58 cal lyman mold trouble

[Matt85]

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

 

[jdkerstetter]

With the surface imperfections that you describe it's more than likely that your mold was not kept hot enough. Steel takes longer to heat up than brass and aluminum.

Some guys rest 'em partially in the molten lead to heat it up and during breaks to keep 'em hot. Enjoy, J.D.

 

[necchi]

jd nailed it.
It's not really about the lead being hot or hotter, it's about the mold being hot enough.
Float the mold till lead drops off it.
The first 10-15 ball are scrap, then once the mold get's to temp it's about keeping the rythm to keep it at a working temp.
It's hard to do when it's cold outside.
I try to cast in spring and fall when outside temps are 50-60, don't get me wrong you can cast anytime but too cold and it's tuff to keep lead an molds hot, too hot and it's just plain no fun.

 

[M. De Land]

Good advice already given! I would recommend a lead thermometer and keep the melt at 750 degrees.
Strip the mold with break cleaner or acetone before using and smoke it with a wood shack match. All you need is an invisable coating, it does not have to turn black.
When the melt has reached 750 degrees F. put the corner of your Lyman mold in the melt for a count of five. Now start pouring balls. If they are frosted it means the mold is to hot but this hurts nothing and will wipe off with your fingers when cooled. As stated , cadence will now work as your thermostat and determine your production rate. MD

 

[majg1234]

as already stated the mold is too cool

 

[George T.]

Their molds can be darned hard to degrease. I second break cleaner for that. It does sound as though the mold and lead were to cool. It is some times helpfull to flux and skim the lead as well! Geo. T.

 

[Matt85]

With the surface imperfections that you describe it's more than likely that your mold was not kept hot enough. Steel takes longer to heat up than brass and aluminum.

Some guys rest 'em partially in the molten lead to heat it up and during breaks to keep 'em hot. Enjoy, J.D.

i thought this might be the problem but i was continuously casting at a rapid rate for more then 90 balls. i took no breaks and the mold had lead in in about ever 5 seconds. the first 15-20 balls were extra bad which i figured was the mold warming up. but still outa the 90 or so balls cast maby onley 5-8 are really useable.

maby setting the mold in the lead is a good idea. thats one option i havent tried.

as for the lead being too cold. i started the lead out at te normal setting for casting with my other molds. i kept trying at higher temps untell it got so hot it was continously developing a gold flakey layer on top and casting became impossible.

im no stranger to having to cast quickly. brass and aluminum molds will cool very fast if you are not quick. i can cast perfect balls all day long with my aluminum and brass molds. i wish Lee made a .570, seems like their molds are better then these Lyman molds (and less expensive).

-matt

 

[M. De Land]

Just an opportunity to expand your casting knowledge Matt! You'll figure it out. MD

 

[Little Wattsy]

With the surface imperfections that you describe it's more than likely that your mold was not kept hot enough. Steel takes longer to heat up than brass and aluminum.

Some guys rest 'em partially in the molten lead to heat it up and during breaks to keep 'em hot. Enjoy, J.D.

yep... :thumbsup:

 

[BrownBear]

Your account reminds me of my RCBS double for .350 balls. It's just a massive chunk of steel comparatively speaking, and those little bitty balls just don't let enough lead in to do a good job of helping to heat it up. The milling is smooth as a baby's butt, yet on my first couple of uses I had just about identical results to yours.

Yeah, it's not Lyman, but I bet the fix is related.

I rest the blocks across the top of my furnace the minute I turn it on, then dunk a corner for about 10 minutes before I even start casting. I run the temp higher when starting out, too. Finally I fill and let it sit closed for bout a minute, then do it again 3 or 4 times. Finally I can start to get almost decent balls. Go through a dozen pours or so, and things suddenly settle down. At that point I turn my furnace back down to "normal" because there is such a thing as too hot, and you're probably there by the time the mold starts behaving.

Sound like a lot of trouble? Maybe, but here's the thing. Once that mold gets hot enough and the lead temp is right, it just purrs along. Turns out perfect balls so smoothly it's almost monotonous.

My solution to the long startup is simple. I just cast a whole lot more balls than I think I'll need for a while, then I can put off the next casting session for quite a while.

 

[ssettle]

Don't really know if this relates or not but I was having an issue with my lyman 45/70 mold not filling out properly and I found a web site on casting that helped me tune my mold to get the best out of it if eveything else is right. It talked about cleaning and stoning the mold blocks to get the proper venting. I used a stone on the spure cutter and the top of the mold to get a good flat surface and also to put a very slight bevel on the block under the cutter. Also said to make sure the vents that are cut into the blocks are clean as molding will start to clog them up. After I did what I figured was needed eveything worked as I hoped it would. Bullet production improved greatly with very few bad ones. Hope everything works out.

 

[RADeO]

...I found a web site on casting that helped me tune my mold to get the best out of it if eveything else is right.

Any chance of posting a link to that site? I for one would appreciate it. Thanks. :thumbsup:

 

[Matt85]

Your account reminds me of my RCBS double for .350 balls. It's just a massive chunk of steel comparatively speaking, and those little bitty balls just don't let enough lead in to do a good job of helping to heat it up. The milling is smooth as a baby's butt, yet on my first couple of uses I had just about identical results to yours.

Yeah, it's not Lyman, but I bet the fix is related.

I rest the blocks across the top of my furnace the minute I turn it on, then dunk a corner for about 10 minutes before I even start casting. I run the temp higher when starting out, too. Finally I fill and let it sit closed for bout a minute, then do it again 3 or 4 times. Finally I can start to get almost decent balls. Go through a dozen pours or so, and things suddenly settle down. At that point I turn my furnace back down to "normal" because there is such a thing as too hot, and you're probably there by the time the mold starts behaving.

Sound like a lot of trouble? Maybe, but here's the thing. Once that mold gets hot enough and the lead temp is right, it just purrs along. Turns out perfect balls so smoothly it's almost monotonous.

My solution to the long startup is simple. I just cast a whole lot more balls than I think I'll need for a while, then I can put off the next casting session for quite a while.

ill give this a try, thanks brownbear.

another idea ive had is to set my mold on my electric stove top set to low or maby even the notch above low while my lead is melting. this would hopefully preheat the mold enough to make casting possible.

-matt

 

[Eljay]

another idea ive had is to set my mold on my electric stove top set to low or maby even the notch above low while my lead is melting. this would hopefully preheat the mold enough to make casting possible.

-matt

Some people use a hot plate for that.

 

[BrownBear]

another idea ive had is to set my mold on my electric stove top set to low or maby even the notch above low while my lead is melting. this would hopefully preheat the mold enough to make casting possible.

Eek! :shocked2:

I'm no metalurgist and am repeating second hand dope, but I was always warned against that. Dunno what temps are involved or if it's fact or not, but the fear is in warping the blocks from too much heat.

Might be just my heebey jeebeys talking, but I'd sure get multiple opinions of some of the smart metal workers here on the site before doing so.

 

[necchi]

Eek! :shocked2:
but the fear is in warping the blocks from too much heat.

Bingo!
I ain't no smart metal worker guy, but I can speak from the experiance of warping the sprue plate on a set of lyman dies trying to heat the darn thing on the stove, the metals heated at a different rate and the sprue cutter bent beyond repair, replacement cost was $11.99 plus shipping. (back then)

Floating a closed steel mold in molten lead is a tried and true method of pre-heating that's decades old.
There's little need to reinvent the wheel here when using those expensive dies.

 

[M. De Land]

The best thing you can do for a Lyman mold, of which I have plenty, is to screw off the sprue plate and pitch it as far as you cab throw it and replace with one of the thick after market sprue plates.
Lymans ain't much of a mold any way once you've tried a custom like Paul Jones or Steve Brooks makes but they can be made to work much better with a thick sprue plate. MD

 

[necchi]

Who makes that?
I didn't know there was an after market plate, I just used the factory rpl.

 

[M. De Land]

I think I got mine from Brownell's some years ago but I don't see them in the catalog any more. I'll do some hunting and see if I can find the source I used. They are 3/16s thick and keep a good head of heat over the mold cavity along with a load of molten lead to draw from as the casting cools and shrinks. MD

 

[BrownBear]

Here ya go.