Lee sprue plate not flush

[yondering]

I picked up a couple new lee molds the other day, which are the best quality I've seen in a Lee mold so far, with one exception. 2 of the 3 molds have sprue plates that don't sit perfectly flush with the top of the mold. You can see daylight between the mold and sprue plate, and this, of course, resulted in flashing at the base of the boolits once the mold got up to temp.
The good people at Lee said I can just send the molds back, but personally, I'd rather fix them myself rather than pay the postage and wait some ?? number of weeks. Have any of you had good luck fixing this problem?
I'm guessing it's the sprue plate that isn't flat, rather than the top of the mold, but I don't know for sure yet. I was planning to take the sprue plate off and sand the bottom face flat. Any input?

[docone31]

I have two molds like that.
I just size them, and either scratch the flash off with my fingernail, or the gas check smooths things out.
I have not found it interfers.

[DLCTEX]

The one mold I have had that problem with had a slight curve to the plate, maybe caused by the way they are stamped out. I sanded it flat by starting with my belt sander, holding the plate against a piece of thin plywood nailed to a piece of 3/4 plywood with some brad nails. The thin plywood was thicker than the plate to start with, but was quickly eaten away by the sander. I finished with fine sandpaper laid on the cast iron bed of my planer/jointer. DALE

[Bullshop]

It may be as simple to fix as just loosening the screw. If you take any mold you have aluminum iron or other and hold it up to the light. Completely loosen the screw so the plate sits flat on the blocks. Then slowly tighten the screw. At some point you will see the end farthest away from the screw raise up off the blocks. That is how I adjust all the sprue plates on my molds. I tighten them to just before the plate begins to lift off the blocks. So in the case of your Lee molds the plate and the blocks may be flat, just not square to each other due to the screw being too tight.
Blessings
BIC/BS

[yondering]

Thanks Bullshop, that's good advice. That's why I post my questions here!

docone31, on my flat base molds, that's not a problem, but one of these is a bevel base design, so the sizing die doesn't clean up the flashing. I cast a batch of these already, and ended up cleaning the flashing off each one with my pocketknife. It's too thick for my thumbnail.

[Maven]

As Bullshop said, maybe the fix is as simple as loosening the screw. However, if that doesn't work, and while the screw is loose, remove it and the sprue plate. Next, take the sprue plate and mount it in a bench vise with the screw hole in the padded jaws to ~1/8" deeper than its diameter and at ~45 degree angle. Then strike it sharply, but not with all your might, with a hammer. If you hit it too hard, simply hit the opposite side. Test fit it to your mold; repeat until it's perfect. Polish the underside of the plate and the area around the screw hole and install it on your mold blocks. Btw, you may want to use a high temperature Loctite to secure the screw, or barring that, drill & tap for a set screw. Good luck and hope this helps!

[HeavyMetal]

Picked up a used Lee single cav in 44 full wadcutter.

Planned to use it as a "checking" boolit for alloy hardness. First couple I got out of it had substantial flash on the boolit base.

Cooled it off and then pulled the plate. laid it in the Mill table and saw it was bowed in the middle.

A bit of sanding with 220 showed polished edges but no center contact.

Several "light" blows with a small ball been hammer and it was polishing all the way across.

A quick move to 600 got a nice finish on the base and then I heated it up with a propane torch and applied Bull plate lube!

Next day I put it together and tried it out. Flash gone!