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Hobie 16 Hull Delamination Repair Resin Type
http://www.hobie.com/au/en/forums/viewtopic.php?f=20&t=70455		 Page 1 of 1
Author:  Kitsuneonbass [ Wed Nov 30, 2022 5:24 pm ]
Post subject:  Hobie 16 Hull Delamination Repair Resin Type
G'day Everyone.
Can't seem to find if this has been posted before, so I'll ask here.
I have two 1970's era Hobie 16's and have to fix some delamination on both of them, especially forward decks (too many years out in the Queensland Sun).
The old girls are only being used for family fun, their racing days are over.
Thing is, I know HOW to fix the delamination, the question is, what type of resin??
West system epoxy?
Polyester resin?
Vinyl ester resin?
Can't seem to find a consensus on what type is best!
Any professionals out there who have done this successfully?
Thanks in advance.

Foxy
Author:  rattle 'n hum [ Tue Dec 06, 2022 3:13 am ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
I have done/seen this repair done several times. I believe that the consensus is to use epoxy since it's stronger (and less expensive?) than poly or vinylester. The West System products are nice and pricey, but there are lots of alternatives (in US at least). I've heard Git-Rot and G-flex recommended. Personally, I use the cheapest laminating epoxy I can find...like from these guys.... [url]https://fgci.com/shop/?filters=product_cat[68][/url]

It's not like you are building a wood strip canoe, furniture, kitchen countertop...you just need the strength.
Author:  srm [ Tue Dec 06, 2022 10:27 am ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
I agree, use a low viscosity laminating epoxy resin. If the resin just runs into the hull, then you may have some voids in the inner fiberglass layer which are allowing the resin to pass through. In that case, you can try adding thickener, but I would start with just straight resin.

You can’t go wrong with West Systems. I personally use epoxy from USComposites.com. They are a lower cost option that has always worked well for me.

sm
Author:  ChuckC [ Tue Dec 06, 2022 11:15 am ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
Definitely epoxy resin - it "glues" better than polyester or vinyl ester. Don't know why, it just does. And, for this project, the cheapest "laminating" resin you can find (won't really be "cheap"). You want laminating resin for its thin viscosity so it'll flow into the holes you drill. Slow set to give you time, etc.

Good luck!
Author:  Kitsuneonbass [ Mon Dec 19, 2022 7:49 pm ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
Thanks guys.
Epoxy (especially Wests) is the most expensive type here.
Was going to use Vinyl ester, but might give the epoxy from Boatcraft Pacific a try first.
Cheers,

And a Merry Christmas to all!
Author:  mmiller [ Thu Dec 22, 2022 12:20 pm ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
Be sure it is laminating resin and not finishing resin. Laminating resins are somewhat flexible when cured. That is better than hard and brittle.
Author:  Tim H16 [ Sun Dec 25, 2022 11:49 am ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
Matt,

If a finishing resin is "hard and brittle", then is it more resistant to abrasion from sand? For example, is it better for a "bottom job touchup" where the existing fiberglass cloth is still intact?

I do a bottom job on my 84H16 about twice a year and for the last two years I have been using the vinyl ester resin with the polyester gelcoat with good results.
Author:  mmiller [ Mon Dec 26, 2022 1:57 pm ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
Gel Coat is hard and brittle, so good for a stiff wear area (keels). The deck delamination areas are somewhat flexible, so less brittle material is preferred.
Author:  dchall8 [ Thu Feb 26, 2026 11:06 pm ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
I'm not a fiberglass guy, so I'll stay away from the ins and outs of that aspect of the boat. I do have a suggestion, though.

I had a 70s era and an 80s era 16 back in the day. The older one was owned by a dentist and pretty much junk when I got it. The decks in front of the pylons were soft. It was my first boat, and I never knew better. My experience with the drain plugs was that I never got all the water out of the hulls. Whatever - I let my ex have it when she moved away. The newer boat was owned by a professional Hobie cat guy. When he got the boat new, he cut a 5" inspection ports about 10 inches in front of the pylons and covered them with inspection port covers from Viking Marine. But today you can get inspection port covers on Amazon, so that's easy. The idea of the covers was, of course, to cover the gaping holes in the hulls. They kept most of the water out, but not all of the water. After a day of sailing I placed the boat so that the stern was raised enough to make the hulls below the access holes the low spot. Then I sponged the water out of the hulls and left the covers off over night for full evaporation. I never once opened the drain plugs on that boat. When the hulls were completely dry, I screwed the covers back on. The decks and sides of that boat were like new when I sold it.
Author:  Tim H16 [ Fri Feb 27, 2026 2:34 pm ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
To drain the water out of the hulls of my 84H16, I use my trailer to drain the hulls.

1) back the trailer down so it's wheels are a few feet from the water's edge (I do not put my trailer in the saltwater due to corrosion).

2) float your boat so the bows are just barely on the trailer's rear rollers.

3) connect the trailer winch strap's hook around the front cross beam next to the mast step (don't connect the strap to either the dolphin striker rod or post, as this could cause them to bend or cause problems with your mast step).

4) use the trailer's winch to pull the boat up onto the trailer until both of the transom drain plugs are just barely out of the water.

5) open the transom drain plugs to drain the water out, then partially screw the plugs back in so the hulls can breathe (remember to tighten your drain plugs next time before launching the boat).

Image



I personally would not add 5" access ports in front of your forward pylons just so you could get the water out of your hulls. This is a very stressed location and the holes only make it weaker. Of course, if a bow already has severe delamination or a pylon boot has come loose, then you may need to put an access port in (preferably just behind the forward pylons is better location). You may also have to add access ports between your rear pylons an transom, if you need to rebuilt your transoms or thru bolt your gudgeons.

Image
Author:  dchall8 [ Wed Mar 04, 2026 11:18 pm ]
Post subject:  Re: Hobie 16 Hull Delamination Repair Resin Type
Tim H16 wrote:
I personally would not add 5" access ports in front of your forward pylons just so you could get the water out of your hulls. This is a very stressed location and the holes only make it weaker.

Yikes! Picture is worth a thousand words. I had heard that the area was weaker, but it was more like an urban legend than something anyone had experienced. Matt, since you were at the company for some time, do you have a handle on hull breakage and where it's most likely to happen?

For what it's worth my boat had been sailed, overloaded beyond the min crew weight by 50 pounds, in very heavy wind where we capsized 3x in one race. The ports in the boat were several inches fore of the break on that boat. I'm not trying to imply anything or say I wasn't sailing perilously close to calamity. The port hole cover was screwed in and not caulked, so the screws and the cover parts would carry the compression forces. Another aspect to this is that holes are often drilled into shell structures to temporarily relieve the stresses from a crack. Usually the hole is very small relative to the length of the crack.

Let's see. The bottom of the hull would be in tension from weight bearing on the pylons and upward forces at the bridle. The deck would be in compression from the same forces. Lots to think about. This is something that would require data on hull breakages and analysis of the causes.

Anyway, thanks a lot for confirming the legend and posting the photo.
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