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Phenolic sheet

K

kd410se

New Member
I work at Spruce and have access to this stuff at a good discount. My question is would it be a good product to use as deck coring in areas that require a strong hold, like stanchion bases and the bow, like as a base for the windlass? Obviously I would be covering in in fiberglass and doing the entire deck would be cost-prohibitive but in areas where you’d like the coring to be moisture impervious it seems like it would work great…

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Phenolic sheet is hard, and the only way to make it conform to curved shapes such as a deck is to cut it into small blocks. I think an easier way, and much cheaper is to use a heat formable hard foam and shape it to what you need. Use something like 15 lb density at least if possible.
 
I was thinking if I could kerf the underside it would give it just enough flex to conform to simple curves. If I’m not mistaken, I would only need 3/8” thick sheet, correct?
 
For a deck core, or as a backing plate? The deck on the Morgan is already cored with plywood. Do you have rot that you are trying to repair? If that is the case, I would use plywood as original. FWIW, the factory core is cut into approx 8" squares.

If you are looking to add strength to stanchions (the bulwark is not cored) or the windlass, backing plates should be used. The purpose of a backing plate is to spread the load, Stainless, Aluminum, GRP sheets, or plywood would all work well. Phenolic would probably be fine also.
 
I was actually thinking of using it in place of the plywood core in the bow (and stanchion plates) as I’d never have to worry about it getting soaked. It would be a fantastic backing plate material for a windlass also. Working at Spruce I have access to West Systems epoxy, all manner of spray lube (Boeshield T-9, Tri Flow etc), stainless hardware, electrical stuff, Biaxial fiberglass etc… along with marine grade plywood and many other sailboat refitting type supplies. The job itself kinda sucks, but the employee discount makes up for a lot of evils, lol!!
 
As a core, the plywood inside the upper and lower glass is very strong, especially with a good sized backing plate. And it easy to protect the core. Just oversize drill the hole with a Fortner bit, leaving the bottom layer of glass (if you can, but if not, it is not fatal) and fill the hole with epoxy, and redrill for the fastener. Also, use "Marine How To" butyl tape as bedding compund; it never leaks
I sometimes I put a 3/8" ply plate, followed up with aluminum. Officially, I think the aluminum is supposed to get thinner as the edge approaches, but I don't have tools to do that.

Morgan, at least in 1979, put NO backing plates behind the stanchions. And they are a bear to access, requiring minor interior demolition to access them all and sometimes drilling off the top of the bolts. Finally, the stanchion bases are too thin and bend under constant use. When everything was stripped off my boat for painting, I added 1/8" of stainless to the bases and had my machinist make me threaded backing plates. Those are now glued to the inside of the gunwales. If you go that route, be aware of this eccentric feature: the bolt hole arrangement was slightly different on each of my stanchion bases, as if the machinist did it freehand, with no jig. But, of course, other parts of the vessel are well thought out and well built. But they are production boats, with what, 500 or so built in the 382,383, and 384 models.
 
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