Fillet Brazing Stainless Steel
12-13-16, 07:24 AM
#26
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I ordered a KVA stainless frame from a fairly well known builder who does NOT do lugged stainless. I wanted a non painted frame for ease of maintenance. I was floored when he sent some pictures last week - the frame is fillet brazed rather than Tig welded. I was under the assumption that you were not supposed to fillet braze Stainless. I am not at all happy with how it looks. His reply is that he finds it distorts the tubing less with brazing than with Tig welding. I never asked if it would be Tig welded I thought that was the only option if it was not lugged.
Opinions please, is this an acceptable joining method?
Jeff
Opinions please, is this an acceptable joining method?
Jeff
12-13-16, 11:31 AM
#27
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What you say is true for the Reynolds 921 material, as far as I know.
12-13-16, 11:33 PM
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huh, is that an argument from authority? I have considered getting my PE, what specialty would know this? Structural engineering? Do you have a source you can cite, because I would like to look it up?
I would assume that the tubing manufacturers know pretty well about their material, and they definitely know that we are using silver on their stainless tubes. Someone was selling 921 on ebay recently, and I considered buying it. Reynolds mentions silver brazing as a possible joining method for 921.
On edit: it looks like it would be a concern with a stressed tube during brazing. So it's important not to over-fixture a frame. I am not sure how the heat treat of these tubes leave the internal stress state of the tubing. That could also be a potential problem. But you can't make the blanket statement that these are incompatible processes. By that logic, the long standing successful brazing of steel tubes with LFB should cause LME due to the copper in the LFB
I would assume that the tubing manufacturers know pretty well about their material, and they definitely know that we are using silver on their stainless tubes. Someone was selling 921 on ebay recently, and I considered buying it. Reynolds mentions silver brazing as a possible joining method for 921.
On edit: it looks like it would be a concern with a stressed tube during brazing. So it's important not to over-fixture a frame. I am not sure how the heat treat of these tubes leave the internal stress state of the tubing. That could also be a potential problem. But you can't make the blanket statement that these are incompatible processes. By that logic, the long standing successful brazing of steel tubes with LFB should cause LME due to the copper in the LFB
Last edited by unterhausen; 12-13-16 at 11:42 PM.
