Screwing a deck

[tidclacy]

My deck is balsa-wood sandwich ( Jeaneau Sun Odyssey 32.2 ). I want to attach a restraining harness for my liferaft on the forward deck. Never having dared to drill or screw anything on to a deck before how do I go about it. What screws to use etc.

 

[30boat]

My deck is balsa-wood sandwich ( Jeaneau Sun Odyssey 32.2 ). I want to attach a restraining harness for my liferaft on the forward deck. Never having dared to drill or screw anything on to a deck before how do I go about it. What screws to use etc.

Screwing won't be strong enough.You'll have to through bolt and fit large washers or backing pads.In order to ensure the balsa wood doesnt get wet the core around the hole can be removed and replaced with epoxy resin.Or just use plenty of good quality sealant .I have four U bolts on deck for that purpose and it works well.

 

[prv]

Having spent weeks last winter replacing a deck core (fortunately only a small aft deck) that was saturated by inexpertly-drilled holes, I would disagree that "plenty of sealant" is enough to keep water out of cored decks. You absolutely need to isolate the core with resin, probably thickened epoxy.

There are plenty of guides online on how to do this, and I'm sure others will explain here as well.

EDIT: Here's a random online guide I just found: http://dan.pfeiffer.net/boat/hdwrinst.htm . A couple of his points seem to be extra frills not normally used - his modified allen-key "chisels" are traditionally replaced with a bent nail in a drill chuck, and I've not heard of tapping a thread into the epoxy before - you'd usually just drill a plain hole.

Pete

 

[LadyInBed]

Along with other advise, bolt through and I would also use a spacer tube through the hole to stop any deck compression.

 

[30boat]

Having spent weeks last winter replacing a deck core (fortunately only a small aft deck) that was saturated by inexpertly-drilled holes, I would disagree that "plenty of sealant" is enough to keep water out of cored decks. You absolutely need to isolate the core with resin, probably thickened epoxy.

There are plenty of guides online on how to do this, and I'm sure others will explain here as well.

EDIT: Here's a random online guide I just found: http://dan.pfeiffer.net/boat/hdwrinst.htm . A couple of his points seem to be extra frills not normally used - his modified allen-key "chisels" are traditionally replaced with a bent nail in a drill chuck, and I've not heard of tapping a thread into the epoxy before - you'd usually just drill a plain hole.

Pete

Epoxy resin is the only sure fire way of ensuring that water won't penetrate the core but modern sealants like CT1 adhere so well that the results will be essentially the same.Having said that I would use the resin system everytime.

 

[prv]

I would also use a spacer tube through the hole to stop any deck compression.

If you make the epoxy plug properly that will do the same job.

Pete