Roy Mc Bride 14 Dec 05 09:09
what both Al and Kevin say is quite correct,coats of epoxy over bare ply work well,we have done many such boats.....a 1934 Knud Reimers Tumlaren,cold moulded over the original Carvel planks......two DD mini transats,a George Buhler Diesel Duck 38,a DD 34 and a Dix 43........ Optimist and various Dinghys ,all plywood /epoxy and no glass cloth,just the epoxy coats and a good system of top coats of paints.....they will last litteraly a 'Life Time',honest!
tip, do not wet out glass cloth with epoxy on a cool morning,as the air warms up during the morning,it will force air out of the wood/ply below and cause bubbles...try to do such work when the day has warmed up,as the place cools ,it will then suck in rather than blow out!
Roy Mc Bride @ www.ckdboats.com
Roy Mc Bride 11 Dec 05 01:25
Cape Town here,
we have many years of experience with epoxies, we use and sell Resoluton 816 epoxies all the time.... our largest build todate is a wood/epoxy Dix 43....... its the only one in wood to date, all of the others being steel or alloy.. the boat took one man (me) six weeks to build the hull only,the hull ,deck and bulkheads unit took a collective 14 months,all spare time stuff. with just two coats of 816 epoxy as a coating to the bare Ockume Marine BS1088 plywoods,with no glass cloth,excepting high load areas like winch mountpods,cockpit sides and the aft boarding platform,the entire structure was then painted with an International Paints P/U system....... epoxy etch primer the Interthane 990 white top coats....... a system was devised to do the decks non slip areas too....... its simple..... mask out the areas after application of the primer, apply one coat of 990 topcoat,then sieve Teak Sawdust from a domestic Sieve untill the area is covered...... when the paint is dry you can then remove all of the excess sawdust (to be reused on the next panel) then apply two coats of 990 P/U Top Coat to suit what ever shade you choose... the yacht Flying Cloud, Dix 43 has had some eight years exposure to the really harsh UV found in Cape Town, it is still perfect and shows no sign of wear,even after six years of stepping aboard in the same place each evening....... its the most cost effective paint system and non slip deck surface you will find. regards Roy Mc Bride @ www.ckdboats.com
Al Meyer 08 Dec 05 18:42
I'm not that experienced, but I used System Three Clear Coat (2 coats) as a sealer - no cloth - on my Penobscot. The wood I used was meranti BS6566. It was launched in June 2004, which isn't really long enough to be considered a good test, but so far I haven't seen any problems with checking, and the treatment was the designer's recommendation.
Beautiful boat, Chuck. She's gonna be fine.
Chris Ostlind 08 Dec 05 11:52
Natural Luddites.. What a cool reference point for consideration.
Come to think of it... I'd be more than inclined to paint that on the transom of my next boat.
Kevin Beddoe 08 Dec 05 09:56
I've got experience using epoxy over plywood with glass cloth and without. You will get "checking" on some types of ply after awhile that could cause moisture intrusion if you don't glass it, but I've never heard any debate that using epoxy directly over ply was an issue.
Tom Lathrop 08 Dec 05 08:21
Looking good. It's going to be a fine boat.
Try to find builders who are both experienced and have used epoxy on plywood. If they give instances of bad experience and recommend against it, you should consider not using epoxy on ply. All the negatives I hear are from people who have "heard" about problems or are natural ludites.