WBP PLYWOOD

Clyde_Wanderer

Clyde_Wanderer

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Can one use WBP plywood, in instead of marine ply, for use on a boat, ie, I will be renewing the floors, (or bilge transverse bulkheads )on my boat while feinforcing inner hull around keel area, and have been advised to make them 1" thick ply, but they will be completly laminated in, and I can get a sheet of 18mm wbp ply in B&Q for £35, so thought of using it and doubling it up, ie, gluing two peices together before cutting it to shape and preparing it for laminating.
Would like to know your thoughts?
Cheers, Eamonn.
 
WBP is fine inside the boat. I used it when building my now 20 year old boat with no problems. I suggest you find a timber merchants and buy a better quality than B&Q sell as I have found their ply is pretty substandard.
 
My local woodman tells me that it's the same adhesives used but marine ply is guaranteed void-free where as Wbp is not.
Do not buy at B&Q
Find your local woodman who supplies joiners and the building trade. Many £s cheaper. They often have huge stocks of offcuts as well. Ours has some dubious name like Kendal Cut2Size or somesuch, but a great bloke and a huge range of woods.
 
Presumably you are renewing the old floors because they are rotten. If you don't use the best quality marine ply you will soon be replacing them again. Good quality marine ply, as sold by Robbins Ltd, Bristol, is expensive but the largest cost in this repair is going to be the labour, not the materials. Even if you don't consider your time as a cost you don't want to waste it.
 
I would go along with all that. Generally, and excepting cheap and nasty WBP, there isn't much difference between WBP and Marine Ply, except that Marine Ply is guaranteed to have no air voids within it. If all the edges are well sealed with epoxy, I can't see you having any problems with it.......
 
You trying to Lakesailor me? /forums/images/graemlins/wink.gif

And what's this all about? /forums/images/graemlins/crazy.gif /forums/images/graemlins/crazy.gif /forums/images/graemlins/crazy.gif /forums/images/graemlins/crazy.gif
 
NO! ya just bloody well typed faster than me is all! /forums/images/graemlins/grin.gif

I dunno what this /forums/images/graemlins/crazy.gif is all about? it has just appeared in the smilies, I think it's a sleepy?
 
Eamon

You could try Hulley Marine, here in Dumbarton, for Bryunzeel ply. He is the Northern distributer see Here.

Phone: 01389 742438

Probably more expensive - but the stuff for the job.

Regards
Donald
 
There is a wide range of quality in WBP. look for B.S. 1455. certainly I used it for decking in a small fishing boat, and in my wheelhouse at the moment, it wore through but never delaminated. when I used marine ply for the wheelhouse structure it did delaminate. I think it's a bit of a lottery. Got some WBP that's been out in the yard for 18 months, still good, cost £18 for 18mm 3years ago.

Just realised you are going to laminate it, do you mean encapsulate in GRP? SFIA permits use of WBP in the structure if encapsulated. In any case you often get a better bond with GRP on WBP than on marine ply, which can have a harder surface.
 
If you really want to go cheap....Wickes is cheaper than B+Q and better quality imo (ie less crap ).

One trick with inferior plywoods is to simply examine the end grain- how many gaps can you see?

Now look across the faces,
one will be rougher,the other ''better''face may still may have a) areas of graincoloured filler, b) ripples which mask voids and creases just below the surface and which will always show through..c) eliptical fillets of wood inserted to piece in gaps and voids on the surface itself...
Myself I am not averse to using inferior ply JUDICIOUSLY (bunk base or shelves mebbe)but for what you describe,well,.. in one years time will the extra £50 cost of the Bruynzeel dogs bollox be that important in the greater scheme of things?
 
You can certainly use WBP plywood, as previous replies have indicated. Do consider 'flow-coating' your chosen ply in epoxy resin ( or even cheaper polyester resin ) as this seals the cells of the wood against moisture. For how, ask any marine vendor of epoxy resn packs ( West, etc. )

It's easy and effective.

/forums/images/graemlins/wink.gif
 
Oh No!!!!! Should I scrap my 34 year old boat as a matter of urgency?! That's got plywood bulkheads bonded in with polyester!

OK, I agree that epoxy definitely sticks better and soaks into the wood fibres better than polyester but I don't think there's anything wrong with using polyester as long as the joint is designed accordingly!
 
G'day Bilbobaggins,

Sorry, but I have to disagree.

Quote:
You can certainly use WBP plywood, as previous replies have indicated. Do consider 'flow-coating' your chosen ply in epoxy resin as this seals the cells of the wood against moisture. For how, ask any marine vendor of epoxy resin packs ( West, etc. )

Standard polyester resin will not stick to most timber surfaces in the long term application, also note the same resin is far less effective as a barrier to prevent moisture entry.

An epoxy should be used, if applying to ply you can thin the epoxy by adding metho up to 40% by volume after mixing the resin and hardener; this can be applied till it will no longer soak into the ply, most of it soaks into the exposed end grain.

Finish with 2 coats of full epoxy resin and lightly sand with a 200 Grit, just enough to remove the gloss is fine.

Stringers or ribs etc should be bedded on a mixture of resin and micro fibres and a well rounded gusset formed at the base (using a plastic spoon) for the glass to flow over, thus avoiding 'hard' corners.

Hope this helps

Avagoodweekend......
 
G'day Eamonn,

Yes you can use construction grade ply, but you need to do some preparation first.

After you have shaped the ply with a nice well rounded top to make it easy to glass, mix some epoxy resin and hardener then add 40% by volume of Methylated spirit, this will thin the resin and allow it to penetrate into the exposed end grain of the ply, keep dabbing it on wet on wet till it will absorb no more, then when it gets tacky add two coats wet on wet of full strength resin.

When cured sand with a 250 grit, just enough to remove the gloss and no more will be fine.

The new stringers, ribs or bearers should be placed on a bed of epoxy mixed with Micro Fibres and the bottom should have enough to form a nice rounded gusset, use the back of a large plastic spoon for this.

All you need to do after this has cured is give the gusset a light sand as above and you are ready to glass up.

Hope this helps.

Avagoodweekend......
 
The 'how-to' info is all in here - and in free leaflets produced by the distributors of West System products around the country.

Gougeon.jpg



'Flocoating' (sic) is described on p. 83-84, and involves coating a sheet of ply with resin on both sides, then cutting out the required shapes - rather than the other way around. This frequently saves time, and labour-costs as well, especially if you have previously marked-up your ply sheet with the outline of your floors, bearers, etc, such that there will be little wasted wood.

[ QUOTE ]
"...Although there is some waste involved with leftover pieces of resin coated plywood that may be discarded, the overall savings in application and finishing time can far more than offset this waste.

[/ QUOTE ]

I don't intend to respond to our 'contentious cousin of a goana'. You can do this swiftly, cheaply and effectively, then go sailing - or you can spend the next 3 months faffing about doing marquetry and cabinet-making.

Disagreements on what technique is best should be referred to the Gougeon Brothers.

Good luck with your boat.


/forums/images/graemlins/wink.gif
 
[ QUOTE ]
Dear Gougeon Brothers.

I've done as you said, but am now left with having to epoxy all the cut edges again.
Did I do it wrong.....

[/ QUOTE ]

Oh dear, as mine are shaped like a capital 'A' with a well rounded top I have only a thin line at the bottom of the 'A'. Did I do it wrong as well then?

Avagoodweeknd......
 
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