Fiberglass Repair Method and Specific Product Recomendations

Well, last year there was a strong storm at the cottage and it took my new to me Hobie 16 right off the cross bars I had it sitting on and tossed it down the lake. After recovering it the next morning I noticed the damage to one of the hulls.

I'd like to repair this but have no prior experience with fiberglass repair. I'm pretty handy and willing to take on the project, but there seems to almost be information overload and I don't know what product I should use or how crazy I really should get with this repair (cutting out damage and fiberglass or filling it with some sort of putty). The boat itself is a 1974 Hobie 16, so it's a bit old and ugly already.

I called Hobie directly and they told me to "bog and flog it" and that I can just use gel coat putty. I really am not sure what qualifies as gel coat putty and West Marine said they never heard of gel coat putty. Also not being a Hobie employee in California, I'm not sure I know how to "bog and flog". So I figured I'd ask the members here in this forum. Some really good direction would be very helpful and specific products and where to get them would be greatly appreciated (preferably through Amazon).

If I did it right, I think there should be a link to the pics of the damage below this sentence. This is my first time in this or really any other forum and it doesn't seem very easy to navigate or post pics, so my apologies in advance if the pics don't show up in this or in the link below.

https://photos.app.goo.gl/Qo3DWuvJSN7MYDGg8

Dunno much about structural fiberglass repairs myself, so I defer to experts. But here’s gel coat putty:

https://www.fgci.com/item/128600/FGCI-G ... -catalyst/

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H16 2002 "Islands" Sail No. 107432

Any competent fibreglass shop can repair that.

So can you, if you have time......
Always use safety equipment, goggles, mask etc

Gently grind out the damaged area, feathering the gelcoat as you go,
use the autobody trick of a piece of string through the hole to 'pull back' on the fibreglass mat you will wet and insert into the hole to provide structure to the inside layer

Layup smaller trimmed pieces of good quality fibreglass with good quality polyester, smaller, then larger to match the feathering.
Sand in between layering of the pieces.
Finish with gelcoat

Sand and polish and go sailing.

At the 2009 Nationals in Kingston ON, I saw Mark Modderman do a 'quick' repair on a smaller hole in under 2 hours.
However, I will also say that he is an expert.
Do do lots of You Tube searches, and look on this Forum for more advice.

_________________
2015 H16, with spin,
SOLD 1989 Hobie SX18 Sail # 1947 "In Theory..."
'Only two things are infinite, the universe, and human stupidity. But I'm not sure about the former.'

A Hobie hull is composed of an inner and out layer of fiberglass surrounding a thin (roughly 3/8” thick) foam core - what is known as a “sandwich construction.” From the picture, it looks like the outer skin has been cracked and the foam core has been damaged, can’t see the inner skin. To repair, you essentially need to remove each of the damaged components and then build back up individually. So you will need to cut or grind out all of the cracked and damaged outer skin and taper sand back the surrounding areas at least 2” beyond the damage. Remove all loose core material and inspect the inner skin. If its undamaged, I would recommend just filling the void where the core was removed with thickened resin or putty (like Formula 27). Its not an ideal repair method, but should be sufficient given the size of the damage is relatively small. After the putty cures, rough sand it and then laminate several layers of fiberglass over the area to build back the outer skin. Each layer of cloth being slightly larger than the one before. Chopped strand mat with polyester resin should be fine and will be the easiest to work with. If the inside skin of the hull is also damaged, then it will also need to be repaired. Given the location of the damage, the easiest way to gain access would probably be to cut a hole in the deckfor a 5” access port. After you finish the structural part of the repair, you will need to fill and fair the outside of the hull. Formula 27 filler works well for this. Then, if you are concerned about cosmetics, spray or brush on gelcoat to finish the repair.

Materials you’ll need. Latex gloves, safety glasses, paper towels, mixing cups, disposable 1” brushes, various grades of sand paper, acetone, polyester laminating resin with hardener and surfacing agent, fiberglass cloth or chopped strand mat, Formula 27 filler (or similar), white gelcoat with wax additive.

You can also check the March/April and May/June 2008 Hotline issues for repair info.

http://www.w1dm.com/Projects/HOTLINE/Hotline.html

sm