Author Topic: Sand blasting then brown  (Read 1592 times)

Offline Scota4570

  • Hero Member
  • *****
  • Posts: 2259
Sand blasting then brown
« on: November 11, 2018, 01:37:21 AM »
I did an experiment.  I draw file a new barrel.  I then sand blasted it with Harbor Freight 70 grit aluminum oxide using their cheap gravity feed gun.  Just enough to remove the shine of the steel.  I did not degrease. 

I heated the barrel using a propane torch and an gasoline plumbers torch.  When it read about 200* with the IR thermometer, BC plumb brown.  Three passes applied with pillow ticking.  It reacted quickly and evenly to the BC.  Then it sat over night in a damp towel humidity chamber.  After I carded and wiped it down with ammonia solution.  I then heated the barrel again and coated with melted bees wax.  No after rust at all. 

It tuned out really good.  Very even and dark plumb satin effect.  It is not rough at all.  It is much smoother than Browning Mountain rifles.  I suspect the microscopic roughness was dissolved by the BC and the resulting finish was smoother than before rusting.  The roughness helped the BC to react quickly and evenly.  It also seems to make the rust coating more tenacious.  I go no bald spots while carding with steel wool and a brass brush. 

I am very happy with it, I will be trying this again.  I will probably never painstakingly polish before I brown again. 

Offline Mike Brooks

  • Hero Member
  • *****
  • Posts: 13235
    • Mike Brooks Gunmaker
Re: Sand blasting then brown
« Reply #1 on: November 11, 2018, 01:43:53 AM »
Did you loose the sharp corners with the sand blasting? Not important to me but for others that may be an issue.
NEW WEBSITE! www.mikebrooksflintlocks.com
Say, any of you boys smithies? Or, if not smithies per se, were you otherwise trained in the metallurgic arts before straitened circumstances forced you into a life of aimless wanderin'?

Offline Scota4570

  • Hero Member
  • *****
  • Posts: 2259
Re: Sand blasting then brown
« Reply #2 on: November 11, 2018, 01:50:19 AM »
No. I don't make them razor sharp anyway.  The slight variations are finger prints in the wax. 



« Last Edit: November 11, 2018, 01:52:54 AM by Scota4570 »

Offline Mike Brooks

  • Hero Member
  • *****
  • Posts: 13235
    • Mike Brooks Gunmaker
Re: Sand blasting then brown
« Reply #3 on: November 11, 2018, 05:22:33 PM »
Looks good to me.
NEW WEBSITE! www.mikebrooksflintlocks.com
Say, any of you boys smithies? Or, if not smithies per se, were you otherwise trained in the metallurgic arts before straitened circumstances forced you into a life of aimless wanderin'?

Offline Hungry Horse

  • Hero Member
  • *****
  • Posts: 5415
Re: Sand blasting then brown
« Reply #4 on: November 11, 2018, 06:59:06 PM »
Sand blasting was a big deal for builders about thirty five years ago. Besides everybody trying to get that old timey look, many were trying to make the barrel less reflective. As is always the case it got taken to extremes.
 I am currently helping another shooter/collector rescue a very nice longrifle that got the sandblasting treatment not only on the barrel, but the lockplate as well. These parts look like they were dug out of the ground. The cold browning solution that was used was pretty aggressive to start with, and applying it to etched metal made almost impossible to stop.
 I urge caution using this technique, it can get out of hand pretty easily.
 The dark textured browning so often seen on modern muzzleloaders is most likely not what the new gun had on it. Old browning recipes often call the color “plum brown”, or a clear reddish brown, the dark chocolate color seen today is likely modern builders duplicating what they see on antiques today, after a hundred and fifty years of no oil, in a closet, or attic.

  Hungry Horse

Offline Scota4570

  • Hero Member
  • *****
  • Posts: 2259
Re: Sand blasting then brown
« Reply #5 on: November 12, 2018, 03:38:00 AM »
"These parts look like they were dug out of the ground" 

Sounds like larger grit and higher pressure, much more aggressive than what I did.  I had no intention of making it look neglected or old.

I used #70 grit and a gravity feed gun from HF.  100 PSI.  I stayed about 10" away from the barrel.  I did not use a cabinet and high pressure.  The blast was just enough to get rid of ALMOST all of the shine from the draw filing when viewed in sunlight.   

The slightly roughened texture seem to have given the browning chemical a "tooth" to react with.  Like skuff sanding before you paint?  After browning and carding it looks smooth again but not shiny.  The flats are still sharp.  If you look close remnants of the draw file are visible. Refer to my picture above. 
« Last Edit: November 12, 2018, 03:40:18 AM by Scota4570 »

Offline Marcruger

  • Hero Member
  • *****
  • Posts: 3664
Re: Sand blasting then brown
« Reply #6 on: November 12, 2018, 05:06:03 AM »
Looks pretty "silky" from where I am sitting. I thought from reading that it would be more matte.  I like it.  God Bless,   Marc

Offline flehto

  • Hero Member
  • *****
  • Posts: 3335
Re: Sand blasting then brown
« Reply #7 on: November 12, 2018, 05:10:13 PM »
Years ago I used toilet bowl cleaner on a bbl  and an etched. matte light gray  surface was the result. Because the surface had "tooth", the browning solution uniformly  wetted the surface. The finished "brown" color  was way  too dark  so   the bbl was refinished down to shiny steel and then rebrowned and the result was an etched , matte texture w/ a nice  reddish brown color. If the draw filing is followed by a light rub w/ 220 grit paper and a cleaning, no other prep is necessary. ...especially w/ a strong reagent such as LMF. ....Fred


why is pablo neruda famous
« Last Edit: November 12, 2018, 05:15:10 PM by flehto »