To all,

My friend went shooting with a Remington 870 Express Synthetic while it was snowing.  The case lining got wet and he didn't realize it - put it in the closet for a week, and now the entire shotgun is covered in surface rust.  I tried rubbing it down with Break Free CLP and some rags.  It removed some of the stuff on the top of the finish, but the rust has penetrated deeper.  

It is the bargain basement 870.  It's not blued, but its a sort of crackle finish.  Not sure exactly what it is, but it isin't particularly tough.  

What can be done to fix this?  Steel wool and brake cleaner?  I'd like to avoid refinishing it but I fear that using anything abrasive on the surface will necessitate it.

Thanks guys.

I've had good luck using 0000 steel wool and gun oil on blued guns, but I'm not sure how it would effect the finish on the 870 express.  I'd try it in a inconspicuous area first.  If the rust has left pits, refinishing may be in order.....

The finish is  standard gun blue applied over a bead blasted surface.
Steel wool and other abrasives will damage the finish.

Get a can of Kroil, although CLP Breakfree will do.

Liberally apply it to the rusty areas and let stand for a day or two.

After soaking for a few days, apply more, then give the rusty areas a scrubbing with a brass "toothbrush".
This will loosen the rust without removing the bluing.

Wipe off the dirty lube, then spray the entire gun, inside and out, dripping wet with CLP Breakfree in the aerosol can.  

Let stand 20 minutes to "soak" into the rough blued finish, then wipe off the excess.  
This will build up a layer of Teflon in the rough finish and will protect it from further rust, and will continue to loosen and remove any remaining rust.

When using CLP Breakfree, SHAKE THE DICKENS out of the can.  It settles and needs to be well mixed.

ive always used a really fine steel wool on my guns if they got any rust....works well and doesnt damage your gun.

I have the exact same shotgun but with the wood stock. It is a bead-blasted and blued finish.

Try the brass brush as mentioned above or some 0000 steel wool and a good oil. You may not get it all, and some of the inactive rust/discoloration may remain. If you want, you can degrease the area afterwards and put on some cold blue to hide the rust/removed blueing. With the bead-blasted finish, it should actually blend in pretty good. You can also buy a can of the spray on coating like Gun-Kote or Duracoat to refinish the shotgun.

Or you can take it to a local gunsmith and have them bead-blast it and give it a parkerized or black-oxide  finish. It will look just like new.

Try a small tube of Flitz, that stuff will work wonders.  It is not as abrasive as steel wool, plus it has some chemicals to prevent rusting.

Quoted: The finish is  standard gun blue applied over a bead blasted surface. Steel wool and other abrasives will damage the finish. Get a can of Kroil, although CLP Breakfree will do. Liberally apply it to the rusty areas and let stand for a day or two. After soaking for a few days, apply more, then give the rusty areas a scrubbing with a brass "toothbrush". This will loosen the rust without removing the bluing. Wipe off the dirty lube, then spray the entire gun, inside and out, dripping wet with CLP Breakfree in the aerosol can.   Let stand 20 minutes to "soak" into the rough blued finish, then wipe off the excess.   This will build up a layer of Teflon in the rough finish and will protect it from further rust, and will continue to loosen and remove any remaining rust. When using CLP Breakfree, SHAKE THE DICKENS out of the can.  It settles and needs to be well mixed.

Soaking in Kroil  and brass brushing is absolutely the way to go.

Quoted: The finish is  standard gun blue applied over a bead blasted surface. Steel wool and other abrasives will damage the finish. Get a can of Kroil, although CLP Breakfree will do. Liberally apply it to the rusty areas and let stand for a day or two. After soaking for a few days, apply more, then give the rusty areas a scrubbing with a brass "toothbrush". This will loosen the rust without removing the bluing. Wipe off the dirty lube, then spray the entire gun, inside and out, dripping wet with CLP Breakfree in the aerosol can.   Let stand 20 minutes to "soak" into the rough blued finish, then wipe off the excess.   This will build up a layer of Teflon in the rough finish and will protect it from further rust, and will continue to loosen and remove any remaining rust. When using CLP Breakfree, SHAKE THE DICKENS out of the can.  It settles and needs to be well mixed.

I was with ya ,till you said Breakfree in a can..
Bottle all the way
But good info either way.

Bead blast and re blue... That's the only way to be sure!!

Add me too the 0000 steel wool list, before I use the steel wool I put some gun oil on my finger and rub a lite coating on the area thats to get rubbed with the steel wool....Never tried it on an 870 though, might want to try a small area first.....

steel wool+cold blue

It's a GD 870 Express for Christs sake. Just tell him to clean off the rust and paint it if it bothers him so much.

http://www.theruststore.com/Abrasives-C7.aspx

rub it with a nickel.