Wood for boats

Discussion in 'Watercraft' started by Jacob Peterson, May 14, 2009.

  1. Im building a set of small lockers and anchor boxes. I was going to use a plywood, some sort of sealant covered in marine grade paint. WOuld that be suffecient? they dont need to be pretty, just effective. What do you guys think the best wood to use is? I don't have very much $$$$, so it can't be some weird exotic hard wood or something.:D
  2. Plywood is fine. If you use paint, varnish, or marine epoxy it will last longer. A lot of people just use a milk crate, a cut off bleach jug, or a some kind of rubbermaid box. Plastics actually works really well for that kind of thing because they're corners are usually have a radius, and are very durable.
    Here is one point to ponder about plywood for you. Cheaper plywood like fir (it really isn't fir anymore) does not cost that much less than mahogany in the long run. If it is something you are going to look at for a long time, use a "product" that you will be happy with, either for it's practicality, economic, or for it's aesthetic value.
    See you out there.
    Tom C.
  3. the import birch or muranti ply at tacoma plywood is pretty cheap right now
    less than 30 for 1/2 inch
    i dont put plywood on a boat w/o some epoxy

    if you want to get fancy take normal epoxy and thin both parts 30% by volume before mixing it

    its important that you thin the un mixed parts
    then mix it and you have a penetrating epoxy that the ply will drink in like its the last beer
    soak the edges good
    good luck
  4. All glue used in plywood manufacturing is waterproof, the problem is that in non-marine grade plywood there are voids in the interior veneers. This is where the water hides and and eventually causes rot.

    If you don't have much money then you can probably get away with a good Fir plywood and an oil based paint. Just make the boxes removable so when they start to deteriorate you can replace them.

    I will tell you that your anchor box will get beat to death and a milk crate is a good option, also you will be much happier in the long run if you just buy marine grade plywood and epoxy and do it right one time.

    Good luck!
  5. Mark's absolutely correct here-don't try to "save money" by getting cheap wood. I've had/restored more wood sailboats than you can shake a stick at, and while wood's the most beautiful thing to look at when it's all spiffed up, it's the complete pain in the ass to maintain. if you're willing to sand and varnish, then by all means, go for wood! Even though I'm retired, taking a chunk of my fishing or bird shooting time to maintain the wood, well..... Her Ladyship and I are going to Red's today to check out one of the ClackaCraft drifters.

    Don't skimp on quality wood, so avoid Lumberjerk completely-go with quality marine woods!
  6. Having had a really beautiful Rays River Dory kit 17' African Mahogany drift boat since 1996, fishing it at least 20 days per year, I don't find the maintenance at all time consuming if you have a place to keep it inside. Every two to three years, I turn it over and re-exopy and fill dents in the bottom, put a coat or two of Teak Oil on the interior and a few coats of varnish on the exterior. Total time is maybe 8 hours and I do it in the early spring when there is not much else going on (I do have a heated shop). So 8 hours every 2-3 years is not cutting into my bird hunting or fly fishing time and I still work! A wooden drift boat is SO nice to row, (having rowed a lot in Hydes and Clacka's) that it is worth it! Also, when I'm in Montana or Idaho with my WA license plate, I find at the boat launch guides come over to check out my boat and give me fishing advice, which is different than the treatment I've received from locals when I'm in my pontoon boat. Rick
  7. Call Edensaw

    I got 12 sheets of 6 and 12mm Hydroteck marine plywood for less than 50 a sheet.

    Be sure to use and epoxy sealer

  8. Jacob, there is a lot of debate over these issues on a regular basis. Here is some sober advice to help you save money:

    If all you need is 1/4 inch plywood, then buy a sheet or two of Ultraply XL at Lowes. It costs $20 a sheet. It uses waterproof glue and it is does not have voids on the inner plys. Do not use luan plywood at $12 a sheet because the quality has dropped considerably to the point it should not even be looked at.

    As for paint, you should give this a thorough read. Dave Carnell is a retired chemical engineer and a boatbuilder for 50 years:

    He has some excellent advice on epoxy too:

    You can email Dave and ask questions. He recently helped me with a minor issue.

  9. What do you thin the epoxy with?

    It is a good thing to seal the cut edges of plywood with epoxy because it will wick up water there.
  10. you can thin epoxy w/ toluene sp? or acetone
    ive had good luck w/ both
    an old schooler told me that acetone has some h2o so thats why he uses toluene
    and he worked on the Dukes and Aril Flynns boats

    the edges of ply are vulnerable but this mixture will soak in like mad
    don't forget to thin before mixing
    good luck on the project
  11. ps my mom grew up in deerborn
  12. Ditto on Edensaw for boatbuilding wood and plywood, they are the pros.

    I would not thin epoxy as much as prescribed here. I would use Smith's Clear Penetrating Epoxy Sealer,( CPES) which is a very thin formulation of epoxy meant to seal surfaces prior to painting or varnishing. It is also used to penetrate wood with the CPES epoxy prior to more layers of standard (unthinned) mixed epoxy. When using epoxy this way you dont let it fully cure between coats. You let it get sticky and then you add more fresh epoxy over that. Make sure that all surfaces of the wood are fully coated. This is called hot coating and it provides a very god chemical bond between layers of epoxy. This is the proven technique for water resistant coating of plywood and other wood in boats. Once you get done sealing with epoxy it is a good idea to let it cure for a week prior to washing down with hot water and soap, thorough final rinse, let dry well, then paint or varnish prep as normal. In the end this will save time, money and materials and will last longer.

    Check out the West System of epoxy formulations. Also see Gougeon Brothers Boatbuilders They have great technical advise as well. There are no good shortcuts around their advice. Epoxy is toxic so keep it off of your skin at all times. Dont breathe epoxy dust, wear a respirator.
  13. smiths is a thinned epoxy
    just trying to save money
    i totally agree with said method of aplication
  14. Here is another tip for penetrating epoxy.

    Get your wood parts as hot as possible before applying the epoxy, then if at all possible cool the parts, say in air conditioning, immediately after applying the epoxy. The microscopic gas pockets in the wood will shrink and the wood will suck up the epoxy like a vacuum.

    What ever you do DON'T heat the parts after you apply the epoxy or the out gassing will cause bubbles to appear in your otherwise beautiful project. LOTS OF BUBBLES.
  15. Thanls guys, I got to sort some stuff out befor I get this sone, but its second on my to do list
  16. I did some quick research on thinning epoxy and using commercial epoxy sealers (which is epoxy thinned with a solvent). I found this very useful article at this link: http://www.seqair.com/skunkworks/Glues/WestSystem/Thinning/Thinning.html

    Here is an excerpt:

    "Water resistance of a piece of wood is not enhanced by deep penetration. Wrapping wood in plastic makes a pretty good waterproof seal without any penetration at all. Likewise, an epoxy coating on the surface is more water-resistant than a thinned epoxy coating that has penetrated deeply into the wood because, in most instances, the epoxy thinned with solvent is porous (emphasis added. I remember reading somewhere else that the solvent leaves little holes in the epoxy resin).

    Figure1. MEE of various combinations of thinned and unthinned epoxy at six weeks exposure to 100% humidity.

    The USDA Forest Products Laboratory developed the Moisture Exclusion Effectiveness (MEE) test. It is a measure of how much moisture is absorbed by wood when it is continuously exposed to 100% humidity. Higher numbers mean the wood has absorbed more moisture while lower numbers indicate less moisture is absorbed. You can see that epoxy with solvent added is not nearly as moisture resistant as un-thinned epoxy (Figure 1). However, if you need an epoxy coated surface that is less of a vapor barrier, thinning West System epoxy with solvent is a valid way to achieve this."

    I think I will avoid thinning the epoxy as I build my boat.
  17. If you thinned the epoxy yourself, using a proprietary solvent, and did nothing else over that penetrating epoxy application, you would indeed have a resultant "porous surface" and very little water resistance. In general thinned epoxy is not going to provide the same molecular structure, nor strength and water resistance, as normal epoxy mixes.

    Smiths Clear Penetrating Epoxy Sealer CPES ( or any other brand of factory thin epoxy mixes) is not merely thinned with solvent and sold that way. It is a thinner formulation than "normal" epoxy mixes. It is used as a first application sealer prior to subsequent applications of normally mixed epoxy. It does indeed penetrate wood and plywood surfaces, pores and joints very well. In use one wets and coats the surfaces repeatedly while the CPES mix is still watery thin.

    Usually then three to four following applications of normal mix epoxy are recommended,( this is prior to final over-painting or varnishing), to achieve a "water proof" status. You can think of the Clear Penetrating Epoxy Sealer as a "primer" to regular epoxy and it does enhance water resistant and waterproof qualities. Look up the previously recommended "Epoxy Hot Coating" method.

    I would not get the wood "as hot as possible". Simply warming the surface for a while is adequate. Very high temperatures accellerate epoxy curing times and can actually interfere with bonding and penetration. The result is an epoxy that may be weaker and brittler. A great old trick is to use a hot lamp or old electric blanket to warm the surfaces for an hour. Then remove the heat, apply the epoxy and then let it cool as it sets without additional heat. Note that epoxies require a nearly room temperature for adequate curing.

    Also take a look at www.woodenboatvb.com and see the Building/Repair Forum pages there.

    By the way, under a previous post: Dave Carnells work on the paint issue is fantastic and he is widely respected.
  18. Bob,

    Thanks for making that point. I was in a hurry with the post and certainly over simplified, I should have stated that the ambient air temperature in the room can be raised then lowered to create the reverse of out gassing. Rob White explained this thoroughly in Woodenboat and I have used it on occasion to great effect.

    I suspect that we are all postulating way over the aspirations of the original poster.
  19. The use of a penetrating epoxy sealer only enhances the natural attributes of the wood. Wood wants to breathe. Locking it up completely with fiberglass or epoxy can have bad side affects. If there is any damage to the outer coating and moisture gets in, being "sealed" in will promote rot.
  20. Thanks Bob, I was referring to the previous post about thinning your own epoxy. BTW: The rest of the article in the link is well worth reading.

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