Gunsmithing Blasting media questions

[RobfromME]

Good afternoon, all,

I found plenty of good info here on blasting media for prep before paint/coatings, however I couldn't find info to the following:

What is the best type and grit size of blast media to use before parkerizing that will preserve the markings, etc. such as on an M1 Garand, M1 Carbine, etc?

I've heard to use Al Oxide, don't use Al Oxide, use glass beads, don't use glass beads and so on, but not from those who've done it or been concerned with preserving the markings. I've seen quite a few gun show examples that were blasted to the point that markings were lost.

The guns I will be blasting are not collectors, therefore refinishing is not to affect the value.

Thanks in advance to your thoughts and experiences.

Warmest regards,
Rob

 

[colchester]

Re: Blasting media questions

I use 80 or 120 grit alox. I have not had any issues with removing or degrading markings or edges. Youre not looking to get real aggressive with it just want to give it a complete blasting. I have used glass beads instead of alox for parkerizing but I feel alox gives superior results.Glass beads are great if youre going to blue of black oxide after blasting

 

[High Binder]

Re: Blasting media questions

I would go with glass but even with glass beads you can still wear down the markings. Glass beads are fine enough to get into the really hard to get to seams so that may be good or bad.

Aluminum oxide is very hard and will give it a beating if not done carefully and fast.

 

[Silverbullet2]

Re: Blasting media questions

I blast with #5 glass beads, with a bit of Al Oxide mixed in. I run 45PSI, and with my set-up, has never wore any kind of marking down. Experiment a bit, JPG

 

[Sniperhandle]

Re: Blasting media questions

I use glass beads, it gives it a super smooth finish. and preserves all marks. I do not recommend it for use when using duracoat or other spray on finishes though, it does not give the coatings much to adhere to.

 

[gunnergirl81]

Re: Blasting media questions

Alox is better for parkerizing, it gives a nice surface for the reaction to bite into. Its easy to protect markings with careful application. In other words don't dwell over areas you don't want to wear. Degrease and thorougly clean the nooks and crannys and you won't have any issues with poor parker or white sludge buildup. Small delecate parts, and aluminum stuff we'll glass bead or go with LOW pressure. The problem with glass bead is that it degrades quick and loses its effectiveness. Other than that the only thing to consider is down the road use. After a lot of use on regular steel Alox will transfer material to stainless steel surfaces you blast and cause discoloration.

 

[RobfromME]

Re: Blasting media questions

Good morning,

Thanks for all the good info. Very helpful!

HighBinder, Sniperhandle - what size glass beads do you use?

stealth man - what size glass beads do you use? I'm planning on using 40 psi to start...to high? to low?

Kenda - what grit size Alox would you suggest? What pressure is low for your particular setup? Thanks for the GREAT info regarding the blasting of stainless after regular steel.

Thanks again to everyone for the comments so far. I appreciate it!

Warmest regards,
Rob

 

[CS223]

Re: Blasting media questions

If you have a pressure pot blasting cabinet, 40 PSI with 80-100 grit abrasive will do fine, throttle back the abrasive flow to give yourself more working time and to see what you're doing. I've done things like 1919 sights, even some electo-etched parts and there was no loss of detail. The coarser abrasive will give you more of a "sparkly" Parkerizing finish, finer abrasive more of a satin finish. I don't care for beads for Parkerizing prep.

If you have a siphon cabinet, then you might struggle at 40 PSI to get enough abrasive flow, siphon blasting will test your sanity. Get some scrap, use a vibratory engraver or scribe to make some marks and tweak & practice to dial in.

 

[gtaylor1023]

Re: Blasting media questions

120 grit atox is a great product - like mentioned above glass is great for a raw finish but Cerakoat has a tough time grabbin'

 

[RobfromME]

Re: Blasting media questions

Gentlemen,

Thanks again for all the great input! It has been very helpful. As I get my blasting cabinet put together, this info will be put to good use! (It was a cabinet from work they replaced and were going to throw out....probably cheaper to buy a new one, but what that hell).

Once again, I appreciate the help and input!

Warmest regards,
Rob