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Sendaro
12-22-2010, 08:28 PM
Greetings, I'm new to this form and need some help with a casting problem that I'm having. About a month ago I started to get back into casting again after selling all my casting equipment back in 1986. Back then I cast pistol bullets from linotype and had good results. Now I've started to cast again, but for a rifle this time. The rifle is and old Stevens 44 in 32-40. I have been doing OK with casting the boolitz untill this past weekend. The problem I'm have maybe a contaminant in my lead that I'm useing. Here is what is happening. I have been running the pot temp. around 650 degrees and laddle pouring in single and double cavity molds. The boolitz started to cast nice and fill out well and then they looked like they were wrinkled and not filling out well after casting nearly 1/3 of the pot. I turned the temp. up and they again started to look good. It was running at 750 degrees at that time. Then the boolitzs started to drop wrinkled and not filled out again like the mold was cold, but it wqas not. I smoked the mold and fluxed the pot all to no avail. Does this sound like I have a bad batch of lead? Would like to hear what you may think the problem is. I have been using a Lyman Big Dipper pot and Lyman thermometer to tell the temp. My laddle seems to have a coating building up as I'm work. I keep it in the pot when I'm not pouring, and dip to the bottom before I make a pour. When I weigh the bullet that are cast from this lead they should weigh in at 165 to 168 grain for the SAECO #632 mould that I'm using. However they are dropping out at 171 grains. Does it sound like the tin was burned out of the alloy or there was not enough tin in it in the firs plase. I'm puzzeled and need advice. Should I just throw out the material and try to find some new lead and tin? [smilie=b:

runfiverun
12-22-2010, 09:06 PM
i think you just oxidized out the tin you had.
each time you take the ladle out and in you are introducing more oxygen into the alloy.
you need to flux the alloy a bit more. i'd use an oxygen barrier.
if the stuff on your ladle looks greyish silver it's just oxidized alloy, and most likely most of your tin.
wrinkles are usually heat related or oil in the mold.

lwknight
12-22-2010, 10:17 PM
Sound lik you accidently got some lube on the mold and it migrated to the cavity.

HeavyMetal
12-22-2010, 10:39 PM
First welcome second I join lwknight in the belief that you have lube moving around on the mold.

What are you using to lube the sprue plate with? It could be as simple as reducing how much your putting on.

Sendaro
12-22-2010, 10:43 PM
No bullet lube got anywhere near the mold, so I have to think that I cooked the tin out of the aloy. Did I do this by having the temp. up to 750 degrees? At this point shoud I just try adding some tin? The bullets are very soft, as I can dig my finger nail into the them very easy. Didn't seem to have all this trouble with the bottom pour pot I had years ago. Thanks for the advice and I welcome all I can get.

docone31
12-22-2010, 10:51 PM
Your mold is too cool.
As to the first castings filling out, and then getting wrinkled, as your level of melt decreases, and you have been casting, the mold, and melt are cooling.
It sounds like you are spending too much time on the thermometer! All my molds like it hot, and I keep my melt on 9 in the pot.
Try them a little hotter on the mold. See what happens before you worry about tin. I would also bet the lube lands are a little rounded on the corners on the unwrinkled castings.
Just a thought.

lwknight
12-23-2010, 12:53 AM
Adding tin will make very soft lead feel not so soft but really does not give you much hardness.
Unless I'm just blind , you did not specify what alloy mix that you are using. Even wheel weight alloy will feel soft till it aged for awhile (2 to 6 weeks ) depending on a host of factors.
Its antimony that hardens and how much depends on the cooling rate.

geargnasher
12-23-2010, 01:39 AM
Wrinkled boolits are caused by one of two things: Mould too cold or oil/contaminants in cavities. The mould my have oil deep in the pores or coming out of the sprue plate screw threads that creeps out and gets into the cavities after a while.

If you had a contaminant in your alloy you would have rounded edges to your boolits (poor fillout), but likely not wrinkles if the mold is hot enough.

If you cast with an alloy containing any tin, keep the temperature below 725*, 650 is plenty hot for clip-on wheel weight alloy.

"Flux" with sawdust or any kind of wax/oil, light the fumes if using the latter, and stir with a dry stick, working the oxide scum against the sides of the pot until only a fine grey ash remains, skim the ash with a spoon, preheat the mould, and resume casting. These are not "wives' tales", the hydrocarbons and carbon monoxide created by smoldering sawdust or poorly burning wax change PbO and CO plus a little pure carbon create Pb and CO2.

Gear

lwknight
12-23-2010, 02:37 AM
It just dawned on me that if ladel casting that one could get wax or whatever used for flux into the mold pretty easily.

Sendaro
12-23-2010, 09:35 AM
I have tried to make a 1 part tin to 25 parts of lead aloy. I used pure lead and mixed in 50/50 solder. I have been running the temp at 750 degrees and that may be part of the problem. I have also been dropping old alox bullet lube into my laddle an pushing it into the melt to flux the pot. I have also tried some flux that a friend gave me called MARVELUX. Again I'm sturring the melt with the laddle. OK, it is starting to sound like I'm not fluxing the melt the proper way. I have much to learn. Please advise the proper way to flux the melt. The edges of the boolitz are round in places and not quite filled out. Should I try adding some tin to the lead that I have been using and try it again. It also sounds like it would be a good idea to clean my molds again. What do you suggest that I use to clean the molds with. To all of you who have replied I wish to say thank you. I would really like to get past this problem and get on with casting some good boolitz. Sendaro

HORNET
12-23-2010, 10:20 AM
I think that old ALOX lube is a good part of the problem. That stuff will melt and won't burn off, it just coats everything and clogs the vents in the mold. Can you get some clean, dry sawdust? Clean your molds again (a good soak in mineral spirits followed by boiling with a little Dawn dish soap and a clean hot rinse). Should probably clean your ladle too. Use about a heaping tablespoon of sawdust at a time and flux your pot a couple of times as gear suggested.
The Marvelux is OK as a flux but it is hygroscopic and can build up and help rust your pot. If you boil out the pot once in a while, it's not too bad but sawdust is cheaper and easier to get.
Preheat the molds and ladle and try again. Try around 675° or so and let us know how it goes. This isn't all that hard once you figure a few things out.
BTW, NEVER lube a mold with that alox lube either. Stuff gets everywhere you don't want it to be.

dragonrider
12-23-2010, 10:24 AM
For fluxing use sawdust, any species will do but I am told that cedar smells nice. I use oak because that is what I work with in my wood shop. Pour about 1/2" of sawdust on top of your melt and let it sit there until it burns completely. You can speed that up but tossing a match on it once it gets smoking real good. In your house or basement this could be a problem especialy with a SWMBO. OK now that it is all nice and black it is also nice and DRY, very important. Now scoop up ladlesful and pour back into the pot repeatedly. Then stir the pot with a VERY DRY stick scrubbing on the sides and bottom while doing so. Remove the crud that is now on the top, get it all, and then repeat the above process again. This time do not remove the ash, maybe even add more sawdust until you have enough ash to cover the surface of the lead, this will prevent oxidation.

HORNET
12-23-2010, 11:38 AM
I don't think the ash layer will work. He says he's ladle casting. Ash and Kitty litter layers work on bottom-pour pots, though.

45-70 Chevroner
12-23-2010, 12:16 PM
I don't want to ruffle anyones feelings, but once tin is introduced to a pot of lead whether it is WW or pure lead. It "will not burn out or rise to the surface" once it is stired in it's in there. If you can show me a way to seperate tin from lead I will show you how to be a millionaire. Foundarys can't seperate it and no amount of heating it will seperate it. As for his question I hardly every cast with temps lower than 800 degrees. Mold temp. and cleanlyness have the most enfluence on good casting that along with clean lead. Although there are a lot of other veriables and usually you have to find what works best for you.

lwknight
12-23-2010, 12:21 PM
Chev, there are a lot of posts here that will show you how to deplete the alloy of tin.
It oxidizes and stays on top then gets skinned off and eventually the dross skimmed off and will amount to a lot of wasted tin.
Reprocessing dross yields a very tin rich alloy that could be as much as 90 percent tin.
Several members here can attest to that.

runfiverun
12-23-2010, 02:56 PM
the foundrys use zinc to remove tin from scrap alloys.
remember tin likes lead but will abandon it for other elements like zinc and antimony in a heartbeat.
that is what causes problems in an alloy that has more tin than antimony. as it cools the free chain of tin is trying to alloy with free lead and can't do it fast enough, which leaves tin spots in the alloy.
tin will migrate to the top of your pot through convection of the alloy, it readily oxidizes.
and is the first thing in your alloy to do so.

the alox in your ladle could easily be your problem use something else to flux and stir your pot.

MGySgt
12-23-2010, 04:01 PM
Back to hjis original problem. Good boolits, then wrinkled and then good.
Unless you are using a RCBS, WAAGE or Lyman pot you are going to have different temps by the amount of lead in the pot - Mainly Lee's do this.

He is Ladel pouring. He gets his mould hot enough to start and than it and his melt cools off. He stis/fluxes his melt and reheats his mould and everything is good again.

Try a higher temp on your pot and a faster tempo.

I ladel pour all my boolits, from single to 6 bangers. the single cavity is the hardest to keep to temp.

25 to 1 should make great boolits.

Fluxing - your old boolit lube at 750 degrees will burn off - light the smoke and get rid of the smoke. I use parrifin/candle wax. Do not use an oxidizer block on top of your melt unless you are using a bottom pour ladel (yes there are out there - Rothwell makes them). You will get that stuff in your ladel and boolits!

Also, small caliber (22, 25) are harder to keep the mould hot unless you go above 800 degrees. 50 degrees in your melt can make a big difference.

Drew

canyon-ghost
12-23-2010, 04:36 PM
If the ladle coats over, you aren't skimming the lead enough. Take the top surface off so it doesn't build up. When you bullets start wrinkling, are you slowing down, maybe leaving the mold open too long?

Ron

PS: if you get dross in the ladle and end up pouring it in the mold, you messed up. I use a teaspoon with holes drilled in it to skim the pot. If I have to, I do it often to keep pouring from the old Mirror-Bright.

Sendaro
12-24-2010, 08:29 AM
Sorting through all the advice that you all have given I find at I may have contaminated my laddle and mold by trying to flux the pot with old alox. Also that I may have skimmed off the tin in what I thought was dross. So my plan is as follows. No.1 clean the molds. No.2 clean the laddle. Stop using alox to flux the pot, and add some tin to the lead that I now have. I have a friend that has a RCBS bottom pour pot that has invited me to try it. I plan to within the next week or so. You guys have been a big help. Thanks for making the new Jack feel accepted into the group. I plan to keep working at this and learn to cast good boolitz. Sendaro

45-70 Chevroner
12-24-2010, 12:42 PM
lwknight: I don't know where they got thier information or where the 90 percent came from but this came from a Chemical analysis web site.
Tin:
Discription:
A very malleable silver white metal that forms a protective oxide on its surface that prevents it from reacting to oxygen.
I also read an artical by a Chemist that said if you know a way to seperate Tin from lead I can show you a way to be a millionaire. I don't have the artical any more, I probably lost it in one of my moves. I think I will believe a chemist before I take the word of some one that has only the experience of casting boolits. I don't mean to sound critical of casters as I am one my self. A little resurch goes a long way. The drouse on the surface of a melt is a natural thing when it comes to lead of any type ie. impuritys. It even occures on the surface of pure lead which has no tin in it.

45-70 Chevroner
12-24-2010, 01:30 PM
I did a little more resurch and found this.
Continuous methad of removing tin from lead.
United States Patent 4496394
The invention relates to a continuous method of removing tin from lead. The method comprises maintaining a pool of molten lead at a temerature of from 510 degrees C. to 570 degrees C. "My quote 510 degrees C. is a lot higher temp. than can be achieved by a home caster." introducing molten lead into the pool, injecting chlorine and oxygen into the mo;lten lead in an amount to react with tin present as an impurity in the lead to form a tin-containing dross an then separating the lead from the dross.
You can find this artical on google just look for "the process for separating tin from lead."
The artical I read by the chemist was probably 30 or 40 years old and it looks like someone made a million dollars or probably more if the process was profitable. If you read this artical you will see that a home caster will never ever be able to separate tin from lead.

Jailer
12-24-2010, 01:45 PM
Try a higher temp on your pot and a faster tempo.


Drew

I was having the exact same problem as the OP and doing as suggested above solved the problem for me. For me with my Lee mold 780 seemed to be the magic number and I had to keep up a very brisk pace for good fill out.

I was smoking my molds and the bullets were coming out more frosted the faster I went. I gave the mold a good shot of brake cleaner, raised the temp on the pot and increased the tempo and the bullets started dropping perfect and all were within 1 grain of each other when I weighed them.