This may be an old topic, but wanted to share some recent success. I've been looking for a way to repair cracked or broken cast iron or other iron parts. I'm not a welder, so Silver Solder seemed the way to go. I repaired a cracked burner on a Coleman 457 and you can see the results of fettling the pressure guage on a separate post. For delicate work, a butane pencil torch works fine. For larger parts, try a propane torch or MAPP Gas rig. I've not had to go to MAPP Gas yet. Can't say it enough - its the flux. 45% silver has a higher melt point than 56%. This can be used to your advantage when soldering adjacent parts. Use the 45% first and it won't melt when using the 56%. You can also buy a heat absorbing paste that will prevent heat migration. The 56% has enough elongation (stretch) to accomodate the expansion and contraction of cast iron. Clean to bright metal, apply flux, preheat the part to 350 F and then heat the area of repair to dull cherry red. Apply the solder and be amazed. The key is the flux. I've tried many, but the one that works best is Hi Temp flux from Vulcan's Workshop on eBay. http://stores.ebay.com/Vulcans-Workshop. He's got a kit that has 45% and 56% wire and flux. The common white flux will not work. You might also try jeweler's supply houses. Its difficult to find someone to sell the small quantities you need. Well, back to the shop. Hope this is of interest. Cheers, Bud
I would think it's because the higher temperatures involved require more complex oxygen supplied equipment and the related much higher cost. Gerry
If you mean using a brazing rod/torch - brazing brass is a really delicate game, the filler rod melts at the same temperature that the stove would.....
