AM
I set mine on an electric hot plate to preheat. I put a light switch dimmer in line with the hot plate to control the heat. The temp control on cheap hot plates are an on off switch and don't work very well.

Carl

dragonrider
07-05-2010, 12:21 PM
I dip mine in the lead pot. 2 to 3 minutes is usually enough. Aluminum or steel.

theperfessor
07-05-2010, 12:30 PM
A cheap hot plate is a wonderful thing to have. I put an aluminum plate on mine and use it to preheat my mold and a stack of ingots, cuts down time when recharging furnace. I control mine w/a home made PID controller, it keeps it from overheating and melting ingots.

Tom-ADC
07-05-2010, 01:32 PM
I was still getting some wrinkling and figured my mold isn't hot enough I'll try this and see how it works.

selmerfan
07-05-2010, 01:46 PM
Hot plate! I won't cast without one. I put it on about med to med-high and set my molds on it when I plug the pot in. First casts are perfect, sometimes even a little frosty, every time, both aluminum and iron molds. I've tried the preheat with the pot thing and the mold seems to be inconsistently hot, as well as dipping corners, same problem. The answer - HOT PLATE!!!

HeavyMetal
07-05-2010, 01:54 PM
bought a hot plate two years ago and it was one of the best investments for casting I ever made!

Made a couple special plates to sit on top of it, one for my 4 and 6 banger molds the other for my HP mold pins.

In use I put a mold on the hot plate and set it for medium, then put the second mold on top of the pot to heat up while the alloy melts.

Generally everthing is ready to go about the same time. I then turn the dial down on the hot plate to just over low and start casting and rotating molds off the hot plate.

Found that if I set the mold on the hot plate so that the sprue plate contacts it my base fill out goes to almost 100%.

Cherokee
07-05-2010, 02:32 PM
Hot plate - Iron or Alum molds. Medium heat. Usually good bullets from first or second pour.

Tom-ADC
07-05-2010, 02:43 PM
I'll search around for a hot plate but just putting the lee molds n the pot made a world of difference boolits are good to go, I had polished one of them and it was really nice. I put my Saeco steel mold in the pot and went into a mild panic I had a big chunck of lead with handles on it:bigsmyl2: But left it in long enough to heat up and it to produced good boolits. Hot plate will make it a little smoother I'm sure.
But the wrinkles are gone and even had a frosty one or two boolits.
Thanks to all:cbpour:

docone31
07-05-2010, 02:46 PM
I put Kitty Litter in my pot. I put my molds on the Kitty Litter prior to casting.
I have yet to have wrinkles except my first mold, and casting experience.
The litter also picks up the crud also. In time, it turns into powder and I can dump it.

RP
07-05-2010, 03:12 PM
I use both the top of the pot and a hotplate when I fire up the pot I place the mold on top of the pot and it heats with the lead. If iam going to be using more than one mold I fire up the hot plate and set the molds Iam going to use on it. Also it will keep the mold at the right temp giving you a break thats needed for the older casters well thats what I hear lol.

jawjaboy
07-05-2010, 03:25 PM
I use a hot plate with a 3" wide, 1/4" thick piece of steel flatbar. The washers are used to level the mould so as to sit flat on the steel bar.

Not a very good pic of it.


http://i56.photobucket.com/albums/g194/jawjaboy/IMG_0681.jpg

fredj338
07-05-2010, 03:49 PM
I find resting the molds on the pot edge gets them plenty hot for casting. Usually only needs one or two fills to start perfect bullets. I almsot always cast w/ two molds & rotate them when they start getting frosty. The iron molds in my MagmaCaster get noi preheat, but I still get good bullets in 5-6 fills.

geargnasher
07-05-2010, 04:20 PM
With ALL my two cavities, either aluminum or iron, I dip them 1/4" or so in the melt until the lead quits sticking to the blocks. Then I dunk the tip of the sprue plate for 15-20 seconds and start casting away.

For Lee six-cavity moulds, I think it is impossible to cast without a hotplate. Preheat it by setting it bottom-down on the plate on about medium and forget about it for ten minutes. If you don't get it up to temp before pouring, you'll break your sprue handle trying to cut the cold sprues. I broke one (even being aware of the problem) just casting two cavities in a warm but not hot enough mould. Sprue was rock-hard before I could get those two cavities filled.

Hot plate works for two-bangers, too, just takes too long IMO.

Gear

Marlin Junky
07-05-2010, 05:22 PM
Hot plate - Iron or Alum molds. Medium heat. Usually good bullets from first or second pour.

What Cherokee said above. Big, heavy iron alloy molds like SAECO .30 cal's get set on medium-high to high though. Any electric hot plate at Wal-Mart should be fine but if it's one that has the old fashioned metal coil, place a sheet of heavy gauge metal between the coil and the mold (ala jawjaboy) for more even heating. You might want to do that anyway to avoid the possibility of overheating an aluminum mold.

MJ

walltube
07-05-2010, 06:00 PM
I use a clothes pressing iron. Inverted, with the iron's handle held (gently) :) within the jaws of a clamp on vice. The irons flat pressing suface is a dandy for 4x or 6x cavity moulds. Adjusting the temp is easy with the fabric heat control. How much heat for aluminum? Not more than would scorch cotton or linen. I am assuming you have some experience pressing clothes ?? ;)

This iron doubles as a lube heater.

Tom-ADC
07-06-2010, 03:23 PM
Today I used my bottom pour pot and left the steel mold on top while the lead melted, boolits came up great, I think the bottom pour is a little easier for me, I seem to shake a tad using a ladle, old age I guess.:Fire:

wiljen
07-06-2010, 03:27 PM
Hotplate for me

Muddy Creek Sam
07-06-2010, 03:49 PM
I use a hotplate with a CI griddle, with a slight lip, to heat mold and preheat extra ingots.

Sam :D

casterofboolits
07-06-2010, 05:03 PM
I use the top of my RCBS 10 Kilo pot to preheat my molds. Even works with eight cavity H&G molds.

Tom-ADC
07-06-2010, 11:01 PM
Out of 60 or so I keep 50 all looked great, young boolits (no wrinkles) I did the standard pan lube on them and tomorrow I'l load them for a future range trip.

DLCTEX
07-10-2010, 05:29 PM
With ALL my two cavities, either aluminum or iron, I dip them 1/4" or so in the melt until the lead quits sticking to the blocks. Then I dunk the tip of the sprue plate for 15-20 seconds and start casting away.

For Lee six-cavity moulds, I think it is impossible to cast without a hotplate. Preheat it by setting it bottom-down on the plate on about medium and forget about it for ten minutes. If you don't get it up to temp before pouring, you'll break your sprue handle trying to cut the cold sprues. I broke one (even being aware of the problem) just casting two cavities in a warm but not hot enough mould. Sprue was rock-hard before I could get those two cavities filled.

Hot plate works for two-bangers, too, just takes too long IMO.

Gear

+1 on , but I don't own any six cavity moulds, yet.

theperfessor
07-11-2010, 12:11 PM
I used to use the "dip a corner in the pot" method before I got a hotplate and it works fine for 1 and 2 cavity molds. Just be careful, it's also a good way to get bits of leads stuck inside the mold between the faces if you don't hold the mold tightly shut while you're doing it.

Nothing wrong with doing it this way, just beware of the down side.

Tazman1602
07-18-2010, 04:59 PM
Hot plate - Iron or Alum molds. Medium heat. Usually good bullets from first or second pour.

+1

$10 Hot plate from Walgreens while picking up prescriptions a while back was one of the best things I've gotten for casting. Cured a ton of headaches...........

Art

RP
07-18-2010, 05:33 PM
Right now its hot enough outside just sitting them in the sun should do it. I how many guys out there have tried a mircowave to preheat I am sure someone has tried it.

qajaq59
07-18-2010, 05:53 PM
I loaded 200 rounds for my 30-30 this morning and if I hadn't started real early they'd have taken me out of the garage on a stretcher.
And if you put a mold in the microwave I think the wife will be happy when you buy her a new one!

Tom-ADC
07-19-2010, 12:07 PM
I would think a microwave because the mold is metal would do a bunch of arcing and possibly ruin he mold?

wills
07-19-2010, 12:42 PM
Make an aluminum foil “boat”, float the mold in the boat on top of the alloy. No problems with alloy sticking to the mold.

Mal Paso
07-19-2010, 10:44 PM
The Case Trimmer money got spent on a Colt I couldn't live without and by the time I get caught up I'm going to need Powder and Primers. Sooo I'll stick with a big chunk of steel plate on my propane stove. I know just how big the flame needs to be now and quite often get good boolits on the first pour. One thing with the molds I have, the handle attaching screw can drift down and hold the mold bottom off the plate. Something I check between pots.


Mal