SHINY ON THE OUTSIDE RUSTY ON THE INSIDE
If rust is hidden - is it really there?
By James Nicholas
Just because you can't see it, does not mean it's not there. A customer called and said he put together an AR-15 a couple of months ago and wanted to refinish the barrel. He wanted something more tactical and the stainless steel barrel did not match his style. Well this gun had been wet and did not have any type of oil to protect the barrel. The stainless steel "was not supposed to rust" so no one bothered to take even basic measures to clean, protect or dry the rifle.
I started to disassemble the upper, and locked it in the vice to remove the barrel nut. As I started to unscrew the barrel nut I could hear a powder grinding sound almost as if sand was in the nut rubbing against the barrel.
After getting the barrel nut off, you can see what I was left with. A nice new stainless steel barrel that was only a month old and it was rusty. When I rubbed my finger in the rust it was moist and had a mildew smell to it. This rifle had to have been dropped in some kind of Alabama swamp water and not fully cleaned up afterwards. This water sat in-between the barrel and barrel nut and in a month had rusted enough to already show pitting. The Upper and barrel nut were fine since they are aluminum but the stainless steel is rust resistant not rust proof.
First step in this restoration was to hit it with some steel wool and oil. All of the loose stuff came off but as you can see around the indexing ring it is caked on good.
Step two is to kill and remove the rust. I put the barrel in my large blast cabinet and hit it at 90psi with 80 grit aluminum oxide. As you can see above a couple minutes abrasive blasting cut right through the rust down to fresh raw metal. The little black looking specks is the pitting in the metal. once the metal is pitted and gone it is hard to put back. Imagine the damage in a couple more months.
After abrasive blasting the whole barrel and chemically degreasing it It was off to spray it in KG Gunkote. KG Gunkote is a protective coating that will protect metal against rust. KG is not a miracle cure and you will still have to do maintenance on your firearms. But it makes it a heck of lot easier to do so. If you look real close you can still see the pitting, KG will not get rid of that, but now the whole thing is sealed and protected.
Gunsmithing Trick Above is a barrel from another project. So how do you abrasive blast a barrel without ruining the chamber and inside of the barrel? Easy Use play-dough and stuff the barrel. It is soft and can easily be packed in to protect areas you do not want to blast. You can also use the is technique to refinish scopes as well. Use a napkin to protect the glass and then pack in the soft clay making it even with the bell housing. Spray or blast away. When the play-dough is soft it can be picked out, or if you let it dry out it will be hard and shrink, easily removed.
Above our like new blasted barrel ready for refinishing and reassembly. Rust is like a living organism that will eat, spread and destroy what ever it can. Simply oiling and cleaning the barrel would have prevented this. Even if you do not have the tools to remove the barrel WD-40 is made for this exact purpose to displace water. If your rifle takes a swim dry it off as best you can, then spray the gun down in all the nooks and crannies to remove the water. Then blast it with air to get rid of the excess WD-40. Now oil and clean as normal. Remember just because you can not see the rust, does not mean it is not hiding slowly eating your gun away.