DRAGONFLY Trimarans User Forum

Several years ago I purchased a 1989 Dragonfly 800 at a real good price. The boat sat outside in a storage lot for 11 years. The boat was mfg by pc mould in canada. I love the boat, but there are some serious delamination issues. After 3-4 years, i'm finally cutting out some of the bad sections and re-glassing using epoxy and bi-axial cloth (2 layers 17 oz) over Baltek balsacore.
It would seem that the adhesive Pc Mould used to glue the balsa core to the outside layer of polyester and glass didn't hold. It actually has a slight foamy texture.

So one question is what came first, delam or water? any thoughts?

Previous owner or their repairman tried to inject epoxy resin in cabin roof on starboard side. some held some didn't.

Note: once adhesive is exposed to air, it dries eventually and is very hard.

This image shows the area around the window after I've cut away the glass and removed the core material. The area below the window has already been replaced. I tried reusing the cutaway glass sheet after replaceing the core but that looks like crap and will need a lot of fairing to make it acceptable.

http://images1.snapfish.com/232323232%7 ... A249ot1lsi

Some the core material is just mush.
http://images1.snapfish.com/232323232%7 ... 5335nu0mrj

Well, if you've been there and done that, send a post

Working on a similar issue on the amas on my 25. There's some delamination on the cabin top as well, but that may have to wait for next winter to be addressed. I have to find a a stopping point for the improvements in order to have a starting point for the sailing. I always figured that I'd go at it from the outside, but your approach is interesting, too.

I found more delaminated glass on the outboard side of an ama where an earlier repair had failed. The core bond adhesive has gotten wet and failed. Not sure if due to moisture or physical damage from some other object. I removed a one by three foot section of exterior skin in order to get back to a good area in all directions and will replace the foam and exterior glass.
It appears the exterior glass is only two layers of mat, vs. the inner layup being heavy roving. This runs counter to my understanding of sandwich construction which generally has an external layup two to three times heavier than the internal one. I accept that there's a great deal I don't know about foam sandwich composite construction but this laminate schedule seems like a pretty poor approach to me.