Friday, May 8, 2009

A good workout and TMI (for most people anyway)

Great workout with John and Kat the morning-- 30 second intervals with 30 seconds of rest. Wow do they make you feel anaerobic! I was glad to be doing this around others people or it would have been difficult to maintain the intensity

Thursday's Data

This next part casued me to stay up way too late and was interesting enough for me to stay up even later writing this account.

OK, now I have the jig, and the foam core, so it is time to get to work on the details of laminating the composite. I etched the aluminum parts before bonding them with epoxy. I used West System 860, it is a two part etch that you paint on and them wash off, easy enough!




I understand that if the carbon fiber touches the metal parts directly it will make a battery of sorts and that will cause galvanic corrosion (not sure exactly what that is) BUT I put a piece of 4oz S-cloth around the bottom bracket shell and the head tube to provide a little fiberglass insulation. I plan to do the same for the rear drop outs.




I filled the void between the foam and the bottom Bracket shell and the head tube with micro balloons mixed with expoxy.










A couple of years ago I was looking for some carbon fiber at US Composite's website, and everything, I mean everything was out of stock and not available on account of the world wide shortage of carbon fiber cloth-- Except for some really heavy 18oz cloth. I bought a couple yards and then really had no use for it, until now anyway. I used 2 peices to go around the back (inside) of the bottom bracket shell and the head tube, so it wrapped around the metal parts and then left a tab to attach to when I laminate the rest of the CF.

Then I temporary taped down the CF cloth down against the foam core.








I let the epoxy cure around the Bottom bracket for 4 hours. When I took the tape off I discovered that The foam had shifted to one side. I was worried about this at the time because everything ended up under plastic and tape. I thought about how I might loosen the nicely etched and bonded metal from the composite. I thought out how big of a problem would it be if the BB stuck out 1/8 inch more on one side than the other. Then I realized I could cut the foam around the whole assemble and shift it back into postion and then re-epoxy it in place, and re-fair the foam-- that is what I did.


I repeated the same process with the head tube.

1 comment:

  1. This is just fascinating. Keeep up the reports.
    I really like the workout graphics too.
    See you in Finchford tomorrow.
    John

    ReplyDelete