Block alignment

[yondering]

I have an aluminum NEI mold that's been sitting on the shelf for a long time, haven't used it since I first started casting. I recently got interested in this one again, and found that the mold blocks aren't aligned perfectly in the horizontal direction. It's very hard to see it on the mold, but is obvious on a sized boolit. When looking down on the mold from above, the left block is shifted rearward of the right block. The alignment pins and holes aren't damaged, it appears the mold was made this way. This mold has 2 pins at the bottom corners.

The mis-alignment is only a few thousandths (~.002" as best I can tell), so I could lap the mold to get everything centered up. Problem is, the nose is a bore riding design, so lapping would make the nose too large. Is there an effective way to correct this mis-alignment? I've considered holding one block in a vice, and gently tapping the other block back in the right direction. This would leave the alignment a little sloppy, so I'd have to peen some material back in the holes. I think this would work, but has some potential to mess up the mold worse than it is. Any other suggested methods before I try this?

[JSnover]

Maybe the blocks weren't set up right when the cavity was cut. Have you cast any boolits with it?

[yondering]

Maybe the blocks weren't set up right when the cavity was cut. Have you cast any boolits with it?

Yeah, but like I said, not since I first started casting, in about 2002. I do have a pile of them and can post some pics of the problem maybe tomorrow.

I'm thinking the cavities were cut ok, but the alignment pins were off by a couple thousandths.

[Nrut]

Yondering..
I was having a similar problem with one of my better molds last week. I took the mold off the handles and was able to slide the halves of the mold back and forth ever so slightly. I drifted the alignment pins out a bit until the play disappeared. I haven't casted with that mold since the fix but am pretty sure I solved the problem.. Any way something you might want to try..

[JSnover]

I'd cast a few and measure them. If they're .004 over at the mold line, then the pins will need a little work. If they're not out of round, cast a bunch more :)

[deltaenterprizes]

Yondering..
I was having a similar problem with one of my better molds last week. I took the mold off the handles and was able to slide the halves of the mold back and forth ever so slightly. I drifted the alignment pins out a bit until the play disappeared. I haven't casted with that mold since the fix but am pretty sure I solved the problem.. Any way something you might want to try..

That sounds like the first thing to try.

[yondering]

Yondering..
I was having a similar problem with one of my better molds last week. I took the mold off the handles and was able to slide the halves of the mold back and forth ever so slightly. I drifted the alignment pins out a bit until the play disappeared. I haven't casted with that mold since the fix but am pretty sure I solved the problem.. Any way something you might want to try..

I'd already done that; the blocks were nice and tight but misaligned.

I got it fixed last night though. Mounted the left block in the vice (carefully) clamped on the ends, and tapped the right block back in the right direction just a hair. The fly cutter marks on top of the mold let me gauge the amount of movement, otherwise I would have scribed a line.
This left the blocks with a little wiggle room, so I carefully peened one of the alignment holes a little, and smoothed the mark out with a fine cut file. Works great now!