My Hobie 18 has a slight soft spot just forward of the aft crossbar, port side only. It's not the type of soft spot that you can push in with just a few fingers or thumb, and it doesn't make any cracking sounds, but if you put most of your weight on it, it does depress a lot more than other places. (and there are couple of stress cracks in the gelcoat around the area, from where it has flexed)

So my question is, is it more difficult to inject when the soft spot isn't very bad yet, because there is less delamination for the epoxy to flow through? Is it better to try to repair now, or wait a season for it to get worse, so that it's ultimately easier to get a better repair?

Any thoughts?
Thanks

I would do the repair ASAP

Here is some good info

http://www.hobiecat.com/f…iewtopic.php?f=18&t=1156

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Jack B
Hobie 17
BC, Canada
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I've done several soft spots repairs.... the key is good prep, cool temps and a great grid to inject from area to area. Git-Rot remains a little flexible - which is good up on the bows, but i used some super hard curing epoxy aft, and its as solid as a rock.... makes getting on and off boat from the rear less worrisome. My only dilemma is once the drilled grid is solid and deck repaired, whats the best way to cosmetically cover up the couple dozen holes that's involved in the repair process? Assuming the boat is 30 years old or better without spending another couple (several) hundred bucks fooling around with gel coat, faring, painting ect? opinions?
I guess as long as things are solid and functional all is good?
Tim

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Tim Grover
1996 Hobie Miracle 20
Two Hobie 14's
1983 G-Cat Restored
Memphis TN / North Mississippi
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I thought I would post an update, to help anybody else who might be in this situation later. I went ahead and tried it, even though the soft spot was not yet bad, and the results were not good.

- Drilled a good grid of about 75 holes on a 2 inch grid
- Drilled all the way through to the second layer of glass, even hand spun the drill bit to make sure I was all the way through the foam, but didn't go through the second layer.
- Used Git-Rot, thinking the lower viscosity would help it flow, since I assumed the delamination was not bad, so there might only be small gaps to flow through.

Not one of the holes took any measureable amount of resin. I even pushed so hard on the plunger that the pressure in the syringe cracked the body and it blew the first syringe apart, blowing resin everywhere.

I was hopeful that some of the resin would still soak into the foam, so I waited 7 days before putting any load on it, to make sure the Git-Rot cured. Checked it tonight, it is not noticeably stiffer than before. I guess I will sail it this season, let it get worse, and then see if I can inject into it.

Sounds like a rush job maybe? I did my first soft spot repair ever and did a cross hatch grid over a 2 sq ft area with 1/8' holes, 5-6" apart with a stopper on my hand drill bit, only going through the top layer ( about 3/16' ) and applying pre cut tape where the epoxy oozed as i went up hill on deck and it turned out solid as a rock and was easy. Keep in mind, Git-Rot stays somewhat flexible after curing. I used a bent nail to wallow out the foam in about a 1" internal radius of each hole. I used that in front of pylons. I used commercial epoxy in the rear deck area on one side - same method - and its so tough you can dive off of it. 75 holes?! that sounds super excessive... i prob did 16 holes total and forced the epoxy in very aggressively. Have a spare hobie 16 I'm about to do some of this to... thinking of using a turkey baster type syringe to really get the epoxy spread out and evenly squirted out between layers...
You may have gotten the resin/hardener ratio off a bit? Was it really cold when you did the repair?

In general I found that the epoxy injection was rather easy to do once you prepped the area completely covering in tape before drilling, had lots of pre torn tape bits to stop leakage, small batches of epoxy in a cool location, mix thoroughly then quickly injected until it wouldn't take any more, anywhere near the soft spot and left the whole thing alone for a few days before taking off tape and razor blading off any holes that were hardened raised epoxy. A few of you're favorite beers is key here, it helps to have rock music playing during the whole process too ~ IMHO
Have taken the carpet ride in winds over 20 MPH with my 230# buddy trapped out blasting through 2'-4' waves all summer long and the repairs are rock steady, no spreading and the hulls drain out about a cup after a 6 hr day on the water.

Tim

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Tim Grover
1996 Hobie Miracle 20
Two Hobie 14's
1983 G-Cat Restored
Memphis TN / North Mississippi
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Thanks for the ideas, but definitely not a rush job. I have both hulls completely dissassembled (for other work, bottom job, etc), sitting on racks on saw horses. Fully measured/laid out the holes, masked the area. After drilling with a stop on the bit, I went back and had turnded the bit until you could feel the second layer of glass.
- Epoxy ratio was precisely measured via mixing cups and checked via digital scale, the remining mixed material hardened both in the mixing cup, and in some sample dabs I made.
- This was done in a heated garage, at a constant 60 degrees.
- I had tape prepared to plug holes as epoxy flowed out, but obviously I never needed that.
The reason I wound up with so many holes is that I started with a 6" grid, but when the holes wouldn't take epoxy, I went back and added more at a 2" grid, with hopes that it would still penetrate some area, and be effective. (In hindsight, I should have stopped with the first set of holes). I had considered the bent nail approach, but didn't like the idea of tearing up the foam, if it was still in such good condition.

From everything I have seen, the soft spot was just not bad enough yet. I have seen the ones you can push in with your thumb, mine takes about 150 lbs to deflect about 1/2", but the other hull is rock solid in the same area.

I'm definitely open to other ideas!
At this point, I am going to gelcoat fill the tops of the holes, wetsand, buff, and wait (and hope it holds up this season). Live and learn.

Hmmmmmm, now you've got me thinking.. The areas on my spare H16 that are a little soft might not need repair for another season or two. No 25 year old plus boat is going to have perfect solid hulls unless stored indoors or something.... How soft is too soft? any give at all but no crunching sound? a little flex over a broad area? Is there a rule of thumb for recreational sailors that do mostly inland lakes vs racing in the ocean? I wonder if an injector for epoxy such as a turkey baster can be used to saturate the foam with epoxy if the foam is still pretty rigid?
Tim

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takes about 150 lbs to deflect about 1/2"

I am not sure, this qualify as a "soft spot"...
We are taking about a lighter person to step on a desk to deflect. Soft spot is typically related to actual delamination of the foam from the fiberglass. This obviously to not happen, at least at up to 2 inch hole-to-hole distance.

My guess, if you would make the holes spacing much closer, then some of the resin would penetrate.

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Jack B
Hobie 17
BC, Canada
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