Fibreglass sail boat bulkhead repairs

[W.olly]

Quite amusing...the bit with the void also has their stamp on it!

I really don't buy much of this stuff so maybe I just got lucky!

Maybe I bought the wrong stuff...does say marine ply (left).

View attachment 493182

Maybe very lucky then. Or more unlucky or the way it is now as most products are crap. There. Ould well be voids in 1088 ply these days. Or always hav been. .maybe very small ones like yours is. Who knows.

I can't see the image much good on my phone but I take it that it shows it's a 1088 marine ply.

I jave had 'marine plywood' sold to me once on a. Job
I it into it and it was full.of voids. I bought 8 sheets. The first two had voi.ds. I checked the stamp and it was standard hardwood ply. I took it all back and got my money back . They did try to for me off but I had to prove that it wasn't the correct grade.
That was a George Hill timber aswell.

 

[Pigeon_Droppings2]

I can't see the image much good on my phone but I take it that it shows it's a 1088 marine ply.

I can't read it either!...I could only make out the marine ply bit.

I was reading that 1088 is a voluntary code anyway with zero enforcement?

I'm going to look for a better supplier....I've done too much prep to fit something I'm not happy with!

I've been reading that the Lloyds approved ply might be a more reliable indicator of quality...we will see!

 

[Keith 66]

BS 1088 is an old British standard that refered to the Ply being water & boil proof. It has been stamped on billions of sheets of ply over the last 50 years & today is unenforced & completely meaningless. Not worth the ink its stamped with.
30 or more years ago you could get exterior then marine, both were good. As i said in earlier posts today its a lottery. Most of the european plywood mills have long gone with production shifted to the far east with accompanying lack of quality control.
Much far eastern ply uses eucalyptus or pawlonia cores because the stuff grows very fast in plantations. It isnt very durable either.
Most vital part of ply is the glue if it isnt truly waterproof its crap. Most far eastern ply today doesnt use waterproof glue with some being stuck together with something like wallpaper paste.
Whenever i use some i chuck an offcut in a bucket of water & see what happens. Some lasts a week, some lasts a few days, the worst completely delaminated overnight, that had Bs 1088 stamped on it!
The paradox is Good old Shuttering ply has first class glue that will usually last years.

 

[Misterg]

I really don't buy much of this stuff so maybe I just got lucky!

It's the way it is now.

Good luck finding anything better at any sort of sensible price. I bought quite a bit of 'exterior' ply when I did a camper conversion, and even selecting the best sheets at the (large) builder's merchant, it was rubbish quality - voids & overlapping plys.

50 year old marine ply will still be sound because it was good quality - This is a 30 year old piece of 18mm ply that has been outside, untreated, since 1994 (it was a shed door) and it is still 99% sound.

I bet the current stuff wouldn't last 6 months.

The best ply I've seen recently was the stuff used for 'Dolphin Board' waterproof shower panels (but it has a laminate on one surface).

Might be worth asking around to see if there is a local boat builder who will sell you some decent stuff.

 

[Pigeon_Droppings2]

I guess the foam route leads to more consistent quality. Shame they don't sell the foam panels pre laminated with fibreglass...that would make my life a lot easier.

 

[Pigeon_Droppings2]

I've been recommended a place called Robbins Timber...not cheap but I don't really care at this point. Anyone here used them?

I just don't want to removing it all in 6 months because it's delaminated!

 

[Turbo]

So I've cut my bulkhead...was just going to seal the edges with epoxy and I happen to see this!!

I thought the whole point of marine ply is that there should be no voids for water to get in!

Now I'm thinking this board is not so good?

I think marine ply has more layers than that stuff.

 

[Keith 66]

I've been recommended a place called Robbins Timber...not cheap but I don't really care at this point. Anyone here used them?

I just don't want to removing it all in 6 months because it's delaminated!

Earlier in this thread i mentioned them, 1 Sheet of 8mm Robbins elite £91 + £225 delivery from Bristol to Essex plus £65 vat, A total of £380 odd quid. That price was last week.

To be fair it is first class plywood & the only one available that i would trust apart from Brynzeel & that is even more expensive.

 

[Misterg]

I've been recommended a place called Robbins Timber...not cheap but I don't really care at this point. Anyone here used them?

I haven't used them, but they have an excellent reputation - sort of the Harrods of plywood. If you live close enough to collect, they would be a good option.

 

[Pigeon_Droppings2]

@Keith 66...I've been coming across the PET stuff (foam core) quite a bit in my searches.

On reason I wasn't keen was the limited access would make it difficult to do a good job of applying all the layers...but now I'm thinking maybe I misunderstood.

Would it work out ok if I were to make the foam parts and then create the complete bulkhead "sandwich" in my garage. Then just tab it in like I would a ply bulkhead?

 

[Pigeon_Droppings2]

Try as I might it seems pretty impossible to find a reliable source of ply that doesn't cost a kings ransom....after a week of grinding fibreglass on the boat I have zero desire to do it again in a couple years just because someone stamped 1088 on their ply using a carved up potato!

Lots of doom scrolling later has led me to looking at foam panels using epoxy infusion.....anyone on here done this before. I think it's quite common for making carbon fibre panels.

Other than buying a huge amount of materials at great expense....the actual process seems pretty straightforward.

 

[Newlands]

Earlier in this thread i mentioned them, 1 Sheet of 8mm Robbins elite £91 + £225 delivery from Bristol to Essex plus £65 vat, A total of £380 odd quid. That price was last week.

To be fair it is first class plywood & the only one available that i would trust apart from Brynzeel & that is even more expensive.

I agree - I’ve had stuff from Robbins and it is excellent quality. And I have an offcut of 9mm that has been propping something up in the garden for the last twenty years with absolutely no sign of delamination. I’ve never been able to afford Brynzeel but I doubt that they would sell anything less than the best.
Having said that, for interior work that is going to be encapsulated with resin I would be tempted to use shuttering ply, assuming you can get some that is at least reasonable quality. Scandinavian Birch-faced ply always seems to be good as well, but you’d probably want to do the bucket of water test first.

 

[Pigeon_Droppings2]

tempted to use shuttering ply,

I was also tempted by buffalo board...my logic was it must be good quality board otherwise it would just delaminate.

Not 100% sure epoxy would stick to it....but I could simply remove the resin coating where my tabbing needs to go.

Gaboon ply is the stuff I really wanted...plenty of suppliers...but when you look past the flashy websites and lookup the companies on companies house they don't look so impressive!

 

[Pigeon_Droppings2]

This arrived today...I'm going to have a go at making fibreglass&foam sandwich panels myself.

I was surprised I couldn't simply buy them ready made...seems like maybe there's an opportunity there!

I gave up on sourcing ply...reckon I'll need 2-3 sheets and the cost of the "good stuff" is just crazy....I reckon more expensive than buying all the kit and making the panels myself!