Breathe New Life Into An Old Rib

[Seafarer]

There's a crusty old sailor in a local basin who lost his dinghy and was given a leaky RIB. He's been trying to patch the leaks for a couple of weeks now, but having little success. Thinking about his problem gave me the idea of pouring 2-part urethane foam into the tubes and allowing it to expand. This should completely fill the tubes and restore their shape, while returning their buoyancy.

However, I'm not sure how permanent of a solution this is. I know urethane foam is supposed to be a close-cell foam, but I still hear people talking about it absorbing water if left in constant contact. Does anyone have first-hand experience with this stuff?

[Gallivanters]

"First-Hand experience?"

No

But a very close friend tried this solution when I lived in Guam and the results were not so great, mainly because the dinghy became so heavy and could no longer be considered a yacht tender. It was impossible to lift on deck and a pig to tow. It could still be used to get from the boat to shore but it would no longer stand-up on plane and it took a number of people just to drag the bow onto the sand... and an entire Navy to drag it on it's last voyage to the dumpster. The cost of enough foam to expand the tubes to a low-on-air "looking" state ended-up costing him nearly $500 USD!

Everyone within our circle of friends all concluded that a better approach might have been to remove all of the old tubing and then turn the RIB into a conventional fiberglass dinghy by glassing sides onto the hull section... which another friend did with the same wreck a year later with much better success and at less cost... but greater effort. The result was a fast, light-weight and fine looking hard dinghy "recycled" from a dead RIB.

We needed a chainsaw to cut-up and dispose of the nasty old foam & muck-filled tubes.

To Life!

Kirk

[MMNETSEA]

As Kirk advised : Urethane foam not recommended.

Any idea re. the extent of the leaks? one or 2 places? only one compartment?

[JeanneP]

Many years ago we saw what was once a leaky old RIB with its tubes fiberglassed over. Actually, it was more like a single layer of glass, more to keep the resin immobile until it set. Air filled, it looked terrible but was pretty stable, and since the tubes were still filled with air, it wasn't terribly heavy. Never saw it anywhere except tied up to its owner's boat, but I assume it was functional since nobody tossed it.

[redbopeep]

There's a fellow here in town who gets worn out RIB's from the local dingy shop. He has a source for large diameter PVC and other plastic piping which is used in waterlines. He plastic-welds together a plastic pipe hull which he puts together with the RIB bottom (forget how that part goes together, sorry) and it works great. He makes these for the local liveaboards who are pretty destitute and need a tender. They last at least 5 years he says.

[Seafarer]

RedBoPeep, if you could find out how he makes it work, and what size pipe he uses, I would be in your debt.

I tossed out an add on Craigslist and now I've got people asking me to haul their old RIBs away...

MMNETSEA- to answer your question, one side seems to hold air pretty well. The other side has a fist-sized hole in it!

[redbopeep]

Originally Posted by Seafarer

RedBoPeep, if you could find out how he makes it work, and what size pipe he uses, I would be in your debt.

I tossed out an add on Craigslist and now I've got people asking me to haul their old RIBs away...

MMNETSEA- to answer your question, one side seems to hold air pretty well. The other side has a fist-sized hole in it!

Sorry, I have no way of contacting the fellow. I've just met him once in an anchorage but I do know that he gets the pipes surplus from some waterworks location--they're as big as the original tubes on the dingy were--big! He also obtains the RIB floors from a local dingy repair shop in San Diego--likely to be a place called the Dingy Doctor.

If I were you, I'd just experiment with it. If you've never done any plastic welding, etc, you'll have to read up on it a little bit and figure out what kind of plastic works best for this. I don't know anything about it myself.

Best of luck!

[babylonlarry]

Somewhere, I heard about the idea of taking truck tire inner tubes, cutting and sealing the ends, then opening up the dinghy tubes and inserting the tire tube with valve well positioned, closing up the works and keeping air in the rig. Seemed like a possibility I might try, but after about 20 patches in the hypalon, I found another RIB.