howdya heat up alum mold

[targetshootr]

Cast my first 38-40 boolits today in my first aluminum mold and it took a lot longer before they looked right. Musta dropped 75 before the wrinkles and the shine were gone. l'd pre-heat it but the microwave is strickly for cats. (kiddin')
Also, what's a good way to keep melted lead nearby to cut wait time?

[lar45]

What brand of mold are you useing? My molds from Mountain molds take much longer to heat up than any others.
I use a propane torch to preheat the molds.
With my Lee molds, I have to smoke the cavities on almost all of them. I use a long BBQ lighter. You can sit the mold ontop of the pot to warm up as the lead is coming up to temp. If the mold is small, 1 or 2 cav, then you can dip the corner in the lead and let it sit. This heats it up very fast. You'll probably have to wipe the blocks off to keep any lead from sticking. Also watch out for lead in the screw holes.
I have tried keeping a pan of lead on an electric hot plate and use a small ladle to transfer to my casting pot, then put ingots into the pan.

[dk17hmr]

I am still using my Coleman 2 burner white gas stove. So when I get my lead starting to melt I lean my molds against the pot so they are over the flame. Doing it this way works well for me because I can keep 2 or 3 molds hot enough to cast a varity of bullets in one sitting.

[Dale53]

There are a number of ways to pre-heat a mould. If you are using small aluminum moulds, do as Lar45 suggests and dip the CLOSED mould into the lead for as much as a minute or so. Using steel moulds then two to three minutes is about right. Using large, steel gang moulds, I pre-heat them on a hot plate. You do NOT want the mould to get as hot as the molten metal. That can result in molten lead sticking to the inside of the mould. Instead, shoot for 400-450 degrees with the mould with your metal at 650-750 degrees as an example.

I only cast about a 22 lb pot full before I quit. I fill the pot at least three quarters full and bring the metal up to heat before I start casting.

However, when I was doing commercial casting, I had a separate 20 lb pot (just a Saeco dip pot) that I alloyed the metal in and kept hot for transfer to my bottom pour pot. That way I had a continuous flow of hot metal. Using one pot, you can pre-heat ingots on a hot plate or the edges of the casting pot. That helps reduce the "cool down" time when adding ingots.

Dale53

[Castaway]

My guess is that the problem was oil contamination casuing the wrinkles. Took 75 castings to burn it off

[eka]

I spray with brake cleaner and then scrub with hot water and Dawn detergent. Then while the pot is heating up, I place my mould in a stainless pot on a electric burner to heat up. As the lead is getting hot, but not really at optimum temp., I pour the lead into the mould and cut the sprues. I then leave the bullets in the mould and back on the hot plate until the melt is at the right temp. Good bullets in just a couple of casts if not the first try. I keep ingots hot, but not melting in a stainless post beside the casting pot on another electric burner. I add the hot ingots to the melt and welcome a short break. I put my mould back on the other electric burner to keep it up to temp. You are back in business in just a minute or so.
Just what seems to work for me.

Keith

[chunkum]

Spray mould with non chlorinated brake cleaner when cold and then, if fillout is still not right, again when hot . I pre-heat the moulds on a hot plate. You can keep several hot on one hot plate. It works good.
c.

[Buckshot]

...............Sit the blocks on top of the pot while th ealloy is melting. WHen it's up to temp I stick a corner or the end of the blocks into the alloy for about a 10 count. Usually good to go after that. I even do that to iron blocks, but they say not to.

.............Buckshot

[1Shirt]

As usual, I agree with Buckshot, and have been doing it his way since Lee first started making molds.
1Shirt:coffee:

[targetshootr]

Lots of good ideas. This is 6 cav alum mold from NEI with Lee handles. I kept it on top of the Pro-Melt as the lead was melting but it didn't seem to get all that warm so I'll find a hot plate or use a torch. Been using a torch to get the lead going through the spout. Really need a second pot to keep melted lead in.

[BPCS]

I place the cleaned mould on the burner of a gas stove and allow the flame to just touch the bottom of the mould. After about 10 minutes the mould is ready for casting.

[targetshootr]

With direct flame is there any chance of warping? (Not me, the mold.)

[mooman76]

Those 6 bangers are a bugger to get hot. Liek they said stick the corner of the mould in the lead to heat it up. I usually use a count to 20 for 2 cavity a nd a couple seconds less for single. A good rule of thumb is when you pull the mould out of the lead and there is a clump of solidified lead still stuck to it, it isn't hot enough yet. Just keep doing it until the lead falls loose. The six bangers I put the mould on top to preheat and the key is to have everything ready and close by to keep your lead and mould hot. You need a big pot for this one or by the time you get it hot enough you will run out. Keep putting small amounts of lead in the pot as you go to keep the level up. I pour excess lead on the mould when first starting out to help the mould get hot faster and you need a big ladel also or your lead will harden too fast! I use a juice can cut off and atached to a broom handel to have one big enough! Also I use a cast iron pot on a cook stove for the 6er!

[RANGER RICK]

I usually sit my open molds under the cast master pot and turn it on .
They are ready to go when the mix is at the right temp to start up another session of glee .

RR

[MT Gianni]

I find that I need to stick a corner of a 4-6 cavity mold in the melt for at least 90-120 seconds then cast 1 cavity, the one that was in the melt, twice, adding aditional cavitys after every 2nd pour to get the mold fully up to temp. With the Lee;s it keeps you from breaking sprue plate handles. Gianni.

[gitano]

Compared to most here, I am a fairly inexperienced caster. That said:

I rarely use anything other than single cavity molds. For those (Lee) molds, I simply cast until they come out 'right'. In almost every mold I use that takes about 12 cycles. I have 'preheated' the molds, but find that in the end, no time is saved with preheating. Your mileage may vary.

Paul

[9.3X62AL]

Lotta good ideas here. One other thing to remember is that aluminum blocks transfer heat more quickly than do iron/steel blocks, and I usually have to smoke the cavities to slow heat transfer. This prevents the cold mold/wrinkled boolit effect to some extent. Aluminum blocks also SHED heat more quickly than do the iron/steel critters.

MT Gianni's info is VERY good stuff if you don't use a hot plate or other heat source to pre-heat larger blocks. John saved a lot of sprue cutters from an untimely demise with that bit.