BYYB Forums

I am installing oarlocks on my boat and wonder if I should epoxy or caulk the wooden part of the assembly to the deck top or caulk and bolt it down?  The assembly consists of a 4" diameter, 1" thick, circular block of mahogany wood with a hole in the middle to receive a top mount rowlock socket.  There is a matching hole in the deck as the top mount rowlock socket column is longer then the thickness of the wooden part.  Also the shaft on the round oarlock is longer then the top mount rowlock socket column so a matching hole through the deck was a necessity.  The top mount rowlock socket is held in place by two "10 screws or bolts.  I got the idea of drilling the holes for those bolts through the mahogany block and deck so I could bolt the top mount rowlock socket in place rather then just screwing it down to the wooden block.

The plans called for a piece of 2/4, attached to the inside of the boat side, to stick up through the deck and so raise the oarlocks above the deck and rubrail.  I didn't care for the look or cutting the deck and stringer to fit the 2/4 so I went with the mahogany wooden block to raise the oarlock and reinfocrce the deck. My idea was to epoxy the wooden blocks in place then bolt down the top mount rowlock sockets.  After dry fitting them I began to wonder if using one of the marine adhesive sealants, like Sikaflex 291, might not be a better idea?  The advantages to using an adhesive sealant would be if I wanted to change the setup in the future and didn't want to have to sand off the epoxy used to glue the disks in place.  My concern is will the adhesive sealant and bolts be strong enough to hold the assembly?

Oar locks take a great deal of strain, especially with a boat shaped like a Weekender. Technically, through bolts should be strong enough, but reality suggests that these will loosen in time and moisture will get into places you'd rather it not gain a foot hold.

Test your oar lock location a few times. Find the comfortable place for them to live then epoxy the crap out of them. That's what I would do, but as I said, technically through bolts should be enough.

The last our locks I installed on a fairly heavy boat had 2 5/8" of solid wood (including the decking) which the lock was inserted into. The reinforcement block on top was 3/4" thick by 12" long mahogany, over a 1/4" deck which had a laminate of 1 by Douglas fir stock (2x) under the deck, also about a foot long. The lock flange was through bolted with 1/4" machine screws and the lock shank was bonded with thickened epoxy, so it fit the shank hole precisely. It wasn't bonded down, but received a 3M-101 bedding. I figured the fit was so good and the bolt more then strong enough that actually gluing it in place wasn't necessary.

No, adhesive/sealant isn't strong enough to hold a lock (not even 3M-5200), the fasteners must do their job or it must be bonded. The real key is enough support under the locks so they don't distort the deck as you use them. The lock supports I roughly described above were used to lift the boat (they were at the balance point during the roll over) when I painted the bottom of the boat and again when I hoisted it onto a trailer. This is how strong the general area needs to be.

Thanks for the great info Paul.  This is on my Triad, not a Weekender, so only a 250 pound, 12 foot boat.    The 4" cicular mahogany wood pieces, on top of the deck, were to provide a bit of support as well as the 1" height but your comments on supporting the deck now have me concerned.  The holes through the deck for the rowlock socket column and 2 bolts cut into the stringers that connecet the deck and sides.  I think I will add a short piece of 1x2 along the underside of the deck up against the those stringers.  A 4" piece would match the circular wood on top but there is nothing preventing me form making it longer then 4".  It will be under the deck edge out of the way.  Do you think it should be more then a 1x2 or longer then 4"?  With some epoxy and wood flour it would become part of that top stringer and the bolts holding the oarlocks would secure through it?

Make the 1x2 considerably loner then a few inches. The longer it is, the more it will spread out the twisting loads imposed by the locks in use. My under deck reinforcements were 12" long and made from 2 pieces of 1x4 (by 12" long) that were both glued and screwed to the underside of the side deck.

The piece on top of the deck is just to lift the lock up, so the oars don't bang into stuff, like comings, toe rails, cleats, etc. during the stroke.