Patching a Dinghy

[zeehag]

sailvyu--west marine dinks are , last i heard, made of pvc. they last 5 yrs in temrperate zones and lots less time in tropics. they do not repair well at all.
hypalon needs the 2 part glue and mek to clean the abraded surfaces. nothing else works well enough to call it fixed. i know--had a dinghy--achilles hypalon, 1984, with 64 holes in it--i made that dink last 4 yrs without needing patch renewal.
is worth doing the patches correctly.
have funa nd good luck. the 2 part glue, last i bought any , was 14 dollars for the glue. i had to buy my hypalon bits separately , as well as the mek. good luck.

[SV Demeter]

Used the two part glue. No MEK sorry Zee. Used alcohol then acetone then abraded with 60grit then more alcohol and acetone. Glue was a real PITA to mix though. Seems to have kicked off and patch feels very well attached. Need another 48hrs before I can really pump up the dink. Have about 80% inflated now.
Thanks everyone.

[ErikFinn]

ok, I seem to have f***ed up my hypalon patch repair. Everything went well until just before the finish line when I was positioning the patch over the target area I somehow managed to get it just a little bit off the correct place, position was just difficult enough for me; tried to pull it off but managed to tear the hypalon outer layer off the tube. I'm gutted. Well I just pressed the patch there but to say the least I'm less than satisfied.

Lessons learnt:
1) Never ever use antifoul paint on Hypalon. (The previous owner had done this, causing blistering and delamination of the hypalon)
2) Never leave your dinghy out deflated with kinks and bends on the Hypalon, this will stress and eventually damage the hypalon.
2) If the spot is in a difficult place, better let a professional do the job. Unless you are happy with a not so great result. ( I suppose I could do much better job now that I've "practised" but I hate this kind of learning... )

Question is: Is there an easy way to take the patch off? I used Hypalon 2-part glue. (Not sure what brand, it came from a Hypalon repair shop.

[hellosailor]

"Question is: Is there an easy way to take the patch off?"
From what I've been told, a two-part hypalon adhesive makes a fusion weld. The new material is literally fused into the old, and there's no way to separate them. Which would leave you with grinding it down/off, the same way a shoemaker grinds down extra material.
If you can patch next to it, or over it all, and leave it in place, that might be the best fix.

[zeehag]

eric finn--just patch over the two patches and make them one. it works, i promise--i had a 62 patch 1984 achilles dink last for over 4 yrs of hard use. 2 part glue and more hypalon... goodluck!

[Sailorman Ed]

+1 for 5200 but note, I think it says NOT to clean with alcohol and you need to keep it out of the water for at least 24 hours (should be 48hr) I also used the 5200 to build up a water leak where the transom hinged to the rigid bottom, not perfect and not pretty but no more water coming in.

Now, anyone got a suggestion for my bent nylon oar lock (WM Zodiac) with the old style. The new stronger replacements were about $70 I think - ouch!!

[seacap]

West System G/Flex. Just did a difficult repair next to rub rail (hypalon). No more leak.

Local bareboat company uses G/Flex for all there inflatable repairs.

GL

[landonshaw]

Fixed the dinghy no leaks! Came into Rodney Bay, St Lucia in stormy weather. Put the dinghy down from the davits and got it caught under the swim ladder. BIG pop and BIG hole!! My wife was happy because she did not like all of the patches. It was 17 years old. I thought it had a few more years.
Now we have a new Zodiac. I hope it lasts for another 17 years for what is cost. Nice having a new dinghy though.

[zeehag]

shoot--all i want is the older avon someone wants to rid selves of for a newer rigid--i want a roll up..LOL even with many patches....

[ErikFinn]

Well my "practice patch" holds air well, but with the help of soap and paintbrush I found two more small slow leaks. Not a problem in itself now that I'm better at patching, LOL.
The RIB is Australian made "Swift 290M" hypalon dinghy with an aluminium hard bottom. Its now 9 years old - manufactured 2004 - and it planes with just me aboard with the 3hp Yamaha 2-stroke outboard. Its a good package, not too big and not too heavy, the outboard weighs 16,5kg (about 36lbs) and the RIB about 45kg/98lbs but unfortunately the maintenance has been neglected. A new comparable RIB costing around 2500 USD I figure I'll have a professional service it in Langkawi or Phuket and hopefully I can then still get a few more years of reliable service out of it.
BTW, I was in contact with Swift Marine as they claim a "10 year Fabric Warranty", but I was told to send it over to Australia (from Malaysia) for inspection, which I kindly rejected...

[hellosailor]

Erik-
FWIW Zodiac used to make their liferafts and dinks with glued seams, and the French government prohibited the life rafts from being recertified after ten year of age on the grounds that the glued seams simply become unreliable at that age. So Zodiac-US said, directly.
I don't know if that reflects glue technology, or a poor choice of something at Zodiac, but you might want to contact the maker and ask them how well their products age, since your dink is now reaching the same magic age. Playing "whack-a-mole" with leaky seams can be a very futile exercise.

[night mission]

Preparing to repair a small hole on an Achilles. Got the proper materials, (2 part PolyMarine, TEK, and hypalon patch). Have read the suggestions on this blog and other sources. My question. I have seams that have pulled away as a result of scraping along 2x4 supports on a dingy rack. I would like to glue them down at the same time I patch the hole. I figure to have plenty of adhesive (250 ml) and would like to reseal these (non leaking) seams. Anyone have an opinion, for or against doing this. Suggestions would be welcome.

[hellosailor]

night, there's only two ways to seal bad seams.

First, get exceptionally lucky and just glom in new glue.

Second, and more reliably, you need to open up the seams, clean off all old glue residue with sandpaper, solvent clean the material, and then reglue them. Not an easy job because if the seams aren't opened up and really cleaned perfectly, the glue will only hold the old failed glue together and they'll open up again.

[night mission]

Thanks for the reply. The seams aren't leaking, I only want to keep them from peeling back any more than they have already. I definitely don't want to do anything that would create a problem that doesn't (currently) exist. I'll clean the seems throughly and glue down the flaps. I need to figure out how to keep the couple seems compressed while also patching the known leak.

[hellosailor]

If the seams are still holding and you just want to reinforce them, then you might want to apply a strip over them, maybe 3-4" wide so it overlaps both sides very well. Ideally hypalon but I would expect you could find rubber tape at a professional electrical supply house (it was used to waterproof splice) or cut long strips from truck inner tubes, which can sometimes be had for free at tire shops--with the odd puncture in them.

To keep them compressed, sandbags, bricks, phone books....couple of 2x4's and some c-clamps or cinderblock weights if they can be made to fit?