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I'm new to bullet casting and I'm having a problem. There are pits/inclusions in almost all of the bullets I've cast (see picture below). I cannot see any dirt in the pits, but they look almost like the pits that are left after rust is cleaned off of steel. Nothing I do seems to help and after a few hundred bullets (which I have re-melted) I'm not sure what else to try. The Lyman handbook of casting mentions something about calcium (or some contaminant) that causes inclusions; is there any way to get rid of it? Here is what I am using (all new): Lyman Mag 20 pot Saeco #62433 mould and handles Wheel weights Flux (I think it may be beeswax; it's yellow and hard (about the consistency of candle wax, but the smoke smells like beeswax) Here's what I have done up to now: Cleaned the moulds with denatured alcohol and a nylon brush (three times) Fluxed the lead a number of times--there's no more dirt that I can see Emptied and cleaned the pot, put the lead back in, and fluxed again Cast with high lead temps (got pitted bullets with frost) Cast with low lead temps (got pitted shiny bullets) Dropped bullets as soon as sprue hardened Dropped 50 seconds after pouring Dropped at various times in between Tried opening up valve to pour lead quickly Closed it down to pour slowly So far, nothing has helped. I'm wondering if it's an alloy problem or fluxing problem. Any advice would be very much appreciated---thanks in advance! | ||
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almost looks like you have some pits in your mold blocks check them closly to be honest i dont think that they will effect your accuracy that much I would try another mold and see if you have the same problem before id blame the alloy. | |||
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Mould blocks are flawless--clean and smooth. But you are right--that's exactly what the pits look like. I thought it might be dross in the bottom of the pot that was going through the spout, but the pits do not have anything in them and there are no flecks of dross on the cloth I use to catch the bullets. Just to make sure, I emptied the pot, cleaned it, and re-melted the lead (using one of my wife's muffin tins in the process). But the pits remain. I'm going to try some more casting today if time permits. I really want to get this problem figured out. | |||
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Liljohn Here's a possibility. If you put some sort of rust preventitive on your molds each time you finish casting, what you may be seeing is the gases from the rust preventitive coming out of the pores of the mold's metal. Another possibility, there's some form of gas working itself out of the lead as it poured in the mold. In the past I've had the same problem. I cut the cotton off a Q-tip and used the cardboard stem as a scraper for the inside of the mold to clean out the grooves, etc. Plus I wanted to see if there was something on the sides of the mold that I could not see, all I got was a bit of carbon from the smoking the mold. Another way I solved. or avoided, this problem, is to raise the pot temp and increase the distance between to lead spout and the sprue cutter. This lets the lead free fall into the mold and any air in the mold gets ejected real fast. Hope these help. Jim | |||
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You mention "smoking the mold". What is this? I've heard of this before but I don't know what it is or what it is supposed to do. You might be on to something here when you say the pits are caused by gas coming from somewhere. I've cleaned the molds with denatured alcohol, heated them considerably by casting with the pot's thermostat up high, and inspected them with a magnifying glass. There is nothing I can see, but if gas escapes from pores in the metal I could see this problem arising. I lowered the mold below the spout by about 1/2 inch (from about 3/16 to 11/16 or so). Mainly because the sprue is often more than 3/16" thick. The additional 1/2" did not affect the problem; do you think I should go more? 1" maybe? I don't wan to go too far or I'll misjudge and miss the mold, but I could probably go another 1/4 or 1/2". | |||
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Another thing to try is 'scouring' the cavity with a hard lead pencil. Work it over really good, in every nook and cranny. Do this after a good bath in acetone. Blow the loose lead dust out. I've done several moulds this way and improved castability. Also be sure the vent lines are clean so air can escape. One of the guys who shoots with us had used Marvelux as an experiment. Ever since that single episode he has had the same problem you are experiencing, even after cleaning his pot. Doesn't seem to affect accuracy, but the boolits do appear to be pitted. I would not say that the Marvelux has caused the problem, but all other things being equal it's a bit difficult to explain. sundog | |||
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liljon...It may be a fluxing problem and an allow problem all mixed up. Looks as if there's some slag in your alloy which is not being removed by the fluxing. This could be trash of some kind or some kind of metal contaminate. If this is the problem, it might be cured by a good fluxing, let the melt sit for about 30 minutes and then skim any impurities off. If this doesn't work. I'd pour ingots out of this batch, sit them aside and try another batch of alloy. Looks like the bullets are coming out fine except for that./beagle | |||
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Liljohn: From the information you've provided I think you're looking at the typical bottom-pour-pot-blues. That is to say: The bottom pour pot almost always generates dirty looking bullets due to the normal contamination that settles to the bottom of the pot. This condition is so previlent that many bullet casters have come to consider it "normal" and keep right on shooting dirty looking bullets. And, they are right to a degree: These marginal looking bullets WILL shoot quite well. The cure is to pour bullets by the ladle method. It is somewhat slower but more flexable and once a fellow learns the technique I believe there is a smaller percentage of toss-backs such that the lack of a certain speed is of no consiquence. Good afternoon, Forrest | |||
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quote:Thanks! [ 05-14-2003, 01:28: Message edited by: liljohn ] | |||
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quote:I think I'll get a dipper and try it. It's an easy solution that will at least isolate the problem to the pot. Thanks! | |||
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Liljohn Consider that 100% of all commericially made cast bullets are bottom poured! From the commercial cast bullets I've seen they are beautifully cast, some of them look like jewlry. Jim | |||
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liljohn, good advice from all. Here's a thot though. When you flux how do you do it? IMO you need to stir the he!! out of the melt at least in the beginning when using wheelweights to get all the paint, rubber, plastic, and other crud out. Need to get the flux down into and not just on top of the melt. I and some others use a (dry) stick to stir with also. Scrape the sides of the pot with the stick and stir the bottom. Many will tell you DO NOT use marvelux. I don't know, I've never used it and prob'ly won't. I mostly use pine sawdust with a high resin content. The smoke smells good and it works for me. I think you've an alloy problem rather than the mold. At least from what I saw in the photo. When I've had problems with unclean molds, I've not gotten the color yu have in those includions. More to try. Regards, Woody | |||
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quote:Two things--How do you stir? I do it as if I'm stirring a can of paint. I'm using a stainless spoon that I hold with a pair of vice grips. I can stir pretty hard, but with the rounded nose it does not effectively scrape the bottom (which was obvious when I emptied the pot. there was residue on the bottom). Also, I may not be stirring long enough. Using beeswax, I've stirred until the wax is gone (about 30 seconds or a minute). I have read two different methods of fluxing. One said to use a pea-sized bit of beeswax, the other said to put enough beeswax on top of the melt to cover to a depth of 1/4". I used the pea-sized bit at first, but the pits did not go away. So I tried the latter, but it was messy and I think incorrect. When I put in a couple of spoonsful of wax, the smoke was intense and it burst into flame. You say you are using pine sawdust with a high resin content. What exactly is that? Regular sawdust? What is the resin? Where can I get this? I think you (and the other guys) are right. There's a problem with contaminants that can be fixed. I've just got to figure out the right solution. As Arkypete says, most commercial bullets are bottom poured and they look good. There's no reason mine shouldn't also. If I can find your pine sawdust, I'll try it. It is somewhat important that I find something that does not smoke too much and smells pleasant. I live close to other people and a couple of businesses and I don't want to draw too much attention to myself. Thanks for the advice. [ 05-14-2003, 07:35: Message edited by: liljohn ] | |||
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I have had a higher percentage of keeper bullets with ladle casting than with bottom pour. However, many other casters of my aquaintance have success with bottom-pour. I flux with candle wax and light the fumes, if they do not self-ignite. I stir with an RCBS ladle that has a fin on the bottom and use this fin to scrape the sides of the pot. (Stir and scrape vigorously.) Fluxing with Marvelux will cause a buildup on the sides of the pot which can be removed by boiling water in the pot. Marvelux can accumulate on a skimming spoon, attract moisture, and cause a mini steam explosion unless you pass the spoon through a flame to eliminate the moisture at the beginning of each casting session. Hope this helps, curmudgeon | |||
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liljohn any DRY sawdust will work well for flux, I gave up on beeswax a long time ago, I did not have any problems with marvellux but I did not see any great advantage either. This may be heresy but I wouldn't worry about crud on the inside of the pot, as long as it is stuck on the sides and bottom of the pot it tends to stay there and so it doesn't get into your mold. Wheelweights as an alloy source always runs the risk of getting contaminants in your mix. Do you go through the weights you buy and get rid of anything not clearly what you want? I remember having a terrible time with a batch once that had "tape on" weights for mag wheels in the bucket, which I left in the batch. It turned out that these "weights" had aluminum in them as a stiffener so that batch never did cast worth spit. (preaching about to commence) Before I forget, quit trying to fix your problems by turning up the temperature. It is the number one way for you to get lead poisoning and it is not necessary, you can cast great bullets at 50-75 degrees above melting temp. Even with "adequate" ventilation a hot pot will evaporate lead into the air you breath. Try a new batch of wheelweights, maybe add some solder to increase the tin content by 1 percent and hopefully this will be a fix. good luck Guy | |||
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I think a new batch of wheelweights is in order. I've tried refluxing, treating and cleaning the molds, etc, and nothing has worked. The sawdust did do an excellent job of cleaning things up, though. I'll use that method of fluxing from now on. I think the metal is contaminated. I'm going to try another batch with virgin alloy just to eliminate the contamination variable. I appreciate the help everyone has offered. Lots of good and timely advice for the beginners and experts alike. Thanks! | |||
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Liljohn Another couple of suggestions. I went to the local Goodwill and bought a couple of soup spoons, heavy stainless steel. I've not noticed any difference in the patterns of the spoons effecting the bullets. One of the spoons got 5 or 6 holes drilled into the bowl portion for stirring and the other was left as is. I also found at yard sales or Goodwill a couple of Vise grips which I clamped onto the butt of the spoon to use as a grip. The holy spoon is used for stirring and the unaltered spoon for dipping crud out of the pot and bashing the stray bug. I flux twice at the beginning of each pot of new alloy. The first time cleans out the crud from what ever the ingots may have picked up since the wheel weights cleaned and cast into ingots. Then I used a stainless steel dinner knife/butter knife, also from Goodwill, to scrape around the sides and bottom of the pot to remove anything there, then I flux and stir again. Then I'm ready to cast. I think you asked and I forgot to respond to the question about smoking the mold cavities with a butane lighter. This puts a layer of carbon on the inside of the mold cavities which eases casting good well filled out bullets. Just why it works I have no idea. Jim | |||
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quote:I most always cast a few from each batch of wheelweights to assure myself that the ingots I'm about to put away aren't contaminated with something that will not make good bullets. Using a known bullet, it also tells me something about the composition of that particular batch weightwise. Regards, Woody | |||
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I ran into the same problem today making up some RCBS 300 grn,fluxed the pot 3 times and didnt cure it,so I shut it off and cleaned the pot out real good...no go...just for the heck of it I stopped pouring out the bottom and used my dipper instead,bullets were perfect from then on. | |||
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The problem w/ wheel weights is you really don't know what you are casting w/. I cast from a bottom pour pot exclusively & have cast 10's of 1,000 of bullets. I used to use wheel weights until I had the same problem you are having. If you get a wheel weight that is cast w/ something other than lead/antimony/tin, you are going to have this problem & you can flux until hell freezes over & not solve the problem. I now buy linotype in bulk & it is reasonably priced. You might try mixing the metal you have w/ some linotype & reflux, but I think it is time to scrap it & start over. You can check your casting technique by starting w/ straight lino & casting your bullets. Then you'll know your technique is fine, although it sounds like you have been doing everything right. | |||
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Fred is right! Wheel Weights of late are made of just about any Alloy. Beware of the ones that have rusted clips but the weight looks shiny. Aluminum and Zinc are the contaminants that cause your problems. Clean your pot out throughly with a powered wire brush and try some virging alloy. Bet your problems go away. Steve From New Joisey | |||
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WHEN YOU FLUX YOUR POT DO YOU HAVE A LONG SPOON THAT REACHED THE BOTTOM OF THE POT? WHEN EVER I'M CASTING I ALWAYS VERY CAREFULLY STIR THE FLUX TO THE BOTTOM OF THE POT. IT SOUNDS LIKE YOUR PROBLEM IS THERE.BE CAREFUL AND JUST KINDA STIR THE FLUX DOWN TO BOTTOM BY SLOWLY PUSHING THE TOP LEAD DOWN AND GENTLY SCRAPE THE BOTTOM WHERE THE CRAP THATS GIVING YOU GRIEF IS IT SHOULD COME TO THE TOP WITH THE FLUX. | |||
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