A problem casting

[fastfire]

The last 4 days have been trying to get good boolits from this NOE 60gn RN.
The alloy is 25% lino spacers 75% cow. Keep getting an area just above the driving band that is not fully filled out and frosty in the same area.
Have tried temps from 640-770. I get an occasional good boolit and seldom any wrinkles just the area in the picture that is frosted. Tried cooling the mold till I got wrinkles and hot enough for total frosting.110130

[R.M.]

If I get wrinkles, I get the mold and pot hotter. I get good results when my thermometer reads 800. I have no idea how accurate that is, and don't really care. When I get good boolits, I 'm happy.

[Tatume]

When you got "total frosting" could you still detect a difference in the area that you photographed? If not, then I suggest that those are the most consistent and accurate bullets possible.

[44man]

It is caused by a HOT spot, same problems with a LEE TL boolit where bands frost and refuse to fill.

[Toymaker]

When that happens I get out the soft toothbrush and lye soap and give the mold a good scrubbing. Then it gets an alcohol bath and an acetone rinse followed by an hour or two in the hot sun. I carefully pre-heat the mold and try again. If it still happens I crank up the temperature. I've found that most thermometers are guides, not gospel. If I want to know for sure I get out the thermocouple. If I get frosted bullets I take one (cooled) and rub it down with a felt/flannel cloth. That should make them shine nicely. Then I examine the bullet under a magnifying glass. If the bullet does not have a crystalline lattice appearance it's good. If it does, something's too hot.

[fastfire]

I use a PID for temp control and yes it is a NOE 225-70

[Larry Gibson]

The alloy is 25% lino spacers 75% cow.

Your alloy is excessive in antimony content and very low in tin content. What you see is the antimony not in solution with the lead. Both of those alloy are high antimony and low tin and mixing them just exasperates the situation. The antimony hardens 1st before the lead and shrinks more. Adding tin to the alloy will mix with the antimony forming SbSn and will go into solution with the lead.

Add 2% tin to the alloy, flux well and try that at 725 degrees.

Larry Gibson

[fastfire]

Thanks Larry, I'll add 2% tin and give it another try.
I'm getting a lot of I think TIN floating on top of the pot tried stirring it back in but just comes back up top.
Is this tin? I don't like fluxing it the casting pot.

[bangerjim]

Larry beat me to the answer, but I feel he IS right! And you really do not know that those lino spacers are true lino alloy. Many are much softer. Some I have are darn near pure lead. They do not need to be hard because all they do is fill a space between the lines of type.


You must flux/reduce in the casting pot. If you are running that hot, the Sn will form almost immediately! I use beeswax to reduce and not sawdust. The wax almost instantly forms a shiny surface and leaves very little black crude behind. And if you are not TOO hot, beeswax will not flare up like common paraffin...and smells GREAT! Just stir it in real good and watch the magic happen.

Try it............. you will save your SN in the pot. I reduce with beeswax at least 3 times during a 20# casting session.

But add some Sn!

banger

[fastfire]

OK, where do I get bees wax?

[dondiego]

OK, where do I get bees wax?

Bee hives are a good source..............as are bee keepers that raid said hives for honey. Also I believe that a member here, Randyrat? sells it.

[Springfield]

Lots of places online, or try Michael's or any other craft/cutsie stuff store. I think Tandy leather may carry it also. Personally I find a sawdust/beeswax mix works the best. I find it difficult to get a total flame going on top, enough to cover the top of the casting pot. The sawdust acts as a wick and helps spread the flame out.

[bangerjim]

Support our own! Randyrat is a vendor on here that sells good beeswax. Check him out.

Also Woodcraft stores sell beeswax and Carnuba wax.

banger

[jmort]

+ 1
I got mine from Randy Rat. Great Vendor.

[44man]

The alloy is 25% lino spacers 75% cow.

Your alloy is excessive in antimony content and very low in tin content. What you see is the antimony not in solution with the lead. Both of those alloy are high antimony and low tin and mixing them just exasperates the situation. The antimony hardens 1st before the lead and shrinks more. Adding tin to the alloy will mix with the antimony forming SbSn and will go into solution with the lead.

Add 2% tin to the alloy, flux well and try that at 725 degrees.

Larry Gibson
Good call Larry.

[runfiverun]

It is caused by a HOT spot, same problems with a LEE TL boolit where bands frost and refuse to fill.

saving myself some typing.
hold the mold more perpendicular.

[Larry Gibson]

Larry beat me to the answer, but I feel he IS right! And you really do not know that those lino spacers are true lino alloy. Many are much softer. Some I have are darn near pure lead. They do not need to be hard because all they do is fill a space between the lines of type.


You must flux/reduce in the casting pot. If you are running that hot, the Sn will form almost immediately! I use beeswax to reduce and not sawdust. The wax almost instantly forms a shiny surface and leaves very little black crude behind. And if you are not TOO hot, beeswax will not flare up like common paraffin...and smells GREAT! Just stir it in real good and watch the magic happen.

Try it............. you will save your SN in the pot. I reduce with beeswax at least 3 times during a 20# casting session.

But add some Sn!

banger

All the above:cbpour:

Larry Gibson

[fastfire]

Ok, I'll get a bunch of beeswax, But in the mean time until I get my hands on it what is a more easily assessable flux?
Parifin?

[jimb16]

It will work. I have access to a lot of it and use it as flux in the pot all the time. Just be aware that it will flash ignite so be careful you don't get burned or set the house on fire. Use a small amount at a time till you see just how much you need to work with.

[fastfire]

It will work. I have access to a lot of it and use it as flux in the pot all the time. Just be aware that it will flash ignite so be careful you don't get burned or set the house on fire. Use a small amount at a time till you see just how much you need to work with.

Thanks