screws through the deck - epoxy, sealant or nothing

I have just added decklines, pad eyes, rudder mount and hatch straps to my sport tandem.  I didn't bother with any glue, epoxy or sealant on the screws.  I am thinking of removing the screws and coating the threads in unthickened epoxy.  Is this either necessary or worthwhile from a strength or sealing point of view?


 Mick Moore

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RE: screws through the deck - epoxy, sealant or nothing

Unsealed screws have the potential to let in water, depending on how tight the screw fit is and how the boat is used. If it rarely gets wet and is stored dry, you can go years without seeing a problem. However, once you do see a problem, the fixes are usually very visible. Not such a big deal on painted boats, but potentially serious for varnished ones. Either the wood turns black from water exposure or it develops a spot of actual rot which must be cut away and repaired. So prevention can be worth it.

The best prevention is the drill-fill-drill method described in the Tips for Boatbuilders. This puts a permanent layer of thickened epoxy between the screw and the wood. A silicone sealant is 2nd best because there's no way to guarantee that every bit of the wood has sufficient sealant over it. On the other hand, as long as the entrance to the hole is completely sealed, no water will get in and you don't need complete internal coverage. So as a practical matter , both work just fine.

Brushing epoxy on the screw has the same limitations as using silicone sealant, but with the added complication that instead of a flexible coat of sealant you end up with a more brittle layer of epoxy. If anything "pops" the screw, the barrier could break and let water in. But, it's better than nothing and will probably last as long as you need it to. Which is typically until you need to remove the screws to refinish the hull to get rid of all the scratches you've accumulated since the last time.

Have fun,




RE: screws through the deck - epoxy, sealant or nothing

Laszlo offers some good advise. Additionally, remember that you may want to remove this rigging at some time to refinish your boat. 3M 4200 sealant is a product made speificlly for this purpose. SEEYA Jack

RE: screws through the deck - epoxy, sealant or nothing

Thanks guys.  I don't think that there should be too much pressure on the screws so I think that I'll try the epoxy method. 

 Thanks again,


RE: screws through the deck - epoxy, sealant or nothing

Mike, the epoxy drill fill drill method is very good however remember that any throught bolts need to be beded in 4200 or they can leak. Probably not a problem in a kayak but a reality none the less.   SEEYA Jack

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