Suggestions on replacement deck (lightning sailboat)

Discussion in 'Wooden Boat Building and Restoration' started by ldrumond, Feb 2, 2005.

  1. ldrumond
    Joined: Feb 2005
    Posts: 16
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: SW Ontario

    ldrumond Ya...I look like him

    Hello everyone;
    Just joined forum.
    Have just acquired a 50s vintage "lightning" woodie.
    This project boat was half way through a restoration then abandoned in a barn for a number of years.
    Construction is cedar plank, some minimal structural work was required and seemingly well accomplished, ei: centerboard trunk, keelson and some deck ribs.
    Boat has been completely wooded down in and out and planking sems sound, interior had multiple coats of West system applied.
    Am now exploring options on how to complete her.
    My main concern is how to build the deck, she now sits with deck ribs exposed.
    Incuded with this project is a large quantity of ash material the previous owner had intended on using for decking.
    Material dimension is 1/4"x1"x12' and has been sitting with the boat high and dry for years.
    Any suggestions on how one might proceed with this material, if it is indeed suitable.
    BTW: am an average level hobby woodworker with adequate tools however this is my first foray into boatbuilding and judging by reading these posts, it seems to pay to ask first.
    Thanks,
    Lou
     
  2. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    The big question you need to answer is "Do you plan to be a competitive racer in the Lightning class?" If so, there may be methods, techniques and requirements under the rules that will force your hand in the rebuilding of this fine little sailor. Contacting the class association may be the first thing you need to do, to insure you don't step over the rules line. The most competitive racers are using the foam cored 'glass versions of this fine S&S design, so the likelihood of being completive in the local fleet is low.

    The 'glass and epoxy work on her, combined with being heavier then her more modern counterparts, means you'll be a back of the fleet boat, on the race course. You'll need to have a measurement ticket for her. This will have to be done by the Lightning association and amounts to measuring and maybe weighing.

    If you want this little S&S speedster design for a dayboat with little regard to the class association, then a plywood deck would be the strongest, driest, transmit more deck loads to the hull and be the easiest to install. The ash could be cut up into tongue and groove and laid over the beams, but will not be as tight, leak free nor transmit as much loading as the ply will. It may be heavier to use ash in dimensions thick enough to wear well and have adequate strength for a laid deck.
     
  3. WoodButcher
    Joined: Jan 2005
    Posts: 19
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Midwest USA

    WoodButcher Junior Member

    "...Construction is cedar plank..."

    "... interior had multiple coats of West system applied..."





    Is this a good idea, i.e. epoxy coating planking?

    I thought conventional planking was too unstable
    a base for epoxy ?
     
  4. ldrumond
    Joined: Feb 2005
    Posts: 16
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: SW Ontario

    ldrumond Ya...I look like him

    Thanks for the infromed reply PAR.
    I appreciate the implications relative to being competative in a lightning class.
    Judging by the amount of all Harken hardware, conversion to alum spars and complex rigging and tuning adjustments, this boat was previously raced. It is not my intention
    continue doing so, I basically want a fine looking wooden daysailor and will simplify the running rigging for single handing.
    In doing some research on the WEST site, I've come across deck installations where a strip vaneer was bonded over plywood resulting in a stripped deck pattern with black epoxy filled seams. This is the look I would like. Is it practical? I realize it will involve tons more time, steaming the ash strips and a steep - steep learning curve, however I'm not interested in a quick get it in the water patch job, (I also own a f/g 19' Oday that will keep me sailing) I want this lightning to be a keeper.
    So - would a 1/4" ply underlay covered by a 3/16" ash strip vaneer sound about right?
    If so, what pitfalls do I need to watch out for?

    PS to Woodbutcher -- the interior was already epoxied, frankly I'm more than a little confused by the varied opinions on it's use, however it's there and I'll have to live with it, it doesn't seem practical to strip it off now.
     
  5. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    As a general rule it's not a good idea to epoxy, traditionally constructed hulls, because they aren't designed with this in mind. A structure designed for epoxy is "encapsulated", meaning every square inch is coated and sometimes reinforced with fabrics. These structures, embalm the boat's lumber and keeps them water tight until the breaches in the coatings begin letting in water.

    Traditional construction relies on design, fasteners and good joints to hold back the wet stuff. Each part will have a relationship with other pieces around it, all working as a community of members, totaling a boat. These pieces may move a bit as the boat is in normal use, epoxy will prevent this and isolated loads will be placed on individual parts that may have been designed as a shared load. Things will begin to break as a result.

    Now that you have the epoxy, it's not easy to remove it. The decks on these boats are rather light and adding over a 1/2" of material and the additional weight of epoxy will result in a deck much heavier then needs be. 3/16 thick layer of anything isn't going to last long under foot. You'd be better off making the deck from full thickness of ash, just to have some substance.

    The techniques seen on WestSystems site are intended as a replacement deck in boat large enough to enjoy one. A fast planning dinghy, requires very light construction to remain a planning dinghy. I think the decks of these were 1/4" ply, you'll be doubling this after the goo and all. The last deck I put down using that technique was 1/2" ply, then 8 oz. cloth set in epoxy and 3/8" teak set in 3M 4200 over that. This was a reasonably thin deck for a laid overlay of teak. You'll be working in considerably smaller dimensions and using lots of epoxy. Both are costly in terms of money, effort and loss of performance. Lightning's are fun, but I wouldn't enjoy it much if it required a lot of wind to get her up on plane. The joy of these is the ability to plane off is relatively light winds. If I wanted to putter around at displacement speeds in a dayboat, I have one with a cabin, room for a cooler of beer and a small outboard or trolling motor to bring me back to the launching ramp when the wind feel off. All this can be easily done on the waterline length of a Lightning. Not much of it can be done in a Lightning. With a cooler of beer (required) aboard you have to leave your sweetie ashore, taking a lot of fun out of the boat. At least that's me . . .

    Bright work is over rated anyway. It only looks nice for a short while after it's done and makes you feel guilty when you drop, bang and scratch it, as will happen when the boat gets used. Use bright rubs or covering boards, paint a nice non skid (varnish surly isn't BTW) coating over a solid ply deck so you don't slip and fall trying to step the stick and embarrass yourself in front of your sweetie (also required) For what it's worth . . .
     
  6. ldrumond
    Joined: Feb 2005
    Posts: 16
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: SW Ontario

    ldrumond Ya...I look like him

    Well PAR, I'm converted.
    The inlaid deck seemed like a nice idea, however in considering the points you made it doesn't seem to make a lot of sense.
    So if I go with the 1/4" ply, would you recommend sticking to the original painted canvas covering or is there a better method?
    Next, your comment on encapsulating the wood in epoxy, since the interior has been done, do you think I should continue with the rest of the hull?
    I seems I've got a compromise on my hands, between traditional methods and living better chemically.
    What are your thoughts on a layer of glass on the bottom for abrassion resistance?
    Thanks,
    Lou
     
  7. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    If you dry sail your boat (trailer) and don't anticipate dragging her over rocks, beaches and the like, I'd leave the outside unsheathed. If you do expect the boat to receive some rough treatment, then a strip of material down the centerline and along the chines would good along way to protecting those pieces.

    A boat of this size can be easily examined and flipped over for repairs. She'll float on and off the trailer during launching and recovery, so unless you intend to bash her up a bit then forget the 'glass and let the wood breath.

    As for canvas or other material, I'd opt for another material. I use Dynel for decks, though your deck doesn't have a lot of crown and weird curves to fit, so 'glass cloth will do and is cheaper. This can be set in epoxy, and will seal up your deck nicely, also providing you with a similar look as canvas, if you don't fill the 'glass weave. Personally I'd just glass the deck seams (if any on this boat) and paint the deck with an anti skid coating. I would CPES the deck stock (plywood) before installation on both sides. This will be the cheapest way to go and still provide a good level of protection from moisture. The only reason I'd 'glass a deck of this size is if the plywood was Douglas fur and the 'glass is used to control surface checking, a common problem with that stock.

    Encapsulation means just that, total coverage on every piece. It doesn't work without total coverage, so unless you intend to completely disassemble the boat, stick by stick, coat each and put back together, forget about it. The coated deck and inside will help hold off standing water (like rain when you forget to cover it) Your new deck will have good protection with all the ply being coated, so the weather surfaces should hold up well, if you maintain the coatings (chase down dings, nicks and stuff) Good Luck . . .
     
  8. WoodButcher
    Joined: Jan 2005
    Posts: 19
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Midwest USA

    WoodButcher Junior Member

    "....I would CPES the deck stock ..."


    Since you brought up the subject of CPES:

    I have seen some people swear by this stuff,
    while others swear at it.

    How does Smith's compare to the penetrating epoxy of
    others? How about to "home-brew" penetrating epoxy
    (epoxy thinned 10% (+,-) with xylene?)

    If one were going to "encapsulate" plywood with epoxy,
    should the first coat be penetrating epoxy, with subsequent
    coats being unthinned epoxy? Can one apply a coat
    of unthinned epoxy over the penetrating epoxy before it
    has fully curred, or must one what until the epoxy hardens
    and the solvents have evaporated? Does pentrating
    epoxy tend to blush?

    Unthinned epoxy apparently won't prevent checking in fir
    ply; will penetrating epoxy? And if penetrating epoxy
    won't prevent checking, won't water penetrate the ply
    through the checks, negating the benefits of using the
    epoxy in the first place?

    Lots of questions on the subject of epoxy

    By the way; without taking a detailed survey, it
    appears to me that those who repair old boats tend
    to be the ones who love Smiths's, while those who
    mostly build new don't seem to think much of it.
     
  9. ldrumond
    Joined: Feb 2005
    Posts: 16
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: SW Ontario

    ldrumond Ya...I look like him

    PAR;
    OK, I'll go with your suggestion to CPES the deck stock, glass the seams and top it off with anti skid. (any suggestions on brand of anti skid?)
    Fastening the deck -- will glueing it down suffice or glue and screw?
    If screws are required, I'm anticipating issues relative to hiding the screw heads. 1/4" stock doesn't seem to leave much room for errors. Suggestions on acceptable methods?
    As for the bottom - I don't anticipate rough use in the sense of abrasion, however the boat will sit in fresh water at my dock for the season not dry sailed.
    I expect this may change the requirement for bottom coating ??
    BTW - I've been searching my area for plywood, in reading some of your posts, there seems to be a science to marine grade plywood. The calls I've made to suppliers in my area, so far result in an offer of 1/4" mahogany marine plywood good 2 sides $90 cdn a sheet. Is this likely what I need? They never heard of anything called Okoume, even a so called specialty wood outfit only expanded the selection by offering teak plywood good one side at twice the price. I read in one of your posts your musings that a material called MDO might be suitable for decking. Any thoughts, lots of sign outfits around, they might be able to source it for me.

    Thanks,
     

  10. PAR
    Joined: Nov 2003
    Posts: 19,126
    Likes: 498, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I don't have a particular brand favorite in an anti skid as generally I make my own. There are a number of materials you can use for the texture used in this type of coating, each having pros and cons and a loyal following of fans. Personally I use sand, others use sea shells, walnut shells, ground up glass, all sorts of materials. I use sand because it's traditional and tough, but can be difficult to remove sometimes. Walnut shells are easier to remove, though I never have had to scrape at the stuff.

    Fasteners are always a good idea, though the embalm in goo crowd will say it isn't necessary when using their favorite brand of epoxy (insert ad here) The thin deck means you'll not be able to bung the fastener tops in a traditional fashion. Counter sink screws just below the surface and use a putty, again I usually mix up a batch for the specific need I may have for the application. There are many choices in this too. I like softer materials for this type of filling, but others use hard stuff like epoxy. I like soft stuff so I don't have to tear things up when it comes time to remove the part.

    Your season is reasonably short up there, but in either case, I'd still not sheath the bottom in glass. Grind it to bare wood and CPES it if you like, but a good bottom paint will be in order. Don't cut corners on the bottom paint, unlike a lot of things in life, paint generally follows the "you get what you pay for" rule. A gallon of good stuff isn't that cheap, but it will coat the bottom of your boat a few times, because you'll only use a small amount of it on a Lightning. This boat is very easy to rig and launch, it wasn't really designed to sit on a mooring or dock. It's life will be shorter if it's mast is left in place and the boat bobs around afloat. She'll need be covered or a pump and battery installed, neither of which she is well designed for, though still can be done. She'd like it a lot more if she could live on a small batch of beach with her stick beside her, maybe under a small lean too roof. At her age, she deserves some respect and care.

    Plywood is interesting stuff, in spite of all the grading systems and insurance company requirements there is a wide margin of availability, quality, construction and durability. You don't need much, which will make your ability to find some even more difficult. Drag out the phone book and look up local boat builders. Use the net, library and anything else you can think of to find builders. They order stock all the time and an extra sheet or two on their next delivery will not kill them. MDO doesn't come in the thickness you need. You'll feel real guilty painting over mahogany or teak faced plywood, but if it's all that you can get, you may well have to get married to the stuff.

    Do yourself a favor and dig up some construction drawings for the boat. You may have luck with the International Lightning Association web site. I'm working from the memory of the last one I saw opened up 20 years ago. The drawings will show you things that are missing and the way it should go together. Association members may be able to provide you with much detail and it's likely there are Lightning's local to you, that could be used as reference. Try the local sailing clubs, they always have a few old farts that remember when the Lightning was first designed, the changes made in the class, the flaws, etc. Besides the stories they'll have makes a trip worth it.
     
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.