How much Git Rot is needed for a delam fix?

I just pumped two quarts of "Git Rot" into my two hulls...both delaminated forward of the pylons and one also delaminated under the tramp between pylons. Drilled 52 holes to cover the areas, filled each until stuff came out of the previous hole and after curing for two days the soft spots don't crunch anymore but the top layer is as spongy as ever.
Is this normal for an 83 Hobie 16 delam project?

Not normal. If the epoxy filled the voids, it should be solid. I suspect it drained out into the hull. The inner layer of glass may have been cracked or drilled through.

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Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Will a second and third attempt show some improvement or do I need to try cutting and filling in the voids?

If it is leaking out into the hull and you can't stop that... you may need to get in and cut out the delams. Then build back up with foam or solid glass.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Did you drill through just the outer layer of glass? If you drilled all the way through the resin is leaking into the hull.

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Nope, very cautious. No leaks due to holes drilled by me and using a mirror and flashlight through the inspection ports just froward of the pylons, here doesn't seem to be any seepage through the base fiberglass either.
I expect I'll have to cut the top layer off with the Dremmel and replace the foam but I really don't want to do that if at all possible.

You can try more GitRot. It is possible that the layers expanded with the pressure of the resin going in, but after that it continued to flow further out which left voids.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Foam replacement is the easy part. Get some two part closed cell stuff, mix it up and pour. Let it sit for a few hours to insure it has all gone off and cooled, and shape with a Sureform tool.

Use some heavy glass to finish. I like the stuff that's a combo of woven and mat. Put a light coat of resin on the foam and let it go off before applying the glass. That'll keep the foam from sucking up the resin applied to the glass.

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Thanks, I intend to give it one more round of CPES and see if that starts to fill the voids. The small soft spots have hardened very nicely but the center sections are still spongy.
If the second dose doesn't make a substantial difference I'll be foaming and glassing away.

Cut one soft spot open this weekend. Found very little delamination between the top and the foam. Instead what I found was that the bottom of the foam had separated from the inside of the hull and that the inside had lost much of its integrity. My sponginess isn't from delam on the top but from failure of the inside bottom.
Not sure how to correct this but am thinking about turning the hull upside down, making a few small access holes and flowing regular epoxy resin into the hull so it coats the inside of the hull top (now bottom when upside down).
Thoughts?

All this is going to do is add weight, not strength. The fiberglass deck skins need to be bonded to the foam core of the deck. Coating the external surface of the bottom skin with epoxy will not achieve this. You need to get the epoxy between the foam and the fiberglass skin either through injection or by cutting off the top of the deck (outer glass skin and foam core), coating the bond surface of the bottom skin with epoxy, and then sticking the top of the deck back on (yuck). If the fiberglass inner skin is also fractured, then that also needs to be fixed by laminating new glass.

If you can't fix it by simple injection, it's going to take a lot of work to get these 29 year old hulls back on the water.
sm

I guess that's what I was going for, a solid inner skin for the foam to rest on and then more CPES to re-make the connection. Right now the inner doesn't seem capable of supporting a good bond as I get about 1/4 inch of deflection when pressing in on my softest parts. It doesn't leak through when I inject from the top but it's so spongie that I'm sure it will give way if stepped on while righting.

two quarts of git rot seems like another problem The stuff must be leaking somewhere. Sometimes even a hobie hull must be retired old ones are pretty easy to find and are good insurance when you are offshore and the wind is blowing like stink Easing the worry of failure in the back of your mind is worth the cost of some old hulls

FlyNavy:
This is just a thought, is it possible the git rot is too thin and able to drain a little too much. I've had pretty good success with just West 105 epoxy thinned with 5-10% denatured alcohol (also quite a bit cheaper when you are talking gallons). I use those empty fillable caulk tubes they sell at West marine, you can develop quite a bit of pressure with the caulk gun, pumps into all the nooks and crannys. Might be stronger as well. Just hope the boat still floats when your all done though.

I have never worked on an H16 hull, but have had to fix rot and delamination on several boats, one test I do to see if I have the viscosity right on the epoxy is to pour some over a test strip of scotch brite, if it's a solid brick when your done, the viscosity is correct, if it is still spongy and flexible, the viscosity of the epoxy might be too thin. I'm guessing none of this applies to your repair, but it never hurts to think things through. Also everything has to be very dry inside in my experience, if it's still wet inside the epoxy turns white and doesn't wick in and work properly in my experience.
Bob

4 quarts.

My repair of an '80 H16 port hull this summer took 4 quarts of git-rot ~$220. If a good hull was close I might have grabbed it.
The hull was soft bow to stern. I injected the epoxy in the center hole. Sometimes it took a second application to fill.

Other tips:
Poke a small hole in the applicator. (I used a bike spoke)
Try a 4" hole to hole pattern. Git-rot packaging suggests 2". I found this to be too close.
Use formula 27 over the top of the holes.

Good luck, Blair (kansas)

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H