Base Fill out.

[Brad]

Another thing I have learned from a specific mould is that the sprue plate must be a bit loose.
My 30 Sil mould from MP hates a snug sprue plate. The tighter it gets the more I get flashing on the bases of the cavities farthest from the pivot point. Let the plate swing loose and the flashing goes away.

 

[Rick]

Good point, when you put pressure on one end it raises the other end up. Not just MP, it's just the nature of the beast but a pretty simple fix.

 

[Brad]

But how many new guys think "I have flashing, plate must be loose" and snug it down tighter and tighter. This is one of those counter intuitive things some people just never understand.
One end goes down, the other goes up. Duh

I will admit to having been one of those guys in the past......

 

[Rick]

Sure, probably all of us have. I used to do that until one day I had a palm to forehead moment.

 

[Ben]

Do we have to confess to the past ? ? ?

 

[Rick]

Yeah, no reason not to. I've probably at one time or another in the last 35 years made about every dumb mistake there is and some no doubt more than once. There have been plenty of palm to forehead moments over the years as something pretty obvious finally sunk in.

 

[Brad]

Ah, but those old lessons learned the hard way are the ones we value the most.
I did the hard cast period, used some mould release, and heaven forbid, I smoked moulds.

 

[Ian]

 

[freebullet]

That is all part of what makes us as capable as we are today, so long as we learned from those mistakes.

 

[358156hp]

Loose sprue plate are a nuisance to me and my ladle. Other causes of flashing & flanging include pressure casting, higher than necessary alloy temps, and really high tin content, especially in conjunction with high pot temps. This combination introduced me to whiskers on the bullets. I knew I had really messed up the day I got almost all these symptoms at once. My first cure was to buy a pot thermometer. The best $20.00 I ever spent.

 

[Bret4207]

The learning curve with cast can be steeper for some than others. I've done everything in the line of boneheaded mistakes you can possibly make. Even after 30 some years at it I still find myself looking for a magic or complex answer to a simple problem. And if it costs me some money, that a seems to make it all the more attractive for some reason. Duh! I've got several moulds that PO's took the file to. Sad too, because not a one of them fixed the actual problem. Nice to see a conservative approach to venting in the areas that sometimes need venting.

 

[Pistolero]

I think you should send that H&G 68 mold to Erik and have him fix it. His work is so good it is really
worth it, especially for a great old mold like that one.

 

[Grump]

Yeah, this explains why when I took great pains to get the sprue flat and in full contact with the top of the RCBS mould, my base fill went to crap. It's been a year since using it, but IIRC I backed off the sprue plate bolt just enough to let it breathe but still tight enough to prevent finning...which held for about 50 pours or less per run. The bolt and allen set screw system made that ritual easy enough. It's still a bother I would love to leave behind.

Might break that top edge along the lines (literally) of the well-proven vent lines of our best-performing moulds.

 

[Elric]

Loose sprue plate are a nuisance to me and my ladle.

Uh, I run with a swinging sprue plate. With a SC, it is not an issue, but with DC, I futz about casting the farther cavity first, to anchor the plate...

This concept of breaking the top inner edges pleases me. If this reduces, if not eliminates, bad base fill, then maybe I can tighten the plate so it is just a wee bit tighter than free swinging. Getting to pleasant casting sessions, slowly... With Lyman split lock rings, I belt sand the ends so they don't dig into the plate, leave the plate swing, and either ladle or bottom pour (mould tells me which)...

I have a few non-vented, and those tricks only get you so far... breaking the top corners MAY help...

 

[62chevy]

Ben I tried yo fix for poor base fill out and on the Lee 452-200-RF it work like a charm but on the Lee C309-180-R round and then straight to flashing. Thought I had ruined the mold but because I use a Colman stove for casting and a RCBS 10 # pot the temp like to stay over 725. I started casting with a hot plate but was using it to heat my mold. Broke out a torch made a wind break stuck the Lyman thermometer in and remelted some bullets. The temp never got above 650 but at that temp it made some beautiful bullets that dropped out of the mold with a little shack.

Think I'll leave the Colman for making ingots.

 

[Ben]

I don't have much luck with anything but my ladle and my 20 lb. pot.

Ben

 

[James W. Miner]

DO NOT try to lap a plate, it just never works. You will get a rocker. lapping mold tops is as bad.
If there is a burr at the cutting hole, A swipe with about 400 grit is enough.
Making my own molds and plates has had me run into the problems. lapping anything just made things worse.
My cure was to use an end mill to re-cut. It is the only way to have a snug plate fit. I don't like the flop with a loose plate.
I leave the end mill marks on the mold top and bottom of the plate. That reduces friction, holds lube, prevents galling and vents better. I also swipe the edges with a fine file. One stroke is enough.
To polish the plate will just add more trouble. The only thing to do to a plate is to round edges and polish them.
Before I cherry mold blocks I make passes with an end mill across the blocks. No matter how tight I make a plate, you will see no light gap under them.

 

[62chevy]

I don't have much luck with anything but my ladle and my 20 lb. pot.

Ben

I have a 2 quart Dutch Oven and a Lyman ladle. The Lyman to me is hard to use, guess if I used it more then I'd get the hang of it but so far the Lee ladle works better for me.

Now I need to do the file trick to my Lee TL314-90-SWC, half went back in the pot today. Tomorrow I'll give it one pass then cast 15 or 20 times and repeat as needed.