Armory Sponsor
Posted: 3/26/2014 5:55:56 AM EDT
| Hi, I have a rifle in which I cut the barrel & recrowned the muzzle. I want to sweat (solder) a ramp type front sight on it. I know I have to tin the sight & remove the bluing from the barrel were the sight will be sweated on. My question is, after I clamp the sight to the barrel & heat them, will the heat & flame from the torch damage the bluing on the surrounding area of the sight on the barrel? Thank you in advance. |
|
If you use soft solder, the temperature needed to melt and flow the solder is lower then the temps needed to damage the bluing.
Even the 3% silver bearing soft solder melts and flows at 450 degrees or less and won't harm the blue if you're careful not to overheat the metal. Evenly heat both the barrel and the sight. This helps prevent over heating. Where the problem is, is the flux. It tends to bubble out of the joint onto the bluing, which instantly strips the blue where the acid contacts it. You can limit that by using only the least amount of flux you can. A good way of doing that is to tin the sight base itself. Remove the bluing from the bottom of the base, apply solder and flux and heat until it melts. While it's liquid use a cheap pocket size screwdriver to "massage" the solder onto the base area, then allow to cool on it's own. Depending on the fit of the sight to the barrel, if possible you want to leave a thin border of bluing around the edges of the sight. This helps prevent solder from showing. Use a small file to carefully remove the bluing from the barrel. What you want to do is use a very sharp pencil to draw around the sight on the barrel, then remove the bluing by staying inside the pencil outline. This prevents having bare metal showing around the sight base. Use cleaners and solvents to throughly clean the bare area on the barrel, dry, then apply only the thinnest coating of flux, staying on the bare area inside the outline. Clamp the sight on the barrel and heat just until the solder melts, then allow to cool on it's own. After it's cool, use hot soapy water and a toothbrush to scrub the entire barrel and sight area to remove the flux. Hopefully only a small amount of bluing will have been damaged. After cleaning, you can use cold blue, or possibly even better, some paint to touch up any bare spots. Note that cold blue tends do stain or damage the original blue, so paint may be a better option, and paint wont promote rust like cold blue can. |
Armory Sponsor