are teak and marine plywood a must??

Discussion in 'Materials' started by rodmar, Apr 23, 2008.

  1. rodmar
    Joined: Apr 2008
    Posts: 18
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: mexico

    rodmar Junior Member

    Ok, teak wood and marine plywood are expensive, very expensive and hard to get... the quiestion is... what are the other options?? can i use regular plywood? for the hull? if i varnish it with marine varnish, will that do? what other wood can i use for decking?? i do not want to use fiberglass because first of all i have no idea of where to find it and what to buy! steel will make my boat heavier and is more expensive than marine plywood i think, and alluminium is very, very expensive!!!! sooo any suggestions??
     
  2. alan white
    Joined: Mar 2007
    Posts: 3,731
    Likes: 121, Points: 0, Legacy Rep: 1404
    Location: maine

    alan white Senior Member

    I see you are repeating a thread I just left. Anyhow, I neglected to discuss varnish. Varnish is used to allow you to see the wood grain obviously, but paint is cheaper, longer lasting between coats, USES a quarter as many coats to begin with, and can hide any flaw because you can use filler to fix dents, gouges, nicks, etc..
    In any case, varnish is an old recipe, hundreds of years old. Lately, some other formulations (chemicals of course) have been marketed and they will outlast spar varnish. The problem is that they should be taken down to the wood once they do wear out. Spar varnish, if recoated scrupulously on a regular basis, can last for a couple of decades.
    I paint most surfaces and varnish a few nicities like coamings and rub rails. While I like the look of varnished wood, the work it takes is not worth all the bother to me.

    Alan
     
  3. mariner 40
    Joined: Nov 2005
    Posts: 59
    Likes: 1, Points: 0, Legacy Rep: 11
    Location: Salem, Indiana

    mariner 40 Junior Member

    Alan

    This has nothing to do with this thread. Just read your post and like your logic. I have a 40' mariner that needs some serious work. Do you know anyone with wood and glass skills who is interested in working on a boat in southern indiaian for a couple months? After the bad lungs and divorce I can't afford a commerical shop and all I want to do to it. If you know anyone, send me a mail.
    mike
     
  4. Kaptin-Jer
    Joined: Mar 2004
    Posts: 570
    Likes: 18, Points: 0, Legacy Rep: 206
    Location: South Florida

    Kaptin-Jer Semi-Pro

    What size / type of boat are you trying to build / refit? Size will determine a great deal. Type of boat will also dictate material. Is it a round bottom, hard chine, row boat, sail boat, inboard out board---You need to be more specific.
    Alan, Varnish will not solve his question- to use regular plywood for a hull-- He would have to epoxy encapsulate then paint, and that is still not a 100% replacement for marine ply, which I encapsulate also. The varnish will not protect/waterproof the plywood, and epoxy will only slow down the inevitable. Especially if the boat stays in the water.
     
  5. alan white
    Joined: Mar 2007
    Posts: 3,731
    Likes: 121, Points: 0, Legacy Rep: 1404
    Location: maine

    alan white Senior Member

    Thankyou. I wish I did know someone---- better still, that I kived next door. Keep asking and just maybe someone nearby will take notice.
    Best of luck,

    Alan
     
  6. mariner 40
    Joined: Nov 2005
    Posts: 59
    Likes: 1, Points: 0, Legacy Rep: 11
    Location: Salem, Indiana

    mariner 40 Junior Member

    Thanks Alan

    I'm looking but, hard to find a shipwright in Indiana. Lots of auto glass men but need someone who knows safe and unsafe. Plan on living on her for a while when she is in the water. If you hear of a traveling shipwright, send him or her my way. Haven't met a woman shipwright but will not leave the option open. haha
     
  7. rodmar
    Joined: Apr 2008
    Posts: 18
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: mexico

    rodmar Junior Member

    i want to build a 23 to 26 sailboat, i want it to be fast, with no camping comodities just as a day sailer and i might have the possibility of take with me so it wont be in the water more thant a a day or two in a row!
     
  8. Kaptin-Jer
    Joined: Mar 2004
    Posts: 570
    Likes: 18, Points: 0, Legacy Rep: 206
    Location: South Florida

    Kaptin-Jer Semi-Pro

    There are some good kits if you are a novice builder that will provide the correct material shipped direct to your garage, or you can get plans with full size patterns. Go on line to Wooden boat.com, and check out the recommendations in this forum for Plans / kits. A long time ago I built a Glen-L 26' from a partial kit (just the laser cut mahogany stringers) I seem to remember 2 layers of 1/2" Marine plywood, but the plans were good and service was also good.
    Any plywood that you use will need to be sealed with epoxy, but epoxy will break down from UV exposure so it needs to be covered with a good paint. I hope that gets you looking in the right direction.
     
  9. Kaptin-Jer
    Joined: Mar 2004
    Posts: 570
    Likes: 18, Points: 0, Legacy Rep: 206
    Location: South Florida

    Kaptin-Jer Semi-Pro

    By the way there are some good racing designs that the Aussies and New Zealanders have turned into racing class kits. Do some research. They are pretty wild.
     

  10. Aethelwulffe
    Joined: Jun 2008
    Posts: 34
    Likes: 2, Points: 0, Legacy Rep: 29
    Location: Tampa Bay

    Aethelwulffe Junior Member

    I love working with hardwood marine plywood. I use it in my house as well. Why? Well, as I am in a coastal stilt house, all the properties that make it good for boats apply. What is more, it is easier to work with, far more dependable, and only (really) marginally more expensive than retail purchased trash from Home depot.
    I long looked down on marine fir ply, but that was wrong. Fir makes an great choice for marine application. It is a proven performer.

    Lessons to abide by in materials choice:

    If someone says "it is just as good if you just seal it with resin" then they are full of it. With real marine plywood, it actually stands up better if it is merely painted, and no attempt to keep salt water away from it is made. You should always make sure that your designs will drain away sweet water (rain and the like), but painted marine plywood will last longer than you will...unless you are dumb enough to trap it away from free oxygen and allow anaerobic bacteria to start eating it (I.e. trap it in some resin and allow a tiny penetration to get to it). I make this statement based on my years at the Texas A&M corrosion lab in the 1980's and 90's, as well as years of ripping apart old plywood boats, both resin smeared and no. I am not able to cite this with a link, as my permissions here do not let me do so but here is an attempt h t t p : // www . fpl. fs.fed .us/documnts /pd f2002/cle mo0266a.pdf Take the spaces out of this and you can copy and paste the link to do some reading on brown and white fungus and a variety of bacterial that are involved in the rot process and how they metabolize wood.
    Glue, species, and veneer solidity are of primary importance, but the design and usage of the material are important as well. Joinery, fastening, bedding, and drainage are all of great importance to the material's longivity. There are very old wooden boats out there that still have a lot of life, and there are some that are 15 years old with a rotted keels due to frame mortices or some other unwarranted practice.
    Upshot: unless this boat is intended to take you fishing for one weekend, use the correct material. You will spend more money and time using inadequate material in an attempt to get it to last 5 years, where the good stuff will last far beyond that. I would recommend 1088 certified okume plywood for most of your projects. Fir is usually not any less expensive. A sheet of 1/2' should not cost any more than $65 dollars wholesale. I build boats up to 23' using mostly 3/8" okume (plywood lap or hard-chine).

    For dimensional lumber: Domestics that are great include White Cedar (beautiful, strong, soft, very light, very rot resistant) Red cedar (almost as good as white), white oak, ash and of course good old fir. Yellow pine may be used carefully.
    Domestics to aviod at all cost in a boat:
    Red Oak
    Poplar
    Maple
    These species rot if you look at them.
     
    Last edited: Jun 30, 2008
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.