Hull has fiberglass stringers, how to attach fiberglassed plywood to stringers

[Dewpoint]

Hello, new here, lurker for around a year. Told my boat was junk, take it to the dump because a small amount of deck rot. The "professionals" said the deck rot is ten times worse below deck so the stringers are dust. Boat is junk. I tore the deck off (I shouldn't have it was fine, thanks "professionals!) and am in the stages of replacement.

I am cutting wood now and fiberglassing it this week. But I want to know what to do about attaching the deck to the stringers. I will glass in the top of the deck to the sides of the hull but what will be adequate below. I thought about using 3M 5200 as that is a thicker product to fill in any invisible gaps but I'd rather use the vinyl-ester resin I will be using as I will have some left over. The boat is a 1974 Winner Wildcat with 85 hp Evinrude.

Also, I need to get ride of the old chopstrand on the stringers... thoughts?

http://imgur.com/n499Oq9

http://imgur.com/NmCsSIF

http://imgur.com/foJU4jL

 

[JASinIL2006]

I have fiberglass stringers, and I attached the deck by laying down a layer of thickened resin with chopped fiberglass strands (referred to around here as peanut butter) and then I used stainless steel screws to pull the deck down to the stringers. (When I pulled out the old deck, it was held down with thickened resin and long staples.) I then filled the screw heads and seams with thickened resin, too. Very solid! Just be sure to pre-drill the holes into the fiberglass stringers. If you don't you'll pop the heads of a lot of screws. These stainless screws are brittle.

Unless it's really loose, why remove the stuff from the top of the stringers? Is it adding too much thickness or is it uneven or something? Can't you just leave it there?

 

[Woodonglass]

Welcome to iBoats! Yeah the Old Winners really were Winners of a Boat. Their Stringer systems were some of the BEST!!! I'd recommend Sanding them down with 60 grit to clean them up and then drilling some 1/4" holes in them down low to ensure they have not become water logged. If they don't start draining water then you should be good to go. If they do then you have some thinking to do. The stringers could be Foam cored and then glassed. If all that foam coring has become waterlogged it will have added hundreds of pounds of weight to the boat and the foam will have lost all of it's flotation benefit. You should seriously consider cutting the caps off the stringers and removing/replacing the foam cores and then recapping the stringers. This is not a serious project to undertake but a needed one if they are in fact waterlogged. IF they are not foam filled and waterlogged and just hollow glass, then sand em down and then do the deck. I'd do this first and then get back to us.

 

[kcassells]

You can grind them clean, wipe down with some acetone {wear gloves} And you'll have a good new surface to bond onto with a PB mixture, screws too!. Pre drill like above said and then ea. screw dip into a resin mix or 5200 prior to sinking them in. Make heads just below deck and pb over them too.
You're new deck should also be sealed with resin at the least. Alot of guys put a layer of csm on the underside to eliminate water troubles.

 

[johnnybgood]

The Steiger Caft I have been working on had the original deck 3/4" plywood with 1 layer of CSM and screwed to the fiberglass stringers. They used what looked like 5200 and in a lot of places it never was sealed to the deck. I have been screwing the new deck down and using PB thickened resin in place of the 5200

 

[kcassells]

Cool, IMHO that will provide a better joint/seal. Plus 5200 takes awhile to cure.