Plywood Bottoms. Hold On. Before You Judge.

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Original Plywood bottom

The other day we all looked at a very beautiful boat. Yet she sure had some bottom issues and I spoke about creative solutions. Now. To be clear. If your boat is a special boat. Then a 5200 bottom is for sure the way to go. But. As I have matured in this passion, my mind has opened to different options for different reasons. For example, living out West where its a dry climate. A fiberglassed bottom makes 100% sense. Done well, as they do at Sierra Boat Company.

What ever is under all that fiberglass? I don’t want to find out! YIKES!

Stinky has been encased in Fiberglass since the early 60’s and guess what. She still floats ..ish. If she had been that barn for 40 years without that? Not sure what sort of wreck I would be dealing with. And since she is a painted boat. Who cares? Not me!

Can it be done?

Now here is a thought I have had, and makes a ton of sense for certain boats. The boats that are not worth the money to replace a bottom on. take a 17 foot utility. When a new bottom is required, you are gonna put plywood down anyway, then cover in planks. Why? For an original appearance? Thats really it. So put another hit of plywood on with some 5200. Done.

Plywood with a thin coat of Fiberglass

Like fast done. And to take it even a step further. A cruiser like the other day? Think how may cruisers could be saved this way? Think how many 17 utilities could be saved, used and loved. Ya ya, so shoot me. Its not a crazy idea.

All the Cavalier cruisers had plywood bottoms. They are great

Cold molded bottoms, fiberglass over plywood, heck, if it gets you out boating safely in a boat that would otherwise sit in your garage half done. DO IT!

Only your hairdresser will know.. and some fish!

24 replies
  1. John Rothert
    John Rothert says:

    Agree totally and always have. Lots of nice boats have been lost to well intended plans to put on a new bottom…either the owner never gets around to it and it languishes until death under the tarp or somebody botches the attempt at a 5200 job, never quite gets it to the water etc etc. Ply is the guy! If you want to just
    Go Boating….like I am going to do Today!
    John in Va.

  2. Tim Robinson
    Tim Robinson says:

    Nothing wrong with a true cold molded plywood bottom. Just make sure you use a certified and stamped 1088. When replacing a bottom with 1088 marine plywood you don’t have to cover the plywood with fiberglass but is recommended for abrasion resistance. The fiberglass does not need to be heavy 10 to 12 ounce will do.

  3. Danny B
    Danny B says:

    My boat’s haul is all plywood. The bottom was replaced in the early ’90s when the boat was about 30 years old, it took about a week, and the cost was very reasonable. It’s still solid, dry, and leak-free after 30 years and is very low maintenance. Given the cost and time savings, it seems like an option more should consider if it can be done properly on a boat that was originally built with a planked bottom. Yes I understand the implications related to originality, judging, and resale. However, it may mean the difference between a boat being saved vs. that same boat deemed uneconomical to repair, and thus relegated to the burn pile.

  4. Mark in Ohio (sometimes da U P )
    Mark in Ohio (sometimes da U P ) says:

    “Just an old plywood boat” Alan Jackson. Hell they have even wrote songs about them.

  5. JimF
    JimF says:

    I also agree. I replaced the bottom of my 1930 Chris-Craft Model 100 “Moxie” over 25 years ago with two layers of plywood covered with fiberglass cloth and have never had a problem. Since then I have put dozens of 5200 bottoms on boats but my last restoration was a 1956 Capri and I decided to do another 2-layer plywood bottom covered with glass. Saved a lot of time and is probably as strong and durable as any other bottom.

  6. Kent Volmerding
    Kent Volmerding says:

    My 1955 Century Arabian. Was a total basket case when I started. Back in the days I restored it, money was tight. Plywood bottom with WEST system epoxy. Total rebuild done over 30 years ago, no leaks and still as good as new.

  7. Dick Dowi
    Dick Dowi says:

    I’ve always joked that plywood is a great boat building material until you get it wet… and to an extent, that is very true. However, properly done and maintained, there is no reason not to use it on a classic and it can benefit a utility, adding stiffness and solidity to an otherwise original hull. When we restored “Tango” in the late ’80’s, I used Lloyds-rated, marine-certified plywood for the inner layer rather than the traditional diagonal mahogany. Except for significant damage done to the bottom by he subsequent owner, it held up very well, even though the overall construction was traditional – we used no epoxies. That boat was my first restoration experience. She has now been re-bottomed with plywood and epoxy and was just re-launched in Idaho. Saved again, that Red & White has a long life ahead! If I decide to re-do the bottom on “Sindbad” (still original – 1939 – cypress over oak) I will go the plywood and epoxy route.

    Here is a picture of one of my plywood boats… 55 years young!

  8. clueless in atlanta
    clueless in atlanta says:

    this is a good conversation; thanks matt for bringing it to the surface.

    my question/concern is that in due time we’ll be taking a chainsaw to these 5200 bottoms (perhaps i way off here).

    epoxy bottoms crack; moisture through cracks is enough to make for problems in 20 years.

    **i’ve heard there are new/reproduction boats with lots of mushy spots.

    I get the ease of putting your boat in & out without the soak factor of the traditional bottom, but look at how LONG tradition bottoms have lasted!

    question: out of 10o restored bottoms, how many used the old/traditional method utilized when the boat was built?

    guess i’m just an old school purist, and i’ve got lots to learn about modern techniques!

  9. don vogt
    don vogt says:

    clueless, my guess would be 1 out of 100 and the rest either 5200 or epoxy. I had mine done traditionally, and it is fine. yes, it has to be soaked each spring but no big deal. something to be said for being a purist.

  10. KW
    KW says:

    It is like most things depends on material ie 1088 and whos doing the work. Chris Craft started doing inner bottoms in the 1950s and Riva started doing there entire bottoms in plywood in the late 50s and it worked out fine stood the test of time.

    • George N Burgess
      George N Burgess says:

      I have a 1950 Chris Craft U-18 with the traditional double bottom which was repaired in 1980 by replacing some skin planking with new cloth and compound between layers. Most of the original outer planking was reinstalled. The boat has been in the same boathouse and hoist year round, I do not trailer the boat. So far no problems with the bottom.

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