help with wrinkles

[35isit]

I cast some .357 LBT 200LFN the other day. I used straight wheel weight. They were perfect. Lubrisized and shot some and accuracy was outstanding. I cast some today and things didn't go as well. Pot was set at same temp setting. I don't have thermometer. Alloy was all smelted at the same time. But now about 90% of the bullets I've culled have a wrinkle on gas check shank. Some have it also on the bottom driving band just above the shank. Rest of bullet is perfect. Base is full. It measures .360. Edges are sharp. The bullet is perfect except for it looks like the area on the mold of the shank looks like it is cold. [B]ut I cast 3 pots and was starting to cull my bullets when I noticed it.

Please help. Anyone have any ideas. Do I have to remelt and start over? Again my first session was perfect just what I was expecting. Thanks in advance. I can't post pictures. I hope I explained myself well enough.

[RP]

Oil maybe has gotten into your mould clean it good and test would be my first move. Other is if you cast three pots i would think the oil would have burned off leaveing a stain or something hows the mould look inside?

[docone31]

Count how long it takes for the sprue to freeze.
If it takes six seconds, good. Longer than that, mold too hot. Less time, mold too cool.

[35isit]

Ricky P hit it on the head. I used a #2 pencil lube the sprue plate. I must have let it get inside 3 of the 4 cavities. How do I get it out? It is an aluminum mould. Will hot water and a soft nylon brush work? I see now the bullets have an indentation from whats in the cavity.

[462]

35isit,
To clean the mould, you can use a toothbrush, HOT water and Dawn dish soap. Dry thoroghly. Brake parts cleaner works, as well.

Yes, you can throw the rejects into the pot and remelt them.

[pjh421]

Good advice so far. You might also wish to look at your vent lines in the suspect area under magnification. I have fixed a number of fill-out problems by gently chasing the vent lines with a carbide scribe. Don't go at it aggressively or you will get flashing because the vent lines can allow alloy to enter instead of just letting the air out. You may have one vent line that has a tiny flake of lead soldered to it. It could also be that where the air leaves the mould cavity there is a bit of closure that will not flow enough air in the time allowed. Most fill-out problems can be solved by cleaning and by having the mould & alloy at just the right temp.

Paul

[mooman76]

I'd try turning up the heat a little. Allot of things efect the temp. Not just lead temp but mould too. Could be you were moving a little slower and didn't quite get it up to temp or some other factor. Try everything mentioned above until you are back to getting good bullets.

[Shiloh]

I'd try turning up the heat a little. Allot of things efect the temp. Not just lead temp but mould too. Could be you were moving a little slower and didn't quite get it up to temp or some other factor. Try everything mentioned above until you are back to getting good bullets.

I second this.

Along with cleaning the mold VERY well. I also scribed lines in a LEE 148 gr TL
Six-Banger. A few lines were a tad too deep and I got a bit of flashing.

It did not affect the performance. After repeated castings, the over-scribed line
seemed to constrict a bit and the flashing is now almost gone.

Shiloh

[35isit]

Thanks for the replies. I gave up on the mold the other night. I put it away and left it alone until now. Under a strong light on 3 of the 4 cavities there appears to be "slag"at the gas check shank bottom driving band area. Carb cleaner and a soft tooth brush will not touch it. I know it's just lead. At least I hope it's just lead. I had turned the pot down from my first casting session. Which all bullets were perfect and didn't have this problem. I was trying to get rid of the frost. My next session I will turn pot back to original setting and see if "slag" comes out.

[sheepdog]

Flux the **** out of your pop scrapping the sides and get it clean as a whistle. If its rusty use some CLR and a old toothbrush.

Once you got a clean pop, clean alloy, 99% of wrinkles are heat related. Make sure the lead is good and hot, mould as hot by letting a corner sit in the lead for awhile, then the sprue plate has to be hot but slightly less so that the mould. Sprue should take 1.5 seconds or so to go solid and spure holes should cut the rear cleanly without tearing the base away.

Follow them rules you should get you a good boolit, or so says the old dogs, I'm a newbie of a year or so myself. [smilie=6:

[HORNET]

A bronze bore brush works fairly well for cleaning stubborn crud out of the cavities on aluminum molds as well as iron ones. I've got a brass brush intended for cleaning suede that works well for cleaning the mold faces once in a while while casting.

[sheepdog]

I would think bronze would be a little rough on aluminum..

[HORNET]

A few turns of the brush by hand doesn't seem to do any damage. The wires are small in diameter and bend fairly easily to conform to the contours of the cavities. It will help smooth out small burrs but that seems to be about it. I don't know what it would do if powered by a drill, but we're only talking about getting out some stubborn grunge. If it's real tough, it might take Lee-menting to clean it up.

[DLCTEX]

A #2 lead pencil will not contaminate a mould cavity. I have often used the graphite of pencil lead for a mould release. No harm, no foul. Get the mould hot and the slag will wipe out with a wooden stick or cotton cloth, do not use synthetic cloth!

[DeputyDog25]

I was reading through this thread and something came to mind that I read in a book on casting which was published back in the 40's. The book recommended that you use a toothbrush and toothpaste as they say that the abrasives in the toothpaste are just perfect for cleaning all the nooks and crannies of the mold without doing any damage. They then recommended after scrubbing with the toothpaste to boil the mold in a pot with a small chunk of lye soap, which I guess can be substituted with a small piece of bar soap or dish washing soap and then rinsed thoroughly in hot water and dried completely. Does anyone see any problems with this method, or has 70 years later brought new and improved methods? I personally have not cleaned my mold this way, but I am considering it to see if it makes any changes in my bullets.

[backhoe]

I have had good luck using plain ole backing powder__soda,and rinsing with water. Hope this helps someone.

[prs]

Comet cleansing powder seems to be a popular choice, apply and work in with old tooth brush and rinse well.

prs

[Virginia John]

You mentioned that you didn't use a thermometer, get one and use it.