Will Tin help with this problem ? if so I need a little.

[gray wolf]

I am finding that my ( get from anyplace I can metal ) mostly COWW of unknown origin needs to be cast hotter than I like for good fill out.

Most times in the past I have been able to cast at 650/ 675* at a pace of about 3 pours a Minute.
My bullets drop with a slight frost that rubs off on a pant leg and the bullets are fine and look great. They are filled out and the correct size for sizing.

This season I am having to cast at 700+ and cast very fast in order to fill out the mold, 5 pours + a minute. Any slower and the molds act like they are to cold and I am sure they are not. This has increased the frosting on the bullets to the point that I can see a crystal like structure on the bullet bases and sometimes on the bullets, not a dendrite like look but more like snow flake pattern.

The high heat and fast pace is making my bullets a little small for sizing. Sometimes they size well but have a small section on the bullet that misses the sizer. If I slow down the bullets size OK but are not filled out with all sharp edges.

My molds are Iron and I have one brass mold. So my question is: Will a little tin help out this problem? and if so can I buy a little from someone that wont cost to much, the store in my town wants way more than I can pay for lead free solder.

What do you guys think ?

[kbstenberg]

GW your observations and explanations are very good and peaked my interest. The major frosting would seem to indicate a higher mold temp. But If you slow your pace your bullets show that your mold is on the cool side. I will be checking back to see what the more experienced have to say. What would happen if you only increased cycle speed to only 4 cycles per min.?
Just a guess. I would say that tin wouldn't help wrinkled bullets. I thought tin was to help make edges sharper and more defined. Kevin

[williamwaco]

What is the ambient temperature?

I find that when the air temperature falls I must cast faster.

I use COWW but I always add a little tin.

I get best results at about 4 pours per minute with a two cavity mold.

When it gets up around 80 to 90 degrees, I have to either slow down considerably or use a fan to cool the mold.

It is true that heavy frosting can cause smaller diameters. Remember: Frosting is caused by the mold temperature, not the alloy temperature.

[JSnover]

This season I am having to cast at 700+ and cast very fast in order to fill out the mold, 5 pours + a minute. Any slower and the molds act like they are to cold and I am sure they are not. This has increased the frosting on the bullets to the point that I can see a crystal like structure on the bullet bases and sometimes on the bullets, not a dendrite like look but more like snow flake pattern.

The high heat and fast pace is making my bullets a little small for sizing. Sometimes they size well but have a small section on the bullet that misses the sizer. If I slow down the bullets size OK but are not filled out with all sharp edges.

My molds are Iron and I have one brass mold. So my question is: Will a little tin help out this problem? and if so can I buy a little from someone that wont cost to much, the store in my town wants way more than I can pay for lead free solder.

What do you guys think ?

I think you need to add a little tin. You're having no trouble getting hot enough. Your problem is having to go way too hot for well-filled boolits. I pour mine at 2-3%, you won't have to spend a fortune to get what you need.

[tazman]

I had the same problem. I added a small amount of linotype I had on hand and the problem went away. I would say adding tin would be your cure. It only takes a small amount.

[dbarnhart]

PM me your address. I'll send you some tin. Just pay it forward someday.

[243winxb]

making my bullets a little small for sizing. Add linotype. The antimony will make the bullets larger in diameter. Then dont worry about the frosting or marginal temperature.

[gray wolf]

Just a guess. I would say that tin wouldn't help wrinkled bullets. I thought tin was to help make edges sharper and more defined. Kevin
Hello Kevin, I don't have wrinkled bullets.


Add linotype. The antimony will make the bullets larger in diameter. Then dont worry about the frosting or marginal temperature.
Well I don't have any lino either, but I thought the crystal growth on the surface of the bullets may be an indication of the ratio of lino to tin showing as to heavy on the antimony already. But a good suggestion anyway, thank you.


What is the ambient temperature?Some of the Pre - season casting temps have been cold, I will say that. 45* to 55* F some days windy, some days a decent breeze, I have considered that but I don't have a fix for it,I have to cast out on the deck, we still have snow on the ground here.

I find that when the air temperature falls I must cast faster. I also, the molds get cooler faster. Sometimes in a breeze they can even develop hot spots and cold spots.

I use COWW but I always add a little tin. Yes, that is why I thought the Tin may help me out some.

I get best results at about 4 pours per minute with a two cavity mold.

When it gets up around 80 to 90 degrees, I have to either slow down considerably or use a fan to cool the mold.
Your making some good points

It is true that heavy frosting can cause smaller diameters. Remember: Frosting is caused by the mold temperature, not the alloy temperature. Correct again, casting speed or the lack of can effect the whole process.

[leadman]

Have you done an acid test on your alloy to check for zinc? Sounds just like the problem I had with a batch of "wheel-weight" ingots I bought from a guy. They had zinc in them. I used the Zep root killer to flux the alloy and it worked much better. After using the Zep you do need to add some tin back in also.

[gray wolf]

Have you done an acid test on your alloy to check for zinc? Sounds just like the problem I had with a batch of "wheel-weight" ingots I bought from a guy. They had zinc in them. I used the Zep root killer to flux the alloy and it worked much better. After using the Zep you do need to add some tin back in also.

Thank you, but there is no Zinc in the metal.

[2muchstuf]

GW,
I don't have pure tin but I do have quite a bit of pewter.
It works well for me.
PM me your addy if you would like to try some.
Won't cost you a cent. Be glad to help out.
2

[quilbilly]

If you need some tin in a hurry, go to Walmart in the fishing sinker section. Most Wally Worlds have lead-free splitshot that are 100% tin. About 4 size 7 tin splitshot will "flavor" about 2# of lead. Kind of expensive this way but it is a great way to meter a test pour.

[KYCaster]

Thank you, but there is no Zinc in the metal.


Are you sure?

I am convinced that a good bit of the scrap WW available is contaminated with Zn because the manufacturers are recycling the used WW and not bothering to remove the Zn from their recycled scrap.

The problem will only get worse.

Jerry

[dh2]

http://www.rotometals.com/product-p/solder3070.htm
this is what I am using to add tin to my mix