RIB repair. Hypalon and ?

[skipmac]

Originally Posted by Scout 30

I've got the exact same problem. My rub rail for my '99 Avon R3.41 is sitting on a shelf in the garage. I'm also getting a little lifting around the wood transom. When I called for an estimate a few years ago it was about $500 so I didn't bother since we use our Bauer 10 most of the time. But I will have to tackle this at some point so I'd be very interested to hear the results of your repair.

Keep watching this thread for more opinions and if/when I do the repair I will certainly post the results.

Originally Posted by Scout 30

FYI, the guy I talked to about the repair said that they would use a 2 part hypalon glue & sand the boat & rubrail thoroughly to get off all of the old glue.

I did a trial sanding and this will be a problem. Parts of the old glue (the areas that are very dark brown, almost black) are dry and hard and take a LOT of sanding to get to Hypalon. Areas that are light brown are still tacky and gooey and just ball up and clog the sandpaper. I'm thinking it might take a month of Sundays to sand the dink sides clean.

Originally Posted by Scout 30

On a previous thread REMA SC2000 was given a good recommendation for a transom repair but I've also read about good results with 5200. It was also recommended that I mix the white & black 5200 to get a matching color.

Saw the same. On a couple of older threads several people reported great results and years of use using 5200 but the SC2000 is usually recommended as the correct stuff to use.

[a64pilot]

Try a Dremel with the flexible cable for sanding, maybe even use a wire brush on it.

Might just be possible that Toluene may soften the glue if left on it with with a rag wetted with it?

[skipmac]

Originally Posted by a64pilot

Try a Dremel with the flexible cable for sanding, maybe even use a wire brush on it.

Have been considering this but makes me a little nervous getting that aggressive with my dinghy fabric. Would hate to go to deep and end up with a big hole.

Originally Posted by a64pilot

Might just be possible that Toluene may soften the glue if left on it with a rag wetted with it?

Got most everything in the shed except toluene so headed out later today to find a can and give it a go.

[Chuck Hawley]

I have a few thoughts:

1. The rub rail is not PVC, but probably an extrudable material that has good UV resistance. Look for materials that are compatible with Hypalon, not PVC.

2. Avon used to recommend two glues, which may still be available. For small repairs, they recommended one-part Barge cement. For large repairs, they recommended Bostick glue, which is two-part and more finicky. In fact, I think the original construction of the boats was done with Bostick. As with many issues with inflatable boats, having a clean, rough surface is vital for a good glue joint, as is the temperature and humidity of the conditions under which the repair is made.

3. Rubbing out the air bubbles and getting a really good contact is vital. There are rolling tools (perhaps that could be used for wallpaper or other tasks) that press the pieces together and work all of the air to the edges. I think you can do this with an inflated boat, but pressing against a hard underlying surface would be better if you can keep the fabric flat.

If you use something like 5200, I think you'll only get one chance to do a good job. I'd try a purpose-made cement first.

Chuck Hawley

[hamburking]

I had an Avon Rover 2.81 with the exact same problem. It was particularly annoying when deflated when the rub rail was still holding on a bit. I refrained from tearing it off, and sold it (pretty cheap, with full disclosure of course).

Aside from that, pretty excellent dinghy!

[DrDelmas]

I just did this repair 6 months ago. I sanded the old glue off and cleaned the dingy with. MEK. Using MARINE GOOP, I applied to a 3 foot section at a time and held for a few minutes and kept repeating till all the rail was attached. The temperature was in the 90's which sped up the curring time. I also masked the area.

[Scout 30]

Originally Posted by DrDelmas

I just did this repair 6 months ago. I sanded the old glue off and cleaned the dingy with. MEK. Using MARINE GOOP, I applied to a 3 foot section at a time and held for a few minutes and kept repeating till all the rail was attached. The temperature was in the 90's which sped up the curring time. I also masked the area.

Just reading about Goop. I've never use it but sounds pretty good. Are you happy with the results so far?

[anacapaisland42]

I used Home Depot roofing paint, plasticated, I think it's called White Night, $42 Canadian gallon, 5 coats, good thick layer, looks nice and s t r e t c h e s
Bill

[coolboat30]

Be careful with the toluene. It's hard on your brain cells.

[a64pilot]

This is the ticket for rolling out air bubbles and making the glue stick well, cheap too.
http://www.amazon.com/Wooden-Handle-...s=patch+roller

[Jim Cate]

Don't know about Avons, but the rubbing strake on our Gemeni Hypalon RIB was indeed PVC. According to friends who are dinghy professionals, regluing an old rub rail on a Hypalon dink is very difficult, for in their opinion there are no glues compatible with both materials. There are several problems: 1. Getting the original glue off and the surfaces clean enough for t he contact glue tpes to work well. 2. The PVC has lost much of its plasticizer and has become stiff, making good contact between the surfaces difficult to acheive. 3. This stiffness also increases the forces that try and separate the strake from the hull in normal flexing, and in particular when folding for storage. These pros didn't anticipate a long lasting repair for folks like us who use a dinghy daily and deflate/store it on deck frequently for passages.

Ignoring their advice, we tried several time, using first SC2000 and then when tht failed, a variety of sealant type glues (not including 5200 which was not available where we were). None of these fixes lasted more that a few weeks.

In the end we removed it. Turns out that it is a spray deflector as well as a rubbing strake, and the ride was somewhat wetter. Also worried more about oyster shells etc! In the long run ( maybe a year or so later) the dinghy became quite porous and wouldn't hold air well, so we replaced the tubes. Problem solved.... for a while!

Jim

[Antilag]

Originally Posted by skipmac

Thanks Antilag. Do you happen to recall what brand?

Sorry, I don't remember the brand. Apparently Rema tip top makes a glue that is excellent, but finding it locally seems a hastle.

[hellosailor]

If you can't be sure of an adhesive, maybe 3M's VHB tape would do instead? The wealer versions of VHB are used to permanently bond side moldings on cars, and they just never seem to fall off. VHB is flexible, and at least if it falls off...you won't have to scrape off old glue.


For "clamping" either glue or VHB, I would take the dink ashore, deflate it slightly, then wrap a line around it, from head to tail, all the way on the outside of the whole thing. Reinflate to full pressure, and voila, you've clamped the whole rail under good tension.


Offhand I think VHB takes 48 hours for a full bond to set up, I'd plan on that much time for any material.

[poiu]

I have an Avon too and recently re-stuck the rub rail. I previously tried 5200 as a quick fix for small areas. It worked for a while, but it started to fail and the rail started to fall off in a big way, so I got a tin of Bostik 2 part and re-stuck the whole rub rail. I used toluene to get the old glue off, but I tried acetone too and that was ok. The clean up of old glue was the biggest job. End result was a good strong repair.

I used an edge roller too to press the material together. Buy a good one, mine broke near the end of the job - too flimsy.

If the Bostik isn't easy to get then I imagine there are many other 2 part adhesives specially made for hypalon out there that will work fine.

It was a day of work, so your cost quote isn't a mile out at yard rates.

[jcapo]

Strange that my 3M 4000 attached rub rail holds fine after 3 years of constant UV exposure and 3M 5200 attached rails fail.

Prep maybe.