Buildup of lead on mould
- Thread starter Alstep
- Start date
Try to take a lead ingot and rub the area in question.
It is amazing, lead seems to attract lead.
The lead that is on the mould surface will come off and stick to the ingot.
When I get splatters on the outside of a mold this is also what I do to remove the lead.
Obviously, as soft as lead is, you have no worries about harming any mold.
It is amazing, lead seems to attract lead.
The lead that is on the mould surface will come off and stick to the ingot.
When I get splatters on the outside of a mold this is also what I do to remove the lead.
Obviously, as soft as lead is, you have no worries about harming any mold.
smokeywolf
Well-Known Member
Great idea to use another piece or chunk of lead. I too have used wood or bamboo chopsticks or a tweaker. Same idea as Winelover's skewer.
quicksylver
Well-Known Member
Ah IAN !
Prevention IS the answer, thank you for that.
IMO smoking a mold also allows a gap to occur , giving that little extra lead someplace to go.
Prevention IS the answer, thank you for that.
IMO smoking a mold also allows a gap to occur , giving that little extra lead someplace to go.
Hhmmm . . . the tin thing again. 3% Sn never caused this issue for me, back when I used lino which is 5% Sn didn't cause this. Possible I suppose that if there is an issue that does cause it that Sn could exasperate the problem, think solder and flux. Bullplate or anything else on the block faces that could act as a flux could cause this. For what minor issue I've ever had with getting lead on the block face or mold top a clean terry cloth shop towel usually wipes it off of a hot mold.
Ian
Notorious member
Rick, zillions of people have cast with type metal alloys and Lyman #2 for generations without issues, or without caring if they had issues. I think you're right that there is already an issue to begin with (probably mould or technique related) which is only exacerbated by the reduced surface tension of a higher tin alloy, not necessarily caused by the tin. All I can tell you is when I used to gleefully add 2% tin to everything because that's what "conventional wisdom" told me to do, I had a constant problem with whiskers going into the vent lines and then getting displaced onto the block faces, and also with "leakage" into the crack between halves soldering there. Using less tin in WW metal, or no added tin, made a world of difference to how prone the leaking and sticking problems were, especially the sticking. The more tin, the worse the deposits seemed to want to stick. Additionally, not pressure pouring, not overheating the mould, and making sure the mould is mechanically good and not pouring in a manner that forces molten alloy hard against the crack (like dropping a long stream from the pot directly against the mould seam) all help mitigate this issue for me.
On a brass mould, starting the patina out with a very very light coat of soot from a butane lighter helps prevent lead from tinning both the cavities and the block faces.
On a brass mould, starting the patina out with a very very light coat of soot from a butane lighter helps prevent lead from tinning both the cavities and the block faces.
I use 2% tin in all of my alloys and have for many years and encourage others to for the benefits of using Sn. I have none of the rubbing off in the bore, widening the engraved bullets lands causing leading. I have no issues with the mold faces, vent lines or top of the blocks getting leaded up. I get no whiskers in the vent lines and bullets fall from the mold quite well. I can't figure out what I'm doing wrong.
Ian, not trying to convince you to use Sn because you have already made up your mind that Sn is evil but others read these forums and they deserve to know that there is another side to the coin. If I were encountering any of the lengthy list of evils you ascribe to Sn I would certainly be looking for the problem and starting with the Sn, without having any of these issues I'll continue to enjoy the benefits of Sn. Others will need to decide for themselves.
Ian, not trying to convince you to use Sn because you have already made up your mind that Sn is evil but others read these forums and they deserve to know that there is another side to the coin. If I were encountering any of the lengthy list of evils you ascribe to Sn I would certainly be looking for the problem and starting with the Sn, without having any of these issues I'll continue to enjoy the benefits of Sn. Others will need to decide for themselves.
blackthorn
Active Member
Perhaps adding 2% to WW is "too much of a good thing" since WW already have a certain amount of tin content?
9
9.3X62AL
Guest
Hmmmm......interesting thread flow. I have used high-content tin alloys like Linotype (4%) and Lyman #2 (5%) without inordinate tinning or plating problems. Caveat--I have never messed with a brass mould, just iron, steel, and aluminum. I drop-pour most of my bullets, and only contact-pour (pressure flow) when a mould requires it. Big castings (450 grains+) get dipper-poured.
My principal objection--if you can call it that--to overuse of tin is its very high cost. There is some metallurgic evidence (from far more knowledgeable folks than yours truly) that it is a waste of expensive metal to exceed an alloy's antimony percentage with tin percentage. I have noted that high-content alloys like Ly#2 do a great job of fill-out on small drive bands like those found on Loverin designs--#225438 comes to mind in this context. BEAUTIFUL castings, and scaled to 1/2 of 1% from an established mean my scrap rate was on the order of 8%. Of course, it is a LONG CONTRACT to fill a 1# coffee can with an Ideal 1-cavity 44 grain mould design, but that is beside the point.
My principal objection--if you can call it that--to overuse of tin is its very high cost. There is some metallurgic evidence (from far more knowledgeable folks than yours truly) that it is a waste of expensive metal to exceed an alloy's antimony percentage with tin percentage. I have noted that high-content alloys like Ly#2 do a great job of fill-out on small drive bands like those found on Loverin designs--#225438 comes to mind in this context. BEAUTIFUL castings, and scaled to 1/2 of 1% from an established mean my scrap rate was on the order of 8%. Of course, it is a LONG CONTRACT to fill a 1# coffee can with an Ideal 1-cavity 44 grain mould design, but that is beside the point.
James W. Miner
Active Member
It will be total amount. Have to consider what is already in your alloy. That is a guess and we don't know without a test. But a little more tin does no harm other then add to cost.
When you get lead on mold faces or under the sprue plate, you are the cause with poor casting techniques.
When you get lead on mold faces or under the sprue plate, you are the cause with poor casting techniques.
Clip-on WW is my main alloy, it is all I have used in many years and all of it from the same 800 pound batch all blended together for one uniform batch. Stick-on WW is my soft alloy and is what I have used for many years and all from the same 500 pound batch all blended together for one uniform batch. All of it is well fluxed and in 5 pound ingots. When I add ingots to my pot I weigh the ingots and add 2% pure bar tin by weight. From numerous XrF testing of several WW's from various parts of the country clip-on weights all ran pretty close to 0.5% Sn and 2%+ antimony. That testing was an eye opener for me and WW actually was much more consistent than I expected.
Yes Jim, I agree. Something else is going on because if Sn caused the issues called out by Ian I too would be experiencing these same issues. I am not.
Yes Al, from all of the metals industry papers I read while researching and writing articles on bullet alloy the conventional wisdom in the metals industry is to not exceed the antimony percentage with the tin percentage. Yeah tin has gotten pretty expensive but in one of my more lucid intelligent moments back when tin wasn't so expensive I stocked up on it. Midway used to sell pure bar tin in one pound ingots at 2 bars per order, two pounds of tin at the time was $12, whenever I placed a Midway order I would always include a couple of pounds of tin. I did the same with gas checks, look & see which I had the fewest of at the time and include a couple of boxes of checks, they were about $9-$10 for1k at the time. Today I still have over 30 pounds of tin and the lowest I am on checks is about 5k in any of the calibers I cast for. Sometimes your the windshield, sometimes your the bug. For once in my life I was the windshield.
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Ian
Notorious member
Rick, I think you take some of what I have written a little out of context. I didn't say about tin and land engrave widening what you evidently think I said, please review that thread again for the specifics. Based on what you've written, I'm pretty sure you never would have experienced what I was pointing out......therefore you have no frame of reference to discuss it and very little of what you've experienced below 2K fps applies. Basically you and I are talking about two completely different kinds of shooting, and you haven't found out yet just how much the "rules" you've learned change when you really start to push the velocity envelope. And you know what? You might start working on HV rifle and STILL disagree with me and get great results with a different alloy, I doubt it, but it could happen. Just because I have failures with richer alloys at HV doesn't mean everyone will.
As far as the extra tin exacerbating the problem of little bits of stray bullet alloy sticking here and there (not meaning bullets sticking in the cavity, but lead bits and smears sticking to the blocks or sprue plate) I've found that it does. Lower tin content, easier the stuff flakes off the blocks, sometimes the deposits will just flake off with a fingernail when cool. With just 2% additional tin, it often takes the eraser method to remove it. Alloys with more tin, harder to remove. My mileage. If there's a little gap between the blocks, added tin makes the alloy more likely to flow into them, same way it helps make sharp edges on the bullets. A really hot mould also encourages that effect, regardless of tin content. I have a couple of old worn moulds that need to be run hot but with a very cool alloy with not much tin...or they get little fins where the edges of the cavities are rounded off. If you don't have this problem it's probably because you have good moulds and know what you are doing (no surprise there).
Tin is good, bad, or indifferent, it just depends on who you are and what you're trying to do. I never said tin was "evil", but when employing proper casting techniques I find it largely un-necessary to add more tin than clip-on wheel weights normally have already unless you're trying to make a certain alloy do a certain thing or are needing to add some girth to the bullet. Saying that doesn't make me "wrong", but the wholesale advice to throw 2% bar tin at everything is not necessarily "right" all the time, either, as it took me over 25 years to discover. Like you wrote, people indeed need all the info and figure out what they need for themselves.
As far as the extra tin exacerbating the problem of little bits of stray bullet alloy sticking here and there (not meaning bullets sticking in the cavity, but lead bits and smears sticking to the blocks or sprue plate) I've found that it does. Lower tin content, easier the stuff flakes off the blocks, sometimes the deposits will just flake off with a fingernail when cool. With just 2% additional tin, it often takes the eraser method to remove it. Alloys with more tin, harder to remove. My mileage. If there's a little gap between the blocks, added tin makes the alloy more likely to flow into them, same way it helps make sharp edges on the bullets. A really hot mould also encourages that effect, regardless of tin content. I have a couple of old worn moulds that need to be run hot but with a very cool alloy with not much tin...or they get little fins where the edges of the cavities are rounded off. If you don't have this problem it's probably because you have good moulds and know what you are doing (no surprise there).
Tin is good, bad, or indifferent, it just depends on who you are and what you're trying to do. I never said tin was "evil", but when employing proper casting techniques I find it largely un-necessary to add more tin than clip-on wheel weights normally have already unless you're trying to make a certain alloy do a certain thing or are needing to add some girth to the bullet. Saying that doesn't make me "wrong", but the wholesale advice to throw 2% bar tin at everything is not necessarily "right" all the time, either, as it took me over 25 years to discover. Like you wrote, people indeed need all the info and figure out what they need for themselves.
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Ian, not trying to say your wrong, neither am I try to pick a fight. No doubt in my mind that you accurately posted your findings. My main point is that it's not always the case, like most everything in casting there are many ways to skin the cat.
I do think 62chevy has a good point, reading these forums it seems there are a few who think you can't cast if the pot isn't glowing red.
I do think 62chevy has a good point, reading these forums it seems there are a few who think you can't cast if the pot isn't glowing red.
F
freebullet
Guest
Don't get much on the aluminum molds. It cleans off iron molds pretty easy. It's the brass molds that it seems to solder to at times.
I don't normally have much. It sometimes gets stuck in the vent lines on the block faces. Any left over comes off with a bronze brush.
I don't normally have much. It sometimes gets stuck in the vent lines on the block faces. Any left over comes off with a bronze brush.
Ian
Notorious member
The real buggar for me with brass moulds is wanting to run them too hot and tinning the cavities just inside from the surface of the block face. I say tinning because I don't know what the composition is (probably just bullet metal or oxides thereof). Anyway, once it starts, it builds gradually over time and starts causing the bullets to stick in the cavities. It's very tough to remove without injuring the mould. I found that light coat of butane lighter smoke on a new mould, together with several heating/cooling cycles before casting generally prevents this, even though most of you know that I'm about as anti-smoke as they get. It really does work to help that first session go well and not start problems that will only get worse later. Once brass gets a good patina to it, it's pretty much not going to solder any alloy very easily, even those with a lot of tin in them.