What's wrong with my boolits?

[3jimbo3]

I have a new to me but lightly used 6 cavity Lee mold for 9mm. It was already smoked when I got it, so I lubed it up, heated it and started casting with it. It put out some real quality castings at first then I started noticing deformations and pits in the nose of the boolit. My PID keeps the the melt at the temp I set it for and I have checked it to make sure it was clean but no results yet. What can I do to remedy this?

[jcren]

Blind guess without good pics, but mold contamination is usually the first place to look when getting bubble shaped pits. If your mold blocks have Brown on the mating surface, you used too much lube.

[Teddy (punchie)]

First AL and Brass are harder then steel to use. Clean mold, re-season mold (smoke, what ever you will call it) . I think you are already watching this, but Watch the heat sound like you got it a little too warm , casting too fast. Take a few second to just let it set. Sometimes with some molds I count to 5, others are 15 even 20 some I just cast away. Make sure you have a good alloy, tin too low? First brass mold I used was OKay at first an then I got it too hot and alloy was soldered to the mold, what fun that was.

[mac266]

Yep, it's either got a contaminant, or the mould blocks are getting too hot. Remember aluminum transfers heat much faster than steel or iron, so if you're getting good boolits at the beginning but they later develop problems, you're probably casting too fast. Casting too fast does not allow the blocks to maintain a temperature; rather, it constantly increases their temperature. Try slowing down, especially with aluminum blocks. One trick some folks use is to cast with two moulds at once.

Fill one mould, set it down. Fill a second mould, set it down. Pick up the first mould and break the sprue, dump the boolits, and then fill it again. Set it down. Pick up the second mould and repeat.

Many casters find this method lets them keep their production rate up while slowing down with each individual mould, thus maintaining a proper temperature.

[Sasquatch-1]

I have used Lee molds for about 35 years. The only problem I have from molds that are too hot is frosting. If the deformations are squiggly lines you probably had whatever you used to lube creep into the mold cavity or a low percentage of tin. If they are pits it is probably dirt in your alloy. Look and see if there is discoloration.

As stated above, it's hard to tell without pictures. I am no expert. Just my opinion.

[Wayne Smith]

Humm, pits in the nose. I'm not sure anything is wrong with your boolits, I think they will go down the barrel fine!

Seriously, nose pits are almost always caused by a) oil or grease in the nose or b) dirty alloy.

[3jimbo3]

Hey thanks guys, I will clean and reseason or smoke my molds again. I will also flux my melt some more, although it looks to be very clean maybe I'm missing some dirt in there somewhere. I do have two of the same mold for 9mm so I will give that a try as well. After I go down the line trying these suggestions if it still does this I will take some pics and see what we can figure out. Have a great day everyone

[RobS]

Just clean the mold with hot water and original dawn dish soap. I wouldn't smoke the mold but if you do make sure it's not with a candle as the wax will end up in the mold.

[bangerjim]

Squiggles and pits on the nose? Who cares! It is the fill on the drive bands and the base you should actually be concerned about.

Add some more Sn for better fill-out. I always use 2%. Doubt if it is grease. Grease does not cause distortions over and over in a mold. Only cold molds and cold lead cause wrinkles. I have proved it many MANY times!

I have always smoked my Al molds with a beeswax candle......best there is. Leaves a very thin tight smoke, similar to a lazy acetylene flame. Preheat to casting temp on an electric hotplate and drop perfect boolits from #1.

Hope you find a solution to your problem that is bothering you.

bangerjim

[Wayne Smith]

I have yet to need to smoke a mold. They all, steel, alumunium, and brass all work best naked.

[gwpercle]

Get the mould squeaky clean, scrub well, then tooth brush and acetone scrub. Let the clean mould dry . Then give the mould a spray with Liquid Wrench Dry Lube, dry libe not the penetrating oil stuff.. Give all surfaces a coat even the cavities , top of mould and underside of sprue plate, pins ...ect. . Let dry a few minutes then heat and cast. Discoverd this dry lube stuff works wonders.
Gary