Why are they no longer sharp...Driving bands

[lablover]

Been casting for the last 3 days..Mold started spitting out boolits that had the driving bands a little soft/not crisp. Cleaned the mold very well and it's still happening. Alloy temp is 700-750. I added 1% tin to the WW mix and they started good but then went to pot! Tried a different mold...Same thing. It's almost like the leading edge of the bands look slightly frosted as compared to the rest of the boolits. I keep my NOE 200gr SWC molt at around 440 deg. It seems to like it hot or so I thought. Funny too is the whole boolit looks pretty good except those leading edges.

Looking forward to any suggestion. Funny, this all started when I tried to get the perfect base/bottom of the boolit.



Long day at work and then I went out and tried some more...Yea, that was a mistake!

Joe

[OS OK]

Vent problem? Are the mould faces clean in that area? Are you smoking the mould heavily and plugging vents? I dunnoh...will follow this thread to see what the fix is.

Make sure you post the fix when you find it...OK?

[lablover]

Will do, I will try again tomorrow. I read another post just now and I think I may be running my melt too hot...Worth a try. I remember last year when I started I was getting great looking boolits and I think the pot was at 650ish...Hmmmmmmmm.. couldn't be that easy..Could it?

Oh, no smoke or just a light coat..Cleaned out all the vent lines too...Still no go

EDIT: I will also say my new lee 4-20 has begin to pour at a fast dribble almost..For some reason it starts decent pour then starts to slow down?

[OS OK]

This is a pretty good 'riddle'...from your first post it looks like you are doing everything right on the money!

Are you preheating the mould all the time your Pb pot is coming up to temp?
Are you hitting dead center of the sprue plate hole...not allowing the Pb to hit the edge first and then funnel into the cavity?

Geeez...you got me on this one.

[Tom W.]

Your nozzle is getting plugged on your pot. When it happens to me I take a big paperclip, bend it an unwind it enough so I won't get burned, grab it with some pliers and commence to ream the nozzle. It works great.

[lablover]

This is a pretty good 'riddle'...from your first post it looks like you are doing everything right on the money!

Are you preheating the mould all the time your Pb pot is coming up to temp?
Are you hitting dead center of the sprue plate hole...not allowing the Pb to hit the edge first and then funnel into the cavity?

Geeez...you got me on this one.

Not hitting the hole dead center yet, the mould guide is driving me nuts! I think I may flip it over and try just the flat side. I am pre-heating the mold the whole time pot is coming to temp. But yea, I can't seem to hit that hole dead center....Yet.

[lablover]

Your nozzle is getting plugged on your pot. When it happens to me I take a big paperclip, bend it an unwind it enough so I won't get burned, grab it with some pliers and commence to ream the nozzle. It works great.

Will give that a shot

[OS OK]

Not hitting the hole dead center yet, the mould guide is driving me nuts! I think I may flip it over and try just the flat side. I am pre-heating the mold the whole time pot is coming to temp. But yea, I can't seem to hit that hole dead center....Yet.

OK...that just may be the problem, you loose temp on the Pb like that. Can you raise your pot some so that you can see better what your doing?
On my Lee 20# pot I had to grind off one of the corners of the guide so it would center well on wide moulds...seeing that Pbcoming out of the valve is crucial.

Attachment 202443

I raised my pots just 6" or so and that was enough. Click on the picture and you can see where I ground the edge off the mould guide.

[lablover]

OK...that just may be the problem, you loose temp on the Pb like that. Can you raise your pot some so that you can see better what your doing?
On my Lee 20# pot I had to grind off one of the corners of the guide so it would center well on wide moulds...seeing that Pbcoming out of the valve is crucial.

Attachment 202443

I raised my pots just 6" or so and that was enough. Click on the picture and you can see where I ground the edge off the mould guide.

Thats a great idea! I'll knock one out at work tomorrow at lunch..I'm a cabinet maker..LOL. But yea, I have a heck of a time seeing where that melt is going.

OK, I have to ask being still a newbie..What is PB...

BTW, slick set up. I've been thinking about that pot upgrade that was posted here a bit back..Seems like nice gear..Almost too nice for such an inexpensive pot.

[OS OK]

Pb is lead
Sn is tin
Sb is antimony
Cu is copper

I abbreviate a lot IIRC.

IIRC is If I Remember Correctly

You'll get used to it.

[lablover]

Pb is lead
Sn is tin
Sb is antimony
Cu is copper

I abbreviate a lot IIRC.

IIRC is If I Remember Correctly

You'll get used to it.

OK, I knew that..why did I not remember..Oh yea...Long day at work..Scary, getting old sucks!

Thanks for the reminder...

Looking forward to making that riser for my pots. I have the lee 20 and the 10. I like the way you have the pans under as well. Pretty slick

[DerekP Houston]

The standard mold guide on a 4-20 just annoyed me, I free handed until I had enough sheckles to replace it. Might experiment with lower the melt temp and increasing mold temp...thats my only thing I play with when bad fillout now. Oh, or add more tin

[bosterr]

When I saw that the edges were frosted, the first thing to come to mind was zinc contamination.

[Bzcraig]

Since it's happening with two molds it's definitely a hiccup in your process and think you may already figured it out with not getting lead directly into the mold.

[runfiverun]

shooting lead directly in the hole works best on long skinny bullets.
short fat ones need more venting to work their best.
the sprue hole is a lot of air compared to a few scribed lines.

your frosting issue is a mold temp problem, drop the mold temp about 20-f and I bet it goes away.
white colored rounded edges are the sure signs of frosting.
your probably just getting more efficient at getting the mold emptied and back to being filled again.
try counting while waiting and all the way back to when you started counting. [end of pour]
15-20 second cycles will maintain a molds temperature no problem.
change the rhythm [count time] as needed when you see to shiny, or too hot, on the boolits coming from the mold.

[Jack Stanley]

I notice several off your posts mention long days at work . The solution might be as simple as retiring

Jack

[Tom W.]

Retiring didn't help me much.....maybe sometime after November......

[fredj338]

I tend to pressure cast when hand casting. It seems to give the best fill out with most molds. Also fluxing often seems to help keep the alloy unified. For me that is just stirring often with a wooden paint stick.

[lablover]

Bwahaahhaaaa..I was retired and went back to work! Start at 7 and get home by 4. Just got home early and am debating going to try the new tips!

[lightman]

I'm thinking maybe a vent problem or a flow problem. Maybe not enough pressure or volume to get good fill out.