Dinghy glue repair at transom

[Dougiestyle]

I just acquired this dinghy and the glue joint at the transom has come loose by about 80%. The tubes are in good shape along with the transom rubber.There is some other areas that have a disbond also that could use some glue also. I was wondering if this is repairable with 5200, Stabond, HH-66, Sikaflex 291 marine, or whatever would be the best glue/adhesive?
The dinghy is a small 2 person (PVC), with a max 4hp motor. I have a 3.5hp or small electric.
Thanks Doug

[GordMay]

Greetings and welcome aboard the CF, Doug.


It used to be that inflatable transom repairs were generally considered temporary. I'll be interested to read current opinions.

[Dougiestyle]

I think i would be lucky to get a temporary repair on this one. I am even looking at maybe Dicor non leveling adhesive. May never put a motor on it?
I might pull the tube off on that side to repair. This dinghy was given to me, so that may be all its worth? I think i will be testing different adhesives before i do the transom.
Thanks

[donradcliffe]

Given the dinghy construction and the amount you have invested in it so far, I'd try a tube or two of 5200. Probably work out better than the kid I saw in NYC trying to fiberglass the outside of his inflatable....

[Hardhead]

I'd probably try a tube of liquid nails, and then lashing the 2 tubes tight together with a few cinched wraps of 1/4" rope in a figure "8", just aft of the transom.

Might last for 5 years, who knows? Usually the uglier it is, the longer it lasts.

[Ken Z]

I would use 5200, fully inflate clean surfaces wipe with alcohol.

[KD8NPB]

5200 is not formulated for use on plasticized surfaces (PVC).

Use a two part adhesive formulated for inflatable boats. FOLLOW THE INSTRUCTIONS.

[foufou]

The pl400 adhesive caulk from home depot has very similar qualities as 5200 according to Practical Sailor tests. You might want to give that a try

[newhaul]

For my zodiac bombard I used the proper weaver 2 part pvc adhesive .
Has held up for 2 years so far and showing no signs of failing .
I recommend the correct 2 part adhesive for the pvc to pvc gluing

[duefocena]

Plenty of YouTube on this. Use two part for sure. Pro’s do this in a no humidity environment. Always “double glue) letting the glue dry tacky and then re-coat before bonding.

[ZULU40]

Ive just gone through this with my Zodiac
In my case the transom was plywood and had rotted through and delaminated.

So I had to make a new transom out of 1" marine ply
then figure out how to glue it in the boat which is PVC

The original design had a routed channel each side of the transom
and to this they have 9 holes drilled each side. Then they fit a plastic collar which is heat welded to mechanically adhere the plastic and the plywood. Why am I saying this, the issue is PVC glue will not join to wood, they need the plastic ends to be able to bond the transom in.

Similar things apply to joining the PVC boat material to the transom, so what they do is coat the part with hypalon glue, to which PVC glue will adhere. But basically I had to scrap their original plan and wished for a bit that I had made the transom out of rigid sheet PVC, but it would have been expensive.

In the end I opted for 3M 5200 to glue and fill the sockets each side along with SS 3/8" bolts and washers, and bond the skin of the boat to the transom. Ive heard from others that have had similar experiences thats it has lasted well going back as far as 2 years. But I guess because it wont come apart anymore ultimately it means that this is it for this boat, when the 5200 fails it will be time to replace the boat.

If your fix isnt this traumatic I think I would use PVC adhesive, it just wouldnt have worked for me. Do prep and clean surfaces with MEK if you can get it, acetone if you cant

Images show the old transom and the new part (you can just glimpse what remains of the 9 holes each side), the parts flow coated trial fitted before 5200, and the completed boat all glued up but before the transom was painted blue with 2 pak

[toddster8]

I have also just gone through this with my PVC Zodiac. All the welded seams are fine, but the glued-on floor has been coming loose, a little bit at a time.

I did first attempt to use inexpensive HH-66. It worked great... until the first hot day, when the parts just peeled away and left a big mess that had to be removed.

PolyMarine two-part PVC adhesive is the ticket. I also added an additional layer of PVC tape inside and out around the bow section. Follow directions carefully and don't skimp on preparation. I bought two of the 250 ml kits, before realizing that it would have been cheaper to just buy the liter, in the long run. But the shelf life (IIRC) is only a year or two.

Applying pressure to the seam can require some creativity.

[mvmojo]

I've done numerous dinghy repairs using contact cement including a partial transom re-glue. Thoroughly abrade both surfaces with 60-100 grit sandpaper. Clean with denatured alcohol. Coat both surfaces with contact cement and allow to dry. Re-coat and allow to dry until just barely tacky. Stick the parts together and aggressively rub out any air bubbles. Good to go.

[Valmika]

Originally Posted by KD8NPB

5200 is not formulated for use on plasticized surfaces (PVC).

Use a two part adhesive formulated for inflatable boats. FOLLOW THE INSTRUCTIONS.

Would this work for Hypolan also or what could you use.

[mvmojo]

Contact cement works well on Hypolon. Of course if you want to spend more money, buy the 2 part adhesives. Either can be purchased on www.inflatableboatparts.com. Based on several purchases I've made, they seem to be good folks to deal with.