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Discussion Starter · #1 ·
Hi all,
We hauled out a couple weeks ago, and I've been going over the boat with a fine tooth comb. I'm rebedding all the deck hardware, and have found some gel-coat cracking on the deck, and another below the waterline that I think may involve a little fiberglass work. I'm a complete newbie for the gel-coat/fiberglass repair so I'm starting to do some research. I just bought two books, one by Don Casey "Sailboat Hull and Deck Repair" and another by Roger Marshall "Fiberglass Boat Repair Illustrated".
I'll probably get my supplies from Jamestown, unless anyone has a better source? Is there anything I really need to be aware of that may not be covered in the books? Thanks in advance!
GH
 

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Just for starters, don't let the perfect be the enemy of the good. Not every spider crack in gelcoat needs to be repaired. Gelcoat is really aesthetic, not structural. Learn how to make gelcoat and fiberglass repairs, and make the most important repairs first. Be satisfied with a good job until you develop the skills to do a perfect job. Don't make the job so big that it overwhelms you.
 

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1987 Cape Dory MKII hull #3
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Hi all,
We hauled out a couple weeks ago, and I've been going over the boat with a fine tooth comb. I'm rebedding all the deck hardware, and have found some gel-coat cracking on the deck, and another below the waterline that I think may involve a little fiberglass work. I'm a complete newbie for the gel-coat/fiberglass repair so I'm starting to do some research. I just bought two books, one by Don Casey "Sailboat Hull and Deck Repair" and another by Roger Marshall "Fiberglass Boat Repair Illustrated".
I'll probably get my supplies from Jamestown, unless anyone has a better source? Is there anything I really need to be aware of that may not be covered in the books? Thanks in advance!
GH
================================
do not know if he has anything on gel coat,I really like his videos

 

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Discussion Starter · #4 ·
small update: I ground out the area below the waterline and built it back up with fiberglass a couple weeks ago. Then is sat while I was chasing wily wapiti around in the hills. Today I sanded it down in prep for fairing compound. Looks good to me, and so far it really has been quite simple. It's only about 50F today, so it's going to cure very slowly. I figure I'll give the fairing compound until next weekend, then sand and see if I need another coat. I doubt I'll have enough warm days left this year to put on the barrier coat, but I'm pretty sure that can be done in the spring just before the ablative goes on?
Pics when I get a chance to upload them...
 

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Discussion Starter · #5 ·
First couple of pics show the repair area after laying in the fiberglass. I'm not sure why the peel ply left the line right through the middle of everything, but that area ended up a fair bit proud of where it needed to be, so that was mostly sanded out in prep for fairing.
Grass Wood Gas Rectangle Landscape


And here's what it looked like this afternoon after the first layer of fairing. I'm using Total Boat products, and so far I'm really happy with how it's going. I have also decided that I REALLY like my son's Milwaukee DA sander and Diablo sanding screens. The combination works really well.

Wood Automotive tire Water Shade Table



Closeup view of the repair showing that line from the peel ply. I thought it was interesting that layer of material in the hull with regularly spaced holes or dimples or whatever. That was a fair bit softer than the layers of glass above and below. While I was grinding out the repair area I wasn't sure if that was somehow softened from the crack maybe letting water into it, or just softer material to begin with. SO, I sanded it back a couple inches on each side, checking as I went to see if it got stronger. At the width that you see, I had decided that it was just the way the material feels. That repair is much wider/longer than the original hairline crack, but I wanted to make damn sure there wasn't any hidden damage. If you look in the bottom left corner you'll get an idea of how thick the gelcoat is on this one. I was amazed at how much material I had to sand off just to get through the gelcoat.
Paint Wood Rectangle Dishware Asphalt
 

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is hard to tell from the pic, but I am sure you were able to tell by touch and sound have reach healthy fiberglass, after cleaning the suspected area.
That will be my only concern.
Love working with fiberglass and resins.
Thanks for the follow-up.

Mahalo plenty
 

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I'd be curious to see what the hull crack looked like, before sanding it off. Was it just gelcoat cracks, or did they go through to the glass below?
 

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Closeup view of the repair showing that line from the peel ply. I thought it was interesting that layer of material in the hull with regularly spaced holes or dimples or whatever. That was a fair bit softer than the layers of glass above and below.
That peel ply crease was probably where the peel ply was folded prior to application. Folds in it have memory and don't straighten out easily. It's no issue - the peel ply does what it's supposed to do, and you need to fair regardless.

The layer of material is coremat, which is a thick punched non-glass compressed fabric mat. Sometimes it also contains microballoons. It is soft. Used inside a layup, its purpose is to more quickly bulk up the thickness without using many layers of glass - think of it as a mini core. Used on the outside of a layup, it is to prevent print-through of the underlying glass layers - works better than CSM for this. However, in both cases, it provides very little strength and really soaks up resin.

Mark
 

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Discussion Starter · #10 ·
I'd be curious to see what the hull crack looked like, before sanding it off. Was it just gelcoat cracks, or did they go through to the glass below?
Unfortunately I didn't even think to take pics before I hit it with the grinder! Cracks went into the glass below about 1/8"-3/16". I ground down until I could neither see nor feel any cracks, then tapered out from there.

That peel ply crease was probably where the peel ply was folded prior to application. Folds in it have memory and don't straighten out easily. It's no issue - the peel ply does what it's supposed to do, and you need to fair regardless.

The layer of material is coremat, which is a thick punched non-glass compressed fabric mat. Sometimes it also contains microballoons. It is soft. Used inside a layup, its purpose is to more quickly bulk up the thickness without using many layers of glass - think of it as a mini core. Used on the outside of a layup, it is to prevent print-through of the underlying glass layers - works better than CSM for this. However, in both cases, it provides very little strength and really soaks up resin.

Mark
Thanks for the information on the coremat. That definitely explains and matches with what I was seeing. And hopefully the next time I need to do this project is in the far distant future, but I'll tuck away that tidbit regarding putting it on diagonally. I didn't really pay attention to the crease. In any case, the little divot now only exists in those pics. :)
 

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Unfortunately I didn't even think to take pics before I hit it with the grinder! Cracks went into the glass below about 1/8"-3/16". I ground down until I could neither see nor feel any cracks, then tapered out from there.
Sounds like you did the right thing. I was wondering if this was just cosmetic. What would have caused such damage? Impact? Improper stand placement?
 

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that was my question too.
by the way, I would keep those pics and copies of these thread, in case when you sell your boat somebody may be afraid of what was done, I distrust areas of mismatched color or texture that speaks of unknown damage.
Even will more likely be covered by antifouling paint.
 

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Discussion Starter · #13 · (Edited)
Damage was caused during launch this past spring. First attempt to float it off the boat failed because the boat floated up and the wing keel caught on the supports. No problem, pull it back onto the trailer, pull the lot out of the water and adjust. Except when I pulled it back onto the trailer the angle of the ramp had the bow farther down on the trailer than it should have been. So, when I pulled it all out (and the aft of the boat rotated down into position) the tension on the winch holding the boat on the trailer was also pulling down. That cause one of the front support pads to push into the hull harder. Basically I got flustered about launching and didn't think about the angle change due to the steep launch ramp and caused a small crack.
When I was investigating it I almost thought it was just gelcoat crack. Thankfully I decided to grind it back a bit and found a few broken glass fibers underneath. All told the actual crack in the glass was maybe 6" long and less than 1/8" wide. Once I got the bottom paint off there was also several hairline cracks in the gelcoat. I also found that coremat stuff and wasn't sure if that was damaged so I just kept grinding a bit at a time until I was certain I had nothing but good glass.

Trailer launch solution is that several guys in the marina get together to rent a crane in the spring and fall. $25 up front to help pay for the slings/spreader bar, and everyone splits the cost of the crane. Total for haulout this fall: $75, and next spring should be about $50.
 

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Discussion Starter · #14 ·
Right after I got that last coat of fairing compound on the temps dropped and it hasn't be above about 45 since. The compound was still slightly tacky even after a week. So this past weekend I put my little propane heater on the ground below the boat and ran it on low for several hours, just to gently warm the area up and let the compound cure. After a few hours my IR gun said the surface was up to ~60°, and after several hours I could no longer feel any tackiness across the whole surface. In any case, it looks like finishing those repairs will have to wait until spring warm-up. Right now we have about an inch of snow on the ground.
So, I'll move the boat over to it's winter storage spot and as I get time I can work on interior upgrades.
 
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