'Bondo' for boolet molds?

[Elkins45]

I had even casting for 20+ years using only Al molds before I bought my first iron mold (RCBS) a couple of years ago. In a neglectful act of stupidity I forgot to oil it before leaving it over the winter in my unheated garage.

I went to cast with it last weekend and it's clear that there has been some damage. What used to be a smooth casting mold now takes a good bit of hammering to drop the boolets---so much that I keep loosening the set screw for the sprue plate.

From examining the casts it looks like most of the pitting is in the ogive area rather than the driving bands. I'm thinking of swabbing release agent into the cavity with a Qtip to see if I can make things any better. Any other suggestions on how to fix it? Maybe lapping or leementing?

[Arnie]

I would cast a soft lead bullet with the sprue plate open with a drill bit or screw centered in the bullet base .Then rub fine lapping compound on the bullet and close the mould on the bullet and spin it with a drill motor. If its a flat nose bullet you could try a brass brush spun in the closed mould .Cut the tip off the brush first. Arnie

[longbow]

I suggest trying a rust remover like Naval Jelly or other phosphoric acid rust remover. This will not harm the mould and may remove any little rust bits that are hanging onto your boolits.

If that doesn't work then I second the suggestion to lap but I would be inclined to cast through a nut and turn the lapping boolit by hand. You do not want to remove much metal, just clean up and polish a bit.

Also, make sure when you close the mould that you do not get lapping compound between the mould faces or it will hold the mould open and is an invitation to make oval boolits.

There is a good article on lapping here:

http://www.castpics.net/subsite2/Mol...ldLapping1.pdf

By filing the flat on the boolit you can keep the lapping compound in place until the mould is closed.

Fine valve lapping compound of 400 grit of finer should do the job without much work and without much worry of removing too much metal.

Good luck.

Longbow

[geargnasher]

If it's rust scale that's the issue, use a rust eater (Naval Jelly recommended above is a good one), and maybe polish the cavities a bit with a lap and mild abrasive. If it's deep pits, try soaking a Q-tip in Frankford Arsenal Drop-Out mould release and coat just the cavities with it. After it dries, lap the cavities with Comet, just enough to remove most of the mould release, but leave the pits filled. That stuff is pretty tenacious unless you hit it with brake cleaner or alcohol, and should make a decent "bondo". The only other suggestion I have if it's pitted, and this is the only time you'll see me recommend this, coat the cavities with a heavy layer of butane lighter soot.

Gear

[GP100man]

I have a wadcutter mold that had pits in it from someone leaving boolits in it , anyways they would stik till it thundered !! I cleaned the cavitys with meangreen/tooth brush & put a layer of drop out in the cavitys then just as gear suggested spun precast boolits in the cavitys just enuf to clean the bands but leaving it in the pits.

On a scale from 1-10 the repair was `bout an 8 ,but they drop from the mold & that was my biggest concern as I lubesize em anyways.

Oh yeah , what dropout that did get on the face of the mold I scraped it off & out of the vents before Lyman meenting.

[Horace]

Another rust remover is Evapo-rust.

Horace

[geargnasher]

"Lyman-meenting", not for the faint of heart. Unlike Lee-menting, it usually requires a hydraulic shop press and a lathe, sometimes even a mill or a flycutter.

Gear