New to 6 cav molds

[Hondo 60]

Hey Folks,

I've been casting for about 5 years, so I have a good handle on how to cast with 1 or 2 cav molds.
But I shoot about 10-12k per year.

I decided to get smart & buy a couple of 6 cav molds.
Seems like a different world!

I have a Lee 10lb bottom pour furnace.
It works GREAT for the 2 cav molds.
But not so much with the 6ers.

After pouring 10 times, my bullets still were all wrinkled (too cold).
I went back to the 2cav & 3 pours later I was getting perfectly formed bullets or should I say boolits.

I need to add tin, right?
But how much? where can I find a cheap source?

By the way, I'm using straight wheel weights.
If what I've read is correct, this should be giving me a BHN of around 9, is that correct?

I can't imagine this isn't a sticky, but I couldn't find it.

Thanks.

[Gofaaast]

Your alloy temperature needs to be higher I think.

[claude]

After pouring 10 times, my bullets still were all wrinkled (too cold).

As you said, it sounds like a heat issue, six holers require longer to heat up if you aren't preheating on a hotplate. I know this because I don't preheat on a hotplate and I don't start getting good results until several pours. But after 10 cycles you should be close.

Is there any oil in the six holer? Oil will do that, wrinkles, but it should be gone by that many cycles.

You may be casting at to low a temp for the six holer as well.

All just semi educated guesses, I'm sure the more experienced casters will have good solid info to add, patience..........

[Mitch]

if you get good Boolits from the hole molds you should get good boolits from the 6 hole mold.just get the 6 hole a bit hotter and it should do just as well.WW I have had go all over the map for hardness for 8 to 15bhn most are some where between.I don't know if you have a hot plate for preheating your molds but it helps a lot with the 6 hole molds.whit a hot plate oce you get the right setting figured out a cast or 2 and you will have good boolits.Right here on this site in S&S you will find tin for sale at a decent price or may be the local scrap yard>if you do much reading here at all you should have seen it said many time 2% tin is all you need for good fill.if it were me is I added any tine to cow it would be 1% u se a mix of 50/50 cow and pure I add 2% to this mix.Hope this helps.

Bob

[odfairfaxsub]

Set that mold on top of yOur furnace while the lead melts....it's what I do. Works great

[Hondo 60]

I usually preheat for 30 min. I had the mold on top of the furnace during preheating.
I'll just have to turn the furnace up a bit & try adding a bit more tin.


Mitch - sorry for noob questions, but what is S&S, and what is cow?

[toallmy]

I finally took bangerjim advice on pre heating the molds , and now I love aluminum blocks the more cavities the better . I just set a 1/4 inch thick steal plate on the burner and heat up the mold wile I am waiting for the pot to heat up . Give some more preheating the mold a try .

[Budzilla 19]

S&S stands for swapping and selling and cow stands for clip-on wheel weights. I agree with the 2% tin for good fill out. I believe if you turn up the heat on your pot, and preheat that 6 cavity mold hot, really hot, you will get good boolits right quick! Good luck. Just my .02.

[runfiverun]

you just need more heat in the mold.
try the old dip a corner thing.
then start casting with 1 cavity for a few pours and then 2 and then 3 the heat will creep up the mold and you won't break the sprue cutter.
once you get the thing running smooth your 8 lb pot will be empty.

[Mk42gunner]

Set that mold on top of yOur furnace while the lead melts....it's what I do. Works great

you just need more heat in the mold.
try the old dip a corner thing.
then start casting with 1 cavity for a few pours and then 2 and then 3 the heat will creep up the mold and you won't break the sprue cutter.
once you get the thing running smooth your 8 lb pot will be empty.

These two are what I do with the very same WW alloy that I use for all my other smokeless loads.

I don't use a hotplate; not because I don't think it will work, but because the old farm house I live in is pretty shy on electrical circuits.

Robert

[mold maker]

Six cavity aluminum blocks lose heat fast. If pouring small boolits the heat gained has a hard time keeping up.
As advised, start with a HOT mold, and a fast pace till you get good pours. Any wasted time inspecting with an empty, open mold is allowing it to cool.
Once you get that figured out, it will rain piles of boolits and cause a grin that wont stop.

[Shiloh]

Add tin as a last resort. As stated, try a hotter melt. Hotter works better for some of my molds.
I cast in Spring and late summer. Perfect casting weather for garage casting. Not to hot as to be miserable, and not to cold to chill the melt.

Shiloh

[JonB_in_Glencoe]

I was casting for about a year, before I decided to find a cheap thriftstore Hotplate for use as a Mold oven.
Now, another 6 years later, I can say, that was the biggest single thing to improve my casting hobby. Yes, some molds, like your iron single/double cavity molds, don't really need it...although I use my mold oven for every casting session now that I have it setup. That first year of casting, I use to have to cast 30 minutes worth of wrinkly boolits, to get the mold up to proper operating temperature. now with the mold oven, I am casting good boolits right away...or for sure within the first 5 minutes of the casting session.

Now with that said, "sometimes" a new mold will be troublesome, right out of the gate, especially Lee mold. Usually it takes 3 or 4 casting sessions to "break in" that troublesome mold...I suspect the metal is building up oxides on the surface, allowing for easier release. That is why some people will "smoke" a mold, generally, I won't do that...it is kind of a bandaid.

[Hondo 60]

Thanks for all the replies.
I'll turn up the heat today.

[pjames32]

More heat for the mold as stated above. Also, once you get going, cast faster, look later when you are refilling the pot! Don't slow down to check the boolits. You will cull and remelt later.
PJ

[Echo]

I always set a new ingot on top of the furnace to warm up, and have a stack close by to replace as used. This keeps the alloy level pretty high, and adding a 1-lb warm (well, hot!) ingot to the melt won't drop the temp much. And I have no problems with my 6-bangers...

[Hardcast416taylor]

My suggestions would be the following:

Pre-heat the mold as was described on a covered hotplate.
Getter a larger capacity pot (20 lb.) to make a session more productive.
Get a therometer to check on pot temps.
Add 2% tin to a just WW alloy pot for better fillout.
Run you pot at 700 - 750 degrees to help eliminate wrinkles sooner.
When mold is pre-heated (you think) only do 1 cavity for several throws then do 2 cavities for several throws etc. This ensures you are getting the mold warmed up by this method as well as the pre-heat step. Good luck with all the advice given.

Robert

[Paper Puncher]

Everyone has pretty much covered it.
The hot plate REALLY makes a difference preheating the mold for me.
When I start with one of the big molds I turn the lead temp WAY up. I cast 5 to 10 times (aluminum takes more than my steel molds) as fast as I can. I drop the bullets and sprues off to the side. You should see the sprue puddle start to take a bit longer to cool. At that point in time I am probably throwing good boolits. You can take a quick look at them but don't dally. If they are looking good I keep up a fast pace and will start returning the sprue to the pot and some of those first "warm up boolits" while the sprue is cooling. I will also turn down the pot temp (to 8 on mine) The longer the sprue puddle takes to cool the warmer the mold is. I find if I am getting around a count of 5 to 7 then things seems to work good for me.

Good luck

[HABCAN]

At startup with the LEE pot at max heat, I have always just dipped the molds' corners in the molten lead until they don't 'freeze' the melt and start casting all cavs. After a few cycles you can turn the heat down to save electricity. YMMV.

[gwpercle]

I'm outlet deprived too so the mould goes on top of the pot from the moment it's plugged in , a little corner dipping at the get-go and in a few pours you will be going good. The larger the mould the more heat you will need. I set the Dial of my Lee pot (Production Pot or Magnum Melter) on 7.75 or 8.0 to start as things heat up and boolits start to get a frosty look, I drop back to 7.5. At the end of the run it will get bumped back to 7.25 . I don't have a thermometer and from experience have learned these settings work.
Also it should take your sprue puddle 3 to 5 seconds to frost over , longer and you're a bit too hot. Count to 5, 6 or 7 before opening the mould...the boolit must harden all the way before you cut the sprue.
I have found I can save clip on wheel weight metal by cutting it 50-50 with soft lead and 1 or 2 % tin , that's a good alloy for handgun boolits. I get my tin from some printers spacer type . A friend was in the printing business and gave me a huge box , it's like type metal with no letters, used for spaces in type setting, high in tin , have no idea where to find it now .

Gary