More dummy questions

[tommag]

I have a NEI aluminum mold that won't cut the sprues without leaving a flange. I have tried loose and tight on the sprue-plate with no change. This same alloy works very nicely in my Lee 170fngc and 113 soupcans. I have tried bullet lube, never-seize, pencils, and spray graphite lube on the sprue plate. Maybe Bull-plate will help when it arrives, but I just ordered it last week.

The problem is more pronounced in the hole furthest from the sprue-plate hinge. (2 holer) Maybe some of you might be able to look at the pics and recognize the problem.

Also, if I can't remedy this, would the GC cover up the problem adequately if I use my fingernail to remove the flange? Seems to me any irregularities would throw things out of kilter.

[No_1]

Maybe the spru-plate is warped? Yours pictures are a little fuzzy but from what I can see the top of the mould blocks looks clean and not galled. Take it apart and put the spru-plate up against something flat like a piece of glass. I think you will find your problem.

[rigmarol]

I have an rcbs mold that does that if I'm casting too hot. But not that bad. Does it look like a smear or a casting leak under your sprue plate?

After trying all that you have I think Robert is pointing you in the right direction.

[tommag]

I took the plate off and put it on a thick peice of glass. Seemed like there might be a bit of rocking, but I'm not sure. I used a 16X jeweler's loup and found some dings on the top of the mold block right near the problem hole. They are about .005 in width. I took a pic through the loup and it is not very clear as I am no Ansel Adams. If this looks like the problem, how would I remedy it? I am thinking some sand paper on the glass. I have 600 and 800 grit wet/dry. I may have some 1200 out there somewhere.

[No_1]

Can you feel your fingernail catch on those dings? Do they have a raised lip/edge? If they do then I would just drag a knife blade across them not trying to whittle them but knock the edge off of them.

Notice the heat discoloration on the sprue-plate? Place a piece of very fine (800 is pretty fine stuff) sandpaper on your glass, place the sprue-plate, mould side down and make a few passes using a figure 8 motion. Try to apply soft but even pressure across the whole sprue-plate. With just a few passes you should see the discoloration "go away" from the high spots. If the discoloration completely goes away evenly in just a few passes then the sprue-plate was probobly flat. If it does not then the plate is warped. Not to worry, a little time and a lot of motion will make it flat. If you want to check your work at any point, just "color" the bottom of the sprue-plate with a marker and make a few passes. When I do this kind of work I take my time. If you try to set a speed record doing it then you will probobly do it wrong.

[rigmarol]

No 1, great suggestion, I'm going to use that myself. Thanks.

[44man]

You don't need super fine sandpaper! A few passes on 280 wet or dry will fix the top of the blocks and sprue plate very nice.
I leave the end mill marks on my blocks and plates and get much better casts because it leaves the air out better and the higher points of the cuts lets the plate slide easy with plate lube staying in the grooves. Since I found that smooth is not good, I don't get scratches or gouges on my blocks anymore.
The only thing is to keep things flat and you don't want the plate to rock up when you snug the screw.
Don't get anal and polish the thing, too smooth can make casting more work.

[UweJ]

Are you pouring or laddle casting? Sometimes the lead comes in to fast and it´s better to laddle to get better fill. Just a thought
Uwe