Beadblasting....How to mask?

[krs]

I'm going to be bead blasting parts of the frame and slide on a stainless steel Colt Gold Cup Trophy that I've modified with a well fitted Wilson beavertail grip safety, ambidextrous thumb safeties, checker frontstrap, and some other parts choices.

I want to do the sides of the slide and frame high polished, and have the top of the slide, the underside of the frame and the rear facing parts of the pistol bead blasted to a nice matte finish. Nothing unusual but I'd like to do a nice clean job of it.

I need to know what works to keep the blaster from parts that are not to be blasted. I mean, how do you mask the job?

Regular masking tape will be chewed at by the blast even at low pressures of 20 - 30 psi, and pressure that low doesn't do as good a job as about 60 psi will.

Duct tape is hard to cut to a fine line and would also fray.

The 'blue-line' type of tape I've used for painting doesn't hold up to blasting either,

So...........does anyone know of something that DOES work good for masking off areas to keep them from being glass bead blasted??

 

[rcmodel]

I have long used Scotch 33+ black vinyl electrical tape with perfect results. Sticks good, trims easy, and just does a great job.

The trick is to blast straight-on to the edges & don't stay in one place for a long time.
If you come in at a low angle and get under an edge, any tape will fail.

Oh, and don't stretch it when you put it on the parts.

rcmodel

 

[ieszu]

I was taught to use masking tape.... but as rcmodel said, don't stretch, and don't try and come in at a low enough angel that the bead blast media gets under the edge.

I never used black vinyl electrical tape for bead blasting, only for bluing to mask areas off, but it should work just as well.

 

[rcmodel]

I first started using Black electrical tape for bead blasting about the mid-1960's for tool & die work.

We maintained a gazillion injection mold dies (50 -100 grand a mold) for Hallmark Cards, and found the vinyl tape worked far better then anything else for sand, bead, or vaper-hone masking.

It is truly tough stuff, and very abrasion resistant.

rcmodel

 

[Freedomv]

Try clamping the slide between 2 pieces of wood. Cut the wood to somewhat fit the profile and clamp with small C-clamps. The frame may take a little more difficult because of the variation in thickness but it should not be to difficult.
This will help in handling the parts as you blast them also. Quarter inch or 3/8's inch plywood should work well.

Vern

 

[icebones]

+1 masking tape,

i always used modeling clay to plug up the barrel when sandblastic rifle/shotgun barrels. keps sand out and is easy to clean out.

 

[moooose102]

i have used duct tape with good results. black electrical tape is cheaper, easier to work with and by far more flexible though. i have not tried it,but it sounds like it works.

 

[krs]

Alright! It never occured to me to try electrical tape and I've got a few rolls of 3m tape on hand. Hard to argue with rcmodel's long experience.

The idea of clamping in wood sounds like it has a future here too, as my blasting cabinet isn't all that big and I've gotten the gloves wound up when trying to take different holds on pieces without dropping them into the abyss of the media dump collector.

Good tips - Thanks all!!

 

[dclevinger]

Masking tape is what I use most of the time. 3M book binding tape is great as well. I use it when I have to blast around some engraving to give the work a different look. It's crystal clear so I can trim it right up to the engraving without worry, and it is very sticky so the edges won't roll up while it's being blasted.

David

 

[Robert Hairless]

The trick is to blast straight-on to the edges & don't stay in one place for a long time.
If you come in at a low angle and get under an edge, any tape will fail.

That's the single most important point, in my own limited experience.

 

[krs]

I'm sorta' back and forth about the shiny slabs. Most custom guns I see pictures of that are stainless are either hardchromed or blasted to a satin or a matte finish overall, doing away with gloss.

This is a gold cup that came with polished slab slide and frame. I'm thinking it might look better if all over blasted.

Any opinions?

 

[rcmodel]

All Gold Cups, as well as all older commercial Colts, came with highly polished flats on slide & frame, and bead blasted top of slide and frame edges.

IMO: An overall matt finish on a Gold Cup just wouldn't be right!

rcmodel

 

[krs]

IMO: An overall matt finish on a Gold Cup just wouldn't be right!

Yeah, I know what you mean.....but this one is stainless, doesn't have the sight ridge or the front frame serrations, or the Eliason, Accro, or Champion sights. Except for the rollmarks and the slanted slide serrations it'd be like a silver colored Government model which, IMO, just ain't right either.

Maybe I ought to send it to be Robarred, or Ionbonded , or otherwise blackened. That'd probably look good.

Stainless is such a PITA to keep from getting scratched when it's polished. Nickel is better.

 

[olyeller]

polish after beadblasting??

 

[krs]

Probably doable, but there will come a time when too much work will spoil the gun.
Gotta watch out for rollmarks and edges. I've already taken some metal by fine sanding to remove the pushed up metal around the markings. I did the final polish that Colt's beancounters must have decided was unnecessary many years ago.

 

[Riss]

Blasting will give it that bumpy look. Polishing will make it look shiny and bumpy. It will also take some of the bite out of the blasting and make it a little smoother in the hand.