Reinforced fiberglass for bottom job?

I was picturing a smaller ding in the side! That's not awful. At bit of a pain right at the bow, but at least it'll be easy to sand. srm's link shows pretty much what you can expect for the repair. Sand it down just like in the pictures, until you get to the clean/clear/undamaged fiberglass. Sand down the surrounding gelcoat so that you can "taper in" the repair and then cover it with gel coat. You'll need polyester resin and some fiberglass cloth - West Marine has a "fiberglass repair kit" for ~$35. Cut a few pieces of fiberglass cloth down to size, mix some resin, and away you go!

Cut a few more pieces of fiberglass than you think you'll need - the polyester resin shrinks as it cures. Make sure you're in a well ventilated area - lots of VOC's. Clean the sanded area and wipe it down with some acetone. Once you have the resin mixed, wet out the repair area with the polyester, and wet out each individual piece of cloth - it should become pretty much completely clear. Then start stacking up the layers on the repair area one at a time, stipling them with a brush to make sure there aren't any air bubbles. (gloves are a must) Professionals will only do a few layers at a time for better quality control, but that's not to say that you can't do it all in one go. Once you've got it slightly mounded up, you'll need to cover the repair area with wax paper or saran wrap to seal out the oxygen - otherwise the surface layer won't completely cure/will cure tacky. After it cures, sand it fair (and leave it slighty lower than the surrounding area so you can cover it with gel coat).

Gel coat is the exact same thing - polyester resin with pigment in it. The trick is matching the color. White is easier than darker colors, but it'll likely never be a perfect match. For gel coat, you just need to mix white and black pigment to match the boat color. It's best to do this on a bright sunny day. Mix the gel coat uncatalyzed, put a small drop on the hull next to the repair, and look at it from every angle. Keep adjusting the mix until you can't even tell it's there. Then catalyze the gel coat, apply it to the hull (airbrush is recommended, but it can be rolled or brushed on too) and cover it, or use finishing gel coat - it has a wax in it that will rise to the surface and seal out the air on it's own. Sand it down, polish it up and you're done!

The longest part of the process by far is all the sanding stages and the cure time - 12-24 hrs. Actually applying the fiberglass & gel coat takes maybe 5 minutes each.

_________________
Mike

'79 H18 standard 'Rocketman II' sail #14921 RIP
'78 H18 (unnamed) sail #14921
'08 H16 sail #114312
'97 H21SC sail #238

Here is a link to the "This Old Hobie" "Blind Hole Repair" article: http://www.w1dm.com/projects/HOTLINE/08 ... OTLINE.pdf

One of the keys to the repair (that I didn't show in the link to my pictures above) is using monofilament fishing line to hold the backing piece in place while it cures. It is shown in the "This Old Hobie" article.

Jim

That was my son on the board in this first one!



I think This one was Ben Brown

_________________
H18 '85
H18 '89 "Knotty Passion"
H20 '96 "20/20 Vision"
Fleet 259 Central Coast California

That's cool! Did you make it up to see the Moth championships? I wish those little things weren't so expensive.

Thanks for all the advice guys everyone. I may try the duct tape to get a couple hours in but will be dragging the boat back up to Portland and starting to refinish the hulls and repair - that's why I'm not so bummed about it - I already have a number of dings and gouges to investigate and I need to buff the waterline marks off the hulls. The nice thing is that they're absolutely rock solid so it's worth the time investment. Going to do all the standing rigging too.

Oh, by the way, it did take a bit of time to locate the This Old Hobie articles (thanks Jim for the link too!). I also found an article on spraying gelcoat which was really interesting - Home Depot apparently sells little disposable spray guns for gel coat! Is it worth pinning a link to those articles (mmiller?) or copying them somewhere more easy to find?

Mike