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Old 02-13-2015, 09:08 PM
skjos skjos is offline
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Location: South Sound, WA
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Default Glass Bead Media Testing on 5906 Frame

Here are the results of some media testing I did on a junk 5906 frame (5906 Abuse (Cracked Frame)).

Media Tested:
Ballotini: 170-325 grit, #13 glass beads (GB) purchased from Grainger
Pro-Blast: 80-120 grit, #9 glass beads (GB) purchased from ebay (seller: tacomacompany)
Baking Soda: Arm & Hammer
Central Pneumatic: White Aluminum Oxide (WAO) 220 grit purchased from Harbor Freight (It looks like Harbor Freight has discontinued the 220 grit WAO; this outfit seems to have small quantities at reasonable prices: Panadyne Abrasives)

Note: Media blends are by volume not weight.

Equipment: Speed Blaster gravity fed blaster running at 70psi (except as noted)

PPE: Goggles, respirator, 7mil nitrile gloves, bandana to cover head, ear muffs to cover ears, mechanics one piece suit – I’m blasting outside, not in a booth.


Testing Round One (R1):

Picture #1: in the middle of the trigger guard you can see four finishes coming together. The top left is #9GB only, the bottom left is #9GB + soda, the top right is #13GB only, and the bottom left is #13GB + soda.




Picture #2: left is #9GB, middle is original, right is #13GB




Picture #3: left is #13GB + soda, middle is original + soda, right is #9GB + soda




Picture #4: inside the trigger guard there is a faint line in the middle, the original finish is on top and the original finish + soda is on the bottom.




My impressions on the first round of testing – the #13GB cleaned up the frame much fastener than the #9GB, but the #13GB media left a slightly brighter finish. The soda did a good job at cleaning, but did not remove any of the scratches. When I was blasting with the soda it looked like it was darkening the frame, but after I cleaned it off, the finish in the soda blasted areas was a little lighter.


Testing Round Two:

Picture #5: left is R1 #13GB, upper side of dust cover is a 1:1 WAO/#13GB blend, lower side of dust cover is #13GB at 100psi.




Picture #6: left is R1 #9GB, middle left is 1:4 WAO/#13GB blend, middle is original, middle right is R1 #13GB, right is 1:1 WAO/#13GB blend.




Picture #7: left is #13GB at 100psi, middle left is R1 #13GB + soda, middle is original + soda, middle right is #13GB at 110psi, right is R1 #9GB + soda.




Picture #8: left is R1 #9GB, right is 1:/9 WAO/#13GB blend at 60psi.




Picture #9: 1006 blasted with 1:10 WAO/#13GB blend at 60psi. The sight recess was masked and retains the original finish, the surrounding areas were blasted.






Picture #10: 1006 blasted with 1:10 WAO/#13GB blend at 60psi. The middle recess of the back strap was masked and retains the original finish, the surrounding areas were blasted.




My impressions on the second round of testing – glass beads at higher pressure do provide a flatter finish than lower pressure settings, but the finish is still lighter than the original. Adding aluminum oxide does dramatically change the finish color/brightness. The first blend of 1:1 was surprisingly dark, even the second blend at 1:4 was very dark, but the third blend at 1:9 with lower pressure was very close. It was a little darker when compared to the original finish on the 5906, but when I compared it to the original finish under the grip of a 1006 it was near perfect. I altered the ratio one more time and blasted the 1006 with a 1:10 ratio (5 tsp of WAO per 1 cup of #13GB @60psi); it turned out excellent.


Final Comparison Photos:

The following pictures show the blasted 1006 with some of its brethren that still wear their original finish. I took the photos with and without flash to show the finish in different lighting. The top pistol is a 4506-1, the middle is the blasted 1006, and the bottom is an original 1006.














The only difference I can find is that the blasted 1006 does not feel as smooth as the other two, but this could be because the finish is brand new and the other two have smoothed out over 20+ years.



Here is an bonus picture showing a comparison of WAO grit I used on a project 645 awhile back (645 before and after)

Media Tested:
Abrasive Armory: White Aluminum Oxide 120 grit purchased from ebay (seller: theabrasivearmory)
Central Pneumatic: White Aluminum Oxide 220 grit purchased from Harbor Freight

Picture #11: the knife is 120 grit, the saw blade is 220 grit



I also picked up another 645 recently and had a little refinishing fun (645 Refinishing Fun).

Last edited by skjos; 03-20-2017 at 10:35 PM. Reason: new web server
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