Guest Posted January 9, 2014 Share Posted January 9, 2014 New plywood, BS1088 stuff that will end up painted where seen and left plain, but sealed, where it isn't visual. I want to seal it all up so was thinking of getting off on a bucket of Everdure while I splash that around. Use that or is there something better? Link to post Share on other sites
Kiteroa 8 Posted January 9, 2014 Share Posted January 9, 2014 I've been marinating the piedy in a west system and #7 epoxy thinner brew. Only because it's far cheaper and I had plenty of west. Seems to be doing the trick. Link to post Share on other sites
otto 31 Posted January 9, 2014 Share Posted January 9, 2014 and if your in this arvo might stop by. need a bit of wire crimped onto a bit of bent steel. something for you to hang onto next time we're out Link to post Share on other sites
Guest Posted January 9, 2014 Share Posted January 9, 2014 Marine ply should be fine just as it is. Thats why they make it " marine ply" . Would you paint your chains? Link to post Share on other sites
tuffyluffy 76 Posted January 10, 2014 Share Posted January 10, 2014 Knotty, try the epoxy glueshop (or some name similar) at the bottom of Onehunga Mall Rd in Onehunga. They have an expoxy sealer similar to Everdure but at a fraction of the price. I used it on the interior panels of my boat 3 years ago and have had no issues. Link to post Share on other sites
Dambo 44 Posted January 10, 2014 Share Posted January 10, 2014 I'm with W.T on this - Thinners and Epoxy - My Spencer is a glass-ply sandwitch now How's the piedy going W.T? Link to post Share on other sites
Guest Posted January 10, 2014 Share Posted January 10, 2014 Marine ply should be fine just as it is. Thats why they make it " marine ply" . Would you paint your chains? The 'marine' relates to the glue, quality of the glueing and the amount of allowable voids rather than the longevity of the wood used in a marine or any environment. As a FYI, a lot of this new ply is replacing tantalised construction that has gone rotten and de-laminated. Some grades of construction ply are basically the same as BS1088 ply. The word 'marine' is a marketing one that allows people to inflate the price. Yes we paint the chains often. Why? It just looks pretty but in my eye is a 'Why would ya'. In the US painted chains are common, mind you so is shooting teenagers so I'm knot sure if we can take anything from that. No7 epoxy thinners now in hand, Thanks gents. To lazy to drive to Onehunga as I only need a couple of cups all up. Link to post Share on other sites
Guest Posted January 10, 2014 Share Posted January 10, 2014 zylene Do you realise how nasty that stuff is, it's a shocker. Use with extreme caution. The coat of thinned poxy will be fine, I just want to lock the face layer of ply which is 0.5-1mm at most so a drench coat will seal it up enough it won't absorb water. Anyway get off the internet is must be at least 40 under the boat cover, perfect for a spot of afternoon glass sanding in your undies Was that you peeking the other day you dodgy perv? About 30-35 at the moment I'd say so damn happy I have slow hardener Flowcoating water tanks this arvo... oh and trying to finalise a kitchen. We've not had one for 3-4 weeks so the Wa's patience must be running thin shortly Link to post Share on other sites
wheels 543 Posted January 10, 2014 Share Posted January 10, 2014 Everdure and its ilk are feelgood products of dubious benefit. You "feel" you have sealed your boat against rot by painting on loads of magic soup. Sure if you paint on enough it will eventually seal, but you have paid for about 20% epoxy and 80% cheap thinners for the privilege. Everdure did contain an antifungal early on, but thats also debatable whether it actually did anything as it is locked up in the epoxy matrix. 100% MB DON"T THIN EPOXY!!!!!! International carried out lots of testing and came to the conclusion that their Evadure was actually doing more harm than good. They discovered that as the Epoxy hardened, the last traces of thinners evaporated leaving a microscopic matrix of tunnels in the Epoxy that allowed moisture to get in and become trapped. They discovered that the Moisture added up to a significant increase in weight. The result was that they now suggest not using Evadure or thinned down Epoxy and use pure Epoxy which still penetrates the wood surface OK, but creates a total barrier to any moisture penetration. I would imagine that info is still available on their Website. Link to post Share on other sites
Guest Posted January 10, 2014 Share Posted January 10, 2014 Is marine ply held together with resorcinol? Well I never. According to the esteemed Mr Churchhouse my plywood Spencer is at risk of disintegrating because that stuff doesn't last. That's if it doesn't die of rot first. (And my boat is held together with West Epoxy). Link to post Share on other sites
Steve Pope 243 Posted January 10, 2014 Share Posted January 10, 2014 I have used epoxy thinned with meths 40/60 to good effect. at least so far. Link to post Share on other sites
wheels 543 Posted January 10, 2014 Share Posted January 10, 2014 Is marine ply held together with resorcinol?If you mean the glue holding the layers of Ply together, most likely not. Resorcinol is in the Family of Formaldehydes, but because it is a one part liquid, one part Powder, it is not used in the production of Plywoods. They normally use Urea-Formaldehyde for that purpose. Urea-Formaldehyde glue is also used in the production of MDF's. It is a heat/pressure setting glue, hence the enormous presses that squish all the wood and glue together and almost instantly you have a Sheet of board.Resorcinol glue used in Boat building and also timber built vintage aircraft was common way back before Epoxy. Epoxy is a superior and more versatile Glue, but Resorcinol is still a good glue. It is toxic though. Link to post Share on other sites
Kiteroa 8 Posted January 10, 2014 Share Posted January 10, 2014 I'm with W.T on this - Thinners and Epoxy - My Spencer is a glass-ply sandwitch now How's the piedy going W.T? The Piedy is under control. Just fairing up the bottom. Need to up the pace though. Have been distracted by that crazy seagull race..... Link to post Share on other sites
tuffyluffy 76 Posted January 11, 2014 Share Posted January 11, 2014 Be damed all you everdure skeptics. Our family is still mucking around in a 1985 optimist that was built in the garage out o f ply and treated with the perscribed 10 coats of everdure. I sincerely doubt it would still be as tidy, if still floating had it not been treated with the stuff. It still weighs in pretty well too despite spending half its life stored uncovered outside. Personaly, no wood goes near the interior of my boat without a least three cpoats of thinned epoxy Link to post Share on other sites
Guest Posted January 11, 2014 Share Posted January 11, 2014 epoxy "superior". i don't think so. It just has bulk so fills gaps. Resorcinol is stronger than epoxy, I believe and PVA is about the strongest but of course not waterproof. it all depends on you application. Resorcinol is worth considering over epoxy where the joint is tight and appearance is not too important because of its colour. If the marine ply is made from durable timber paint should be all it needs. Link to post Share on other sites
wheels 543 Posted January 11, 2014 Share Posted January 11, 2014 Resorcinol is stronger than epoxy, I believe and PVA is about the strongest but of course not waterproof. What?? Hell no. Where do you get that idea from?? Epoxy is far superior in strength than Resorcinol. The only advantage Resorcinol ever has over Epoxy is when gluing Tanalised timbers. That is the only time. As for PVA, well firstly, yes in fact there is a water resistant version of it. But PVA glues are so weak, they are not in what is called a "Structural Glue" class which Epoxy and resorcinol both are. PVA is fine for indoor Furniture where screws and other fixings are the primary source of holding. Link to post Share on other sites
Guest Posted January 11, 2014 Share Posted January 11, 2014 You are totally wrong about that Wheels. Have a read here.....http://www.duckworksmagazine.com/08/col ... index5.htm Link to post Share on other sites
Guest Posted January 11, 2014 Share Posted January 11, 2014 I love Cross linked pva, use it to make most of my joinery when its not needed to be waterproof. Screws or nails are not required except to stop the pieces sliding while the glue is wet. It makes wood " grow together" leaving a joint that cannot be seen except for the different grain. Brilliant stuff. Resorcinol is not affected by heat like epoxy and is proven over time . Epoxy is not proven over time. Epoxy glued stuff is usually easy to dismantle as just need a sharp jolt with a hammer and it can come apart. Motorbike , we actually agree! The polyurethane result in Motorbikes link is worth noting, its absolute crap and backs up the results I've had with the sh*t. Link to post Share on other sites
Guest Posted January 11, 2014 Share Posted January 11, 2014 The plan is to wash al the bare ply with a slightly thinned resin. The top ply is thin so it won't take feck all. Some places will be flowcoated as well i.e. inside the water tanks. The 'sealed' ply will be harder and easier to finish. The bits unseen will be better with one coat of that resin than they will be with one coat of paint. One coat is it, 2 are too heavy Link to post Share on other sites
wheels 543 Posted January 11, 2014 Share Posted January 11, 2014 What that test has not shown in the results is, that PVA and Resorcinol both need perfect fitting joints and high clamping pressures to get that level of strength. He did state it, but not shown it as a test result. Epoxy does not require that level of tolerance when making a joint. The other point is, shock. Do you ever here the "crack" in your joinery when you move it or bump it? Both PVA (although there is a PVA that is much more "giving" and is not quite so prone to cracking) and Resorcinol are Hard brittle glues and crack. A major concern with Resorcinol as it ages. Many older Ply/Timber hulls have failed joints due to that very fact. Then there is the type of timber being glued, what else maybe being glued to the timber and things like fairing the edges of joints etc, just making the Epoxy a slightly more versatile all round product. And finally, the strength of Epoxy is in what and how much of an additive is mixed into the Epoxy resin to make it a Glue. This can vary the strength in a huge way. Sorry, but give me Epoxy for Boat building any day. It is by far, a more versatile product and in many cases I still believe it is stronger, even though in some cases it maybe tested as weaker. Oh and I have found that some Epoxies tend to be a little too "hard and brittle" in some cases also. West being one of them. But West can be superior in other area's like wetout. So it all depends. Link to post Share on other sites
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