Fiberglass laminating and how to attach brace question

[dwhite1031]

I have a small bow casting deck and want to extend it back to my consoles. I'm intending on using 3/4" plywood for the extension and bracing. I have a couple of questions on how to accomplish what I want to do.

How do I laminate the braces and new deck with fiberglass?

Should I avoid attaching the braces to the exisiting floor with screws and use a marine epoxy adhesive or 3M 5200 instead (indicated by red)? Should I use cloth and make a transition to the existing deck from the brace as in my illustration (indicated by yellow)?

Thanks,

 

[Bob_VT]

Re: Fiberglass laminating and how to attach brace question

You can use PL adhesive to bed it on and yes the fiberglass tabs will be okay......I would consider some cut triangle knee braces on the inside. Do you really want this permanent? Or do you want to ever get under there and make it removable?

 

[Mark42]

Re: Fiberglass laminating and how to attach brace question

The construction adhesive will be enough to attach the new brace(s) to the old deck. Just be sure to sand/rough up the mating surface first. A few screws can hold them until the adhesive dries. Might want to think about just screwing them to the old deck so it will be easy to remove or modify in the future. Put sealer where the screws pass into the deck to seal it. If you use pressure treated lumber, that is probably all you will need to do for the bracing.

To glass the new deck over, buy some polyester resin and slow cure hardener because you area doing large areas. The Bondo resin will set way too fast for an area that large and it has wax. You want a non-waxed resin, with separate wax for mixing in a final coat or some gel coat to roll on top of the finished glass work.

Cut the cloth (use 6 or 8 oz cloth for ease of application over CSM) to the needed sizes and place aside. Mix about 16oz of resin and pour onto the new deck. Use body filler spreader to quickly spread the resin out evenly over the deck. Then lay the cloth, and lightly press into the resin with the spreader. Mix up more resin and pour on top, use the spreader to get an even coat. Use a disposable paint brush (not the foam stuff, the horse hair brushes) and work out any bubbles below the glass.

Thats pretty much it.

Hard to say how to attach the deck to the gunnels without an actual photo, but screws should work. Get stainless.

 

[dwhite1031]

Re: Fiberglass laminating and how to attach brace question

You can use PL adhesive to bed it on and yes the fiberglass tabs will be okay......I would consider some cut triangle knee braces on the inside. Do you really want this permanent? Or do you want to ever get under there and make it removable?

Thanks for the input. You make a good point. I just might want to make it removable. The main deck where the braces will sit is being replaced as we speak so it will be brand new. Being removable gives me future options that may come to light after I utilize the extended casting deck a few times in real world situation.

 

[dwhite1031]

Re: Fiberglass laminating and how to attach brace question

I was looking at the Evercoat Boat Yard resin, but I see it has wax. Can you use it as a laminate resin and cover it with plastic wrap or something to seal out the air in order to cure the final coat, or would I be better off using a laminating resin and finishing with the Boat Yard resin?

 

[PiratePast40]

Re: Fiberglass laminating and how to attach brace question

The boatyard resin you're talking about is a waxed finish resin. For your application, you should be using a laminating resin.

I had a pretty bad experience with that particular product. Make sure you understand the codes and expiration dates on the bottom of the can before you open it and make sure you get the catalyist that they supply with the resin - it has it's own mix rates that may or may not work with other hardeners. I didn't do that and ended up grinding out everything I layed down. The manufacturer will not guarantee the product after the expiration date - believe me, I know first hand - you're not only out the cost of the material but also all of your time to remove it and lay new mat and resin.