Fiberglassing bridge deck

[Lollygag]

Pretty soon I'm going to get started on fiber glassing the bridge deck. The PO removed the teak but never got past filling the holes. My question is what weight fiber glass should I use. A friend used TAP plastic Knytex but is that really necessary? Would a good 6oz woven cloth be just as tight with much less weight? Any recommendations on TAP plastic epoxy vs. West System? I've used both and don't see any difference.

 

[Capt.Bill11]

Knytex is way over kill. Plain glass mat/woven cloth would work just fine. I'd put on 2 maybe 3 layers.

Either epoxy would be fine.

 

[jleonard]

I would use 1 1/2 oz mat first then roving followed by another layer or 2 of mat.

 

[Wilson]

When I redid my bridge deck I used 1.5 oz chopped mat glass with a marine grade epoxy, forget the brand name. 2 layers over plywood, turned out nice.

 

[RT Firefly]

Greetings,
Mr. A. No matter what cloth/mat you use, make sure your resin (epoxy or polyester) is compatible with the cloth used. Unless things have changed, used to be you shouldn't use "polyester" cloth/mat with an epoxy BUT you could use either resin with an epoxy compatible cloth/mat.

 

[Delta_JimS]

Great point RT.

I sometimes forget to check on that one myself.
Usually use a woven cloth.(not to worry)

 

[psneeld]

Usually mat isn't compatible with epoxy.


I used 3 layers of 6oz cloth on mine.... been fine for 3 years...one thing is be careful not to let resin build up under the 6oz, its pretty light and doesn't have the weight to lay back down and you can easily wind up with a small ridge.

 

[Old deckhand]

Two layers of mat and 13 years later no problems. Surface prep is important.

 

[Lollygag]

When you did your decks, did you do sections at a time or complete the job in one batch? How many layers did you do in a day? How much epoxy did you mix at a time and did you use slow medium or fast hardener? I really only want to do this once.

 

[FF]

A layer or two of mat or roving in EPOXY will seal the deck but is not thick enough to make it stronger or stiffer.

IF its structurally in OK condition , a slather of GRP is fine , but if its rotten down inside , creating a new structure will be longer lasting.

GRP is very strong , and Epoxy is great glue , but neither is at all stiff , unless thick.

If you do not wish to remove the structure a layer or two on the ground clean deck (into the old glass) , with 3/4 foam core material (youre choice) held down to cure with sandbags and covered with 1./4 inch of Polly and GRP will do.

Vacuum bagging might be a bit better , but not for a 1st time attempt.

 

[psneeld]

When you did your decks, did you do sections at a time or complete the job in one batch? How many layers did you do in a day? How much epoxy did you mix at a time and did you use slow medium or fast hardener? I really only want to do this once.

One layer over complete bridge deck at a time. One layer a day. Fast hardener but this really depends on temps you are working in. Mixed what I could work with in the allotted time...usually about a half gallon. Had to cut back if it gelled for the last bit or so.

As I said in my last post, that if you pour the epoxy over the glass and squeegee or roll it in, with the finer cloths you have to make sure you really roll it all out well as the fabric seems to get a few wavy ripples in it if too resin rich.

 

[Wilson]

Yeah what they said. Need to replace any rotted/soft wood or you are wasting your time. One layer a day, do the whole thing not pieces of it. My entire bridge from the seats back was soft, cut it all out, wood was like mud inside. Cleaned it all out, put down new plywood and glassed over that. I might have some pictures I'll look, but I fried a phone recently so I might have lost those pics. Its really a pretty simple job if you are handy at all. Big mess, but simple.

 

[TDunn]

If the deck is sound a layer of 1708 (biaxial glass with 1 oz mat stitched to it) will be more than adequate. You can set it in epoxy, but it will be slow to wet out. Polyester resin will work OK too if you rough up the old surface with 36 grit before glassing. Vinylester resin will give adhesion intermediate between epoxy and polyester with the working characteristics of polyester. The down side of vinylester resin is that it makes some people sick.

Once you have the fabric down, fill the weave with additional coats of your resin of choice, then fair it out with Awl-fair or System 3 quick fair. Those are epoxy based fairing compounds that are easy to sand and adhere well.

For painting I would use a two part paint like Petit Easypoxy 2. When you get to the final coat I find that you can get a great, even, non-skid result by spraying dry non-skid compound onto wet paint with a detail sprayer. When the paint dries, roll on a final coat of paint to seal the non-skid.

 

[Lollygag]

Thanks all. I'll try to remember to take pictures and detail the mess. I plan to test drill several spots across the deck to see if there are wet spots and change my plans if necessary.