posted 04-15-2014 01:23 PM ET (US)        

One unusual aspect of this stern seat is the width. The arms or sides of the wraparound seat are not the full width of the cockpit at the gunwales. There are two teak wooden L-shaped inserts that act as wedges to fill the space between the sides of the seat and the gunwales. Without these wedges the seat would have a much greater tendency to rock back and forth on its tubular legs, which are fastened to the seat base in a manner that is mainly intended to resist vertical forces, not side to side forces.

To further constrain the seat moving side to side, the coaming board at the aft end of the cockpit has two holes drilled and two large (#12) wood screws fasten the seat back to the coaming board. These screws have a tendency to become bent or to shear off if there is a strong and quick movement of the seat back from side to side. Even with the wedges there can be some movement because the seat itself is not completely rigid, and a strong force can move it slightly.

Without the wedges in place at the sides and the seat back being fastened securely to the aft cockpit coaming board, the seat would be very unstable. The wedges have a tendency to work themselves loose over time by moving toward the stern; check them often to be certain they are in place. On my wedges some non-slip material has been applied to the side that abuts against the gunwale coaming. This material is similar to the sort of rubber material used to hold coolers in place or to line the bottom of shelves in kitchen cabinets. It helps to prevent the wedges from moving out of position.

The screw fasteners holding the seat back to the coaming board also tend to loosen. Check them regularly. Once they become a little loose they are prone to becoming sheared off or bent; they also tend to enlarge the holes.

This Spring I am refubishing the seat with some minor repairs. The plywood seat back bottom edge has become delaminated and some of the wood has splintered. I removed several dozen staples holding the upholstery to the wood--they came out very easily as the wood is weak in many places. Upon inspection I found that the seat back is fastened to the seat base by about four wood screws spaced across the width of the seat in the center area. The screws used were oval head wood screws. The screws were either driven deeply into the plywood, causing it to splinter and weaken, or, over time, the wood worked on the screws and broke up around them. All the areas on this plywood seat back edge that are weak are right around the original screw fasteners. The plywood in those areas has lost its bond among the layers and is weak.

Because I did not want to undertake a complete replacement of the seat back--I think it is one piece that has been artfully scored and bent to make the wraparound back--I am in the process of just repairing the damage to the wood around the original four screw fastener holes. I am filling the voids in the plywood with WEST System un-thickened epoxy resin, and, where possible, stuffing the original plywood material back into its layer. I do not plan to reinstall the original four rather large wood screws. In their place I will install six new wood screws of smaller size (#8) and spread the load over a wider area of the plywood with large fender washer. I will place the new fasteners in areas away from the old ones, which are now weaker and damaged wood. I hope this modest repair will stop further damage to the plywood seat back. The plywood seems to be generally in good shape, other than the areas around the original four fasteners, which have become enlarged and broken.

posted 04-16-2014 12:49 AM ET (US)            

The standard transom version uses a stainless steel cross bar to stabilize the seat side to side and fore & aft. The seat does not have the spacers like yours and fits tightly between the sides of the boat. The back of the seat is held by brackets that are around the cross bar and are secured with screws that go into the back of the seat plywood. The cross bar is bolted to the internal gunnel sides and is extremely solid and strong.

The vinyl on my seat (both the bench and seat back) was in good shape, but the seat was wobbly, and the seat back had something structural going on with it. I decided to take the seat components apart, see what was going on, affect repairs, and put the original vinyl skins back on.

The bench part was in very good shape. The plywood was in good condition and it had no rot. So far so good. When I took apart the seat back, it was obvious what the problem was. The entire plywood was black with rot and was falling apart. It was obvious that water had gotten in a number of times, and because the vinyl was wrapped around the bottom of the seat back, it did not allow water to escape or allow the plywood to dry out at all. In fact, there was still enough water that about a cupful ran out after a winter of storage. I wish I had taken some photos but you can imagine how it looked. Yet, the vinyl and foam cushion were in good condition after some cleaning with bleach to get rid of the mildew. All I needed to do was to fabricate a new plywood seat back core.

I let the old plywood dry out a bit and took measurements for the new seat back. As I recall, it was 5/8 or 3/4" plywood. The only tricky part would be tapering and bending the ends. I am sure yours is similar to mine in that it is a rectangular seat back until it nears the gunnels, then starts to curve forward as it decreases in height toward the front of the bench...the wraparound back as you termed it. It looked like the original seat back had the curve bent in by cutting some saw cuts (maybe two) effectively changing the cross section into 3 separate plies of 1/4" which were then easily bent and glued to form the seat back curve or wraparound. I did not have the equipment to duplicate this, but I figured with a number of vertical saw cuts, I could approximate the curve in segments and fill the open cuts with epoxy. It worked like a charm. After cutting the entire seat back out of plywood including the wraparound ends, I made vertical cuts in the seat back with a hand held circular saw. I cut almost to the depth of the last ply on the inside of the seat back curve (ie that part of the seat back facing where people would sit. I cut a groove every inch for about 15" to duplicate the original curve. The now flexible plywood ends were easily bent around a form to produce the needed curve radius. After bending, the plywood was clamped in its final position and thickened WEST System epoxy was forced/putty knived into the cuts made by the circular saw on the outside of the seatback curve. When the epoxy cured, the curve was permanent and very strong. Sanding made it a nice fair curve inside and out. And the whole seatback was given a layer of epoxy to seal it.

When I put the vinyl back on, I relieved it/left it open on the bottom to drain any water that gets inside. I suspect it is near impossible to prevent water from entering via the stitching in the vinyl, the key is to let it drain. I just pulled enough vinyl to staple underneath on the seatback aft side (because you can see it from astern). I terminated the vinyl at the bottom of the seatback plywood on the forward side, because you cannot see it...the bench part of the seat covers it. I am sure that if the seat was originally made this way, the plywood would still be intact as water can run out. Of course the epoxy renders the plywood watertight except where the upholstery vinyl is stapled. (forgot to mention that the original seatback had lots of steel staples...not stainless, monel, or bronze...most were wasted and not holding the material to the plywood.)

I figure this repair saved me the cost of a new seat for some sweat equity and less than $100 in materials. The seat is probably stronger than original, and ready for another 24 years of service. Sure wish I had some photos to post.

posted 04-16-2014 09:55 AM ET (US)            

I always thought it was a bit odd that the seat on my boat was not the same width as the cockpit, and the two teak L-brackets were needed to fill in the gap. The teak L-brackets are beautifully made, so they don't look like something home-made that was whipped up to make the wrong seat fit by a previous owner.

posted 04-16-2014 12:31 PM ET (US)            

On the other hand, the bench part is ventilated. The vinyl wraps around the edges and is stapled on the bottom, but the plywood is say 85% uncovered to the atmosphere. There where also 1" vent holes drilled in the plywood to allow the foam cushioning to breathe. I also treated the bench plywood to a coat of sealing epoxy to prevent future issues.