Re:
OK, next installment..
A wet Easter Sunday, but the replacement tube has arrived.
Run it through the 'butt checker'
to check the butts. These alu tubes are generally pretty good, but the steel ones can sometimes vary by 0.2mm on the thickness and up to 50mm on position :roll:, so it's always best to check them. Also makes sure you know one end from the other
Tube marked up:
Finish prep of frame:
Remains of welds filed back to original tube surfaces. Cleaned out dirt from inside tubes, stainless brushed and de-greased (Acetone):
Thick butt end of tube straight cut to 61.5 degrees:
Seat end cut to length and clamp collar welded on:
Whole frame held on welding table. Frame centreline set at horizontal plane 100mm above table:
Head tube held horizontally:
Vertical dummy axle in dropouts:
Top tube and wishbone held at 100mm OD in V-blocks:
Tack, flip, check alignment and finish welds. Mirror image sequence on L& R sides, finishing at least stressed point where possible. BB end:
Seat end:
Rough file any weld penetration in the seat tube, ream back to round with 28.6mm spiral flute reamer, then steadily out to 29.4mm with an adjustable reamer:
I'll cut off any remaining cable fittings (as requested), re-tap and face the BB, ready to go.
I'm not going to post-repair heat treat this, as Paces are so renowned for cracking, I'm keen not to over treat the existing welds, making them even more brittle. I welded with 5183 filler, rather than the 5356 Pace probably used. This has slightly better resistance to hot cracking at the weld finishes and a better strength in the post-welded (but un-treated) state. Also by upping the wall thickness by the BB from 1.3mm to 2.2mm, and keeping softer wetted edges to the weld pool, I think there should be plenty of strength there.
All the best,