Small wrinkle at seam...

[kamikaze1a]

Using a Lee 6 gang TL mold and find a small wrinkle on the shank of a few of my boolits. It is on the seam where the mold halves meet and usually on the top most band/groove. Once in a shile I find a longer wrinkle that goes across most of the lube grooves from top to bottom. I haven't figured out which hole it is coming from and happens only once in a while, not on every pour. Not sure if it is coming from the same hole for that matter.

Temperature does not seem to be the cause and I can not see any imperfections in the mold. Could it be oil or some other contamination? Maybe the lube I used for the mold's pins or hinge? Or maybe how I fill the mold? I tried smoking the mold more and it did not seem to help. Maybe washing it again?

[mold maker]

How many cycles have you cast with it so far? Bottom pour or ladel? Sounds like oil or wax still in the cavity. Give it another good tooth brush cleaning. I use Dawn and alcohol. Rinse, dry, and try again. Make sure the mold is hot. These require more temp. than iron molds. A faster cycle helps. Raise the alloy temp till you get frosting. One or a combination of them should solve it.
I just broke in 9 of the Lee 6 cavity molds and thats what worked for me.
It usually took 8-10 fast casts to get up to temp, and casting good boolets.
Lots of good info in previous threads.

[yondering]

Take a look at my post here: http://castboolits.gunloads.com/showthread.php?t=34013
Do yours have similar defects? A bunch of people thought it was temperature control, but it turned out to be oil or some other contaminant in the cavities. Lapping the mold gently and degreasing cleaned it up beautifully. Smoking the cavities may help a bit as well.

[kamikaze1a]

Thanks for the tips and links! Though I've just started casting, that mold has already done several thousand boos (abbreviation for boolits? lol). I just started seeing those wrinkles and it's happening even after the mold is hot and even when it's on the verge of being too hot. Melt temp does not seem to be a factor either because I tried raising from 750 to 850 and same thing, every so often a wrinkle... My wrinkle looks pretty much like the image in the link except it's showing up on the lube grooves and smaller. The part that throws me off, it doesn't happen on every pour. I'll try cleaning it again and also try the pencil/graphite thing...will let you all know the outcome.

By the way, using bottom pour melter...

[dardascastbullets]

Using a Lee 6 gang TL mold and find a small wrinkle on the shank of a few of my boolits. It is on the seam where the mold halves meet and usually on the top most band/groove. Once in a shile I find a longer wrinkle that goes across most of the lube grooves from top to bottom. I haven't figured out which hole it is coming from and happens only once in a while, not on every pour. Not sure if it is coming from the same hole for that matter.

Temperature does not seem to be the cause and I can not see any imperfections in the mold. Could it be oil or some other contamination? Maybe the lube I used for the mold's pins or hinge? Or maybe how I fill the mold? I tried smoking the mold more and it did not seem to help. Maybe washing it again?

Kamikaze1a,
You present a very interesting case study in what can go wrong with casting bullets and will go wrong. To reduce the possible causes we have to list the variables that can affect bullet quality.
#1) Alloy content
#2) Alloy temperature
#3) Mould material (cast iron or aluminum
#4) Pour rate
#5) Distance of sprue plate to pour spout
#6) Casting rate
#7) Cleanliness of moulds

Ask yourself if any of the above variables are suspect.
...Do I really have an adequate alloy (one that has enough tin to wet the alloy to the cavities)?
...What is my alloy temperature? Is it in the range of 690 to 735 degrees F?
...What material is my mould made of? (Aluminum requires a longer cooling period that cast iron)
...How fast am I pouring the metal into the cavities? Maybe to slow or too fast? Suggest experimenting with this variable and discovering what results can be expected.
...Am I pouring from a long distance (more than 1 inch) or am I pouring close (possibily with the pour nipple touching the sprue plate's cavity fillet.
...At what rate am I allowing the mould to cool before cycling it again? Too slow will produce wrinkles - too fast will produce frosted and rounded fillets.
...Is my mould squeeky clean?

I guarantee that if you study the above questions you will find your source that is causing the wrinkles. It is not possible to provide an explicit answer to your questions but to provide ideas to troubleshoot is possible.

I trust that this information will help you resolve your issue.:)

Matt Dardas
Dardas Cast Bullets

[kamikaze1a]

Hi Matt, Thanks for that insightful guides. After review, I would say it would most probably be contaminents in my mold, probably lube from the hinge. The part that really makes me pause is why does it not happen on every pour. Temp of melt I try to maintain is 750 and have tried highter as well as lower with no remedy. Also alloy must be good because 99% of castings are fine. Regards to mold temp, rate of fill, height of pour; could the flaw occur only at that one spot of the shank? Which leads me back to mold surface contamination. I'll be cleaning the mold and hopefully, I will eliminate those wrinkles... Thanks again guys!