The top of the hull on my Mystere 5.0 separated recently where the bridal attaches and I am in the process of making the repair. Fortunately the front hull section has a cap on top that I was able to remove so getting inside to make the repairs is easy. My intention was to use West Marine Six 10 epoxy to re-attach the hull cap once I'm finished but I notice that the adhesive that was used oringinally is not epoxy. It is a white, poruous, somewhat brittle and chalky material. Is anyone familiar with what this adhesive is? If so is it still available? Does anyone know of a reason why I shouldn't use the epoxy to re-attach the hull cap? Only thing I can think of is that epoxy may be stronger and more difficult to break in to if there was ever a need to remove the cap?? If anyone has experinece with this please pass long your advice. Thanks.

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Steve - Texas Gulf Coast

91 Mystere 5.0 (sold)
04 Nacra 570 (sold)
08 Hobie Wave
00 Taipan 4.9
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A popular hull deck joint adhesive is 3M 5200. It is a very strong glue and really hard to take apart. I've heard there is now a product to help dissolve it if you do need to take it apart, but 5200 is a very strong and very permanent adhesive. It stays pliable enough to absorb some movement and not crack. If I had a hull deck joint to re-bond I would use some mechanical fasteners and a good bead of 5200. I've learned not to ever use it on something I might ever want to take apart again.

Geoff

Thanks for the input. I'll take a look at the 5200. Hopefully others will have some experience to share as well.

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Steve - Texas Gulf Coast

91 Mystere 5.0 (sold)
04 Nacra 570 (sold)
08 Hobie Wave
00 Taipan 4.9
--

You do NOT want to use 5200 to replace a deck lid (you called it a hull cap). That material in question is Mystere's own putty, and while working for a dealer in Florida 20 years ago, they called it "elephant snot."

I've made a similar version from gel, vinylester resin, fine pieces of chopped mat, and cabosil. You can try 10 Six but I don't know if it would lay up thick enough, as you're building pretty heavily in some areas.

I used the 610 on my Prindle and it seems like it worked well. I haven't take the boat out yet but it seems very strong. It's thickened epoxy and seemed to fill and stay put well. I cut a plywood piece that matched the deck, applied the 610, lay deck on with more 610, layed plywood on top of deck n hatchet strapped into position

I haven't done it myself but the decks on most cat's including yours are structural. A flexible adhesive/sealant (like 5200) wouldn't do it for that application, it would likely fail almost immediately. My understanding is that thre are three choices (all thickend) polyester resin, vinylester resin or epoxy to glue the decks down. Poly resin is not as strong vinylester or epoxy and shrinks much more than the other two. If you use pure epoxy you may never be able to get the decks off again without a reciprocating saw. Vinylester is a hybrid of the two, about half way in between for strength and shrinkage and likely be best choice

My vote is for thickened vinylester resin (you can use chopped mat or colloidal silica to thicken it). Seal with 5200 or sika 281 after the fact just for the extra assurance of leak tightness. If you can't get the vinylester for some reason the other two will do the job.

D.

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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I replaced a hull deck on my Tornado with SIKAFLEX 292 structural adhesive (as opposed to 291 the sealant) and it has held fine it is also easy to use and has a long cure time giving plenty of time to get it right, you need to use the activator with it but it leaves a partly flexible bond
link http://www.sika.com.au/cmi/pdfs/TDS_Sikaflex292.pdf
I believe originaly they used gelcoat mixed with beads to produce a thick paste to adhere the decks

Thanks for all the comments. I called both West Systems and 3M technical support. West systems (Six 10, 106/206/406) did not have an offering jto reccomend that would not be permanent. 3m recommended 5200 for permanent application and 4200 or 4000 UV for a non-permanant application. The 4200/4000UV have about half the tensile strength as 5200 (300 psi versus 600-700 psi). I checked out the Sikaflex 292 and it is polyurathane based adhesive similar in properties to the 3M 5200 (580 psi ). To my knowledge this is the first time the hull deck has been off in 20 years so odds are I'll never need to take it off again but I think I would still prefer to go with a non-permanant adhesive just in case the need does arise?? If anyone is familiar with the 4200 or 4000 UV let me know what your think about these options.

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Steve - Texas Gulf Coast

91 Mystere 5.0 (sold)
04 Nacra 570 (sold)
08 Hobie Wave
00 Taipan 4.9
--

The nice thing about the adhesives (5200 and 292) is that you can cut through them with a sharp knife or razor when you need to remove the decks. I would still be a little concerned because they are both flexible adhesives and I believe the deck needs to be rigidly adhered to the hull to provide stiffness. If 292 works for the Tornado though it would probably work for you. YOu need the adhesive strength so 4200 wouldn't be the right one to use.

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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I would strongly suggest you not use anything that is even remotely "Removable"
I would suggest the strongest bond you can get. If you ever have to get back in the hull deal with it when that time comes. If you plan to come back out and sail in the surf with us i would suggest a very strong epoxy, adhesive, etc.

I wouldnt want you to try with 5200 and end up sinking the boat offshore. You got very lucky last time and made it in before she sunk! I would use the material with the best bond and highest strength.

I suggest making it as pemanent as possible! U dont want it coming off again!

This is Teddy from Surside by the way. I was there. I witnessed the beauty of the hidden 5 gallon bucket first hand!

Like Teddy said, just use some thickened epoxy and be done with it. The decks need to be rigid.

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Rob
OKC
Pile of Nacra parts..
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quick Q yurdle

you ahve a N5.5 and N5.2

when the N5.5 came out nacra boasted it was longer, wider and lighter than the 5.2...

but i see from the texel ratings that the N5.5 is rated as being heavier...

what's your gut feeling on this

which is lighter the 5.2 or 5.5?

You guys have me leaning towards the rigid permanant option. The original puddy was not flexible but not sure whether it was intended to be removeable or not. Once the deck cracked loose it came apart fairly easy but not sure it was intended to do that (might be why it failed). I'm thinking of sticking with my original plan and using the West Six 10 thickened epoxy but it still makes me a little nervous to not have an option to get back inside if needed. Guess that is no different than it was before. Thanks for sharing your experiences.

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Steve - Texas Gulf Coast

91 Mystere 5.0 (sold)
04 Nacra 570 (sold)
08 Hobie Wave
00 Taipan 4.9
--

Aye the epoxy is strong and sticky, but that doesn't mean you can get through it if you need to. If you thicken it some you can make it go farther, and soften it a touch at the same time. It will still be rigid in the way you need it to.

E: I wish I'd spent more time with the 5.5 than I have...if so I'd be able to tell you. So far my gut is that they're about the same, maybe a few pounds one way or the other.

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Rob
OKC
Pile of Nacra parts..
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