Aluminum molds

[fastgun]

I have just ordered 2 Lee six cavity molds. I have cast bullets for about 35 years but the last 34 years have all been with steel molds of two to ten cavities. I am looking for any information on mold prep and casting with aluminum molds. My memory of my first single cavity Lee mold has left me.

[docone31]

They need to soak for a few days in mineral spirits. Lots of flakes will be on the bottom of the bucket they soak in.
Personally, I prefer Lee Molds. I cut my teeth on them, and I am used to them.
They need heat! Lots of heat.
I watch my sprue.
I like it when the button takes six seconds to freeze. I get good castings that way. Too quickly, and the castings have wrinkles and rounded corners. Too long, and they stay soupy. Miserable casting that way.
Heat them up, watch the sprue, and good luck. Since you are experienced at casting, I think you will pick it up fairly quickly.

[SciFiJim]

There is some good info on prepping Lee molds HERE (http://castboolits.gunloads.com/showthread.php?t=26956&highlight=prep+lee+molds)

[Sprue]

Get them up to temp is key. If you don't it will take a few times to get them running good, unlike the steel molds. The Lee 6 cavs seem to run better when they are hot, just before or at the frosting stage. Keep the pivot points lubed and you'll be fine.

You're probably fully aware of this, I like to polish my cavities in this manner. Remove the sprue plate and place a nut over the cavity, then fill the mold to the top of the nut. Dump them out, add polishing compound to the boolits, place them into the cavities commence polishing them by twisting them with a wrench. Makes purty smooth boolits/cavities, they also release much better.

http://i258.photobucket.com/albums/hh266/spilihp_2007/MoldLapBoolit.jpg

[SciFiJim]

Sprue, do you use a commercial polishing compound or something else (like comet cleanser)?

[docone31]

I use fine grit valve lapping compound. Found at almost any auto parts store.
Just dab on the casting, and s l o w l y close the mold while turning.
Does a great job!
I cast, and toss the castings back into the pot. The grit comes off with the casting.

[kir_kenix]

I really enjoy using aluminum molds. I have more lee molds then everything else combined I think. Sometimes they take a little cleaning up (search Leementing, you'll find like 60,000 posts on the subjet), but on the whole they cast very well for me. They warm up quickly, and allow for some really long casting sessions (partly because you can cast hot and fast with them, and partly because they are muuuuch lighter then iron molds).

Give them a try. Lee molds are by no means the be-all end-all of molds or boolit designs, but they work well for alot of folks out there. Especially if its a caliber that you only will be shooting from time to time, it makes sense to me to buy a cheaper mold and invest that money in primers.

Jon Schram.

[Sprue]

Sprue, do you use a commercial polishing compound or something else (like comet cleanser)?

I use Rubbing Compound, sometimes Polishing Compound, both made by Turtlewax found at wallyworld. Tooth Paste would probably work well too. I wouldn't use anything too abrasive.

I'm not sure about Comet cleanser, its been a long time since I've used that stuff. I can't remember how course that it may or may not be.

[mooman76]

I just clean mine with a good petrolium based cleaner like carb cleaner, and use.

[snaggdit]

I use Rubbing Compound, sometimes Polishing Compound, both made by Turtlewax found at wallyworld. Tooth Paste would probably work well too. I wouldn't use anything too abrasive.

I'm not sure about Comet cleanser, its been a long time since I've used that stuff. I can't remember how course that it may or may not be.

I use the polishing compound too. Wow, that nut idea looks good (with changes). I have been casting a few then drilling a hole centered on the base. Take a finishing nail and use a hammer to flatten the head. Gently pound this "spade" into the hole and use a cordless drill with polishing compound added. 30 seconds and it smooths without losing any size at all. Casting with the nail inside would be more secure.

[shotman]

get the Kroil and you will have a lee that looks as good in 5 yrs as it looks now

[dromia]

Look at the members article in Cast Pics, you will get chapter and verse on Lee mould fettling there.

Wlijen did a GB on a mould fettling kit, it was an excellent kit, a while back and his instructions are there also.

[S.R.Custom]

...You're probably fully aware of this, I like to polish my cavities in this manner. Remove the sprue plate and place a nut over the cavity, then fill the mold to the top of the nut. Dump them out, add polishing compound to the boolits, place them into the cavities commence polishing them by twisting them with a wrench...

Similar to that, I drill a hole in the base of the bullet, and screw in a hex head self-tapping/sheet metal screw. With the appropriate bit I spin the boolit in the cavity with a cordless screw driver using valve grinding compound for Iron blocks, Flitz or GunBrite for aluminum. Carried a step further it's possible to not only get a good polish, but enlarge the driving bands a couple thousandths of an inch...

[NuJudge]

Brake cleaner. Pre-heat. Apply microscopic amounts of Bullplate to locating pins, top of blocks and bottom of sprue plate. If they don't cast well once hot, use mold spray.

[Jack Stanley]

The "nutty" idea looks way better than what I used to do . I doubted that
I could get a drill centered on the base of a bullet so what I did was hold a small nail with needle nose pliers and use a ladle to cast around it . I forget what I used to lap with way back then but recent jobs have used LBT bore lap .

It work well with a couple of old Lyman molds from years gone by ...... and sometimes I wish I wouldn't have let those molds go by . :roll:

Jack

[44man]

When I get a new Lee, I hit the cavity edges with a piece of Scotch-Brite to deburr and scrub the whole mold with hot water and dish soap, lube with Bull plate and go. Rapine mold prep works too.
I only lap if needed.
When I make an aluminum mold, dish soap does the job too and the first boolit will be perfect after preheating.

[Bret4207]

I do things a little differently. I look at the mould closely and see if it looks like it needs "Leementing" I've had several that needed nothing, others needed major surgery. After that I wash them down good in carb cleaner and a toothbrush and follow that with brake cleaner. Then I get her nice and hot and see how she does. Many times that's all that I need.

My point is not all Lees need plastic surgery. Some do fine from the factory. I have over 20 Lee's at least and more than half do fine without the "doctoring". Most benefit from at least breaking the edges though, not all require extensive work.

[jim4065]

That method of Sprue's looks much better than what I've been doing, which was to drill a hole and run in a screw. Never could get it on center.

[Echo]

I used toothpaste for lapping one of my Al molds, but will use Bon Ami in the future. Bon Ami is made with feldspar, a very benign abrasive. Their slogan (showing a chick fresh from the shell) is "Hasn't scratched yet".