U-bolt fitting - bedding threads in epoxy

[elhix]

My plans include u-bolts for a bridle at the bows. They have their threads embedded in epoxy in a hardwood block that is in turn behind several layers of glass. I have added a similar feature to the two sterns for a drogue bridle.

My question is: does embedding u-bolt threads is epoxy provide the strength necessary?

[jehardiman]

Get a copy of "The Gougeon Brothers on Boat Construction" book. It has an extensive discussion of how to design an epoxy only fitting like that: required hole size, hole depth, strength, etc.

[Petros]

IF the joint was designed and built properly it should hold up just fine. If there is some reason to think this joint will fail? Is there a history of this joint failing? OR are you not confident you can built it properly?

It can also be more durable than a bolted joint, where it can trap moisture and allow rot in a place that is hard to inspect.

[elhix]

I've no reason to believe the joint as described on the plans will fail and certainly feel happy to build it, I was just looking for opinion on this type of fitting rather than the usual bolts and backing plates.

Jehardiman, I should have bought the Gougeons book back in the beginning... I'm reluctant to now as it'll only tell me what I could have done better. Going to have a look on amazon though.

[lewisboats]

I would certainly not consider the threads in epoxy to have the same strength as a backing plate...but the fact that you are only using this system for the bridle ends...you should be able to get away with it for a long time. The fastening is stronger than the rope and the rope will absorb shocks in the system so you should be ok.