Inflatable Dinghy Seams

[Dockhead]

My old Avon 340 Rover RIB has stopped holding air. Which is really weird because all these years, I have thought about the amount of air in it only twice a year -- once at the beginning of winter to make for volume lost to cold, and once at the beginning of summer to let excess pressure off. Period.

Now one tube is quite flat and the others are losing air.

I think I have traced the problem to my having pressure washed the bottom of the rib last fall. I think I screwed up some of the seams.

So now what to do? Try to glue them back together? Write it off? Do it myself? Hire a pro? Is this curtains for the old RIB? They are not cheap to replace, as I discover.

[JPA Cate]

Dockhead,

Sorry to hear about your dinghy.

Can you post a picture of the damage?

We've done a lot of dinghy patching in our time, but never have repaired seams ourselves. Given how you use your dinghy (many passengers, cold waters) would you ever trust it again if mended by an amateur?

Maybe this is the time to downsize the dinghy, less stress on the davits and all.

Ann

[carstenb]

Dockhead

Avon ribs can be repaired. I know it will be costly, but pay someone to do it professionally - you won't regret it

carsten

[Dockhead]

Originally Posted by Ann T. Cate

Dockhead,

Sorry to hear about your dinghy.

Can you post a picture of the damage?

We've done a lot of dinghy patching in our time, but never have repaired seams ourselves. Given how you use your dinghy (many passengers, cold waters) would you ever trust it again if mended by an amateur?

Maybe this is the time to downsize the dinghy, less stress on the davits and all.

Ann

I would like to replace the dink with something lighter and simpler, but it's not in the budget right at the moment.

You can't really see any damage, although it looks like some of the seams are lifting. I guess I could start by gluing the seams back down and see if that helps.

[JPA Cate]

Originally Posted by Dockhead

I would like to replace the dink with something lighter and simpler, but it's not in the budget right at the moment.

You can't really see any damage, although it looks like some of the seams are lifting. I guess I could start by gluing the seams back down and see if that helps.

Dockhead,

Usually this is not as simple as it ought to be. At least where we have been, the humidity has to be low for the glues to bond properly. Gluing takes place in "dry rooms," and they are temperature controlled as well. The difficulties in doing this on the beach somewhere are probably in back of the other's suggestions to have it professionally done, and although we have done a lot of patching on hypalon dinghies, I lean towards having the seams professionally repaired, too.

Aside from the difficulty of just getting a patch up job to work. What needs to happen is that the seam needs to be opened all the way back to where it is still well bonded. Both sides have to be immaculate, and when you go to glue it back, it's about 24 hrs. for the bond to gain full strength. Also, you have to align everything perfectly, or the seam will be obviously funky.

Out here, the glue to use would be SC 4000, mask the areas that need to be glued, be ever so careful, work from the closed end to the open one, and don't allow it accidentally to bond. You can get in a world of hurt. If you try and fail, it will just be more work for the professionals at some time, but it might work to keep you going. And still, I, too, think it is a job for the pros.

Sorry,

Ann

[motion30]

why can't you just clean up the existing seams and then lay the new material over top of it

[thinwater]

Bubble test it first. You are guessing for no reason. It may be a valve.

And I would never power wash anything other than the bottom of a boat or something similarly tough. Nothing I wouldn't hit with a hammer and a scraper. I've seen them do a lot of damage, most often unseen.

[Dockhead]

Originally Posted by Ann T. Cate

Dockhead,

Usually this is not as simple as it ought to be. At least where we have been, the humidity has to be low for the glues to bond properly. Gluing takes place in "dry rooms," and they are temperature controlled as well. The difficulties in doing this on the beach somewhere are probably in back of the other's suggestions to have it professionally done, and although we have done a lot of patching on hypalon dinghies, I lean towards having the seams professionally repaired, too.

Aside from the difficulty of just getting a patch up job to work. What needs to happen is that the seam needs to be opened all the way back to where it is still well bonded. Both sides have to be immaculate, and when you go to glue it back, it's about 24 hrs. for the bond to gain full strength. Also, you have to align everything perfectly, or the seam will be obviously funky.

Out here, the glue to use would be SC 4000, mask the areas that need to be glued, be ever so careful, work from the closed end to the open one, and don't allow it accidentally to bond. You can get in a world of hurt. If you try and fail, it will just be more work for the professionals at some time, but it might work to keep you going. And still, I, too, think it is a job for the pros.

Sorry,

Ann

Thanks, that's useful information. Sounds right. Unfortunately.

[Dockhead]

Originally Posted by thinwater

Bubble test it first. You are guessing for no reason. It may be a valve.

And I would never power wash anything other than the bottom of a boat or something similarly tough. Nothing I wouldn't hit with a hammer and a scraper. I've seen them do a lot of damage, most often unseen.

Pressure washers are incredibly destructive. I should have known better.

I wonder how many teak decks have been ruined by a single pressure washing.

[Wotname]

As Ann states, gluing inflatables is no simple task, especially if it is Hypalon. I had one fail a decade back and had it professionally repaired. It lasted one season. I then repaired it myself and that lasted one season. It was around 10 years old when it first failed.

I researched it extensively and tracked down the proper products although I now forget exactly what they were. I do know cleaning the old glue off was essential and that required heaps of MEK. I had access to a controlled enviroment (humidity and temperature) but even then it was a time consuming and frustrating project.

Bite the bullet and get new one but be careful around the China made ones. They are heavier, at least the cheaper ones are. They will of course be PVC, not Hypalon.

[Dockhead]

Originally Posted by Wotname

As Ann states, gluing inflatables is no simple task, especially if it is Hypalon. I had one fail a decade back and had it professionally repaired. It lasted one season. I then repaired it myself and that lasted one season. It was around 10 years old when it first failed.

I researched it extensively and tracked down the proper products although I now forget exactly what they were. I do know cleaning the old glue off was essential and that required heaps of MEK. I had access to a controlled enviroment (humidity and temperature) but even then it was a time consuming and frustrating project.

Bite the bullet and get new one but be careful around the China made ones. They are heavier, at least the cheaper ones are. They will of course be PVC, not Hypalon.

OK. So I guess professional repair, sale, and replacement is the plan. Will cost some money.

[JPA Cate]

Originally Posted by Dockhead

OK. So I guess professional repair, sale, and replacement is the plan. Will cost some money.

It is really a shame, but we've been told by our Inflatable Boat gurus, that it is difficult to get good quality hypalon these days.

We're into our first year of a PVC re-tubing of our RIB. This PVC, we were told, was manufactured in Germany, hence of more reliable quality. The tubes were made in China, and installed here in Australia. Jim and I made "chaps" for it, to protect it against the UV. Just the other day, I sewed reflective piping to the chaps, to make the dinghy more visible to others at anchor.

Wotname is right, the PVC is heavier than the hypalon was; also, the tubes are a bit larger diameter.

As to cleaning up the glue that preceded the SC4000, it was Toluene that was the thinner for SC2000. Very hard for mere mortals to get now. Maybe it was MEK for the Bostic glue which had such a freaking short shelf life, I don't remember.

It's never convenient to deal with a troubled dinghy. And as to gurneys and teak, our dock neighbor has a Jeanneau motor boat with teak on the afterdeck, and he washes it with the gurney every weekend! I figure it'll be gone by the end of the year, if he keeps it up. But, none of my business.

Good on ya for biting the bullet, DH. The professional repair will be the better way to go.

Ann

[carstenb]

Hypalon dinghies are difficult to find and expensive. Having just bought one, I believe that Zodiac is the only company making them (I could be wrong - that's all that is available in Denmark)

[Jim Cate]

Originally Posted by carstenb

Hypalon dinghies are difficult to find and expensive. Having just bought one, I believe that Zodiac is the only company making them (I could be wrong - that's all that is available in Denmark)

Expensive?Yes! Difficult to find? No!

Many sources here in Australia, lots more in the States. And most Zodiacs are PVC... only their military, expedition and commercial ones are Hypalon these days.

Jim

[carstenb]

Originally Posted by Jim Cate

And most Zodiacs are PVC... only their military, expedition and commercial ones are Hypalon these days.

Jim

Yes Jim

That's the reason they are so expensive (sigh)