Seeking feedback on cold molded Freighter canoe scantlings

Discussion in 'Wooden Boat Building and Restoration' started by Doug Stephens, Sep 7, 2021.

  1. Doug Stephens
    Joined: Sep 2021
    Posts: 4
    Likes: 3, Points: 3
    Location: Anchorage, Alaska

    Doug Stephens New Member

    I an considering purchasing a cold molded freighter canoe. I'd like to post what I know about it and hope to get some feedback on the scantlings / construction.

    The canoe is 20' long with a 5' max beam and 4' wide transom. It was cold molded in the mid 1990's from 2 x 3/16" mahogany planks at 90 degrees to each other and was glued with epoxy resin. The exterior has one layer of 8 ounce S-glass with epoxy, the interior was coated with epoxy but has no fiberglass on it. The transom is 2 x 1/2" plywood, again glued with epoxy and glassed on the outside. The exterior was painted with an alkyd paint which is showing signs of chipping/flaking. The exterior has several keels, stringers or spray rails fastened to it. The interior has a number of oak stringers up near the bow to strengthen the hull. There are three seats acting as bulkheads but I am not sure whether or not they extend all the way to the bottom.

    So, your thoughts on the scantlings and construction? I thought cold molding plywood really needed glass on both the interior and exterior to develop its full strength?

    Would you be concerned about water entry into the plywood and the resulting rot potential?

    How about impact and abrasion resistance?

    What would be the best way to refinish the exterior of the hull?

    What am I missing and/or what should I look for when inspecting it pre-purchase?

    Thanks in advance,

    (I will try to post pictures once my gallery media is approved)
     
  2. Blueknarr
    Joined: Aug 2017
    Posts: 1,204
    Likes: 273, Points: 83
    Location: Colorado

    Blueknarr Senior Member

    Welcome to the group

    Glass on both sides is best. But several decades of use has shown that a single skin is adequate for this vessel. Unless there is evidence of dents or gouges of missing wood, the current FG skin is providing sufficient abrasion resistance.

    Discoloration is the first sign of water induced rot. Soft spots are bad rot. Unfortunately, most sellers won't let you ice pick. So you will have to rely on discolouration.

    Refinishing (if no major damage)
    Workboat -
    exterior - scrape then sand flaking exterior paint with 120 grit.
    Inspect for peeling fiberglass. Epoxy any raw wood.
    Reglass overlapping an inch if necessary.
    Paint with RustOleum no priming needed.

    Interior - same as exterior except use marine varnish. The clear coat will aid in spoting any discolouration before it is problematic.

    Museum piece-
    Add many many hours of longboarding and very expensive two part paint to the workboat plan.

    Good luck
     
    fallguy and bajansailor like this.
  3. fallguy
    Joined: Dec 2016
    Posts: 4,916
    Likes: 891, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    The interior needs to be reviewed for rot or chalking.

    Sand it with 80 grit with a festool rts400 and with the grain only (up and down).

    Boats like this need regular varnish work. I really like Epifanes UV Gloss. If the wood is dry; thin the first coat(s) quite a bit. Three/four is okay unless you are in a sunny clime.

    For rot, it must be removed, it must be soaked with something that will stop it, and the area can be repaired with thickened epoxy.

    A picture would be cool. Those boats are something my uncle used on the Berens River system in Manitoba. I've never seen one.
     
  4. fallguy
    Joined: Dec 2016
    Posts: 4,916
    Likes: 891, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    The alkyd paint may be lead based. When removing it; wear a mask. I really like Interlux Paints fir the exterior. You can call Noahs in Canada or Boat Builder Central in Florida.
     
  5. DCockey
    Joined: Oct 2009
    Posts: 4,980
    Likes: 479, Points: 83, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    Lots of cold molded boats have been built with fiberglass on only one side, or occasionally no fiberglass.

    Perhaps you are thinking of strip planking as typically done for canoes and small boats using thin strips, "bead and cove" joints between the strips and glued with Titebond glue or similar. For that particular type of construction fiberglass/composite sheathing on both exterior and interior is needed because of the relatively low strength of the joints between the strips. This type of construction is closer to a cored construction. It should not be confused with strip construction using thicker strips, fitted joints and mechanical fasteners and/or high strength glue.
     
    TANSL likes this.
  6. Doug Stephens
    Joined: Sep 2021
    Posts: 4
    Likes: 3, Points: 3
    Location: Anchorage, Alaska

    Doug Stephens New Member

    Here are a couple of photographs to look at.

    What I'm hearing is that being glassed on just the outside is fine, I need to inspect carefully for rot, but the rot is repareable, and, I should expect the interior brightwork to need regular varnishing and the exterior a paint job every now and then.

    Given the scantlings, what your thoughts on abrasion and impact resistnace if I were to run this on a shallow or rocky river?

    Thanks for all you feedback so far.
     
  7. Doug Stephens
    Joined: Sep 2021
    Posts: 4
    Likes: 3, Points: 3
    Location: Anchorage, Alaska

    Doug Stephens New Member

  8. wet feet
    Joined: Nov 2004
    Posts: 727
    Likes: 127, Points: 43, Legacy Rep: 124
    Location: East Anglia,England

    wet feet Senior Member

    I don't believe glassing is necessary if the wooden core has sufficient integrity and the history of using easily split cedar has tended to leave a belief that all wooden canoes need a glass covering.If you take a look at the CVRDA website there are a few examples of both hot moulded and cold moulded international 14's that were never glassed and are now more than fifty years old.There may be different use criteria for racing dinghies and freighter canoes and its fair to say that dingy racers don't expect to collide with drifting trees or underwater obstacles while heavily laden.They do have to withstand heavy loads from the rig and the humans making them travel at high speed and are seldom thicker than about 8mm but the most usual construction was three layers of veneer.In the example of the OP,are we looking at conservation primarily?
     
  9. Doug Stephens
    Joined: Sep 2021
    Posts: 4
    Likes: 3, Points: 3
    Location: Anchorage, Alaska

    Doug Stephens New Member

    Not conservation per se. I'm considering purchasing and using it to access a cabin on a lake and camping out of it on other rivers and lakes, as is appropriate for a freighter canoe. On the other hand, I enjoy rehabilitating old things and would do whatever I need to put her back in fine shape and keer her that way. Still, intent is to use the boat as a freighter canoe.
     
  10. fallguy
    Joined: Dec 2016
    Posts: 4,916
    Likes: 891, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Boat bottoms get beat up from rocks quite badly.

    There are a few things you can do to minimize the impact. When I know I am headed to a rocky area, I always make sure to use some keelguard. It is like sticky backed sandpaper. Believe it or not, knee or hip boots help as well. You can always keep the area near launches or landings free of larger, sharp rocks. Regular maintenance is part of this as well. If the bottom gets a lot of bad scratches; it needs paint or varnish touch up. My canoe is cedar strip, so I only use Epifanes UV Gloss. I won't recommend a paint, but a bottom paint for a canoe is NOT boat bottom paint. If the canoe is going to see a lot of bad rocky stuff, you want something hard that builds high. Epoxy neat coats do that. Some guys use graphite in it, but I can't get into it. You don't neatcoat over existing paint. Sanding the paint off that canoe must be done with great caution as sanding through the fiberglass is a major f up. I do see some gouging. You want to remove a bit of the paint somehow and fill those with epoxy putty before repainting.

    Modern two part paints are hard as nails, but not necessarily designed for a week of immersion. And they are also not easy to retouch. When the catalysts kick; the surface becomes too hard for follow on coats to adhere without sanding. I'd avoid most of them, but emc makes a touch up kit for theirs that sprays. Only still not sure I'd immerse a two part long..
     
  11. fallguy
    Joined: Dec 2016
    Posts: 4,916
    Likes: 891, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Standing water is also the death of these cold moulded hulls. So, you really don't want to leave the hull with water in it for extended periods. I think a week is okay, but the boat is safest upside down, with a permanent snap cover, or garaged. If you intend to leave it at a lake cabin; get the custom made cover. Cost about $400-$700.
     

  12. Blueknarr
    Joined: Aug 2017
    Posts: 1,204
    Likes: 273, Points: 83
    Location: Colorado

    Blueknarr Senior Member

    Great news. I see just the exact right amount of damage to add character and prove that it spent years doing exactly what you want to do with it.

    The interior clear is shot. Scrape or sand it all away. Heat will facilitate scraping but also may also facilitate scorched skin and wood.

    An oxalic acid wash will rejuvenate the sole grids.

    My approach to brightwork-
    Two coats neat epoxy
    Adhesion sand
    Three quick coats of gloss varnish.
    Wait one week
    Three quick coats of gloss varnish
    Wait one week
    Three quick coats of gloss varnish

    Every year do an adhesion sand and Three quick coats of gloss varnish.
    Every decade strip back to raw wood and start over
     
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.