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Replace "sinking"/rusting Tacks On Sponsons?

Discussion in 'Wood and Canvas' started by Shari Gnolek, Jan 4, 2019.

  1. Shari Gnolek

    Shari Gnolek Have dog, will paddle

    I'll start off by saying that I appreciate the help I have received so far from this community. This is the first (of many!) dumb questions I'm sure I'll be asking as I begin my first project.

    I removed the sponsons from the Old Town canoe I am starting to repair (built 1961) and the canvas around them. For the most part the wood seems sturdy and does not seem rotten, though there are some strips that will need to be replaced. However, I've noticed that the fasteners used to attach the strips to the sponsons look like they are rusty and are "sinking" into the wood strips (although it could be that they were just driven in that far below surface to begin with because the strips do not seem loose). The fasteners used to hold the planks on the sides look fine, only the tacks on the sponsons seem to be this way. It does look like a few strips on the sponsons were replaced at some point, but not all of them.

    I'm wondering two things:
    - Would a different type of fastener (that was susceptible to rust) have been used on the sponsons when the canoe was originally manufactured?
    - Given the rust at each fastener, should I just replace all of the strips on the sponson?

    For perspective: I am rebuilding this for myself, and plan on keeping it. I don't mind doing extra work to prevent problems later.
     

    Attached Files:

    Last edited: Jan 4, 2019
  2. MGC

    MGC Paddlephile

    Wow...tack hammer wielded by mighty Thor!
    Realistically those tacks look fine. Whoever tacked that really drove the heads home. As long as they are nice and tight there is no harm in leaving them as is. You'll do far more damage removing them than is worth the effort to extract them. They've done their job for over 50 years....once you recanvas they'll be good for 50 more....if were my boat, I'd leave them as is.
    If you decide to dig the out you can use bronze ring nails as replacements, available from some of the supplier/restorers that list here.
     
  3. OP
    OP
    Shari Gnolek

    Shari Gnolek Have dog, will paddle

    Thanks! I will leave them in. The rust threw me off. Why would the manufacturer use something different on the sponsons?
     
  4. MGC

    MGC Paddlephile

    I doubt that anyone will be able to give you a good answer to that. Builders often use what's available and convenient. The sponsons usually stay pretty dry so the nail material isn't especially important and since the nails don't get clinched using a canoe tack (bass or copper) isn't essential. Canoe tacks are made from malleable materials that are easily turned by the form or with a clinching iron...
    I have seen some very nice old canoes that had steel nails securing the ribs to the inside rails, steel screws securing the decks to the rails etc.
    Old Towns built during the second WW were built with steel tacks...brass was not available. The one boat that I owned that had been built with these steel tacks actually had a pretty good hull with very few of the tacks showing signs of failure.
     
  5. Gil Cramer

    Gil Cramer The wooden canoe Shop, Inc.

    The nails in the sponsons are not canoe tacks, and are almost always countersunk well below the cedar strips. Some of the nails at the bottom of the sponsons will be driven into the body of the canoe making it difficult to remove. The solid cedar blocks on the ends will have canoe tacks and four screws holding them to the canoe Two screws will be hidden under the cedar slats. They are a pain to get to. Before removing the sponsons, measure how far the block tips go below shear to make re-assembly easier.
     
  6. OP
    OP
    Shari Gnolek

    Shari Gnolek Have dog, will paddle

    Thanks! Countersunk they were!
    Interestingly, the solid cedar blocks on the end had only one screw in them (and it was hard to get to), but after reading your reply I went and looked and there are three other screw holes in the blocks (and the boat) that weren't being used. This, and a few other oddities, have me convinced that this was not the original canvas. I'll be sure to add more screws when I reattach them.

    As you mentioned I did run into a couple of nails that were driven through the bottom of the sponson, through the canvas layers. What is the reason behind that? Why canvas the boat, and the sponsons and then drive nails through the canvas?

    It also appears that where the sponson meets the hull was caulked (on top of the canvas, but under the paint). It was still stretchy, almost like a silicone caulk. That's not typical right?
     
  7. Gil Cramer

    Gil Cramer The wooden canoe Shop, Inc.

    The sponsons were built on the canoe. The solid cedar ends and stations were fastened to the hull with screws, and then the longitudinal strips were nailed on. This is why the nails extend into the hull along the bottom of the sponson. Flexible caulk , not silicone, was sometimes used on both the top and bottom of the sponson,
     
  8. OP
    OP
    Shari Gnolek

    Shari Gnolek Have dog, will paddle

    So how did that work with the canvas then? Something I read somewhere made me think the sponsons were canvassed/filled before they were attached to the boat, but that must be incorrect. When I removed the first sponson I could see that is was canvassed (with the canvas seam under the outside sponson trim). I'm not sure if the canvas on the backside/boatside of the sponson, or the canvas on the hull under the sponson was filled. I will look more closely when I remove the other one.

    Maybe the more appropriate question is - what is the order for recanvassing/assembling sponsons and are there any good references explaining this?
     
  9. Greg Nolan

    Greg Nolan enthusiast

    For directions with illustrations, see page 172 of The Wood and Canvas Canoe: A Complete Guide to Its History, Construction, Restoration, and Maintenance by Jerry Stelmok and Rollin Thurlow.

    This book, often referred to as the "bible," is available through the WCHA on-line store < http://www.wcha.org/store/wood-canv...tory-construction-restoration-and-maintenance > as well as through other book dealers.
     
    Shari Gnolek likes this.
  10. Dan Miller

    Dan Miller cranky canoeist Staff Member

    Wooden Canoe issue 194 (April 2016) has an excellent article about recanvasing sponsons. Back issues available here: http://wcha.org/store/back-issues

    (edited to correct issue number)
     
    Last edited: Jan 5, 2019
    Shari Gnolek likes this.
  11. Greg Nolan

    Greg Nolan enthusiast

    The April 2016 issue of Wooden Canoe is actually issue 194. The article is very fine indeed, showing a restoration done by Michael Grace, the current WCHA president.
     
    Shari Gnolek likes this.
  12. Dan Miller

    Dan Miller cranky canoeist Staff Member

    Thanks, Greg, I corrected my post.
     

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