old fiberglass

I am working on an old Optimist Pram and after sanding the hull i noticed that the old fiberglass (which is the stringy kind) is not peeling off but the resin has worn off a little and the strings are loose. can i just add more resin over it or maybe add some cloth while i am at it, or do i need to take it off .

Thanks, Blake

 

oh, so i should just put another coat of resin over the old fiberglass. that is what i will do.

Thanks, Kayakn

 

Pictures would help in understanding your sheathing issues.

 

it is pretty much like the fiberglass cloth that is on the corners of the boat does not have any resin on the top and only underneath it and i just wanted to know if i i could but more resin on top of the cloth? or if it would be better to just put more cloth and resin over the old cloth or if i need to take it to bare wood?



Thanks

 

It sounds like your fabric either didn't wetout very well or the weave wasn't filled, so pictures would make a world of difference.

If the weave wasn't filled, you can just apply more resin to fill the weave, but if the wetout wasn't complete, then you've got other issues, which additional coats of resin will not fix.

The bottom line is you have to find out how well stuck the fabric is to the substrate. this can be done a number of ways, all will cause you to repair the small area the test affects. I'd just use a razor and sit open along one of the corners, where it seems least stuck down. Grab the fibers with a pair of pliers and jerk it up at 90 degrees to the surface. If the wetout was good, it'll just pull out of the pliers. If the resin didn't wetout the fabric very well, you'll yank up a hunk of fabric.

The reason you need to do this is simply because if you apply resin over the surface, but the fabric isn't stuck down very well, it'll just be relying on the original bond (which isn't any good) and be a waste of time and money. If the bond is good, then you can apply more resin and more cloth, knowing it will stay stuck, because the original bond is good. It's a bit like painting over poorly stuck paint. The old paint will not let the new, get a good grip and both will fall off pretty easily, but if the old paint is stuck good, then a simple cleaning and scuffing is all the prep you need for a new paint job.

 

As an Optimist is only an 8 foot dinghy, I would simply wet the cloth out again with resin.

playing any deeper may start to open a whole can of worms and you may believe the boat is a total write off, not so is the case, 8 foot dinghys will be quite OK to wet out again and sand , fair and just paint it.

 

I'm up against a similar problem. I have a 12 ft MFG which is a glass open boat, with "hairy" surfaces. Epoxy on it will get beat by the sun, so they must have used some other type of resin to build it?? It's bare glass, inside and out. I really don't want to put paint on it.

 

Any bare or exposed 'glass will get "beat by the sun" regardless of resin used (epoxy, polyester or vinylester). These plastic resins (all of them) must be protected from the elements. Paint, oil based varnish, polyurethane based varnish, linear clear coat and gel coat are typical options to protect the plastic entombed fabrics.

 

Thanks PAR I'll just have to paint the thing I guess. I may come up with a color that wont show nicks and scrapes in contrast to the base color.
PILA