Different types of Marine Ply

[xpertski]

Afternoon all! I had no idea selecting marine ply would be so complicated!

So far I have found there are two key types, Gaboon (Okoume) marine ply which seems the most common, with the marine ply standard being BS1088 and the upper end quality ones also having the Lloyds certification, basically third part verified for quality and consistency. Then there is Sapele which (see www.robbins.co.uk) is £292.83 + Vat and delivery for a 2500x1220 sheet of 18mm marine ply!!! Www.culzeanltd.com has mahogany marine ply with Sapele veneer for £271.33+vat and delivery for the same stuff and size. Cannot see anyone else supplying the same Sapele marine ply, so not really possible to shop around - both provide a 25 yr guarantee.

Who knew it could be so expensive!!!

Other examples are 18mm Okoume from robbins.co.uk at £151.42 (15 year guarantee) and same price from www.marineplystore.co.uk (25’year guarantee) both BS1088 and Lloyds approved.

From what I can tell, BS1088 is the standard but there can be variation in the quality which is where Lloyds approved comes in to, I think, verify consistency of quality by taking random samples from the factory.

Other places include www.edecks.co.uk where they have hardwood marine ply at £58.99 for an 18mm panel. Contacting that company apparently theirs is hardwood timber, not gaboon/okoume timber, and is “Marine grade WBO plywood to BS1088”. I know some use this supplier for RIB floors, certainly is far more affordable!

Oh also - speaking with Humber who say they use either Sapele or Malaysian marine ply (can’t find much info or suppliers at all on the latter), they say theirs is BS1088 but cannot confirm who they get their timber from. Also they say that they coat their underside of decks with clear epoxy which soaks in so looks bare .... I know a few of us thought they didn’t treat the underside at all because you can’t tell... who knows.

Any marine ply experts have any thoughts on the above?

A bit of a mine field but hopefully any discussion on this thread will help others wondering about this topic.

[jeffstevens763@g]

I looked at this a long time ago I guess the application decides the cost I have buffalo ply on my trailer bunks untreated seem to be great after 4 years.
My opinion is if I'm encapsulating ply I buy a desent one then treat it with glass fiber primer which soaks right in to the wood then glass it up /epoxy coat. East coast resin supplies give tech help within 24 hours great company for materials and advice. 36 valley on here has replied to my thread making the mould for my excel 435 he seems to know his onions with glass fiber work.

[GuyC]

I'm not an expert however I've been through the same thought process as you.

The BS 1088 entry standard seems to be set quite low and there are various qualities within the 1088 band. At the cheaper end, the quality control isn't as good leading to voids and the choice of wood for the veneers results in a plywood that isn't as strong and / or as long lasting as the expensive varieties.

The Bruynzeel, Robbins or Culzean ply is fantastically engineered stuff and although it is built to the same standards, the quality controls are more rigorous and they use high quality veneers in the make up of the plywood.

I've mainly used the cheaper end of the BS 1088 range, primarily because I just couldn't justify the cost differential to myself. I put several coats of primer on each sheet paying close attention to the edges. Where sheets butted up to each other I put a skim of Sikaflex on the edges to try and stop water ingress and I've then put undercoat and deck paint down.

I'd have carried out the same process if I'd been using the more expensive ply so only time will tell as to whether it was a false economy.

[xpertski]

Originally Posted by jeffstevens763@g

I looked at this a long time ago I guess the application decides the cost I have buffalo ply on my trailer bunks untreated seem to be great after 4 years.
My opinion is if I'm encapsulating ply I buy a desent one then treat it with glass fiber primer which soaks right in to the wood then glass it up /epoxy coat. East coast resin supplies give tech help within 24 hours great company for materials and advice. 36 valley on here has replied to my thread making the mould for my excel 435 he seems to know his onions with glass fiber work.

Yea I think that’s a good idea, I would think something like an epoxy primer/thinned epoxy to soak in then polyester resin with glass both sides and flow coat on top.

I suppose the quality of the ply importance depends on if water gets in - but water always gets in at some point.

The higher priced stuff is eye watering in price differential though. The quality might be the same as the lower priced stuff but it’s paying for the assurance that it has been independently inspected randomly.

[jeffstevens763@g]

Don't forget the quality of the veneers puts the dosh up I'e the outer veneers which will in most cases will be varnished / epoxyed for a finish, as guy says the quality of vaneers and no voids for the top spec sheets. I do know a boat builder use good quality exteria ply for the floor fully encapsulated with glass and epoxy with proper prep and care I see no reason not to use the cheaper board OMO

[xpertski]

Originally Posted by jeffstevens763@g

Don't forget the quality of the veneers puts the dosh up I'e the outer veneers which will in most cases will be varnished / epoxyed for a finish, as guy says the quality of vaneers and no voids for the top spec sheets. I do know a boat builder use good quality exteria ply for the floor fully encapsulated with glass and epoxy with proper prep and care I see no reason not to use the cheaper board OMO

That’s what I’m thinking provided it’s properly sealed etc

[xpertski]

Originally Posted by GuyC

I'm not an expert however I've been through the same thought process as you.

The BS 1088 entry standard seems to be set quite low and there are various qualities within the 1088 band. At the cheaper end, the quality control isn't as good leading to voids and the choice of wood for the veneers results in a plywood that isn't as strong and / or as long lasting as the expensive varieties.

The Bruynzeel, Robbins or Culzean ply is fantastically engineered stuff and although it is built to the same standards, the quality controls are more rigorous and they use high quality veneers in the make up of the plywood.

I've mainly used the cheaper end of the BS 1088 range, primarily because I just couldn't justify the cost differential to myself. I put several coats of primer on each sheet paying close attention to the edges. Where sheets butted up to each other I put a skim of Sikaflex on the edges to try and stop water ingress and I've then put undercoat and deck paint down.

I'd have carried out the same process if I'd been using the more expensive ply so only time will tell as to whether it was a false economy.

Exactly my thinking

[Pikey Dave]

Not quite sure what your application is, but I’ve used these before. I used the 18mm hexagrip for trailer floors & it’s pretty much bombproof.

http://www.advancedtechnicalpanels.co.uk/

[Steve509926]

Originally Posted by xpertski

Yea I think that’s a good idea, I would think something like an epoxy primer/thinned epoxy to soak in then polyester resin with glass both sides and flow coat on top.

I suppose the quality of the ply importance depends on if water gets in - but water always gets in at some point.

The higher priced stuff is eye watering in price differential though. The quality might be the same as the lower priced stuff but it’s paying for the assurance that it has been independently inspected randomly.

I was going to ask what was your intended use and under what conditions will it be used and stored, but as you intend to glass it and put a flow coat on it, I think you have answered your own question.

Sepple & mahogany are primarily used when a surface is displayed, but both will rot when subjected to any length of time subjected to water. Okoume is a softer wood than Sepple/mahogany and when exposed will rot quicker than than Sepple/mahogany when subjected to water. However as you are going to encapsulate it in glass the difference between Sepple /Mahogany /Okoume is minimal even if water does get in all three will eventually rot.
I don't understand two points you made:-
"they say that they coat their underside of decks with clear epoxy which soaks in so looks bare" - clear epoxy isn't a wood preservative persay so I don't understand why they would do this and some epoxy resin will always be visible on the surface.
The other point is "Marine grade WBO plywood to BS1088” - do you mean WBP, weather and boiling point, which describes the bonding adehisive used in the ply. Basically the glue can withstand 72 hours in boiling water. Notice I said glue and not the wood, any untreated wood subjected to 72 hours in boiling water will break down.
The difference between "Marine grade ply" and "External Grade WBP ply" is not in the adhesive, that should be the same. The difference is down to voids within the ply caused by knots and splits in the wood used. Marine grade ply should have NO voids, external grade ply can have voids up to a certain number and size. The other difference is price!
Personally, unless I was going to have the surface on display (when I would use Sepple Marine ply) I would use a good quality External ply from a reputable supplier. Making sure that all ends are well sealed and all surfaces are well treated before any assembly and covering in glass.

Sorry for being so long winded!!!!!

[beamishken]

Originally Posted by Steve509926

I was going to ask what was your intended use and under what conditions will it be used and stored, but as you intend to glass it and put a flow coat on it, I think you have answered your own question.

Sepple & mahogany are primarily used when a surface is displayed, but both will rot when subjected to any length of time subjected to water. Okoume is a softer wood than Sepple/mahogany and when exposed will rot quicker than than Sepple/mahogany when subjected to water. However as you are going to encapsulate it in glass the difference between Sepple /Mahogany /Okoume is minimal even if water does get in all three will eventually rot.
I don't understand two points you made:-
"they say that they coat their underside of decks with clear epoxy which soaks in so looks bare" - clear epoxy isn't a wood preservative persay so I don't understand why they would do this and some epoxy resin will always be visible on the surface.
The other point is "Marine grade WBO plywood to BS1088” - do you mean WBP, weather and boiling point, which describes the bonding adehisive used in the ply. Basically the glue can withstand 72 hours in boiling water. Notice I said glue and not the wood, any untreated wood subjected to 72 hours in boiling water will break down.
The difference between "Marine grade ply" and "External Grade WBP ply" is not in the adhesive, that should be the same. The difference is down to voids within the ply caused by knots and splits in the wood used. Marine grade ply should have NO voids, external grade ply can have voids up to a certain number and size. The other difference is price!
Personally, unless I was going to have the surface on display (when I would use Sepple Marine ply) I would use a good quality External ply from a reputable supplier. Making sure that all ends are well sealed and all surfaces are well treated before any assembly and covering in glass.

Sorry for being so long winded!!!!!

This is exactly my thoughts too .
I'm pals with two boat builders one builds traditional wooden boats & uses robins elite for varnished timber below the waterline & standard wbp for deck boards seats etc. The other builds in fibreglass and any encapsulated timber is wbp.
Neither think the cheaper grade 'marine' ply is worth the extra cost above the standard wbp

[xpertski]

Originally Posted by Steve509926

I was going to ask what was your intended use and under what conditions will it be used and stored, but as you intend to glass it and put a flow coat on it, I think you have answered your own question.



Sepple & mahogany are primarily used when a surface is displayed, but both will rot when subjected to any length of time subjected to water. Okoume is a softer wood than Sepple/mahogany and when exposed will rot quicker than than Sepple/mahogany when subjected to water. However as you are going to encapsulate it in glass the difference between Sepple /Mahogany /Okoume is minimal even if water does get in all three will eventually rot.

I don't understand two points you made:-

"they say that they coat their underside of decks with clear epoxy which soaks in so looks bare" - clear epoxy isn't a wood preservative persay so I don't understand why they would do this and some epoxy resin will always be visible on the surface.

The other point is "Marine grade WBO plywood to BS1088” - do you mean WBP, weather and boiling point, which describes the bonding adehisive used in the ply. Basically the glue can withstand 72 hours in boiling water. Notice I said glue and not the wood, any untreated wood subjected to 72 hours in boiling water will break down.

The difference between "Marine grade ply" and "External Grade WBP ply" is not in the adhesive, that should be the same. The difference is down to voids within the ply caused by knots and splits in the wood used. Marine grade ply should have NO voids, external grade ply can have voids up to a certain number and size. The other difference is price!

Personally, unless I was going to have the surface on display (when I would use Sepple Marine ply) I would use a good quality External ply from a reputable supplier. Making sure that all ends are well sealed and all surfaces are well treated before any assembly and covering in glass.



Sorry for being so long winded!!!!!

Hi there, thanks - my purpose is the deck, replacing it. As you can see below, a bit damp, no rot or delamination, still very solid - but while I’m working on it thought may as well. Also as it seemed to not have any coating I asked Humber why they don’t coat it and that was their reply ... I can’t tell there was any coating at all. Strange ...



Yes I did mean Marine Grade WBP (I made a typo). So it seems there is very little genuine marine ply other than the really expensive stuff which is “marine grade” because the theory is that the inspection process, eg such as Lloyds approved, checks for defects, gaps etc, and a manufacturer can only claim Lloyds approved if there is enough consistency in manufacture.

It does seem that with coating the ply in polyester resin/glass then flow coat, what ply is used inside is actually not as important.

In that sense, given it’s highly possible the Humber floor had no coating at all underside, it did well to only get a bit damp in 16 years since it was built!

Thanks for the replies, interesting topic that having done a search on threads didn’t seem to have been covered in this detail.

Cheers

[HankOnthewater]

The post from "Steve-with-the-long-number" is an excellent one.

[xpertski]

Originally Posted by HankOnthewater

The post from "Steve-with-the-long-number" is an excellent one.

Which one is that?

[Steve509926]

Originally Posted by HankOnthewater

The post from "Steve-with-the-long-number" is an excellent one.

Thanks Hank-from-the-Cotswolds

I've tried Steve from 1 - 1000 in the past, got bored and used my mobile number in the end for forums etc.

[xpertski]

Originally Posted by Steve509926

Thanks Hank-from-the-Cotswolds

I've tried Steve from 1 - 1000 in the past, got bored and used my mobile number in the end for forums etc.

Hi Steve (with the long number [emoji23]) is it the post on the bow locker / seats that is being referred to?

[Steve509926]

Originally Posted by xpertski

Hi Steve (with the long number [emoji23]) is it the post on the bow locker / seats that is being referred to?

Think its #9 in this thread

[xpertski]

@steve

Ah yes of course, I replied to it haha - very useful thanks. Yes agreed with what you said in your post, and re the epoxy coating Humber say they put on the underside ... I guess it could be there but hard to see after 16 years since it was built or ... a bit like the emperor with no clothes!!!

[xpertski]

Originally Posted by GuyC

I'm not an expert however I've been through the same thought process as you.

The BS 1088 entry standard seems to be set quite low and there are various qualities within the 1088 band. At the cheaper end, the quality control isn't as good leading to voids and the choice of wood for the veneers results in a plywood that isn't as strong and / or as long lasting as the expensive varieties.

The Bruynzeel, Robbins or Culzean ply is fantastically engineered stuff and although it is built to the same standards, the quality controls are more rigorous and they use high quality veneers in the make up of the plywood.

I've mainly used the cheaper end of the BS 1088 range, primarily because I just couldn't justify the cost differential to myself. I put several coats of primer on each sheet paying close attention to the edges. Where sheets butted up to each other I put a skim of Sikaflex on the edges to try and stop water ingress and I've then put undercoat and deck paint down.

I'd have carried out the same process if I'd been using the more expensive ply so only time will tell as to whether it was a false economy.

Hi Guy, looking at Bruynzeel, which seems to be the brand name, it seems to be made of Gaboon wood, which I read somewhere is a type of Okoume just a little different. I also read somewhere that whilst it is Gaboon wood they make good quality ply to high standards. So I guess probably similar to the Robbins Super Elite range which is also Gaboon...

It looks like Gaboon/Okoume marine ply relies allot on being glassed for it strength, someone in another forum (google search) said it had a much lower strength psi than Sapele for example (think I read something like 400psi vs 1500psi).

It seems that the best bets for marine ply flooring are the more affordable hardwood plies from eDecks (I’ve asked what hardwood they use but waiting by for a reply, or something like Sapele from Robbins, but more painful on the bank balance.

[xpertski]

For anyone interested - found out from eDecks that their marine ply is Indonesian Maranti, so a hard wood, heavier than Okoume and more rot resistant, cheaper, seems only real down side is it’s finished appearance and that it splinters a bit when cut (splinters are easily sanded down) - but that isn’t a concern for us Ribbers who would use it predominantly for a floor which is glassed and coated with flow coat...

[Steve509926]

Hi xpertski, Gaboon Wood is a very hard Ebony (approx 3000lbs per Sq Ft) mainly used for high end furniture vaneers and inlays, I've never come across Gaboon ply.
Gabon is Okoume - 400lbs Sq Ft Janka hardness
Sapele is a mahogany - 1400 Sq Ft Janka hardness
Indonesian Moranti - depends upon the species but ranges from approx 550lbs - 1500lbs per Sq Ft
Don't just rely upon hardness, it is not an indication of tear/rupture strength or elasticity. Your comment "it splinters a bit", actually it "chips" more than splinters because of the "hardness", but that hardness does make it easier to sand to a good finish.
Most "good" quality WBP ply is made from Okoume or Light Red Meranti. Meranti ply will normally be slightly more expensive than Okoume.
Your correct in saying Meranti is more rot resistant than Okoume, but only slightly.