From: none@none.com99   
      
   On 2/17/2026 8:52 PM, Snag wrote:   
   >    I'm going to try my hand at brazing new carbide on some chipped and   
   > worn boring bars for my mill . I have 3 choices for heat source , O/A ,   
   > TIG , or my induction heater . I also have a couple of choices for braze   
   > filler , phosphor bronze TIG filler , regular brazing rod , and silver   
   > solder if I can find mine . I also have some brass wire , composition   
   > unknown and a few sticks of silphos , though I don't know if that will   
   > stick to steel . I also have both borax and regular brazing flux .   
   >   
   >   The plan is to heat and remove the old/broken insert , apply flux and   
   > a thin piece of brazing filler topped with a new carbide piece , and   
   > heat to brazing temp . After watching a couple of youtube videos it   
   > looks like I may need to hold the new carbide in place as it heats/   
   > cools , I'll probably use a piece of SS TIG filler for that .   
   >   
   >    I just realized that I can replace the carbide teeth on the face mill   
   > that came with my milling machine . I tried to sharpen the cutters on   
   > the lathe , turned out less than optimum . If I do that I'll use the   
   > indexing device I built for sharpening end mills to sharpen them . Might   
   > try that to even them up , might turn out I don't need to replace them   
   > right away .   
   >   
   >   Thoughts on heat source and filler selections ?   
      
      
   A quick read tells me silver solder 45% silver or higher is considered   
   "best".   
      
   Silfos (typically 15) is for copper to copper or copper to bronze.  I   
   have a couple pieces I used for soldering copper tube on an AC unit.   
   Silfos is nice for copper as it is supposed to be self fluxing, making   
   out of position work easier in theory.  In reality I only got good   
   joints on the bench.   
      
   Brass can work, but it doesn't stick to the carbide as well as silver.   
      
   I have a small section of 45% silver solder around somewhere and I can   
   tell you it was expensive.  I bought it at the a local welding store,   
   the better one, that doesn't usually gouge me.  It was NOT good enough   
   for repairing band saw blades.  But there should be no flex in your   
   carbide to steel connection.  If you want it you know how to reach me,   
   to remind me of your address.  (If I can find it.)   
      
   There are light fluxes and dark fluxes, and I think those with boron   
   (black brazing flux) is best, but borax might be a poor man's   
   alternative.  They use borax at forging temperatures afterall, (and for   
   some heat treating operations) so it probably won't burn off.   
      
   Some I recalled, some I got from an old This Old Tony Video, and some I   
   double checked using Goggle's AI search function.   
      
      
      
   --   
   Bob La Londe   
   CNC Molds N Stuff   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)