Re-Blueing at Home
I have an old Mossberg 500 that I'd like to refinish. I got the gun 20 years ago as a teenager, but it's been on loan to my cousin for the last 5. Unfortunately, he doesn't exactly treat my gun the way I would, so the finish is in rough shape. Good news is I don't see any pits, but the metal is almost shiny in places. Receiver is black, and I'm not sure about stripping and blueing, or just blueing the barrel. The question is, is this something I can do effectively at home? And if I do, should I go ahead and do the whole thing?
I have yet to see a home blueing job that looked good ( most looked really spotty).
You might find someone on the internet to do it but It would likely cost as much as a new shotgun.
The other alternative would be the baked on finishes but I don think you can get even an 18" barrel in most ovens so unless its rusting up I would just keep it well oiled and in a dry place
Completely refinishing a Mossberg 500 is going to be a challenge, as the barrel and magazine tube are steel, but the receiver is aluminum. For the steel parts, you can get a bottle of touch-up cold-blue solution at most well-stocked gun shops, or at Brownells:
(get the 8-ounce size to do an entire barrel and mag tube; you'll probably have some left over, but that's better than getting caught short)
Use the instructions in the second link, and you'll probably end up with decent results. For the receiver, there are touch-up "pens" (like a permanent marker, for fixing scratches) or acidic solutions used to re-darken aluminum (they are a bit harder to use than the steel blueing solutions), but they almost NEVER match the old aluminum finish, and durability can be weak, too, as exposed/scratched aluminum is soft (as metals go).
If I were you, I'd use a cold-blue solution to touch-up the barrel and magazine tube; and other than deep scratches or worn/dented edges (where I might use a touch-up "pen"), I'd probably just leave the receiver alone.
Blue jobs win or lose on the basis of the preparation.
Home blue jobs look bad because the preparation was bad.
You must first strive for a high-quality surface polish. It doesn't have to be shiny. Dull, with even and tiny scratches is just fine.
To do this, a smooth block of wood is your best friend. Wrap progressively finer and finer grades of emery paper or cloth around the wood, and polish in only one direction, the same direction on every part.
When you have polished with 150 grit, next maybe go to 200 or 300 grit, then you go to 400 grit. Each time you change grit, you need to polish at right angles (90°) to the previous grit's polishing. Then go to 600 grit, changing the direction of rubbing again. And so on, all the way down to crocus cloth, if you want a pretty-smooth polish.
Then get one of Brownells' cold blues, maybe Oxpho Blue, and follow the chemical's instructions to the letter.
When you pay a gunsmith to blue a gun, most of the money goes into the polishing job.
Do it yourself and save.
Likewise Birchwood/Casey has "Aluminum Black" which works on aluminum, a little harder to find, but it's out there, been using it on my 92's frame for years as a touch up.
Thanks for the information. It sounds like something I'd like to tackle. I've refinished several motorcycle components in the past, and while it is a different process, the core is the same. Prep time will be the biggest investment, and that's just fine with me. Just gives me an excuse to spend several hours out in the shop. When I get ready to start the project, I'll take some "before" pictures. Who knows? It may turn out great.
Heck, you already have some metalworking and refinishing experience, what sounds like a good attitude, and you seem willing to invest the time to do the prep work right (rushing/lack-of-patience is the downfall of many folks). Given all this, it's likely to turn out just fine, or at very least, far better than what it looks like right now.
Go for it!
Post some before and after pics, I'd like to see how it comes out. Make us all proud.