CedarGrove357
New member
I have read on intarwebs forums, university google, encyclopedia YouTube, etc. that opinions differ regarding plugging the barrel when rust blueing. So what is the truth? The training manuals I've read say the barrel should be plugged. From what I understand in synopsis, if done professionally, heated caustic acid is used to clean the barrel, then rinsed in hot water, then the salts are administered and the plugs are used to transport the barrel from tank to tank.
Considering the caustic nature of some cleaning solutions it would seem logical to me that the bore needs to be protected from the possibility of etching, pitting, etc. I also understand the potential for pressure to build inside the bore increasing the chance of a plug coming loose with catastrophic results. but if the bore is clean and dry before plugged, what would cause the pressure to build to such a degree as to blow a tightly fitted plug?
I have looked around for barrel plugs commercially made, but haven't found much at all. If I have to "roll my own", thats fine, but what material to use for the plug? Wood or cork has been suggested but then again, its stated to be porous and cork and nitric acid dont mix. Rubber is okay, but can swell if not resistant to caustic chemicals and heat. I would like to build the plugs where there's a screw through the plug, a fixed nut and washer on the inside and a washer and nut on the outside that I can use to compress the material to seal the bore.
One idea I had was using a diameter of threaded rod and creating a plug out of hi-temp silicone sealant with the nut and washer molded in the sealant, using cut shell casings for my mold.
What is the opinion of some of the long time smiths out there? Am I over thinking the problem? Yes, I am newbie smith myself. Thanks.
Considering the caustic nature of some cleaning solutions it would seem logical to me that the bore needs to be protected from the possibility of etching, pitting, etc. I also understand the potential for pressure to build inside the bore increasing the chance of a plug coming loose with catastrophic results. but if the bore is clean and dry before plugged, what would cause the pressure to build to such a degree as to blow a tightly fitted plug?
I have looked around for barrel plugs commercially made, but haven't found much at all. If I have to "roll my own", thats fine, but what material to use for the plug? Wood or cork has been suggested but then again, its stated to be porous and cork and nitric acid dont mix. Rubber is okay, but can swell if not resistant to caustic chemicals and heat. I would like to build the plugs where there's a screw through the plug, a fixed nut and washer on the inside and a washer and nut on the outside that I can use to compress the material to seal the bore.
One idea I had was using a diameter of threaded rod and creating a plug out of hi-temp silicone sealant with the nut and washer molded in the sealant, using cut shell casings for my mold.
What is the opinion of some of the long time smiths out there? Am I over thinking the problem? Yes, I am newbie smith myself. Thanks.