Originally Posted by
Canaboo
I'd be watching everything and going above and beyond any prep work they recommend... The bamboo shouldn't compress the balsa since the carbon/glass lug will lock the bamboo from moving into the balsa.
The lack of proper sealing of the bamboo in their method is a real concern to me.
If you want to seal any of the bamboo, make sure it's the inside of the seat tube. Water getting down in there and sitting on that balsa is a recipe for rot in a high stress area.
Not sure what glue is being recommended for tacking but do yourself a favor and use proper glue.
You may also run into clearance trouble depending on your front 'belt ring' size.
The video show them using JB Weld (5 min thickened epoxy) as the tacking glue. I'd prefer to use proper West System epoxy with a thickener. But it seems the tack up stuff isn't really supposed to hold loads after the carbon layup, correct?
One thing I noted they did not do which is definately not best practise in epoxy work...according to the Gugeon Brothers West System instructional guides, epoxy produces an amine compound during curing and this coats the surface as an "Amine Blush". You should never sand/file a freshly cured surface before removing this material...otherwise you just embed it into the sanded surface and it makes for a poor secondary bonding surface. Can lead to delamination of subsequent layers. The blush is water soluble so a damp rag or light spray & wipe will do.
What are people finishing their frames with if anything? I will ride in wet weather often. Like the idea of polyurethane but does it bond well enough to bamboo?