Marine Ply

[Steve-G]

Hi guys, reading in other posts about Marine Ply vs Exterior grade plys and the horendous costs associated with Marine Ply. making it prohibitive for most people to use.

I am currently rebuilding a 626 Fraser Formula and whilst sussin out prices for ply I rang "Allboard" they have "British Standard" Marine grade sheets (not Aust std.??)

I have just bought 4 12x2400 x 15mm for $92.65 each, they are all hardwood compared to our hoop pine ply. can be used for visible surfaces looks great.


Allboards price is a lot cheaper than anyone else's..

I am not associated with them either.

[Noelm]

that is a pretty good price, the difference in Marine Ply is the outer veneer, normal old structural ply is water proof, but has a rough finish and useless for anything that needs a nice finish, formwork ply is also very good, but it is painted and as such cannot be used for anything except painted or hidden areas.

[Steve-G]

Any idea on what the difference between "British Standard" and "Aust Std" is?

This board has a lightside and a darker side no knotts and looks great with a coat of resin.
$69.90 for a 12mm sheet. +gst of course!

[bigjimg]

The difference is BS 1088 does not have predictable structural performance as compared to AUST STD 2272.You can get structural in any grade face as well,A,S,B,C,or D.But you may have to buy a set qauntity.There is a lot to ply it is not just bits of veneer laminated together.Jim

[oldboot]

Most of the wooden boat guys are using the luan exteriour grade ply these days.

I've used quite a bit of it and its pretty good stuff if you get it from a good source.

not sure about the difference between BS marine and aust standard marine.

both will be "A" bond, which is resourcinol glue, which is "waterproof"

But i seem to remember that aust standard requires no voids. splits or fillers in the intermediate plies...so it will be all "B" grade sheets..remember that "A" grade is "ready to finish"

The luan ply I come across mostly is graded BC, but the better sheets are pretty close to BB, I don't think I have ever come across any full blown voids in the interiour plies, but cracks and splits in the interiour plies are not uncommon..the better sheets are so close to all "B".
It seems more stable and consistent, thickness can vary a little particularly in the thinner sheets.....I've had "9mm" measure as thin as 7.8 and as thick as 9.6.....admittedly that was cheaper product and that variatio wont worry most.

If you buy from a good supplier the sheets will be much better...if it worries you check out one of the local boatie type joints, that supply the woodden boat boys.
In SEQ Boatcraft Pacific are well regarded.


I recon the luan ( meranti, pacific maple, philipine mehogony, seraya or whatever else thay are calling Shorea spicies), its a better material than any of the pine plies for marine use....it accepts finishes and glues exceptionaly well and it seems more stable and resistant.
Hoop can be pretty good but technicaly it isn't a pine, its an araucaria, and still I'd go the luan.

On the other hand I have had and seen some pretty uggly CD pinus, with filled knots in the face ply and big knots in all other plies.....the worse I have had had heaps of tension in the sheet....I had one sheet that sprung 10mm in a straight 2400 rip cut

cheers

[sleepygreg]

Dont know if they have changed the standard in the last few years...but for it to be a true marine ply (stamped as such with the ASA ratings stamp) it had to be hardwood surface laminate, A-bond glue, NO core gaps.

Shorea species go by all those names mentioned, mostly mis identified, and within the shorea species they have a range of durability ratings from 1 to 4...and they are all technically hardwoods. In Terms of finish, most of them will accept a good finish.....and all of them MUST be finished as the key to getting longevity out of it is to make sure the surfaces and more importantly the EDGES are sealed.

Most of the problems I encountered with tension in the sheets came from the imported sheets...note that i said MOST...not ALL. And I really had some concerns about the standards v the stamp that was applied.

[Noelm]

I have seen sheets of structural ply at Bunning that were warped to a degree that would make them almost useless for anything other than nailing on a completely flat surface, and the outer veneer is all split and full of knots and crap.

[oldboot]

Dont know if they have changed the standard in the last few years...but for it to be a true marine ply (stamped as such with the ASA ratings stamp) it had to be hardwood surface laminate, A-bond glue, NO core gaps.

Shorea species go by all those names mentioned, mostly mis identified, and within the shorea species they have a range of durability ratings from 1 to 4...and they are all technically hardwoods. In Terms of finish, most of them will accept a good finish.....and all of them MUST be finished as the key to getting longevity out of it is to make sure the surfaces and more importantly the EDGES are sealed.

Most of the problems I encountered with tension in the sheets came from the imported sheets...note that i said MOST...not ALL. And I really had some concerns about the standards v the stamp that was applied.

Indeed you can get a fabulous finish out of good luan ply......I've built a few furniture pieces ( equipment cabinets) for churches, choke up the grain properly and add just a little colour and it can look pretty nice.

I definitely agree that with any ply you have to seal the surfaces and edges well to get any sort of long term service and durability.....
I recon the luan, because it is hardwood and therefore has tubular grain structure accepts marine epoxy very very well...... besides it glues well with any decent glue

I have left scraps of various ply lying around in the outdoors and the good quality luan seems to look far less uggly after a few months outside than most of the other stuff.

As far as the variability.....oh hell yeh.......there is some very cheap and nasty sheets out there..... but if you use a decent supplier and arent pushing for minimum price the quality can be excelent.

That said......I never buy ply unsighted....even from the best pack, I will reject a couple of sheets before I accept the 3 or 4 I will take back to the workshop.

Remember if you get ply delivered in small quantities they will give sheets off the top of the pack.....sheets that blokes like me rejected.

The worst ply I have seen has been slash pine (l though it is suposed to be stronger).......it tends to be a bit greasy and splintery.....it tends not to dry as well as others like hoop and radiata.....so when they put it in the press and heat it ( not being properly dry) it can look flat..... but after a while it can spring badly and do a good impression of a prawn cracker.

Of all the ply I have used, I have never had a blown sheet of luan, but I have had a few with internal delaminations from local suppliers.

As with any timber.........it pays to select.

cheers

[Noelm]

so from all this, I am going to require about 4 1200X2400 sheets to do the floor of my boat, and by the sounds of it, I might be better served to go to a reputable ply supplier to get it rather than some "off the rack" Bunnings crap? most people who have done floors have just used 12mm hardware store constrction ply. We have a few specialist ply places near me so I might just pay them a visit before I get started.

[Steve-G]

Noelm the sheets I'm useing are cutting up perfectly no deflection at all. Reading the invoice these are "Pink" which seem to be the ones to use.

[Noelm]

hhmm pink, are they painted on the edge or something to identify them? I will be buying mine in the next couple of weeks, so I want to get it all sorted before then.

[Steve-G]

NoNo paint, pink is the grading.

[sleepygreg]

'pink'......WTF......never heard of that as a grading. Oldboot, your still in the game, can you shed any light on that one. I have been out of it for a couple of years....might be a new grading....or a company specific (retailer or wholesaler)term.

Pity its not 17 years ago, as I could have helped you on the spot...used to run Sussex Timber (BBC) at Coburg.

Greg

[Steve-G]

The meranti or "Pink" plywood we get here in Australia is generally very good quality and it's quite pretty stuff. If it is made in Malaysia, unlike the Chinese sourced Okoume, the meranti pink ply probably does meet BS1088. It is considerably cheaper than Okoume. The only downside of the meranti ply is its weight, therefore for smaller boats that use 2 or 3 sheets of ply its a great choice as the weight difference is not going to be significant. For larger boats like the Goat, Okoume is a better choice, but only if it good quality.
Ripped that from "Woodworking Boat Forums"

Pink is the designation for Meranti.

[Noelm]

so, I dont need any "pretty" finish because my floor will be glassed underside and glassed on top as well, then flowcoated, is it recommended to buy any top grade finished ply? I was just going to buy some construction grade and be done with it, but if there is something that will be better I will use it, no use skimping for $50 when the job can be done better/easier/stronger