I'm looking for a Nacra 5.7/570. I've found an older 5.7 that I like, but there is some damage around the top of the shroud chain plates that will need some work. It looks like they have been pulled forwards and backwards, so I'm thinking that the rivet holes have been opened out and that it needs some reinforcement.
Here's my question (not having had a chance to look at a 5.7 up close): can you get access to the inside of the hull where the chain plates mount? I can close up rivet holes and reinforce from the inside, but only if I can get access.
Yes you can. First make sure that the damage is bad enough to repair. A little bit of stress cracking where the chainplate exits the hull is normal. As long as the rivets look solid and the cracking is minor (say less than an inch long) you may be fine just sealing it and sailing.
The way you open the hulls is by working a thin blade (putty knife or thin chisel) around the textured deck on top of the hull. Its a big plate and a slow process but not that difficult. After you go around the deck 3 or 4 times you should break through and be able to pry it off. Note that there is one or two locations where the fiberglass actually bridges across the entire hull in about a 3" width. It good to know this because those places will be the last ones that stick and if you don't realize this you may try to pry too hard and break it like I did. Not a big deal but adds work. In any case. Once off you just need to sand off any remaining glue from the deck and hull with a random orbit palm sander before re-attaching. Re-attach with thickened epoxy, you can buy a tube or make your own with 2 part epoxy and colloidal silica that you mix to toothpaste consistency.
Getting the deck off is about a 2 hour process but isn't rocket science.
Regards,
Dave
Dave Bonin
1981 Nacra 5.2
Awesome - thanks Dave. I didn't realize those deck plates lifted off - that makes it super easy. I even happen to have a pot of colloidal silica sitting around here somewhere!
Here's an album I made, showing what's inside.
http://www.thebeachcats.com/pictures?g2_itemId=82844
This is a 5.2, but the construction is the same.
You might want to consider putting a hatch on each side. Easier, & makes it easy to pump water out of the hulls. I find my 5.7 is a b^tch to drain. It sits on a lift, & you have to tip it up quite high to drain, as the last 2' of the hull slants upwards.
E C Hilliard
Nacra 5.7
Bombardier Invitation
Very handy - thanks.