Deck delaminated

[diver 1]

Has anyone else had a deck de-laminate in a short space of time?

I had the deck on my rib replaced, supposedly by a 'professional', claimed to be 12mm A1 grade marine ply, glassed both side and flow coated on top

Work was done early 2021, got the boat back for sea trial Feb 2021. Boat is dry stored inside on its trailer and has been used very little since due to a combination of COVID and work restrictions.

I've now found the rear deck to have become spongy and without further destructive investigation it appears the layers of ply have separated in places, so much so the aft seats wobble and one has virtually detached. Some areas of the deck feel very weak.

While I wait to find spare time and funds to start this all over again I wondered if anyone else has suffered similar and any ideas what caused it?

Thanks!

[Peter_C]

Why not take it back to the professional and see what he has to say? Standing behind your work is a great way to advertise you are a professional.

[Nasher]

Cough:
https://www.rib.net/forum/f8/nugent-89492.html

[beerbelly]

Originally Posted by diver 1

Has anyone else had a deck de-laminate in a short space of time?

I had the deck on my rib replaced, supposedly by a 'professional', claimed to be 12mm A1 grade marine ply, glassed both side and flow coated on top

Work was done early 2021, got the boat back for sea trial Feb 2021. Boat is dry stored inside on its trailer and has been used very little since due to a combination of COVID and work restrictions.

I've now found the rear deck to have become spongy and without further destructive investigation it appears the layers of ply have separated in places, so much so the aft seats wobble and one has virtually detached. Some areas of the deck feel very weak.

While I wait to find spare time and funds to start this all over again I wondered if anyone else has suffered similar and any ideas what caused it?

Thanks!

sounds like you have used ply thats just too thin a deck should be 18mm.your pro should have suggested taking the tubes off and using 18mm and probably re doing the stringers .jobs like this really cant be done on a budget.

[Steve509926]

Originally Posted by beerbelly

sounds like you have used ply thats just too thin a deck should be 18mm.your pro should have suggested taking the tubes off and using 18mm and probably re doing the stringers .jobs like this really cant be done on a budget.

100% agree

[paulbrown22]

If you need someone else to take a look or advise fairly locally, Tony at the Chandlery Barge/Foulkes and Sons over on the Hamble did the deck and stringers on my Ribtec 9m back in 2015 or so. Took quite a while for them to get it all done, but I was super happy with the outcome and their GRP work was superb.

[69cmw]

Originally Posted by beerbelly

sounds like you have used ply thats just too thin a deck should be 18mm.your pro should have suggested taking the tubes off and using 18mm and probably re doing the stringers .jobs like this really cant be done on a budget.

That’s a fair comment, but surely if it’s 12mm done properly it still should not delaminate in that short a time? 🤷

[beerbelly]

Originally Posted by 69cmw

That’s a fair comment, but surely if it’s 12mm done properly it still should not delaminate in that short a time? 🤷

a very valid point

[Steve509926]

Originally Posted by 69cmw

That’s a fair comment, but surely if it’s 12mm done properly it still should not delaminate in that short a time? ��

I think the term "done properly" is probably where the problem lies.
There are so many different grades and qualities of ply, including different grades and qualities of "marine" ply, which is now widely used as a generic term.
If the job has been done to a price or extra profit, and using 12mm ply would indicate that, who knows what grade of "marine" ply has been used.
Voids & knots within the structure, and the number of layers of plies used to build up the sheet of plywood (ranging from 4 to 24 plies for a 12mm sheet) would have a massive bearing on delamination.
Even the floor in a wetroom, if done properly, should be done using a minimum of 18mm C-D grade exterior ply, and that if encased in glass would probably have lasted longer.
You say glassed top and bottom, are the edges glassed.?

[Fenlander]

I don't know either of the folks involved but I think Nashers post 3 and the link above needs reading in conjunction with the OPs comments. Seems OP went against advice and had a budget job. I had 20yrs with a business working for "the public" and always refused work where the customer wanted a standard lower than my usual.

[Steve509926]

Just shows, always two sides to a story.

[tinker]

12 mm ply isn't strong enough to walk on, it will flex unless it's supported at least every 100mm. Once it starts to move it will delaminate and then the games over.

Wonder if any other company would lay the floor in 12mm? You should ask around and if they will would they guarantee it, that way you can find out who's to blame.

[diver 1]

Originally Posted by paulbrown22

If you need someone else to take a look or advise fairly locally, Tony at the Chandlery Barge/Foulkes and Sons over on the Hamble did the deck and stringers on my Ribtec 9m back in 2015 or so. Took quite a while for them to get it all done, but I was super happy with the outcome and their GRP work was superb.

Cheers Paul worth noting

[diver 1]

Regards to the thickness I consider that I took Ed's lead on that, more detail on this in the thread titled "Nugent"

However, rightly or wrongly I am lead to believe Ribcraft and others still use 12mm ply to this day? Perhaps I am mistaken on this?

[beamishken]

Originally Posted by diver 1

Regards to the thickness I consider that I took Ed's lead on that, more detail on this in the thread titled "Nugent"

However, rightly or wrongly I am lead to believe Ribcraft and others still use 12mm ply to this day? Perhaps I am mistaken on this?

I just cut several holes in the deck of an RC 585 & the ply is 1/2" 13mm, bulkheads are about every 600mm & stringers are spaced well apart, sitting over the outer chines. So quite a big span, surprisingly no glass on the bottom of the deck just a coat of resin to seal by the looks. Even shit ply well sealed should have lasted longer, many bayliners were built with shity shuttering ply & didnt fall apart after 2 years
Not all boats are built the same but if the boat originally had thicker deck then it should have been replaced like for like imho.
Without stripping out its difficult to know why its failed & no one should jump to conclusions. Spats like this don't help anyone & probably better if the two parties had a chat and at least agreed some exploratory stripping to determine the cause. I'm sure 2 resonable guys can come to some agreement rather than bashing lumps out of each other online

[Steve509926]

Originally Posted by beamishken

I just cut several holes in the deck of an RC 585 & the ply is 1/2" 13mm

Bloody hell Ken, cutting holes in your deck is taking peace keeping duties above and beyond

[Pikey Dave]

Originally Posted by beamishken

….Spats like this don't help anyone & probably better if the two parties had a chat and at least agreed some exploratory stripping to determine the cause. I'm sure 2 resonable guys can come to some agreement rather than bashing lumps out of each other online Attachment 142672

^^^^wot he said. Regardless of who is right or wrong, it never ends well for either side when it goes “hot”. If it turns into a public pissing contest, both sides get entrenched deeper & the contest becomes bigger than the original problem. Irrespective of the eventual outcome, neither side will feel like they have won, there is no winner in these cases.

[beamishken]

Originally Posted by Steve509926

Bloody hell Ken, cutting holes in your deck is taking peace keeping duties above and beyond

Believe me not something I wanted to do but needs must had to strip out this bag of sh1t

[GuyC]

Originally Posted by tinker

12 mm ply isn't strong enough to walk on, it will flex unless it's supported at least every 100mm. Once it starts to move it will delaminate and then the games over.

Wonder if any other company would lay the floor in 12mm? You should ask around and if they will would they guarantee it, that way you can find out who's to blame.

Interestingly Pacific 22's which aren't known for their dainty construction make extensive use of 9mm ply for the decks. The deflection in the deck is down to the load, the thickness of the deck, the spacing of the supporting structure and the robustness of the attachment method.

I used 9mm on mine and so far so good. The maximum unsupported span is about 500mm but in general, it's around 250mm. I did paint the edges with epoxy, then paint and finally when I fitted them I put a thin bead of Sika on one edge before butting them up.

There is a school of thought that whilst encapsulating the ply in FRP will keep the moisture out, if there are any breaks in that encapsulation e.g. where a fitting has been screwed on, it can trap moisture.

I hope the two parties can resolve it sensibly.

[Orwell boy]

Originally Posted by beamishken

Believe me not something I wanted to do but needs must had to strip out this bag of sh1t Attachment 142675

Thats exactly same as the wiring Seamark Nunn pulled out of my 5.3 trunking when they re engined ,must be R/C standard , 2004/5 vintage ?