doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Spots when rust blueing, any idea why?? With pic

I always seem to get a few spots like this whenever I rust blue barrels. This is after the first boiling. Usually by the time I am done they are nearly impossible to see, but sometimes I can spot them. Any idea what I may be doing wrong?
Thanks,
CHAZ

That's junk (oily/greasy water) seeping back out from between the ribs & bbls after you pull them from the water.
The void fills with boiling water and mixes with any old oil, solder flux, ect in there and comes back out the way it got in.

Very tough to get that cleaned out w/o a hole for the water to get in and out fast.
Bet those bbls ring like a church bell too.

A tiny hole in the bottom rib just ahead of the forend lug is a start. Sometimes back further by the flats. That one will get covered by the ejector stems in alot of cases when assembled.

You really need another at the muzzle end to get the water to move out quickly when you pull it out of the tank.

Sometimes the front bead hole will lead to the void. If not, sometimes you can drill a tiny hole through the solder that's in between the muzzles and into the void. Carefull you don't drill into a piece of steel filler in there.

Sometimes I just go ahead and melt the solder at the muzzle and shake it out to clear the end. Then solder it back up when done.

Much better and easier than chasing oily water spots around the tubes every pass and hoping the next coat will cover them, cause it won't.

Copper residue in the mix. What are you using as the rusting component? What process did you use to strike up the barrels and get them ready for the process? What solution?

Cheers
T

As Kutter has stated, there was some contamination possibly between the ribs. You didn't mention what type of rusting agent you were using and that would help. I use Laurel Mountain Forge's Browning Solution. It has it's own cleaner mixed in and for me has worked great. I use distilled water for my rustings and also in my etchings.

Most barrels do have some voids between the bottom rib, to check on this I use a .001-,002 feeler gage and go along the bottom rib to check. Sometimes it pays to boil first to get the contaiminants out, then clean thoroughly or in my case just start the rusting with the LMF rusting agent.

Do you pre-clean with acetone before boiling....?....Including inside the weep holes with a syringe liberally and slosh......?.....

I always boil first in a very clean tank with very clean water and check for contamination....and then double check again and make sure that all the weep holes are open and flowing.......always.......

I am using Laurel Mountain, and boiling in distilled water. Now that someone mentioned weeping from between the barrels it makes sense. After I had carded off the barrels I used compressed air to dry them off and when the air hit the weep hole water escaped from between the barrels.

So a good boiling before the first rusting would help this situation? I have not flooded the weep hole with cleaning fluid before either, I will do that as well.

Thanks,
CHAZ

Hoof, instead of compressed air, use a propane torch and run it up and down the barrels to dry them, only warm to the touch and not hot. Plus this will get the moisture out between the ribs. I do this with the barrels standing up and naturally the weep hole is at the bottom.
On some of the older "elsies", take the screw out on the short extension piece between the loop and water table to dry them.

Watch barrels for the next few hours for any residue that comes out of the hole and goes on the metal, wipe it off before it stains the barrels.

Chaz:

I don't use compressed air anywhere near the barrels, weep holes etc...I let them air dry (I live in a dry climate) then lubricate well with EEZOX when finished, including in the weep holes with a syringe....

Be very careful with compressed air around weep holes, you could blow the ribs loose IMO.......or degrade-destroy already weak areas in the solder joints on vintage barrels.......

Get them as clean inside the ribs as possible before the bluing. Otherwise the crud will just appear during the process as shown in the pic and spoil everything.

A trip through the tank with any agitation possible thru what-ever weep-holes/drain holes you can get is best.

Even then as you pull the bbls from the water and in your first coating when you pull them from the water, note if anything including clean water seeps from the ribs anywhere.

At this point, all you want to do is avoid letting it do that. You can by tipping the barrels one way or the other to dump the water inside the ribs towards the end that they will drain out the easiest and quickest.
Trapped in the slow draining end, it builds up for an instant and then decides to leak out those pin hole spots in the rib solder job.

Those small holes are very common dispite the claims otherwise. In over 40yrs of doing this, I can't think of more than a few bbls that didn't have at least a tiny break in the solder joint somewhere. Try and work around them.
The large exit at the muzzle by way of the solder removed works great.

I learned that when I did mostly hot-rust bluing and you had to work fast.

I still dry them out with a propane torch. BBls stuck onto a wooden peg pointed muzzle upwards and slightly forward in a bench vise.
Gently heat the tubes and the breech especially till steam starts to emit from the lower weep hole.
Then you may get a few spurts of hot water, so a paper towel is at the ready to catch it and wipe it from the metal.

A rag with some clean hot water from the tank is usefull for wiping over those spots to clear any spotting from residue that may exist yet in the water from inside the ribs.

At this point it hopefully dribbles down the extractor stem hole and away but you have to watch it doesn't splatter and spot the flats or bbls.

When no more steam is showing,,you may still be getting some smoke. Give it the sniff test.
Don't over heat and ruin the solder joints. The water will evaporate at just over 200F. No real need to get above that very much.
If the tubes start to creak like a ship hull under stress,,back off. You're way over what's needed to dry them.

If you do find a spot in the blue during the bluing process such as caused by one of these leakers,,you can remove it with scotch-brite. I use a maroon colored pad,,sometimes gray to polish it out and blend into the rest of the area.

It will of course leave a steel grey area where the damaged blue came off. But the next coat will generally bring you right back even with the rest as the pores of the steel are allready filled.
No need to scrap the entire job and repolish generally. At least give it a try.

Throw that small square of scotch-brite in the trash as it has the contaminants on it that caused the problem in the first place. If you leave it lying around, chances are you'll grab it again in a moment of polishing need and ruin another job while trying to save it..

I've never used compressed air for anything in the shop,,just never had the hook up.
Some systems allow oil from the compressor into the air line, filters or not.
Something you very much can do without around rust bluing.

It's not uncommon for there to be rosin flux between the ribs/barrels. Find a solvent that will disolve that and use it to flush. Acetone seemed to work by my memory.