Test 12: RTM a Practice Carbon Composite Bicycle Frame Tube Transition

Pressure test:
Composite RTM mold pressure test

Composite RTM mold pressure test closeup

Ready to wrap the bladder and core with dry carbon fabric.
Composite RTM mold parts ready for fabric





This looks like absolute shit.
RTM composite mold with bladder core wrapped in carbon fabric

Silicone added to seal the edges and preserve the desired resin flowpaths.
Composite RTM mold with silicone edge sealant

Assembled transfer mold ready for vacuum bagging.
RTM composite mold assembled ready for bagging

Vacuum applied, resin infused from cup, pressure applied to bladder.
Composite RTM setup

This actually worked well until about 10psi pressure into the condom. I tested the condom to 15psi and it held. But this was without a vacuum bag, and during the actual layup with 10-12psi of vacuum the actual pressure delta across the bladder was over 20psi and it popped. Plus there was a bunch of fibers poking at it. Condoms aren't that thick. Maybe I should have "triple bagged" it?

But the resin had infused completely across the mold interior before the rupture happened. And I sealed the bladder air supply tube to prevent the vacuum from sucking bubbles into the part.

Results in next post.

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