composite hull repair

[sunyatta]

On one of the hulls of my ply/epoxy/glass catamaran, the fiberglass tape has pulled away from the ply to the point where I can pull it off the length of the hull, just along one seam. The boat was constructed of marine mahogany ply and West epoxy. I'm not sure why this happened only to this one area but I need advice on repair. Can I just grind it down and re-apply tape, wet it out, let it cure, and be on my way to prime and paint? Do I need to grind down to just the next epoxy layer, or all the way to wood? All help is appreciated. Bob

[FAST FRED]

If you can grind the surface so 85% of the surface is clean glass , with the fabric showing, a good secondary bond is easy with most epoxy resins.

Get some and do it on a DRY day that is over 50F .

Should be as "good as new" ,

FAST FRED

[Ssor]

How many layers of glass are loose? If only one ply of glass is pulling loose then more likely there was a poor bond between layers. As said above, just grind down to sound structure, wipe the area with acetone and put your repairs in place.

[dimfiber]

Sunyatta, "Tape" with no matt backing? could be the prob.

[Ssor]

Sunyatta,
You have asked our advise. We have asked for some clarification of your problem, Talk to us .
Ross in Bel Air

[yokebutt]

Please, tell us more, failing that i'll give you the three most important factors, surface prep, surface prep and surface prep.

Yokebutt.

[sunyatta]

Sorry all for not responding sooner; work and all that.
Thanks for the responses so far. OK - there is a seam on the outboard side of my port hull from bow to stern where the fiberglass cloth has not bonded to the backing. I can pull it off in strips and get down to the epoxy-covered mahogany plywood panel beneath. I have pulled off what I could and now I am planning on grinding it and then re-glassing. I am not a builder so I'm not quite sure what I'm doing. I've been reading the Gougeon's Wooden Boat Restoration and Repair to get an idea on how to proceed. The ply below the glass cloth seems dry and I can't detect any rot (this is just above the waterline). All ideas and help appreciated. Thanks.