GTA
All Springer/NP/PCP Air Gun Discussion General => Projectiles => Boolit and Pellet Casting => Topic started by: miksatx on August 03, 2019, 09:53:08 PM
-
So my 217-20 mold is casting hairy pellets. Could smoking the mould cause this? Nearly all the pellets I cas this morning was infested with hairs lol.
-
Mike,
These are called whiskers. It is caused by too much pressure in the casting process forcing the lead to enter the breathing channels on either sice of the cavity.
they actually scratch off easily, and for the most part, the pellets bases will be virtually perfect due to the pressure casting. ;)
It is fine line between too much pressure and not enough when pressure casting. Takes practice, and gained experience. 8)
Mike
-
Alternately, you may have the HB pins set a fraction too high, and the mould is not closing properly.... bleeding lead out between the two halves....
Bob
-
I don't use tin in my mix because of whiskers and I only use 99.9% lead. I eventually will be getting me another pot that has temp control so I can lower the temp. I never got whiskers like that though, they were barely visible compared to the ones you're getting. I'd probably suspect a better adjustments of the pins and if that's the case it could ruin the mold continuing to use it like that, it would cause the cavity to deform at the bottom of the skirt.
-
Well I cleaned up the mould again resmoked the mould. Had 1 pin that looked a smigen deeper pryed it up abit. Turned on the furnace we will see how it does.
-
So still getting whiskers just as bad plus now getting them on my hunter mag pellets. It's funny I cast up a couple hundred in magnum yesterday not one whisker. Will dump this pot of recycled pellet lead. And go back to the 99.9 hopefully the whiskers will disappear.
-
If you cast many like them , tumble them some ....