Patching a Dinghy

[GordMay]

Greetings and welcome aboard the CF, BobL.

Thanks for sharing.

[lancelot9898]

I used Tear-Aid Type A patch on my 25 year old Archilles a few months back and it seems to work well on a slow leaking seam. Not much prep either other than an alcohol wipe. On line it was about half the price that WM wanted. A box contains several patches and I think it's under $10.

[hellosailor]

IIRC the Gorilla Super Glue says "remains flexible" on the label. In contrast to regular "superglue" products, it is designed to be used on flexible materials. Could it be the hypalon miracle cure? <G>

[Jim Cate]

G'Day Landon and others,

The situation that Landon describes is a common one. All the approved Hypalon adhesives are contact cements. They have NO ability to fill gaps, just to stick two flat surfaces together. So, when trying to seal a leak near a lap joint it is difficult to bend the patch material so that it actually contacts the hull surface right along the edge of the seam, and a small leakage path is formed along that edge.

FWIW, (and I know that this approaches blasphemy) I have successfully used Sikaflex 291 and other similar products to repair these sites. One cuts the repair material in the conventional way, scuffs and cleans the surfaces with an organic solvent (MEK, Trichlor, acetone, etc) slathers the patch and base surfaces with the Sikaflex, being careful to fill the area along the edge of the seam, and assembles with light pressure. This is done with the tubes deflated, of course. Allow to cure for 12-24 hours, reinflate, and check for leaks. Has worked for me. Oh, I don't use 5200 because of the long cure time, but it would work as well if you were patient enough.

It may be true that these adhesives are not "approved" for use on Hypalon, but in fact they are not highly stressed in this application, and the bond strength is adequate to seal the low pressure air. I would not use them to bond on D-rings or oar locks or other stressed components though.

Cheers,

Jim

[kiltym]

I have at least 10-15 patches on our dinghy (yes, we need a new one if anyone knows a good used dinghy in the Caribbean for sale....).

Anyway, after 4 years and talking to lots of salty types, here is what I have found to work the best. May not be the prettiest and easiest to clean up, but the patches work just fine and stay for a long time, and costs way less then the fancy 2-part glue.

If you have a brand new dinghy and want it looking brand new still, hire a professional.

Anyway......

Deflate the dinghy so that there isn't a lot of air pressure in the tube. You still want some resistance, so not totally flat (assuming the leak isn't that bad).

Crazy glue on the actual place the hole is a great stop gap. It wont last very long (maybe a week), but will keep it sealed for a bit and is very easy to put some "gel" super glue onto the spot. Will set up in < 1 hr so its a fast way to get going again if you are in a rush.

Then I use 5200 (the fast cure one). And if possible, use 2 small boards and a clamp to apply good pressure for about 18-24 hrs. If its in a place a clamp wont work, you have to spend the time with your fingers and keep pressure on the patch until the 5200 sets up. As the patch starts to stick better, let some more air our of the tube so you are not pushing air pressure back under the patch. This usually takes 1-2 hours of patience to make sure the patch is OK. Then leave it for 18-24 hours.

Done this lots of times, works well. But, you do typically get some 5200 around the edges which some people might not like the appearance of.

Yes, do rough up the surface (both on the dinghy and the patch itself) and clean it as your would any patch repair too. Also, this is for hypalon, never tried it on PVC.

[GordMay]

Originally Posted by hellosailor

IIRC the Gorilla Super Glue says "remains flexible" on the label. In contrast to regular "superglue" products, it is designed to be used on flexible materials. Could it be the hypalon miracle cure? <G>

I believe it also says, "NOT for outdoor use."

[Tia Bu]

I've used 5200 on lots of dinghy patches, both on a hypalon and a PVC dinghy. It works great, especially in places where a patch can't sit flat because of a seam. The 5200 fills in the void quite well.

I clean the area very well with Acetone, rough it up with sandpaper, and, as others have said, keep the patch on during curing with a weight, a clamp, or even duct tape (careful getting the duct tape back off).

I use fast-cure 5200 and let it cure at least 24 hours before use.

[teejayevans]

Originally Posted by motion30

After reading these and other forums on patching a hypalon dinghy, I came to the understanding I could not match the conditions need to have a sucessuful repair. Its summer here and the humidity is high and I have no place beside the boatyard to work I called the local inflatable repair guy who picked up and delivered three patches and pick up was $220 and no leake

I quick check of my area doesn't come up with any "Inflatable repair" businesses, how did you find this guy?
Tom

[landonshaw]

I ended up taking my dinghy to Johnny Sails in Grenada. I have always found him to be slow, but his work has been very good. So, away 5 weeks, got back from the States and he is not done. Looks like he just started last week. Anyway, he has given me a dinghy until it is done. It was looking good and was inflated. Let you know haw it lasts.

[SV Demeter]

I have what should be a pretty straight forward patch on a caribe hypalon dink to do and am looking for some advice. We are anchored in the lagoon in St. Martin so if anyone is local give a shout either here or hail Demeter on VHF 14. I want to learn how to do this right.

The hole is not near a seam and is just a small tear or puncture about 1/4" in length. It had a temporary stick on patch that just failed. I bought a kit (Adeco for hypalon from Island Waterworld) with two part glue but the instructions are not very good. They say

1. rough up both surfaces.

2. Add 10% of the activator to the glue and mix well, mixture is good for 10 minutes. ( ok so how precise does this 10% need to be cause I dont have a good way to measure it)

3. spread the mixture on both sides and wait for 10 minutes, then spread them with another hand. (must be bad translations here, how can the mixture only be good for 10min but I have to wait 10 min for it to get ready?)

4. After 20 minutes put the two sides together and press carefully with a shaped piece of wood. (ok so now im waiting 20 minutes for the glue to induct or get ready for use but the first instruction said the mix was only good for 10 min? Assuming I can get blocks on the patched area should I clamp it up then?)

5. Work will be completed in 72 hours. (this is the hard part as we use the dinghy a lot, will have to make a plan to be dinghyless for 72 hours)

Last night I cleaned the area with alcohol and made a two piece patch with some preservation tape that has held well overnight but I doubt it will work for long.

[sailvayu]

I vote using 5200 fast cure. I have a west marine dinghy that the bottom came off, tried the expensive glue only to have it completely fail (I followed all instructions) before I could get it back in the water. The 5200 has held up for 2 years now with no signs of failing.

[SV Demeter]

Seems to be a lot of support for 5200. Thinking I will give that a go this evening. I figure if it doesn't work I can always clean it up and try the 72 hour method. Need to first see if I have some fast cure 5200 on board. Chandleries in st Martin closed today.

[zeehag]

DO NOT USE 5200 unless you wish a very ugly dinghy with incosistent patch function.
use mek to clean the newly abraded surface of hypalon, then when dry, use the 2 part dinghy glue. it is a very excellent fix and lasts many many many years. i know--btdt..LOL
have fun and good luck.

[hellosailor]

Ted, if you treat it like brain surgery, it should work. When I say brain surgery, I mean, surgical cleanliness bordering on sterile. Assuming that you've got the right glue (not outdated, not spoiled, not for the wrong material) most glues will fail if there is any contamination. So first, use alcohol or a similar zero-residue solvent to clean the area. Work your way OUT from the damage, expanding the clean area. Use paper towels & throw them away, the goal is to absorb and remove any possible contamination or leaching from the plastic.

Now go back and do it again. You do this before roughing up the surfaces, because sanding just embeds any surface contaminants into the material, ensuring failure if you don't start with a clean surface.

"1. rough up both surfaces.

"2. Add 10% of the activator to the glue and mix well, mixture is good for 10 minutes. ( ok so how precise does this 10% need to be cause I dont have a good way to measure it) "
>>Measuring can take some practice. Is the activator a watery liquid? OK, then buy an eyedropper, place ten drops of water or honey on a CLEAN surface, take a second eyedropper and place ONE drop of the water net to it, stare at it until you get a feel for the proportion. Or, take a piece of clean heavy foil, draw a square about an inch or two wide on it. Draw lines on the square to make it into a tic-tac-toe board, so there ar nine squares. If you cover the square with glue, and now just cover the center square with activator? Right, you'll have 9:1 so you'll have 10% activator.

The proportions are usually not critical, there's room for human error.

"3. spread the mixture on both sides and wait for 10 minutes, then spread them with another hand. (must be bad translations here, how can the mixture only be good for 10min but I have to wait 10 min for it to get ready?)"
Definitely some translation errors. Usually, with a 2-part contact cement, you should spread it on both sides and wait for the glue to either get tacky, or get almost dry, so you can lightly touch a fingertip to it and pull it away, with no glue on your finger. Or glove.

"4. After 20 minutes put the two sides together and press carefully with a shaped piece of wood. (ok so now im waiting 20 minutes for the glue to induct or get ready for use but the first instruction said the mix was only good for 10 min? Assuming I can get blocks on the patched area should I clamp it up then?)"
You may want to try contacting the manufacturer, or asking at the shop where you bought it. Again, there's usually room for error and moisture and temperature affect things. It might pay to make a couple of practice spots--right on the dinghy if you want. Give one a 10-minute time, give another 20, apply and clamp to small patches in some obscure place and come back in eight hours to see which one bonded better.

"5. Work will be completed in 72 hours. (this is the hard part as we use the dinghy a lot, will have to make a plan to be dinghyless for 72 hours)"
I suspect they mean the FINAL CURE is not completed for 72 hours. In which case, you can't rush things, you'll need to leave it clamped and set so it cures 100%.

With all these patches, clamping the patch until it has finished curing and setting up makes a difference. Scrap wood and a c-clamp, or a pile of stones if you can't clamp...

Even with the tolerances for human error and environment, all these glues really need to be applied as directed to make a permanent repair. If you can't give it 72 hours, do what you can, keep the duct tape handy, and expect you'll need to redo it with a bigger patch somewhere down the line.


About 5200? You know it eventually hardens up rock solid. That would give you a hard spot on the dink, and possibly cause the patch to either lift, or chafe around the edges.

If you can find "Goop", which is a brand of high quality one-part urethane glue (sold in hardware stores in the US, in about 9 flavors targeted for shoe repairs, plumbing, general fixing, etc.) that might be a better idea. Stays flexible.

[SV Demeter]

Yeah I suspect using the right glue is the best idea. I just need to get set up to be without the dinghy for 72 hrs. Will try talking to some folks around here who have used this glue before and see what they think. My preservation tape patch is holding so far so we should be able to get the kids to the Christmas party today and we already stocked up on beer and rum (priorities right).

I just thought maybe the 5200 fast cure was a faster method although knowing it cures hard keeps me thinking its not the best solution.

Will get my materials in order and figure a time to get this done right. We do have an optimist dinghy onboard so if the rum gets low someone can get to shore I suppose...