remove lead build up in mold?

[Wilson]

My molds have taken a beating. I scratched the surface of my Lyman trying to remove the lead smears, but was able to resurface it by following the directions posted elsewhere. I’ve also stripped the Lee six cavity spure plate hinge bolt, but I found the fix for that too. My question is how do I remove the lead that has built up in two of the Lyman cavities? I tried to scrape it out with an awl. I tried heating it up with a Bic lighter. I'm hoping I can recondition it even though it has paid for itself after 12,000 bullets.
Thanks

[hiram]

Heat the mold and bruch with a bronze bore brush.

[RogerWatsonfromIdaho]

Wilson,
I suggest you do not use metal tools on bullet moulds because they might scratch the bullet cavities. I have been using a torch which burns oxygen and MAPP gas to melt the lead and then wipe it off the mould with a cloth. This works better when the mould is hot from casting as I then do not have to heat the lead as long to get it melted. Previously I used a torch which burned propane mixed with air. This was much slower to melt the lead. The torch which burns oxygen and MAPP gas is expensive to run as the oxygen bottle contains 1.4 ounces and costs $9.99 I have not tried melting lead off aluminum moulds.
Roger

[docone31]

Remove the handles, float the mold in the pot untill the smeared lead becomes liquid.
With a damp rag, rub off the lead.
Do not use any ferrous tools in the cavity, any nonferrous awls, points, scrapers ok, but no ferrous. It will scratch the cavity itself.
Since it is a smear, rather than a soldering, it will be fairly simple to remove. It can be tenacious though, there will be oxides on the metal that gives the lead and edge to hold onto.
After removeing the smears, and with the mold hot, I would toss it into oil to cool. There will be some annealing with the temperature rise, the quenching might, might retemper the mold.
I would then make some castings with a nut on the sprue, and very lightly smear lapping compound on the casting and spin it.
Shiney molds make shiney casings.

[Wilson]

Thanks for the tips. I'm going out to work on it now.

[Calamity Jake]

"I would toss it into oil to cool."

I don't beleave I would cool it in oil, It will create a crust(OXIDES) on the mold and is difficult to get off.

The mold material is not heat treated to begin with so heating hot enough to just melt the lead smears will not change it's machancal properties

[FISH4BUGS]

I take a propane torch and melt the lead smears and wipe them (quickly) with a rag. Works every time. Use a QTip in the cavities.

[montana_charlie]

My molds have taken a beating. I scratched the surface of my Lyman trying to remove the lead smears, but was able to resurface it...

how do I remove the lead that has built up in two of the Lyman cavities? I tried to scrape it out with an awl...
It would appear that you are in need of some advice that keeps your hands empty of steel tools...since the first lesson went unlearned.

It's pretty easy to build a home made 'Foul Out' like the one sold by Outer's.
Try that...
CM

[dardascastbullets]

My molds have taken a beating. I scratched the surface of my Lyman trying to remove the lead smears, but was able to resurface it by following the directions posted elsewhere. I’ve also stripped the Lee six cavity spure plate hinge bolt, but I found the fix for that too. My question is how do I remove the lead that has built up in two of the Lyman cavities? I tried to scrape it out with an awl. I tried heating it up with a Bic lighter. I'm hoping I can recondition it even though it has paid for itself after 12,000 bullets.
Thanks

The only way that I have ever cleaned my moulds is with a very sharp safety blade positioned on its side and swept over the face of the moulds to shave off the alloy flashing buildup. Then, I use my trusty old electric pencil eraser with pink erasers to remove the remaining flashing. I also use a very fine sharpening stone to remove any possible burrs from the top of the moulds. My moulds have seen millions upon millions of cycles and they cast great bullets just like they did when I purchased them many years ago.

Isolate your awl from your casting room - it does not belong there! The use of an awl on a bullet mould is very unhealthy! You stated that your mould has casted 12,000 bullets. Well, that is a very young life indeed! A bullet mould should serve you for millions of cycles if you take good care of it. Unless you have gouged the cavity surfaces to the point where the alloy is clinging to the possible gouges?

The other point that you make has me baffled. You mentioned that you have lead buildup in the cavities. I believe that you are experiencing flashing buildup on the edges of the cavities and the suggestion that I offered above will take care of that.

I trust that this will help you.

[VintageRifle]

I heat the mold until the lead melts and use a cloth to wipe it out. If I get a lead smear on the top of the mould, I just wipe it off with the leather gloves I am wearing.

[longbow]

You've got a lot of good advice on heating the mould and wiping out the lead. That is one of the safer methods in my view.

The question I have is how did you get lead build up in the cavities in the first place?

The only time I have ever gotten any lead build up on the surface of a mould cavity was due to overheating by pre-heating the mould too hot and having my alloy too hot as well, resulting in a bit of soldering action when I cast. I did the heat and wipe routine then smoked the cavities so stop any more soldering. And of course cooled things down a little.

Occasionally I may get a bit of flashing or some splash that leaves small bits of lead between the mould faces and usually they just wipe off unless they are trapped in a vent line. Then a piece of hardwood or a brass or copper rod can be used to scrape them off iron moulds. Wood or plastic only on aluminum. Never use steel especialy hardened steel like an awl or screwdriver.

If you have damaged the mould cavity by scratching it, you may be able to lap it to remove the scratch or at least enough to remove any troublesome burrs. If you decide to do this then you should read up on how to lap/hone a mould in the "moulds" section here:

http://www.castpics.net/

Take it slow and easy or you will have an oversize mould.

Any time I have lapped an iron mould I have heat blued it again by heating with a torch. Normally the blue will return to the polished iron after much use casting but I like to reblue first to avoid sticking and possible soldering. Some people use cold blue for the same purpose.

I also oil my moulds after use to avoid any chance of corrosion. Some people do and some people don't. I always have and always will. I have no trouble wiping off oil before casting.

Longbow

[JohnH]

Like leading in your barrel, leading of your mold blocks is easier to prevent than remove. First thing, go to the parts store and get some Permatex high temp lube. A small tube is just a couple bucks and will last a long time. Before you cast, squeeze a dab onto a peice of cardboard, take a Q-tip roll the end in it and lightly coat either the top of the blocks of the bottom of the sprue plate, NOT both. Second, cast with two molds, alternately filling and emptying them. I empty and refill one, then set it down, empty and refill the other for a couple hours. it is easy to cast 700-900 bullets without rushing this way. This method makes my casting time more productive and I've not had near the trouble of lead smear build up. Also, cast as cool as you can 650 degrees is good temp. The hotter the metal the more it wants to flow into the vent lines. Also be sure the mold is closing properly. When cold , hold it to the light. If you can see light through the parting line of the blocks, the mold needs attention. Don't "slam" the molds closed. This creates unnessicary wear on the mold guide pins and alignment surfaces. Burrs in these areas will prevent full closure and add to the misery of lead lead buiildups.

[NSP64]

I too use the heat and wipe method.

[shotman]

when are you all going to try the Kroil Get some and try it I got a Qt and put in coffee can leave molds in it and take out and cast. It WORKS dont wipe off just cast . you dont need to lube. you dont need to smoke just cast

[montana_charlie]

Because our climate is so dry, I don't 'protect' moulds between casting sessions.

I don't consider Kroil to be high up on the list of 'rust preventatives' since it is primarily a penetrating oil.
But, I suppose it's better than no oil at all...if a guy does need something.

If I can remember to do it, I plan to try your 'Kroil trick' next time I heat up a pot of lead...just because it sounds so 'wrong'.
CM

[testhop]

i use the heat and rub
iopen the mould and pour lead over the spot till it mealts then use rough cotton cloth to rub
the smares offit takes onlya few min . some times if the mould is hot enough you can clean
without any added heating

[montana_charlie]

I haven't ever posted this in a 'lead smear removal thread' because I don't know if applies to casting alloys and hot moulds, but...

When I was an electronic technician in the Air Force, I did a lot of soldering...and I was good at it.
During my twenty years, the soldering techniques evolved from simple chores to NASA-quality connections where amount of solder in the joint, and quality of the joint became very precise.
I attended courses like "Micro-Miniature Module Repair" in order to acquire the required expertise.

But, it was a general fact that a soldering tip must be kept 'clean' in order to achieve any quality in a connection. For that purpose, the soldering station was equipped with a damp sponge that you could quickly stroke the soldering tip across to 'shock' the excess alloy from it's surfaces.

For that reason, I think it might be useful to use a damp cloth to wipe a smear off of a mould surface. I haven't needed to remove any, myself, so I haven't tried it.
But, if a smear doesn't respond to other methods, give it a whirl...
CM

[bobkk]

White vinegar mixed 50% with H peroxide will remove lead from a barrel.
Think it would work on molds. I've used it in a leaded barrel. Just let it soak a few minutes.

[Southern Man]

I clean sprue plates and the top of blocks with propane torch.
I turn which ever part I'm working on up side down , direct the flame at the lead smear and it drips off. No wipping or scrubbing.
The only time I get lead there is if I cut sprue to hot.

Southern Man

[mikenbarb]

After you get them cleaned up, Invest in a bottle of Bull Plate Lube from Bullshop. Its great stuff!:-D You can even cut a wiggly spru and it still wont stick and all my molds get it now because its the best out there.

[Wilson]

I've been having trouble getting my computer to post a response. This is my fourth try.
I successfully removed the lead deposits from the cavities by heating it with a Bic lighter. I then chucked up a bore brush in my drill and spun it in the cavity. It took a few times, but its all gone now.
After reading the above posts, I'm sure I over heated the mold on my hot plate "pre-heater". Besides that I was cutting the sprue too quickly. I now have the mold reconditioned and will run it some more next week.
Once again thank you all for your collective wisdom.