Originally Posted by daddybland
How much, if any gap is acceptable? I checked with feeler rods and couldn't find any gaps larger than .3mm. Is that to much?
Depends on what your are going for...
Look at these miters. And the joints probably didn't break. http://wjc.fidean.net/log/2008/09/01...t-tube-miters/
I saw Bernie Mikkelson at a frame builders show a few years ago displaying some bad lug work. There was a joint he pulled apart from an old Sears frame, where there was no miter at all. The ends of the tube had been bashed in with a hammer, shoved into a lug and brazed together. And the joint held up.
I have an old Raleigh Record frame lying around, and if you look into the BB shell you can see none of the tubes were mitered at all. Stays, ST, DT-- all straight cuts. The ST and DT were just jammed together in the shell, no cuts.
I'm not suggesting you start mitering with a hammer, but if the miters on your first frame turn out to be slightly off, don't lose sleep over it. Assuming you braze them well, you'll be fine, and you can work to improve the miters on future frames.