New deck for my old Gibson

Well it has come time to replace the deck on my 36 foot gibson house boat. I have helped and watched a few of these being replaced and it is a huge undertaking. I have the entire deck and all the old wooden supports out, I am down to the fiberglass hull. I plan on using treated lumber for the wooden structure, (framing) to help resist the rot and decay, I have 3/4 inch marine grade plywood to use for the decking, and I plan on using poly resin and fiberglass cloth. The marine plywood has the good glue and voidless core but doesn't have any rot or decay properties so after talking to a few folks, I should seal the bottom side and the all the edges after being cut to size with a good marine varnish, to seal it from all moisture, the top side should seal well with the glass and poly resin, following up painting with a 2 part epoxy paint.

Now I have read in these forums that allot of you all are against using poly resins on decks, it appears as most of you like to use epoxy, why is that? The poly resins are waterproof, my gibson used it from the factory and lasted almost 30 years, and the polys we have today are much better than those of 1972. I am using the poly also to bind the outer wooden members the the fiberglass hull as well as this is what the factory did. I am however replacing the rear engine hatches with ones made from aluminum and making the rear opening one large one instead of two smaller ones, should make for a larger opening to work on the engine bay.

I would appreciate any feed back on this, as well as any questions or any advice or help you could suggest, also I have one question that i haven't been able to figure out, just what is a good way to seal of the screw holes for all the railings and cleats and anything else that must pierce the poly resin and fiberglass decking to seal against water intrusion?? Thanks again for all your help..

 

You have already said you're using poly resin. You want advice at the same time, so here it is:

Send back the marine plywood and the poly resin and take the money and put a portion of it into epoxy and coat both sides of ac grade exterior plywood at least three coats before installation.

Sure, polyester resin is waterproof enough to last a while, and a houseboat deck is not exactly going to be experiencing the stresses of sixty foot waves going 'round the horn.
You could use poly resin then, okay, because much of what makes epoxy the coating of choice is how it remains adhered to stressed structures.
However, using that very expensive marine plywood is more necessary now that the poly has been chosen as a coating.
Analyze the job. Maybe I'm wrong, but I'll bet that an epoxy/AC plywood job is cheaper and easier than a poly resin/marine plywood, and without the stink.
in any case, it's definitely superior.
You see, thirty years ago, plywood was a lot better than it is today, not only AC or AB exterior, but marine plywood as well. voids in the original plywood would have filled eventually and rtotted the deck away prematurely. The martine plywood you bought recently may be good stuff, but if so, you will have paid a princely sum for it, or it might actually have a few rot=inducing voids in it. If you paid $50.00 a sheet more for marine grade than AC would have cost, realize that epoxy resin would in all liklihood have cost an additional $15.00-20.00. Just estimating--- analyze it yourself.

 

deck finished

well i finally got that deck repaired and finished, what a job.
after totally removing all the deck flooring and all the wooden superstrucure, taking everything to the fiberglass hull, i rebuilt using all new wood. once the new wooden structure was in place i generously coated all wood members using the ploy resin. i figure if moisture cant get in it wont rot as quickly.

all the deck flooring i used was the better grade of marine plywood 3/4 inch, was only 69.00 a sheet and i used 7 sheets, i also coated the bottom side and ends with marine varnish 2 coats, and finished up with the poly resin and fiberglass mat for the topside. i also was careful to seal all the bolt and screw holes that went into the deck for railings and cleats, finished with a epoxy paint and some granules for non-skid...turned out great...way better than the factory did it, i did consult Gibson at the factory and they now have a factory rehab and rebuild and the prices for a job like this run in the 15,000-18,000 range with out transportation to their facility.

instead of reusing or making new hatch covers, the openings were way to small and the covers rotted, i made one large opening, 92''x46'' and had aluminum covers made, no more rotting ever, and i have plenty of room to work on anythng i need to without being a contortionist. i did add couple of vent holes in the forward bulkhead to let excess heat and moisture escape, as this was the most troubled area with floor rotting, no factory vents at all, gibson did recomend doing this as they have been doing this for a few years now.

overall it was quite a project, took 2 1/2 months as i did most the work myself, i dont think i would do it again though as it is a huge undertaking. i would help or give anyonelse a hand or advice if needed....river rebel

 

River Rebel - Got photos?

I have a squishy deck on the fly bridge of my 1983 Gibson (36') and it's squishy on the starboard side.

I would love to see photos of what you did to your boat. My plan for next year is to remove just the squishy sections, replace the fiberglass and ribbing, fiberglass the top side, and repaint the entire deck surface so it all matches.

Of course I'll coat all exposed wood with poly to seal it.

What did you use for deck paint? I have the standard cream colored Gibson deck with the brown pain drippings.

Any warnings?

Pat

 

A squishy deck is the finial product of polyester resin coated wood pieces. Of all the boat decks, soles, cabin sides, stringers, engine bears, etc. I've replaced over the years in production boats, the one thing that was common to all of them was polyester resin on wood.

The guy that did his houseboat will be doing it again soon enough for the same reason he had to do it the first time, polyester resin isn't waterproof.

Pat, your project will be best advised to use epoxy in your repairs. Replacing just the squishy areas is a lovely idea, but once you rip up the things you need to, in order to get at the deck, you'll see a lot more damage then just the soft areas. This is normal and the cure is to remove all the rot, cutting back until you know you have good wood. Maybe you'll get lucky and can piece in some repairs, but most find they have to just rip out everything and start over. Also, start a new thread about your project Pat. This one is completed and serviced a different set of issues then yours.

 

Thanks. Epoxy it is. My intent was to remove the rotted deck until I come to solid wood. If it all comes off, that's ok.
Pat

 

RiverRunner,
I have some pictures of what i did to my boat...and as far as if you use epoxy or polyester resin is totally up to you..I have researched it and looked at alot of boats at the repair facilitys and I even had a long talk with the guys at the Gibson factory, who by the way is now offering rehab of their old boats at the factory. Gibson still uses this way in constructing their new boats today, polyester resin, not epoxy. And the original deck and structure lasted 38 years and didn't use all the poly i used when i redid mine, so..i would love to send you some pics of the repairs and maybe talk a little more extensively about what to look out for and so on..And I won't be redoing mine anytime soon, I'll guarantee it.

 

River Rebel,
Thanks for the prompt reply. Please send photos to pboulay@newbizminn.com. My boat spends it summers at the St. Paul Yacht Club in Downton St. Paul, MN on the Mississippi. It's up on blocks and under plastic for the winter. Now is a great time to start planning and learning for 2011. You're advice is most welcome.
Pat