sabre1fv
Plastic
- Joined
- Nov 19, 2013
- Location
- Cupertino, CA
I need to Silver braze some mild steel blocks (like a sleeve) to a 5/8" diameter mild steel shaft; the blocks are not much bigger than the 5/8 shaft and do not have much mass; radial clearance is .001 to .002". The blocks are 1.5" long and I have added a 1/4" hole through two sides to aid in the braze flow and provide an area for adding the braze material in the middle of the block. First attempt failed because I overheated the flux (turned black) - I was using a #4 tip on a oxy/acet welding torch with a slight carburizing flame. I thought about using the rosebud tip, but thought that would be overkill. To me, the big problem seems to be heating up the 5/8 bar without overheating the flux. I did start with clean, well fluxed metal on both parts.
I have machined off the first block (did get some flow of the braze material) and now have about .003 to .004" radial gap, and sanded off the burnt flux. The flux I have is Harris Stay-Silv and I am using Silvaloy A45 brazing alloy. I need maximum surface area adhesion between the bar and blocks so TIG welding or TIG brazing won't work for strength reasons.
I did check several pages of posts under Silver brazing and didn't see any other similar posts.
Thank you in advance for any tips or suggestions you can provide.
-Jim
I have machined off the first block (did get some flow of the braze material) and now have about .003 to .004" radial gap, and sanded off the burnt flux. The flux I have is Harris Stay-Silv and I am using Silvaloy A45 brazing alloy. I need maximum surface area adhesion between the bar and blocks so TIG welding or TIG brazing won't work for strength reasons.
I did check several pages of posts under Silver brazing and didn't see any other similar posts.
Thank you in advance for any tips or suggestions you can provide.
-Jim
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