galling problems

[Bushrat]

I am using an Accurate five cavity mold and it casts great. The problem is the sprue plate galls the top of the mold. The first time it happened I smoothed up the top of the mold and made sure I used a liberal amount of Bull Plate on the mold around the pivot pin where most of the galling occurred. Yesterday I cast again and used Bull Plate as directed. I again got minor galling adjacent to the third hold and around the pivot screw. I love this mold but if I keep dressing up the top, I and going to change this from a 200 grain swc to a 195 with a short driving band. I have had problems with my Lee 6 cavity mold but after more than 25 years of casting with my NEI, four cavity I have never had any sign of galling. What can I do. Is it possible my pivot screw if too tight?

[MtGun44]

Do you have BullPlate on the top of the mold? If not, you should. If you
already do (sounds like you only have it on the pin) maybe antisieze.

Thin film of antisieze in the area, but make sure it cannot get into the
cavities. If you have an molybenum disulphide powder or paste (Molycote Z, IIRC)
or cam lube or the black paste lube they give for putting behind Honda brake
pads will work. A mere trace of these Moly disulphide pastes should do it.

Bill

[Doc_Stihl]

The screws on my sprue plate and the stop loosen up constantly on my accurate molds. I have mine both slated to be drilled and tapped for set screws.

When they get lose they sometimes gouge at the screw.

[mikeym1a]

I have had the same problem with my Lee moulds. What I did was to remove the sprue plate, and use a file on the edges where it was punched out. it left uneven edges on the plate. I cut all the edges at a 45 degree. When I had gone around the perimeter, I put the plate on a new oil stone, and slowly rubbed it back and forth, periodically checking to see what was being removed. The shiny spots on the bottom of the plate will show you where it was high. I then did the same to the top of the mold. When it was smooth, I cleaned it, and reassembled it. I've done that to 4 of my moulds, so far, and they are much smoother in operation. Works for my.

[Bushrat]

My Accurate mold came with set screws, I never realized the galling could be caused by a too loose spure plate. My old NEI has never galled, it has a superior method of anchoring the plate an stop, intstead of a screw it uses a stud anchored in the block and a castillated nut on top of a wave washer topped with a plain washer. I really like my mold but the galling problem is very time consuming. The more suggestions the better. Thanks to those who have already responded

[Silverboolit]

When the mold is new, I always remove the sprue plate and dress the bottom of it flat. I do the edges also. Put a slight bevel on the edge. Works every time and no gouges.

[Marlin Junky]

Change the tension on the sprue plate spring washer by squeezing it in a vise. Also use a small amount of anti-seize on the pivot screw so you can just slightly snug it down and return to the same pressure each time you disassemble the mold for cleaning.

MJ

[Marlin Junky]

My Accurate mold came with set screws, I never realized the galling could be caused by a too loose spure plate. My old NEI has never galled, it has a superior method of anchoring the plate an stop, intstead of a screw it uses a stud anchored in the block and a castillated nut on top of a wave washer topped with a plain washer. I really like my mold but the galling problem is very time consuming. The more suggestions the better. Thanks to those who have already responded

Galling is not caused by the sprue plate being too loose. If your AM came with set screws, then my suggestion above regarding the spring washer does not apply. However, a bit of anti-seize on the hardware will go a long way to extend the life of your mold block threads.

MJ

[44man]

Cutting too soon leaving lead smears.

[Marlin Junky]

Cutting too soon leaving lead smears.

Too much sprue plate tension and/or lack of lubrication also galls aluminum blocks even if there's no lead in the cavities.

MJ