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Thread: Quality Plywood & Epoxy Encapsulation

  1. #1
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    Default Quality Plywood & Epoxy Encapsulation

    I have some new images up on my Flickr site showing why I am a believer in epoxy encapsulation of wood; I wasn't always. Encapsulation entails coating the wood with multiple coats of epoxy, saturating the wood surface and building up a moisture-barrier. The moisture barrier is key for bilges and underbodies as it keeps water out of a laminate and maintains a more constant wood moisture content in timbers. Wood movement and ingress of water is what often gives wooden boats a bad name: high maintenance. Encapsulating forms a stable base for varnish and paint. We tell customers to expect a 10 year life for their paint. After 10 years of normal use they may need to do a fresh coat. That is as good as any fiberglass boat maintenance.

    What convinced us of the merits of epoxy encapsulation was a visit to my friend Steven's house. He has a faering he built with his son that shows the effects of different plywoods and of epoxy coating wood.


    Plywood and Epoxy Encapsulation by Clint Chase Boatbuilder, on Flickr

    You can see three panels in this Faering. The darker plank is Joubert Sapele faced Okoume (varnished), the middle strake is Okoume by Joubert, and the lower plank in the photo is Shelman Okoume. All planks are finished with a Behr spar varnish.


    Plywood and Epoxy Encapsulation by Clint Chase Boatbuilder, on Flickr

    This is the same boat closer up to one of the tanktops. It is Joubert Okoume. The neighboring plank is Shelman Okoume. Both were varnished the same. The tank top is more degraded and molded than the plank. The tank top along the edge of the plank is perfectly clear. This strip was inadvertently epoxy coated when the squeeze out from the glue joint was spread during the clean up process.

    The results? It is clear that the epoxy coated areas of plywood are making the plywood much more durable and holding up much, much better. The sheer strake is probably holding up better because it is higher in the boat and receives less foot traffic and a lower angle of sunlight upon it. The middle strake and tank tops get more direct sunlight. But the different brands of plywood may have to do with the difference between planks made of Joubert vs Shelman. It is too bad Shelman went out of business. Clearly, Sapele holds up great and Steven made a good decision putting it in as the garboard. With that said, I have also seen Sapele planked boats flake and shed paint after many years and these were boats that were not epoxy coats.

    The moral of the story: epoxy encapsulation is a good thing.

    As always more at my blog linked below and please comment with photos of your evidence.
    Last edited by Clinton B Chase; 12-02-2010 at 07:53 AM.
    Clinton B. Chase
    Portland, Maine

    http://tinyurl.com/myboats

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Encapsulation means all four sides - right? Will one coat of System-3 laminating resin usually be enough? I'm not loving epoxy but it sure is forgiving.

    Gary

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    Default Re: Quality Plywood & Epoxy Encapsulation

    All my NC cut planking is laid out on the bench, inside face up. I coat it twice or 3 times depending on the plank (position in the boat), time (I may not be able to get to it within the 72 hour window), and my mood ("ah....good enuf!). 1 coat of S3 lam resin = 2 coats of Clear coat. More later.
    Clinton B. Chase
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    Default Re: Quality Plywood & Epoxy Encapsulation

    Quote Originally Posted by Gary Davis View Post
    Encapsulation means all four sides - right? Will one coat of System-3 laminating resin usually be enough? I'm not loving epoxy but it sure is forgiving.

    Gary
    The only polyhedron with 4 sides or facets, is a tetrahedron. I think you need to think six.
    ..don't judge a man till you've walked a mile in his shoes..

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Usually, I coat the inside face, sand it flat, then coat again at least once to get a nice smooth tipped out finish. The plank is glued on asap (while epoxy is 'green' so to speak). The outer hull is coated after planking before turnover. I usually use S3 'clear coat' resin because it has a greater working time, but it requires at least 3 coats because it is thinner.

    If the planks are lying around, you could coat the exterior face, then flip and coat the interior faces and glue them on while last coat of epoxy is still green. Always hot coat the epoxy to minimize sanding. I like to sand after the first coat because it makes for a nice smooth coat #2 and 3 which means easier sanding later before varnish or paint.

    Boat interiors get System 3 LPU on interior and on the exterior I use a 2-part or 1-part paint depending. The System 3 paint can be applied right over the epoxy and actually sticks better to the epoxy bare than it does to the LPU primer.
    Clinton B. Chase
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    Default Re: Quality Plywood & Epoxy Encapsulation

    One small correction, Clint. The inside of the Elf is coated with Deks Olje. No. 1 first then No. 2. After three years we recoated with another coat of No 2.

    This boat has been left outside all year for 5 years. Upside down in Winter and right side up in summer. The driveway is on the sunny side of the house. At the beginning of this season we put drain plugs in so we wouldn't have to bail it every time it rains. The worst damage to the finish came from it sitting with rainwater in it. But you can clearly see that the epoxy has helped to protect the ply.


    Steven

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Thanks for that correction, Steven, and the note that the boat was full of water at times. Says even more about how well Sapele holds up and why it is such a good choice for garboard and lower broadstrake material. I am inclined to put an extra coat of epoxy on these planks, too.
    Clinton B. Chase
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    Default Re: Quality Plywood & Epoxy Encapsulation

    I think I have 12 sheets left of that 9mm Sapele. I got it for $30 a sheet a few years ago. I put a piece in the dishwasher for over a year. The color faded a little. Maybe for a glued-lap Sjogin?


    Steven

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    Default Re: Quality Plywood & Epoxy Encapsulation

    as an epoxy professional I would agree but want to add: 1) the first coat or so should be solvent thinned for better initial penetration. When sealing with epoxy or any other coating, a MIN of 2 coats. When just coating or painting with epoxy, without fiberglass cloth, consider the flex/brittleness of the epoxy. For most boatbuilding you want a hard brittle epoxy, but for coating you want a less brittle epoxy. We even offer a 'rubber' epoxy that is about a flexible as a tire inner tube.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    I also agree with epoxy encapsulation of plywood. If for nothing else, but to subdue the higher absorption areas of most wood that is used in plywood these days. I cannot count the times that these areas have cost an extra coat of paint overall or extra care with spot priming beforehand.

    It's one thing to have to remove dead (oxidized) paint from a plasticized substrate, but to have to remove dead paint from a substrate that it's primer is also dead, or dead in areas is another. With an encapsulated substrate, you can pretty much count on each successive repaint to last as long as the first and paint film thicknesses to be more consistent throughout and especially with air cured finishes.

    Nothing worse than following the paint can instructions that say to remove any loose or peeling paint etc., only to find that the seemingly sound primer at the time was only a year or so behind with giving up the ghost as well as you watch your renewed finish begin to fail prematurely opposite the areas that were obviously troubled at the time of refinish.

    Unless you like "wooding" your paint surfaces each and every time, it is highly unlikely that your refinish attempts will last consistently, within reason, as long as the first time around did. This condition is most apparent on composite hulls that were only glass taped, over those that were encapsulated. Where the tape is, along with any overrun of epoxy that leeched into the surrounding areas, paint will be the most sound, while the non-epoxy areas will be all but dead right down to the wood.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Paul may have an opinion, but my training says to never thin epoxy and instead use one with the appropriate viscosity for the purpose at hand. I think this may not be the best advice, but I also don't know all the facts.

    I will second what Paul said about coating epoxies...you want one designed for coating so it will flex with the wood. They really are not brittle. A plank can be coated on the bench and later bent over molds/BHDs and the coating will not crack.
    Clinton B. Chase
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    Default Re: Quality Plywood & Epoxy Encapsulation

    I mentioned four sides because, for me, each end is trimmed and then sealed once its on the boat.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Bonda-Glass G4 polyurethane sealer, easy to apply one component moisture curing,my choice over epoxy due to cold/ damp working conditions.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Polyurethanes are brittle, if I understand correctly.
    Clinton B. Chase
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    Default Re: Quality Plywood & Epoxy Encapsulation

    Quote Originally Posted by Clinton B Chase View Post
    Paul may have an opinion, but my training says to never thin epoxy and instead use one with the appropriate viscosity for the purpose at hand. I think this may not be the best advice, but I also don't know all the facts.

    I will second what Paul said about coating epoxies...you want one designed for coating so it will flex with the wood. They really are not brittle. A plank can be coated on the bench and later bent over molds/BHDs and the coating will not crack.
    While Robb White used Tulip Poplar, not marine ply for some of his boats, IIRC, didn't he heat the shop and the epoxy up and then coat the boats thoroughly and then turn the heat down when he finished to let the wood 'drink' in the epoxy?
    "Anyone who says they like portaging is either a liar or crazy."
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    Default Re: Quality Plywood & Epoxy Encapsulation

    This is a site that describes the use of heat with epoxy: http://www.laughingloon.com/epoxy.html

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    Default Re: Quality Plywood & Epoxy Encapsulation

    In my effort to encapsulate sometimes we have issues.

    The last few times I've used epoxy as a coating in my new shop, I have had fish eyes develop in the coating. The first time was sealing the inside of DB case with graphite in clear coat resin (Sys 3). THe second time was today. I should have taken a photo but was too rushed. I mixed clear coat resin and some gray pigment to coat the hull exterior. Did the entire bottom, full of fish eyes. It was getting worse, so I acetone ragged the entire coat off the hull and went home unfulfilled.

    A little research shows that there are a lot of causes. Some info is that the shop stays at 50-55 degrees. The substrate is plywood, sealed with epoxy filler and S3 laminating resin mixture and sanded to 120 grit with some 3M.

    I'll do some tests, it may have been the additive both times. Any other ideas? I may skip the epoxy and go to primer.

    Cheers

    PS thanks for above link. Good info.
    Clinton B. Chase
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    Default Re: Quality Plywood & Epoxy Encapsulation

    Do you guys wonder why this thread died a "natural death" months ago despite your claims to have discovered the latest thing since sliced bread? Do you have any idea how long this "epoxy encapsulation" bunk has been sloshing around the bilges of the wooden boat building industry? I expect most forumites just read it, shook their heads, and said, "Why bother?"

    Facts:

    1. Epoxy is permeable. Water will penetrate it over time. It will impart considerable protection to the surface of plywood, particularly with respect to abrasion resistance, and without it, plywood is pretty well nigh useless for exterior boat work. However, it only penetrates the very surface of the wood. What you end up "encapsulating" more often than not is simply wet wood, a prime breeding ground for fungal decay.

    2. Epoxy is "forgiving," but at a very high price. Taking the time to cut to a better fit costs a LOT less than epoxy. Plywood sure ain't cheap, either.

    3. An epoxy coated plywood boat will never, ever, be worth more than the same design built traditionally of quality boat building materials, and will never, ever, last as long, giving both methods of construction equally good care, meaning it will be worth less faster.

    4. An epoxy coated plywood boat will always cost more than the same design built traditionally of quality boat building materials, labor included.

    5. Getting a decently fair finish on an epoxy sheathed surface requires a high degree of experience and skill, and more than a little work. Few amateurs get it right on the first, or second, attempt.

    6. A epoxy and plywood boat is very, very difficult to repair when that day comes.

    Check the search engine on this site and run "epoxy encapsulation" and see what people who've dealt with it first hand over a considerable period of time think of it. Or look no further than the $140,000 repair bill to replace the "surprisingly" rotted out "epoxy encapsulated" cold molded hull repairs on USS Constellation, only a few years after somebody thought that epoxy "encapsulation" was a good idea. http://articles.baltimoresun.com/201...g-rot-dry-dock

    A guy can build a nice little stitch and glue boat with epoxy and plywood without needing to learn much about boat building or working with wood, and have a lot of fun doing it, but in the end it's a costly shortcut that doesn't really add much of anything to the wooden boat game.

    Sorry, but nobody who's been around the block is buying this flavor of stale kool aid, guys.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    I agree with Bob Cleek except for his points 3, 4 and also 6. But I think he also misses completely on the fact that a monocoque ply/epoxy composite structure can offer substantially better performance in some small boats due to the enormously greater strength to weight ratio than traditional structures can even dream of.

    I like solid wood boats too, but there are some modern designs that would be impossible to build that way. My 20' glued lapstrake Rowan is not only at least a couple hundred pounds lighter than a similar boat of trad. construction, but is also utterly immune to drying out her seams when trailered here and there in the summer sun.

    I don't argue much that Cleek is right when it comes to larger boats that stay in the water, but I think he's totally off base when it comes to trailerable and cartoppable small boats.
    If this post did not meet all of your needs, please consult this thread for more options.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Quote Originally Posted by James McMullen View Post
    I agree with Bob Cleek except for his points 3, 4 and also 6. But I think he also misses completely on the fact that a monocoque ply/epoxy composite structure can offer substantially better performance in some small boats due to the enormously greater strength to weight ratio than traditional structures can even dream of.

    I like solid wood boats too, but there are some modern designs that would be impossible to build that way. My 20' glued lapstrake Rowan is not only at least a couple hundred pounds lighter than a similar boat of trad. construction, but is also utterly immune to drying out her seams when trailered here and there in the summer sun.

    I don't argue much that Cleek is right when it comes to larger boats that stay in the water, but I think he's totally off base when it comes to trailerable and cartoppable small boats.
    I won't argue with you on that at all. The technique does have its advantages for boats that are trailered and don't spend most of their time in the water. That goes a long way towards keeping them dry. Also, there's no question that in some designs, lighter weight for length and volume can be achieved over conventional wood construction. I do think that's a function of the design, however. While the art has become rather rare today, the small boat builders of days gone by were able to turn out amazingly lightweight traditionally built hulls, albeit at the cost of strength and durability.

    I suppose what I react to most strongly is the suggestion that "epoxy encapsulation" and epoxy adhesive construction are some sort of magic bullets. It's a lot like musicians feel about playing jazz (which I don't know anything about), they say you can't really improvise until you have mastered the basic elements of musical composition. I guess a lot of popular rock stars may have put the lie to that in the short term, but few without solid grounding in basic music theory have survived the test of time. Plywood and epoxy as a boat construction method tends to be much the same, I fear.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    I'd just point people back to the post #1 and check out the evidence. Other evidence I have seen is a couple boats I coated in epoxy that lasted longer (the paint jobs) next to ones that were not coated.

    Bob makes some good points points, some bad. The one about epoxy being permeable is correct. But it is Sloooooowwwww....compared to other finishes. It must be used well or not used at all, I totally agree with this point by Todd. If we don't get the right mil thickness, it won't act as a barrier coat for a boat that sits in the water. For boats on trailers, it is stabilizing the plywood and maintaining a more even moisture content and it will work.

    His point #2 is not relevant to the topic...we are talking about using epoxy as a coating not a glue, totally different issues.

    Point #3...the Gougeon Bros. findings in the article about their older boats is very interesting and helped me believe more in epoxy wood construction. I think a fabulously built ply-epoxy boat is worth as much as a fabulously built traditional version, labor being the same. They both require their own skillsets. People are paying for that as much as the boat itself.

    The problem in the USS Constellation is they mixed two kinds of construction. A ply epoxy encapsulated hull or cold molded hull works but it has to be done right...100% epoxy or none at all. Water found its way in and it doesn't breathe out in an encapsulated hull.

    Bob said, "A guy can build a nice little stitch and glue boat with epoxy and plywood without needing to learn much about boat building or working with wood, and have a lot of fun doing it, but in the end it's a costly shortcut that doesn't really add much of anything to the wooden boat game."

    I would say that building a ply-epoxy boat can be done without learning much about building or working with wood and have a lot of fun (especially a well done kit boat), but it is not a costly shortcut...building boats this way is a means and a totally unique practice, as unique and specialized as trad. boat construction. It is best if people stuck to what they know and not made comments about what they do not, especially strong comments like this one. I would never make comments about the merits of trad. boat construction...it is not my specialty.

    I'll stick to what I know -- and continue to learn about -- like the subject of this thread.
    Clinton B. Chase
    Portland, Maine

    http://tinyurl.com/myboats

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    Default Re: Quality Plywood & Epoxy Encapsulation

    My experience with my 20+ year old Elver is that epoxy encapsulation is no substitute for starting with good quality wood and construction techniques.

    I have personally removed epoxy encapsulated solid wood with my bare hands, after punching through the still rigid epoxy surface.

    "Crunchy on the outside, brittle fibers on the inside."

    The rotten wood in question seemed to be lumber yard white pine or treated southern yellow pine used for frames around plywood bulkeads, a plank keel, and the fir plywood hull bottom. The red cedar for the strip planked sides and white oak used for the outer keel is fine.

    Brian

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    Default Re: Quality Plywood & Epoxy Encapsulation

    When I sealed/primed my Wee Rob's Okoume plywood hull with West System 105+207 (special coating hardener), there were plenty of fish-eyes. These were scraped flush with the surrounding coat with a card scraper and then painted over - some of the larger ones are still visible, but one needs to be looking for them. The build has taken the last three years and in that time the plywood was stored flat in a rack, uncovered. The small shed/hayloft that the building took place in, was shared with another party whose hobby was cycling. There were numerous cans of spray oil and chain lube of the aerosol variety being used. In my case I attribute the fish-eying to the use of aerosol oils/lubes within the same confined space, not even a boat's length away. I recall reading somewhere - can't remember where - that the use of aerosol oils in the same space as epoxy coating is definitely not a good idea ...

    It may also be a good idea to clean and pre-seal/coat any newly purchased plywood ASAP ?
    Last edited by Songololo; 04-08-2011 at 12:01 PM.
    "Smooth seas do not make skillful sailors". African Proverb

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Quote Originally Posted by Brian Palmer View Post
    I have personally removed epoxy encapsulated solid wood with my bare hands, after punching through the still rigid epoxy surface.

    Brian
    Many times I have seen this, It is common with occume boats that have been stored out doors in the elements (fresh water). In my opinion Occume is a poor choice for boat building.
    I have a test piece of 12mm Sapele ply as a gate latch. It is weathered and gray, but still perfectly sound after ten years in the elements with No Finish at all.
    Don't skimp on the materials.

    Epoxy encapsulated wood is impossible to dry out once it gets wet. Then the fun begins.

    Dry sailed race boats are weighed fairly often, I have noted an increase in weight from two weeks of constant immersion - a glass boat.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    I wonder if after about 5 years, the epoxy becomes hard, very hard, then when you misjudge and hit the dock hard, or when trailing hit some hard potholes. will the hard epoxy crack and then water seeps in without you knowing? If that is the case, it will be hard to find the leak.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Quote Originally Posted by Tom Mac View Post
    I wonder if after about 5 years, the epoxy becomes hard, very hard, then when you misjudge and hit the dock hard, or when trailing hit some hard potholes. will the hard epoxy crack and then water seeps in without you knowing? If that is the case, it will be hard to find the leak.
    More often than not, that is exactly what happens. Sometimes it's a flexion that causes a crack. Sometimes it's a small ding from a sharp edged rock when dragging up on shore. With a lot of use, the failure often occurs on a sharp edge, such as a transom corner, where a combination of flexion and abrasion occurs. The crack need not be substantial. If the boat is left in the water, it will wick into the wood considerably. One frequent accellerating factor is trailering or dry storage in the sun, which can raise the temperature of the wood considerably, expecially in a dark colored boat. When the boat is launched into the much cooler water, and there's any break in the coating beneath the water line, the wood cools and creates a suction within the "encapsulation" that draws the water beneath the coating rapidly. ... But your mileage may vary.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Having owned two 30+ year old plywood boats that lived on moorings, one built more "traditionally "using resorscinol and metal fasteners and one with new at the time epoxy, I can say both lasted incredibly well, even with the most basic of maintenance. Both hulls were more than fine when I sold the boats on.
    Epoxy is nice, but not necessary except as a very good adhesive.
    I should also add that when I bought one of the boats, the antifouling and primer was completely gone in several areas of the hull (exposing bare plywood) and there was exactly no damage. High quality MARINE plywood and appropriate wood species are the key, not band aiding commercial lumber with epoxy.
    I don't think encapsulation does much. Epoxy does make a substrate easier to finish to a high standard, but I still prefer good ventilation and maintenance to a "hose down and forget...fingers crossed" plywood boat. Both my ply boats were open from end to end under the decks, so airflow was not an issue.

  28. #28

    Default Re: Quality Plywood & Epoxy Encapsulation

    Quote Originally Posted by Bob Cleek View Post
    When the boat is launched into the much cooler water, and there's any break in the coating beneath the water line, the wood cools and creates a suction within the "encapsulation" that draws the water beneath the coating rapidly. ... But your mileage may vary.
    This is rather specific information. Do you have experience with this? Please share the details with us. I am about to encapsulate my new build, and would like to know all of the consequences.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    I have probably said this before at some point in the past, I see no sense in the encapsulation of wood if there is a chance that the coating may get damaged,if imoisture finds its way in,your problems will start. Wood needs to breath,at least on one side. My own experience with polyeurathane G4 is that it is as effective as an epoxy as a coating. What is more,G4 is moisture cured,in effect using any residual moisture that is in the surface of the ply to cure itself.

    Top quality plywood will last 25 years and longer with good quality ordinary oil based paint,i have owned,lived on and cruised such boats,that had nothing more than good fastenings and materials in their construction....no taped seams,no fillets,no polyester or epxy to be seen. Construction methods are another issue,for another thread. Suffice to say,i personally would not encapsulate a boat for myself,but i have no problem if other people think its a good idea.

    I agree that a coating such as Polyurathane or epoxy can give a very sound hard base for following paint applications, but i dont think its an absolute neccesary.

    I would be more wary if offered an ecapsulated boat over one that was coated on one side only. I think it really depends on how the boat is used,how old and your own belief system on such matters.I for one gladly pay good money for well built traditional boats. I would not pay the same money for the same boat built in plywood and coated in epoxy......just my opinion.

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    Default Re: Quality Plywood & Epoxy Encapsulation

    Guess what folks, paint encapsulates wood and all types of other materials like Faux woods. Without paint or any type of liquid in a jar, all boats are easy to repair. I will expect a new approach next time on the next "favorite" this that and the other requests in the future. Deal?


    Some of the same folks participating here have argued over time that we must not use anything other than quality "marine" labeled approved paints. Some of you guys have even spend unlimited time telling us that their brand is the only brand to use, reposting about your snake oil as part of a regular diet. Why not at least use mother nature's natural and organic based waterlaced based paints and be done with it, if your only position is that of the possible pitfalls of repair when damaged?

    Or why not take the position that each and every job has a particular "best" recommendation and give up the trashing of product that has a pretty good proven track record of success.

    Every single epoxy thread finds the same willing participants telling us in the case of epoxy how horrible the use of the product would be and not to use it because of the issues of fractures. Duh, well guess what if you ignore repairs when they are needed, your favorite snake oil will not work either. .

    edited to ask how many of the bash epoxy guys wash your boats down with freshwater? You do? Gasp, SINFULL! I say.....
    Next time you pick up that garden hose, think about the damage you are intentionally doing to your own boats demise. If you want to be a purist, grab a bucket of seawater and a cotton mop instead of dishwashing detergent and clorinated reservoir creekwater.
    Last edited by erster; 04-09-2011 at 09:10 AM.

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    Sweden,Scilly Isles, Siberia
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    4,643

    Default Re: Quality Plywood & Epoxy Encapsulation

    touche Erster. Unfortunately i have to use my boat in fresh water......but the only thing she gets is pine tar concoction..... but she not plywood anyway,so this is out of context with the thread.

    I get bashed for mentioning exterior ply and polyester......so be it....what works for some does not work for others, and lets face it...a lot of people HATE maintenance....and it doesnt matter what new goo your boat is covered with,as erster has pointed out, if its not maintained,it will eventually rot anyway. Cheers

  32. #32
    Join Date
    Feb 2000
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    San Francisco Bay
    Posts
    10,061

    Default Re: Quality Plywood & Epoxy Encapsulation

    Come on Erster, "All boats are easy to repair?" Have you ever repaired rotted-to-mush "encapsulated" crap wood edge-nailed strip planking? I've seen more than one beautifully built, relatively new, large and expensive strip-planked "encapsulated" boat needing such repairs and it ain't pretty, or cheap.

  33. #33
    Join Date
    Sep 2010
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    Adelsö, Stockholm, Sweden
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    48

    Default Re: Quality Plywood & Epoxy Encapsulation

    I get the feeling two completely different building methods get mixed up in this thread.

    A "traditionally" built solid wood vessel is as far as I understand almost impossible to "encapsulate". There is just too many places where water might penetrate and it is more or less doomed to fail (!?). I think this is where we have most of the cases of rotten wood behind epoxy.

    However for a epoxy/wood (plywood, strip, cold moulding) design the "encapsulation" idea makes more sense since all the pieces involved are already glued together (there will be very little ventilation of the outer ply's if the inside of the boat is left untreated) and there is a much bigger chance of actually encapsulating the structure, assuming if your wood is properly dried.

    So before we know which technology is used it will be difficult to come to a final verdict....

    /A
    Last edited by A_gus; 04-09-2011 at 05:09 PM. Reason: Spelling

  34. #34
    Join Date
    Jun 2006
    Posts
    3,775

    Default Re: Quality Plywood & Epoxy Encapsulation

    Quote Originally Posted by Bob Cleek View Post
    Come on Erster, "All boats are easy to repair?" Have you ever repaired rotted-to-mush "encapsulated" crap wood edge-nailed strip planking? I've seen more than one beautifully built, relatively new, large and expensive strip-planked "encapsulated" boat needing such repairs and it ain't pretty, or cheap.
    Actually I never thought that you would ever admit building a strip plank boat using crap wood and covering the wood up with goop and even admit to having to have fixed it.

    But anyway Strip plank construction, glad you brought it up. I use a couple of well known species for strip plank building. Its called white cedar and even red cedar on occasions. While a lot of folks encapsulate their carvel planks fastened with heavy metal and "tee shirt" materials with red lead, primers and enamel paints, I normally use an alternative material to glue the strips and then finish the strips on both sides with epoxy resin. I see no adverse affect of the contrasting products for the mental satisfaction myself of protecting the bare woods. Can you give us a reason why I should forgo the use of epoxy as a sealcoat?

    Of course numerous building methods have their preferred ointments that work to a builders and owners favor and to hopefully extend the life of the completed hull. Unlike some I would never attempt to use 5200 between six inch type planks either. But I have used it on strip planked hulls without a single issue.

    Frankly as of yet no one has provided us with an easier method to repair any and all hulls that are neglected or ignored until such time that any material has turned to mush. OF course on occasions we have read that people also go the inferior wood types these days. But have you also been reading about the numerous issues of so called prime choice lumber being used on our sponsors Lumberyard Skiffs too on this very forum that built your preferred building method?

    But when talking about repairs, most jobs are nasty and greuling to down right frustrating for young and old to fit in certain areas thats dimly lit or spaces half the size of our hands.

    The process is identical of the old days gone by even though some of the steps are a bit different. Grab the bull by the horns and start digging. Thats one thing that no computer or computer wiz has ever figured an easier way around it.


    As a side note, lets talk a bit about your preferred method of boat building and repairs of the same. Second thought thats probably not the best thing to do. Landlocked sailors removing fungus amongus while some of us FAUX Woodaholics are enjoying the water sports during the warmer periods of our country have little humor when this is brought to their attention. Cheeerrrrrsssss

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