Old Wooden Mast Repair

Discussion in 'Boat Design' started by MastSplit, Jul 2, 2008.

  1. MastSplit
    Joined: Oct 2007
    Posts: 9
    Likes: 2, Points: 0, Legacy Rep: 43
    Location: Ottawa, Canada

    MastSplit Junior Member

    I have a 1949 International 14 sailboat in really good shape. However, the original, hollow, Sitka spruce mast has suffered a slight delamination about 6 feet above the base. I think it's repairable by loading (bending) the mast to open the "split", injecting a good adhesive into the crack, unloading it, then reverse loading it to close the crack, clamping it, fibreglassing the cured area with 4 oz cloth and resin.

    Does anyone have any opinions on this repair?
    What is a good adhesive to use in the fine crack?
    Comments, please?

    MastSplit in Ottawa, Canada
     
  2. keith66
    Joined: Sep 2007
    Posts: 346
    Likes: 31, Points: 28, Legacy Rep: 168
    Location: Essex UK

    keith66 Senior Member

    It is very likely that it will have been glued originally with Casein glue or an early urea formaldehyde. If it has started to split it is a waste of time doing just one section. Take all the fittings of and take a sharp steel blade (i have used a machete before) and insert it into the glue line, you may have to make a start with a very fine saw first. Tap the blade along and the mast will crack into its two halves. I have rebuilt many such spars and normally they just fall in half with ease. If the split threatens to run off away from the glue line stick the saw in the join and get past the sticky bit.
    Once the spar is in its two halves clean the old glue off and reglue it.
    You will need plenty of clamps or big cable ties & wedges It will help if you have a long straight bench to put the spar on when clamping up as the spar might end up bent under weight of clamps, it need only be a couple of straight 4x2's on trestles
    Best glue to use would be a good Urea formaldehyde such as Aerolite if you can get it or Aerodux, Avoid epoxy glue as the UV will attack it. atb!
     
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  3. MastSplit
    Joined: Oct 2007
    Posts: 9
    Likes: 2, Points: 0, Legacy Rep: 43
    Location: Ottawa, Canada

    MastSplit Junior Member

    Thanks for the advice, keith66. I don't think I'm going to have to split the whole mast to achieve the repair. Rather, I will separate the area and repair locally using a resorcinol adhesive. Trouble is, I can't find a Canadian source for this product.
    I've searched the internet for it and found the "chemical-supermarket.com" to offer phenol-resorcinol-formaldehyde (PRF) adhesives in the form of three specific products which are: Weldwood Resorcinol (DAP); Aerodux-500; and, G-1131 now called Penacolite.
    But I still cannot find a Canadian source for any of them, and an attempt to order on-line from "chemical-supermarket.com" produces a note that says, "no shipping arrangements can be made".
    Rather discouraging!
    Anyone who knows a Canadian source for PRF adhesivs, please speak up.

    MastSplit
     
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