Pitting around screw holes

Boogiest · June 11, 2013, 11:15 PM

How do I smooth pitting around screw holes. I'm prepping for a refinish

Dixie Gunsmithing · June 12, 2013, 12:10 AM

First, it's according to how bad and deep the pits are. If they are bad, then you may have a big job in getting them out, without really dishing out the hole.

Holes are generally polished, like this, with another screw or pin installed, even with the surface, they keep the wheel from dishing it out. Plus, you want to use a coarse grit for the pits, like 120 grit, and use a fresh loaded, stitched wheel, with light pressure, as heavy pressure is what makes the dishing worse. Another alternative is a belt sander, using around 120 grit, as the belt is backed up so it cant form into the hole. A large drum sander could do it too, then go over it with 220 grit, then 400 to blend it all in.

Boogiest · June 12, 2013, 12:31 AM

Thanks for the response! For color case hardening, what level of polish is needed. The holes I'm talking about are on the side of the receiver from a marlin '94. So just flat sand the entire side far enough down until the pitting is removed. I guess at a point I'm going to have to figure out how much of the pitting I'm gonna want to live with, cause that could remove allot of metal.

Dixie Gunsmithing · June 12, 2013, 07:08 AM

Marlin would have used 400 grit on the frame, and maybe stopped off on 220 grit for the barrel, but it's according to how old it is, and the manufacturing process.

400 grit is almost a mirror finish, and with 220, you can still see the cut lines in the work that the grit leaves, similar to where a fine brush would have been ran across something.

On the frame sides, on the finish polishing, the lines with the 400 grit generally run front to rear on the frame, not from top to bottom. It's best to use a magnifying glass to inspect the steel, as it can tell you the direction of the final polishing wheel cuts or lines on the metal, if you can't see them clearly.

On screws and pins, you can finish those with 220 grit by rotating the ends and screw heads as you polish them. Some of these were actually rougher than that from the factory.

Finally, and the most important, keep all the edges sharp, just like the factory, as that will stick out like a sore thumb, even worse than screw holes. However, case hardening doesn't stick out as bad as bluing either.

Boogiest · June 12, 2013, 02:09 PM

Thanks again

June 11, 2013, 11:15 PM	#1
Boogiest Junior Member Join Date: June 8, 2013 Posts: 6	Pitting around screw holes How do I smooth pitting around screw holes. I'm prepping for a refinish

June 12, 2013, 12:10 AM	#2
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	First, it's according to how bad and deep the pits are. If they are bad, then you may have a big job in getting them out, without really dishing out the hole. Holes are generally polished, like this, with another screw or pin installed, even with the surface, they keep the wheel from dishing it out. Plus, you want to use a coarse grit for the pits, like 120 grit, and use a fresh loaded, stitched wheel, with light pressure, as heavy pressure is what makes the dishing worse. Another alternative is a belt sander, using around 120 grit, as the belt is backed up so it cant form into the hole. A large drum sander could do it too, then go over it with 220 grit, then 400 to blend it all in.

June 12, 2013, 12:31 AM	#3
Boogiest Junior Member Join Date: June 8, 2013 Posts: 6	Thanks for the response! For color case hardening, what level of polish is needed. The holes I'm talking about are on the side of the receiver from a marlin '94. So just flat sand the entire side far enough down until the pitting is removed. I guess at a point I'm going to have to figure out how much of the pitting I'm gonna want to live with, cause that could remove allot of metal.

June 12, 2013, 07:08 AM	#4
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	Marlin would have used 400 grit on the frame, and maybe stopped off on 220 grit for the barrel, but it's according to how old it is, and the manufacturing process. 400 grit is almost a mirror finish, and with 220, you can still see the cut lines in the work that the grit leaves, similar to where a fine brush would have been ran across something. On the frame sides, on the finish polishing, the lines with the 400 grit generally run front to rear on the frame, not from top to bottom. It's best to use a magnifying glass to inspect the steel, as it can tell you the direction of the final polishing wheel cuts or lines on the metal, if you can't see them clearly. On screws and pins, you can finish those with 220 grit by rotating the ends and screw heads as you polish them. Some of these were actually rougher than that from the factory. Finally, and the most important, keep all the edges sharp, just like the factory, as that will stick out like a sore thumb, even worse than screw holes. However, case hardening doesn't stick out as bad as bluing either.

June 12, 2013, 02:09 PM	#5
Boogiest Junior Member Join Date: June 8, 2013 Posts: 6	Thanks again