58 cal lyman mold trouble

[Dphar]

i just got my new Lyman .570 mold from track in the mail yesterday so i figured id do some casting today. this proved to be a miserable failure. i spent about an hour and a half trying to cast with onley about 8 usable looking balls to show for it. all my balls were coming out with major surface flaws or covered in wrinkles. i kept trying to turn up my heat figuring thats what usually causes wrinkles but this didnt help.

im not very new to casting, ive been casting .490, .685, and .695 balls for months now with great success. the thing is all of these were done with brass and aluminum molds. this is my first steel mold.

any advice?

-matt

Did you completely degrease the mould? If not you may have to soak it in solvent or spray it with brake cleaner then dry it carefully.
Did you run the temp high enough and make sure the mould was hot? I let the pot heat for about 1 hour with the mould on the edge of the pot. Then flux with Marvellux or Beeswax (light the smoke) stirring well with a ladle or large spoon, Marvellux should not be gotten on the ladle. Scoop off the dross to remove dirts and crap from the pot.
Did you inspect the vent lines for burrs and remove them? I use a graver or a 3 square needle file with one edge ground smooth to clean the lines. DON'T MAKE THEM WIDER OR DEEPER. Be VERY careful. Just deburr them at the ends. A magnifier is a great aid in this to see if the lines were plugged by cutting the cavity.
THEN when the mould is warm use a wooden kitchen match to smoke the cavity this may work wonders.
Bullet casting is a learned skill and it takes time to figure it out. I run my Lyman Magdipper pot as hot as it will go when pouring RBs cause lead does not cast as well as lead:tin alloys do. It has a higher melt temp.
Once the mould is casting well maintain a uniform casting speed. If the mould seems to be getting too hot, it should take a few seconds for the sprue to set but not too long since excess heat can stick lead to the mould especially where its rubbed by the sprue plate. I tend to leave a generous sprue on the plate too especially if the mould needs the heat at the start of a session.

I often swing the mould by dropping my arm past my side 2-3 times after the sprue as set to create air flow over the mould before cutting the sprue off. This slows the casting rate and lets the mould cool if it seems to be getting too hot.

Dan

 

[Matt85]

ok finally got this mold sorted out!

spent just under 2 hours casting which yielded 74 serviceable balls. the balls measure in at .570 x .572 +/- .001. they weigh in between 275 and 277 grains with the average being around 275.7. i culled any that weighed under 275.0 or had major surface flaws.

the trick to get the mold to work was to set a corner of the mold in the lead to heat up the mold. at first i let the mold sit to long so the balls came out frosted but after cooling down a little the balls started coming out perfect. the onley remaining issue i had with the mold is the bolt that holds the sprew cutter on slowly worked its way out while casting. next time i should be able to be more productive without having to perform any trial and error to get the balls to come out right.

thanks for the advice all, this hobby would be alot tougher without this forum!

-matt

 

[BrownBear]

Congrats Matt. You sticking to it and working on the problem rather than simply whining or drawing quick conclusions is part of the equation, too. Well done! :thumbsup:

 

[Billnpatti]

First, I'd recommend getting a lead thermometer so you can be sure of the temperature of your lead. When it is right, put the corner of your mold in the molten lead and leave it there until you can pull it out and not have any solid lead stuck to the side of your mold or in your pot. That lets you know that the mold is the same temp as your lead (which you now is the right temp. because of the thermometer) and will give you good balls.....no wrinkles and no frost. Oh, be sure to smoke the inside of your mold with a candle, butane log lighter, etc. so the balls will drop out more easily.

 

[Matt85]

First, I'd recommend getting a lead thermometer so you can be sure of the temperature of your lead. When it is right, put the corner of your mold in the molten lead and leave it there until you can pull it out and not have any solid lead stuck to the side of your mold or in your pot. That lets you know that the mold is the same temp as your lead (which you now is the right temp. because of the thermometer) and will give you good balls.....no wrinkles and no frost. Oh, be sure to smoke the inside of your mold with a candle, butane log lighter, etc. so the balls will drop out more easily.

where can i get a good lead thermometer? i bought one a while back from cabelas but it didnt seem to work right.

-matt

 

[BrownBear]

First, I'd recommend getting a lead thermometer so you can be sure of the temperature of your lead. When it is right, put the corner of your mold in the molten lead and leave it there until you can pull it out and not have any solid lead stuck to the side of your mold or in your pot. That lets you know that the mold is the same temp as your lead (which you now is the right temp. because of the thermometer) and will give you good balls.....no wrinkles and no frost. Oh, be sure to smoke the inside of your mold with a candle, butane log lighter, etc. so the balls will drop out more easily.

where can i get a good lead thermometer? i bought one a while back from cabelas but it didnt seem to work right.

-matt

Dunno if they still make them, but I can't imagine not. I picked up a Lyman a few years back for surprisingly litte buxx, and it works dandy.

 

[necchi]

I got the Lyman one from Track a few years ago.
The trick is to use the little clip thing and keep the probe suspended.(PITA)
If it makes contact with the pot anyplace, it'll read false.

 

[M. De Land]

I don't leave the thermometer in the melt , just spot check it from time to time by inserting the probe into the middle of the melt and holding it there by the dial until it stops climbing.
I always wipe the probe off with a clean rag right after withdrawal. MD