Hobie Forums

delamination repair
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Author:  stuckonanisland [ Mon Jul 30, 2018 12:35 pm ]
Post subject:  delamination repair

I have a question for the experts. I have a large soft spot on the inside of one hull basically under the forward pilon. I plan on using injection of resin to repair it. My question is can I use qcell like in ding repair on a surfboard to get more volume in the fill area? The area is about 10" X 18-24". This is the only soft spot on either hull and I really would like to save it. Thanks ahead of time.

Author:  mmiller [ Tue Jul 31, 2018 9:04 am ]
Post subject:  Re: delamination repair

The void is paper thin. Like pages of a book. You want to avoid expanding the layers with a bunch of material, so minimal pressure and allow the material to flow outwards of the injection spots.

You can possibly anchor the layers together by injecting a small amount in a variety of places... let it set up... then come back for the broader area once the layers are partially held together.

Author:  stuckonanisland [ Tue Jul 31, 2018 2:05 pm ]
Post subject:  Re: delamination repair

Outstanding, thanks for your reply. I am going to pull the hull this weekend and get to work. Thanks again

Author:  stuckonanisland [ Wed Aug 08, 2018 9:55 am ]
Post subject:  Re: delamination repair

I have got quite a bit done with the repair. Seems to be going well. propped hull up to get gravity to help with flow of resin, working my way up the soft spot. Had to stop due to incoming weathers. covered everything with plastic to keep it dry. Had another question: Why would only one hull have any issues? I cannot find anything on the other. Also both hulls have had a less than optimal paint job on them. going to get to sanding them both down after the repair. Planning on re-gel coating them. Or is there a better option as far as durability and integrity of the hulls? Thanks for any input as I am learning as I go.

Author:  srm [ Wed Aug 08, 2018 12:15 pm ]
Post subject:  Re: delamination repair

There are a few reasons one hull could delaminate and not the other. Most likely it is due to inconsistencies in the manufacturing of the hull. Hobie (especially early on and also later when Hobie was cranking out thousands of boats a year) did not always have the greatest quality control. You have to keep in mind that manufacturing the hulls is largely done by hand. The operators layup pieces of fiberglass cloth and foam into a mold and manually "paint" on resin to glue everything together. If there are voids between the cloth/foam (bridging) or if there are "resin starved" areas, the hull will be weakend. It may take years to develop, but the weaker areas will eventually develop into areas of delamination (soft spots).

Another potential cause of soft spots would be if the hull was damaged at some point. For example, if someone backed their car into the hull, dropped a heavy object onto the deck, repeatedly stepped on the decks, or over-tightened trailer tiedowns across the deck, this could cause the inner fiberglass skin to crack and/or the foam core to be damaged which will eventually lead to a soft spot. The soft spot may start out small, but with repeated flexing, it will continue to grow.

The last cause would be if the hulls were stored for long periods of time with water in them, the water can eventually migrate into the fiberglass and the foam core. Excessive moisture inside the hull combined with seasonal heating and cooling of the hull can cause delamination.


Author:  speed633 [ Wed Aug 08, 2018 12:39 pm ]
Post subject:  Re: delamination repair

Soft spots on top of the hull in front of the tramp are often caused by clumsy apes like me. If someone was monkeying around on your hull and fell, driving a knee hard into the deck, the hull might be damaged. Over time this can grow as people jump around on the bows raising the jib.

As far as the paint, not sure if anyone can tell you whats underneath. Ideally you will be able to strip or abrade the paint, without taking out the gel coat. For the most part the gel coat holds up quite well, even if it fades a bit. Once you get rid of the paint, a quick day or two of polishing will bring back a lot of the lost luster in your gel coat.

There is a pretty good chance the bottom of the hulls is missing gel coat (probably left on the beach). You can reapply gel coat just along the bottom, throw more glass at it, or just accept that your boat looks better upside up vs upside down.

Author:  stuckonanisland [ Wed Aug 08, 2018 1:27 pm ]
Post subject:  Re: delamination repair

The decks on this cat are both in good shape. the inner side of the starboard hull is where the problems were found. I'm patient and willing to do the work. The bottoms are going to get a new layer or tow of glass as I get closer to putting on the gel coat. They have been worn down some but still showing blue "primer". I am using boatyard resin with what I am thinking are great results. The areas injected are rock solid. I just need to get the time to finish with the filling. Hopefully removing the paint well enough to get the gel to adhere good is my next concern. Wish me luck!

Author:  rattle 'n hum [ Thu Aug 09, 2018 3:05 pm ]
Post subject:  Re: delamination repair

I'd recommend that you check to make sure the pylon shoe is not loose while you're at it. That's where damage from a loose shoe would occur, but usually it cracks the hull from the inside out. Plenty of info on the forums for the (much more involved) loose shoe repair.

Author:  speed633 [ Fri Aug 10, 2018 1:40 pm ]
Post subject:  Re: delamination repair

I had a loose shoe once... wasn't too hard to fix and it has stayed fixed for 10 years. Compared to the paint stripping and gel coating the loose shoe is a relatively quick fix, IMHO. In my case it was pretty obviously loose (clunk clunk) and there was a pretty clear telltale crack on the inside of the hull, alongside the pylon.

Author:  stuckonanisland [ Mon Aug 13, 2018 6:24 am ]
Post subject:  Re: delamination repair

Well so far so good. everything is rigid I did find another soft area and it seems to have the crunchy foam sound this on outside of same hull midway between the pylons. Well here's to another day of drilling and filling. I was wondering if a micro-fiber filler can be used prior to gelcoat? The large area that is now filled and solid as can be has a slight low spot in it. Also has anyone used traction pad type material on the top of the decks? Seems like a fairly good idea. Thanks for any input

Author:  speed633 [ Mon Aug 13, 2018 8:05 am ]
Post subject:  Re: delamination repair

There are a variety of fillers that work well with polyester resin. Even when mixed to a peanut butter like consistency these fillers have a tendency to sag a little, so try to apply to a horizontal surface.

As far as improving your food hold while trapped out:

Author:  srm [ Tue Aug 14, 2018 7:27 am ]
Post subject:  Re: delamination repair

Formula 27 is a fast drying polyester based putty that works well for filling and fairing uneven surfaces.

Regarding traction pads, they really aren't necessary on the decks. You will basically never be standing on any part of the deck of a Hobie 14 while sailing (and really should avoid standing on the decks at all times to prevent them from delaminating).

But it's definitely a good idea to put traction material on the side rails from the shroud tang aft. This is where you will be standing when trapped out.


Author:  stuckonanisland [ Tue Aug 14, 2018 2:22 pm ]
Post subject:  Re: delamination repair

Thanks I will pick up some of the 27. Appreciate the input Another question for anyone if the foam is crunchy should I be a little more aggressive when pressing around the soft area that way the resin will surely flow into the area completely or just let it be and fill as before? I really dont get it though one hull has the softness and the other has none to be found. Oh well keeps me busy(out of trouble) and eventually my son will have his Hobie

Author:  srm [ Tue Aug 14, 2018 5:40 pm ]
Post subject:  Re: delamination repair

Flex the soft area (push down and relax the hull repeatedly) to help disperse the resin around the delam while you inject the resin.


Author:  A1cnc [ Wed Aug 15, 2018 6:38 am ]
Post subject:  Re: delamination repair

When it comes to removing the paint, I would use a stripper made for fiberglass and plastic scrapers. As others said the gelcoat is pretty tough. You may find it to be in surprisingly good shape under the paint unless they really sanded the heck out of it before painting.

One other possibility is if the paint is rough but well adhered you could try wet-sanding it to smooth it.

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