Whats this rumor about epoxy might not be so great at encapsulation after all

Discussion in 'Materials' started by Boston, Jan 20, 2011.

  1. Boston

    Boston Previous Member

    Ya I'd love to know how much strength is retains over given time intervals. Seems every time I ask I get the same cryptic answer, "there are some boats that lasted 50 years". I'm thinking whats the degradation in strength characteristics for each say ten year period, and under what conditions, temp, humidity, sunshine, salt or fresh water exposure. I'd love to read some real data rather than the "well it lasts a really long time" I keep getting out of the West system people.
     
  2. TeddyDiver
    Joined: Dec 2007
    Posts: 2,614
    Likes: 136, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

    Maybe we'll just have to wait another 50yrs to see if those well done and well cared boats get any problems.. and then wait another 50 yrs more.. and..
    BR Teddy
     
  3. Boston

    Boston Previous Member

    I'm sure the industry has been doing longevity testing for as long as they have been producing the stuff. Its just they don't release the info as far as I can tell. Maybe there are some independent studies but I've called and asked for specifics several times and all I get is shined on about how a particular boat lasted 50 years or that "some" boats have been out there going on 30 and 40 years. I'd like specifics not hearsay. One thing is certain and that is that BP-A leaches out of the stuff and if its leaching something like that, its got a life span, I'd like to know what it is.
     
  4. mark775

    mark775 Guest

    You know, Bos, I started in West. I am now happy with Systems Three. I am just learning that there is a world of other epoxies with all manner of properties, different rates, temperatures, and light curing. Seems one can work under light missing a part of the spectrum (I'm not sure exactly how it works), go home, flipping on the full spectrum as you walk out, and return to a cured product in the morning. With nearly unlimited pot life (within job parameters), pre-pregs with temperature cure, etc.. In short, good to work with.
    I don't know how long the stuff lasts - only that it's long enough. I'm sold, I know that... and you know what a skeptic I am. My next boat I build (not skiffs) will be largely CF/epoxy pre-preg with some areas cored and it will last my lifetime, then some. I have had my hands all over these epoxy boats and tho I have only recently made the switch (mostly) myself, I see it as superior as a water barrier and adhesive. I don't believe I will willingly do a secondary bond with poly again. Maybe Herman or Jimbo will come back and tell you some specifics. I think they are, or were, both in the business. "Better than anything else" isn't enough for you?
     
  5. Boston

    Boston Previous Member

    ya one of the first things I looked into when I got on here was adhesives and what seems to be the top dog. Turns out its epoxy, I never did really like that option just cause its so chalk full of chemicals but oh well I suppose I'm stuck with it ( sorry had to ). I just thought its been a couple of years and maybe things had changed. I"v heard the occasional grumbling and thought I'd throw out the question. West is overpriced from what I hear thrown around and ya there's lots of alternatives. I would like to read some actual longevity studies tho. Kinda drives me nuts to use a material without knowing as much as I can learn about it.

    Paul
    where's that data you were talking about
    I'd sure love to read something definitive about this stuff
     
  6. mark775

    mark775 Guest

    You are a perfectionist. I know the problem.
     
  7. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 116, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    In 1993 I installed a fold down ss. swim ladder on a plywood base to a clients dock. The tide cycle makes the base of the ladder wet and dry every day. The base is Three planks of 12mm marine ply epoxy glued together . This ply foundation was epoxy coated with several coats of west system, 545 primed, awlgriped , installed with galvanised lag bolts 5200 bedded to a concrete wall. The paint is faded but the swim ladder foundation looks is great shape. Epoxy is a very effective sealer to moisture uptake in wood.
     
  8. Boston

    Boston Previous Member

    But we're still talking anecdotal evidence. Where is the detailed studies, where are the industry standards for durability and under what conditions, strength and flexibility over time. Why all the secrecy, how come I'm not staring at ten studies of 1000 samples various groups of which are subjected to different levels of stress and aging techniques. Then the various groups compared and averaged, then tested again against other sample groups. If I'm going to be spending a huge chunk of change on goop I want to know how good that goop really is or more accurately, isn't.

    anyone actually have any laboratory tests on specific formulations, OK its still considered the standard, soooooo, define standard and were are the details of what standard performance is.
     
  9. TeddyDiver
    Joined: Dec 2007
    Posts: 2,614
    Likes: 136, Points: 73, Legacy Rep: 1650
    Location: Finland/Norway

    TeddyDiver Gollywobbler

    But that's more a matter of the specific application you are talking about.. You know in the commercial aircrafts it's all evaluated, each part individually regardless of the material it's made of. In boat building with greater safety factors it's boils down to maintenance and care..
     
  10. CatBuilder

    CatBuilder Previous Member

    Boston, the evidence and rigorous testing you are looking for is in the "on boatbuildung" book by the Gougeon brothers. Take a read. They did extensive lab testing and published all the results.
     
  11. michael pierzga
    Joined: Dec 2008
    Posts: 4,862
    Likes: 116, Points: 0, Legacy Rep: 1180
    Location: spain

    michael pierzga Senior Member

    Consult the west epoxy book , I remember both moisture and cycle testing figures for epoxy in the book. The question of boatbuilding materials never is...what lasts forever ?, but what material gives the best combination of strength, price, workabilty and durability. Epoxy structures give a good combination,. Even if you constructed your boat out of a block of Maine granite it will revert back to dust..
     
  12. bntii
    Joined: Jun 2006
    Posts: 731
    Likes: 97, Points: 28, Legacy Rep: 1324
    Location: MD

    bntii Senior Member


    Sorry PAR- too many years of house framing and the lingo.
    Restated: Use quality materials and sound practice..
    As I do primarily repairs/restoration, in my world in I don't really have to worry about this is so much.
    You build far more than I do & may face the issue daily.

    Boston- what kind of build are we talking about here?
    GRP, cold mold, framed & ply sheathed?

    What kind of parts you talking about encapsulating?
    It sounds like your build depends on it?

    Just now I have a contract to replace some 15' of a cabin house side. As built it is 6/4 solid mahogany plank bedded to a ply/GRP deck and a cold molded house.
    When built it was sealed/encapsulated with epoxy and glued to the deck and house with epoxy. There is a large eyebrow at the top joint and a bead of sealant at the bottom.
    Over time the brittle glue up failed allowing water to enter the plank via the fasteners top and bottom. Additionally miss-sized fasteners at the ports caused the plank to crack which eventually ran along the grain.
    As the whole mess started to rot inside the owner tried to seal it up with penetrating epoxy.

    Epoxy was miss-used in this build and the poor use of thinned down junk for repairs did nothing to address the root causes of a structural failure in the vessel.
    Pay attention to bedding and fasteners and don't expect epoxy to magically protect larger timbers.

    There is plenty of research about water migration and saturation of epoxy structures when submerged.
    I don't believe that the degree of water take up found in this research is in the present context a mechanism of failure for epoxy encapsulated parts.
     
  13. wardd
    Joined: Apr 2009
    Posts: 897
    Likes: 37, Points: 0, Legacy Rep: 442
    Location: usa

    wardd Senior Member

    how does casein stack up against epoxy for strength of bond, longevity, waterproofness, ease of use, working life, and cost

    and other waterproof glues

    I meant Resorcinol: glue
     
  14. Fanie
    Joined: Oct 2007
    Posts: 4,604
    Likes: 177, Points: 63, Legacy Rep: 2484
    Location: Colonial "Sick Africa"

    Fanie Fanie

    That's it, finally agreeing epoxy sucks. It leaks water like a sif. You can use it but you will sit with the results. Just ask Larry Pardey :D

    I hope that would flare the old epoxy / polyester thing up again because I'm tired of it :rolleyes:

    Everything leaks eventually, even people. If a boat lasts 50 years your children won't be interested in some old boat when they're young and by the time they get to your age they won't wont be seen near anything that old...

    Hey, how about for some museum ? I know they collect old stuff... or used to.
     

  15. mark775

    mark775 Guest

    bntii apologizes to another for the other's rudeness! Points for trying hard not to cause trouble...
     
    1 person likes this.
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.