Dinghy Floor to Tube Attachment

[sailorboy1]

My PVC dinghy has a small section back at the transom where the seam that attaches the floor to the tube has come unglued/sealed. This I think has been going on for a year based on the water in the dinghy each morning, but I finally found it.

So looking for suggestions to try to reglue/seal it. This will be an unperfect fix as I greatly doubt I have a way to haul it out and get it really really clean. So my current thinking is high tech: 1- clean as best as possible 2-fill it with adhesive caulk 3-duct tape it down till it cures. 4-drink a lot so the illusion that it will work enough takes in my brain.

But I am open to other low tech possible methods

[verb88]

Clean it as best as possible... add several liberal coats of flex seal. Let it cure

[sailorboy1]

nothing but a bump post as normally the chance for people to fix something get more attention

[GordMay]

I fixed the same problem, on my PVC zodiac, by separating & cleaning (not very well) the joint, then re-glueing with 3M ‘5200' (polyurethane), and (permanently) clamping with (2) light aluminum flat bars (inside & out). Used ‘5200', supplemented with 6-32 nuts and bolts on clamp strips.
Lasted several years, until dinghy was destroyed. Certainly would have lasted much longer
Good luck!

[sailorboy1]

I have to attach the floor to the tube. So only glue/tape can be used.

dinghies, right up there in the most expense "cheap" in the boating world

[GordMay]

Originally Posted by sailorboy1

I have to attach the floor to the tube. So only glue/tape can be used...

Oops, my mistake! I misread it as "transom to floor".
PVC to PVC requires a solvent cement.

[PirateGuy]

Following as I have a similar or identical problem with my WM pvc solid floor deflatable. I was proud to have fixed an air leak, but the water coming in between the Fiberglas hull bottom and tube is proving to be far more problematic- and the only thing that’s drinking are my feet in the cold water in the bottom of my dinghy.

I ran my dink onto the beach, removed everything, turned it over to let dry. I cleaned seams with fresh water, then isopropyl alcohol, then even some pvc cleaner intended for gluing pipe joints. I couldn’t find anything obvious to cause the leakage, but proceeded to caulk some suspect seams around the transom/hull bottom/tube corner junction using a two part polyurethane. I had enough daylight to allow the polyurethane to set more or less properly. I put the dinghy back in the water, and voila, wet feet again.

A couple of days ago, I repeated some of this process, but with interior seams in mind. Even with purposeful tube deflation, the bottom/tube seam is difficult to get into and clean properly. This time, as I had no single obvious point of failure, I used a tube of inexpensive caulk to try to seal most of the nearly 8ft long junction between the tube and hull bottom. Being a one part caulk that relies on air curing and the short winter days, the caulk was far from adequately cured when I put back in as the sun was setting. Voila - wet feet again.

At least the caulk application greatly narrowed down where the leak is because I could see where the water was oozing through. My conclusion- my cleaning was inadequate and I need to use a quicker setting caulk. I live on the hook so my out of water time can be limited.

[Hillbilly]

Had similar problem. Interspersed among several repair attempts, problem got progressively worse until finally entire bottom separated from tubes, back to the transom, where it drifted underneath and found the prop.

Solvent glues are difficult under the best of circumstances since they require intimate contact and pressure. Late in the game I found a product by Locktite, Marine Adhesive Sealant, which I recall is recommended for vinyl. Never tried it on then-abandoned dinghie but tried it on some vinyl scraps and it had good adhesion and enough body to seal better than solvent adhesives. Previously I had actually used ShoeGoo in small separations with good results and was tempted to do the entire restoration with it but by that time was just fed up with it.

In the meantime til you can get clean and dry, you probably will have to go with a stopgap, as you say.

[Redline452]

I have had some good results with "Final Fix", a heavy grey plastic-like adhesive in a caulking tube.



https://ca.binnacle.com/p13001/Final...duct_info.html


Fixed some leaks in the tube-to-transom section of my Zodiac YL310 RIB, and on a friend's inflatable. Also applied outside patches to (finally!) seal annoying slow leaks on the aft end of the tubes. It's been a couple of years and still holding well.



I have an older YL310 (non-RIB) dinghy whose floor has mostly separated from the tubes, which I plan to try resurrecting as a COVID garage project.

[GordMay]

Polyurethane adhesive sealants are moisture cured.
Curing of polyurethane sealants occurs at approximately 1/16” (1.66mm) depth per day, at 75°F (24°C), and 50% RH, depending on the specific formula.
The cure time will increase as the temperature and/or humidity decreases. A good rule of thumb is an additional 24 hours of cure, for every 10°F (-12°C) decrease in temperature.
Very light misting, when humidity is below 30% RH, can speed up skinning, and enhance curing.

[Palarran]

Why are you making this repair so hard sounding?

[captnknopf]

I had a similar problem with a Mercury pvc dingy. I used West G flex. Several other people have had good luck with it and I tried it and it worked great. Glued the transom to a tube and tube to bottom.

[sailorboy1]

Originally Posted by Palarran

Why are you making this repair so hard sounding?

well let's hear you easy one then

[GordMay]

Originally Posted by captnknopf

I had a similar problem with a Mercury pvc dingy. I used West G flex. Several other people have had good luck with it and I tried it and it worked great. Glued the transom to a tube and tube to bottom.

The best tensile adhesion [not that great] of PVC, using G/Flex 655 Epoxy, is with Alcohol wipe & Flame treat.
See ➥ https://www.westsystem.com/specialty...adhesion-data/