doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Hot bluing and solder joints

We know that the salts from a hot blue bath will attack rib joints and many of us have seen the results. But, a thought occurred to me ........ is it a given that there will always be hidden damage from an old hot blue? As I understand it there must be a pit, void, or some entryway into the area underneath the rib(s) for the salts to enter and remain after the bluing job. But, are there always pinholes or other places where the solder isn't sound?

I would think that, in the absence of weep holes, which all doubles don't have, a good, sound solder job could keep all the bluing solution outside. Hoping someone who has done a lot of barrel work on old doubles would comment.

Thanks, SRH

The hot blue chemicals start the breakdown of the solder inside or out. It may take longer if it's only on the exterior, but it will fail. I saw a set of Perazzi barrels that a guy bought cheap because they were coming apart from a hot blue. Pretty sure those barrels were tight to start with.

Silver solder & braze are completely unaffected by hot bluing. Most all modern production sxs�s & o/u�s barrels are hot blued. There are of course exceptions.

Soft solder is definitely affected by the bluing solution, but it�s probably more affected by the heat that is applied during the process that starts to break down the joint.

If ribs are properly laid.....there should absolutely be no need for weep holes, etc. weep holes are a good sign of a low grade soldering job where the manufacturer was worried about production vs quality. I�ve had to have a few ribs relaid over the years, the worst jobs were on my American guns.

Thanks Mark and Dustin. So, once the breakdown begins, even on the outside, there is no stopping it? Hard for me to imagine, but I defer to experience.

SRH

Hot blue salts affect the lead in the solder joint. Lead-Free solders can be safely hot blued if they have as low or even a bit lower melt temp than the tin/lead solder. It's not the temperature that does them in.

So, can I rightly assume from this that there is no stopping the degradation of the lead solder joints once hot bluing has entered the picture? Rust can be halted, saltwater oxidation on aluminum can be halted, but a hot blued gun with soft soldered ribs is a "walking dead man", either sooner or later?

I don't want to sound argumentative. I just want to determine the facts.

SRH

That is a fact. The only thing you really cannot determine is when the rib will pop. Could be almost immediately, could be 5 or 10 years down the line.

Thanks for everyone's input. Good information.

SRH

However, Lynx line hot blue salts used to add cyanide eggs to the salts when you use them to blue doubles. They said then it won't attack the solder. but the use of the cyanide was VERY deadly (use GOOD ventilation!!!!!)

Were gunsmiths all so ignorant that they weren't aware of "RULE #1"? I understand about PA trapshooters' gunsmiths, but ALL gunsmiths?