I recently scored a sweet deal on an all matching 1978 Romy RPK build. It was built on an NDS receiver which needs a final finish, it still has the blue-ish type stuff on there. The rifle is completely built, just need to finish the receiver.

The original finish on the parts kit is very nice, so I don't want to refinish any of the original parts, just want to finish the receiver to match as closely as posible. Don't want to pull the barrel as it is allready installed and headspaced.

So, I have been reading about Oxpho Blue and how it can closely replicate the black oxide type finish like that that is on my Romy.

So, my questions are:

1) What kind of blast media should I use to get a nice matte finish that will closely replicate the Romy finish?

2) Is Oxpho Blue the way to go for this project? From my research I have read that it can come out almost black or a deep charcoal gray (perfect) if the metal is heated and the surface is blasted with the proper media.

If there's anyone with similar experience I'm in need of some good advice! Thanks in advance for any help!!

I always start with walnut shells and work my way up when removing old finishes. That said, I think you'll end up getting the matte result you're asking for with a fine glass blasting media. Just remember that matte finishes need to be kept properly oiled, or they'll rust a bit easier than a smooth finish.

Believe it or not I use dry play sand in my closed cabinet sand blaster.
I'm very careful to keep the cabinet sealed & exhaust pulled through a filtered shop vac system.
But I get good results like this on my PSL.




It is not enough to heavily roughen the surface but leaves it open enough for a good cold blue job like this.



The trigger & selctor were not blued but match the color.

I do a different type of cold bluing using BIRCHWOOD CASEY Perma-Blue. After cleaning the receiver with alcohol I heat the receiver in a pot of boiling water. After a few minutes in the boiling water I take the receiver out of the water, put it in a heavy plastic zip-lock bag & pour in a full bottle of  Perma-Blue then seal & shake. It covers the receiver almost instantly. When I pull it out of the bag I'll check to see if it is dark enough, if it is not I put it back in the water to heat up again, then back to the bag for another shake.
When I get it dark enough I put it back in the water one last time heat it up, then put it in a clean zip-lock bag & spray a finishing spray of Remington's Rem-oil or any good gun oil. Seal the bag & keep it warm covered in oil for about 12 hrs.

Thanks for the replies guys. Paintballer, that is exactly what I'm going for, that finish on your PSL receiver is awesome!! Just ordered some Perma Blue, gonna play around on some test pieces and see how it comes out.

Thanks again for the advice!

Clean hot metal is the trick!
If you don't get it right blast it, & do it again.

you're an idiot.  Your shop vac is totally insufficient and beach sand dust is a deadly poison.  Might as well blast with asbestos fiber as it has the same effect on your lugs.

NEVER EVER EVER use beach sand in a closed system.

Aluminum oxide or garnet.  I prefer Al02 80#.  Garnet doesn't last as long and even though it is cheaper, I found the Al02 more cost effective in the long run.

Now if you want to blast outside in an open system (pressurized can) with a full respirator and hood, then I guess silica sand is ok.

Thanks for the heads up Mark, I have done a ton of reading about blast media this past week, and have read this over and over. I won't be using a silica based media. Even though I will be blasting outdoors, and have a respirator and goggles, it ain't worth it to me. I'll pick up some alum oxide or glass bead from my local blaster. This is my first blast job, and don't see myself doing any more than one or two a year, if that.

Again, I appreciate the help. Will post pics when I get it dialed in next week.

If you plan on using cold blue (which is really a poor-durability  finish but it is quick and easy) then glass bead is ideal.

For any type of phosphate finish, glass bead gives a poor result.  

Phosphate is a deposition and needs the surface of the metal abraded for good adhesion.

Bluing (and cold blue) is a conversion process, and the peening action of bead is ok for that.

[/quote]

Thanks for the heads up Mark, I have done a ton of reading about blast media this past week, and have read this over and over. I won't be using a silica based media. Even though I will be blasting outdoors, and have a respirator and goggles, it ain't worth it to me. I'll pick up some alum oxide or glass bead from my local blaster. This is my first blast job, and don't see myself doing any more than one or two a year, if that.
.[/quote]

SO I'm a IDIOT now because I read up on the safe exposure limits for industry & my small amount of blasting is far less than those limits. Yes if I was blasting 8 hours a day for a living I would be using a different blasting media. There are acceptable limits for using this blasting media just because you choose not to use it doesn't make me an IDIOT!

[/quote]SO I'm a IDIOT now because I read up on the safe exposure limits for industry & my small amount of blasting is far less than those limits. Yes if I was blasting 8 hours a day for a living I would be using a different blasting media. There are acceptable limits for using this blasting media just because you choose not to use it doesn't make me an IDIOT![/quote]

Yes, you are an idiot.  

Which of course, is your right.  

Others may choose to emulate you, or they may decide that dying from silicosis isn't worth saving a few bucks on a bag of sand.

Well, I picked up some Alum Oxide #80 and blasted the receiver, masked all the original parts, trunions, trigger guard etc, with aluminum foil tape, which held up well to the blast. I picked up a bottle of BC Perma Blue liquid, and a bottle of Oxphoblue cream, just to try them both and see what looked best. The Perma came out shitty, so I went with the Oxpho.

I cleaned the crap outa the bare steel with Simple Green, then a good rub down with denatured alcohol. Heated the receiver with a heat gun to around 200 F. Slathered the Oxpho on for about 10 minutes, working it around and reapplying. cleaned it off and oiled her up. Can't believe how good it came out!! I don't think I could've gotten a better match to the original kit finish. Looks awesome!!

Thanks you guys for the help and sugestions. Not bad for a first timer, huh?