Bead Blasting

[triplefg]

Checked out the metal shop at my art school yesterday. I've got access to anything I could possibly want - three forges, foundry type furnace for casting metal, associated burnout kilns... No mill, though. I was pretty excited to find that I had access to a dedicated bead blasting cabinet, which got me thinking about how I could apply this to guns
I plan on bead blasting the brass furniture on a "hawken" clunker and then putting a dark brown patina on it - maybe later I'll replace it all with wax-cast iron, but for now cheap and easy is the way to go.
My question is, if I bead blast a barrel and tang, will the texture be too "gritty" after I brown it? I realize browning is usually (initially) matte, like all patinas, but the bead blasting I've done so far seems even more so. I think that the bead blasted surface will be more durable - like parkerizing - if it has little tiny pits to cling to. (That's my rational behind blasting the brass hardware.)
Has anyone done this, or seen it done?

 

[Birddog6]

I glass bead blast every part I brown. It opens the pores of the metal & gives you a more even browning. Now it is IMPERATIVE that the glass beads be Clean beads & stuff in the cabinet be clean...... or you will have spots all over it that will not brown........ Also I cut the pressure back to about 40-50 psi. This keeps you from messing up the metal by cutting it & also it keeps you from shattering the beads. You don't want to break the glass beads as you want the beads t stay intack. If they shatter you have glass dust, not beads. Ya can't blast with dust, comprende ?

Anyway, I glass bead it, blow it off with air, soak a doubled paper towel with Brake Drum Cleaner & wipe all parts well with it & put the browning slution to it.

On the patina on the brass parts you want to do just the opposite of what you are thinking. Taks some 600, then 1000, then 1500 paper & polish the brass, then wipe it down with a use patch ya just swabbed the barrel with wipe down good with it, let it sit about 2 weeks & it will be tarnished UNLESS you get gun oil on it. Or get some Birchwood Casey Brass Black & put on it.

:results:

 

[triplefg]

Thanks, Birddog! The reason I wanted to blast the brass is to better mimic the look of the browned iron furniture - I thought the texture would add to the effect, or at least match the texture of the iron parts. Later on I want to re-cast the furniture in iron. I tested the brown patina look on my Zippo, and I thought it looked pretty close.

 

[Wedge]

Be very careful how you bead blast anything and everything you have that you want to keep in perfect condition. The bead blasting should be done on both sides of the object being cleaned or whatever is being done. The problem is that the surface of the metal is stretched by the beading and the article will bow like a banana. I demonstrated this using a peice of 2" x 1/4" steel plate 6" long. I beaded one surface and the plate bowed up about .060" in the middle. I then bead blasted the other side and the plate was forced back to a flat surface. The steel was then machined on one side, removing only 0.010". As soon as the plate was removed from the mill, the plate bowed back to the shape formed after the first beading. If a rifle barrel is glass beaded it too will bow and bend. To successfully glass bead a barrel it should be spun in a lathe at about 200rpm and gently beaded along its length. The spinning of the barrel evens out the stresses of the beading. Polish one side after and the barrel will bow. The brass fitments will also bow if not beaded on both sides evenly. Check out the close up photos of my cannon and you will see the matt finish formed on the surface of the barrel. I hot blued the barrel and the bluing has lasted for over 20 years now. It is still the original bead blasted finish after all this time.
Wedge :m2c:

 

[Birddog6]

That is why you use very Low pressure, as not to distort the metal. You are just basically cleaning it & opening the pores. I have done probably ? 50+ barrels this way for me & others & I have never had a problem with distortion on any of them & they all have shot fine. IMHO, you have more of a chance of barrel deflection by pinning the barrel too tight than glass beading it as I do it. :results: But everyone has their own ways of doing things...

Any Thin materials will in steel, brass, G.S. or Silver will definately distort Very easily when glass beaded even under low pressure, thus why I seldom do it.