Glue for laminating wood mast?

Discussion in 'Materials' started by pwillie, Sep 13, 2015.

  1. pwillie
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    pwillie Junior Member

    I have used 105 but is there any thing better? :?:
     
  2. PAR
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    PAR Yacht Designer/Builder

    Resorcinol is an option, but the joints and faying surfaces need to be perfect, the temperature just right, the glue fresh and sufficient clamping pressure employed during the cure. PVA will do, if the mast is well stayed, but if it's freestanding it'll fail with repeated cycling. Instead of West System, choose one of the discount epoxies and save 50% or more.
     
  3. SukiSolo
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    SukiSolo Senior Member

  4. PAR
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    PAR Yacht Designer/Builder

    Suki, the link you've posted makes statements, but doesn't back them up with anything and though I agree with some of it, I disagree with other portions and would appreciate an explanation to support their views.
     
  5. sprit
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    sprit Junior Member

  6. PAR
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    PAR Yacht Designer/Builder

    Why would you want to use these types of speciality epoxies? Do you really want to stick the mast in an oven and bake at 600 degrees, just to get a cure that could have been had at room temperature? There are dozens of different epoxy formulations, but most will be quite content, with room temperature cure versions.
     
  7. SukiSolo
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    SukiSolo Senior Member

    I'd like to see a bit more too PAR, backing it up. But these guys have been making sticks for a long time, again mainly for UK conditions, though their offshore masts must have a global distribution potential. Trouble is when you try 'new' adhesives you probably are not going to find out the real world life span except by using for 30-40 years. You'll only get the really short failures ie 3-4 years, maybe less, and 'ping' the stick starts to come apart. Personally I'm quite happy with urea based glues on small Sitka masts and booms, and agree that you need tight joints. Resourcinl's good too. But equally I'd be quite happy to use epoxy for joints and sheathing especially if painted white. However I can't back up the latter and say it's good for 30 years though I'm pretty confident it would be, if maintained minimally.

    With respect to the high temperature cure epoxies, good tools in the right place. The important quality to look for (amongst others) is the softening temperature of the cured product not the cure temperature. No good having an epoxy that softens at say 110 deg C when you paint a mast black and sit it out at the equator at mid day.....
     
  8. sprit
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    sprit Junior Member

    My basic question was: can one find epoxies that withstand high temperatures during use, as on a mast.
     
  9. PAR
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    PAR Yacht Designer/Builder

    I've made a lot of epoxy glued sticks without failure from my efforts. Some have broken, but given the circumstances, the glue type wasn't the issue. Epoxy glued spars have been around for a long time, since the early 70's, so I'm reasonably confident the jury is in.

    Describe "high temperatures"? You can get high temperature tolerant formulations, if desired, if this is what you mean, but how high are we talking about, as room temperature cured formulations will tolerate 140 degrees easily. Are you sailing over active volcanos?
     
  10. pwillie
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    pwillie Junior Member

    I decided to use 105 because I have it.....will let you know(pics) when the mast is finished....BTW , I have clear yellow pine that I'm using (mistake?) because that's all I could find in my area...Would Poplar work?. I can get Poplar...
     
  11. PAR
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    PAR Yacht Designer/Builder

    Yeah, your yellow pine (probably short leaf) will likely make a really heavy mast, which isn't very desirable. I've never seen a poplar mast before. It's a little lighter than Douglas fir, but doesn't have the fastener holding power, compression strength, modulus of rupture, etc. of the usual species we use in spars.
     
  12. SukiSolo
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    SukiSolo Senior Member

    Poplar (European) has been used for er, er. sticks, at least this side of the Pond - match sticks!....;)
     
  13. pwillie
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    pwillie Junior Member

    So,does anyone know where I can purchase Fir or spruce?
     
  14. PAR
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    PAR Yacht Designer/Builder

    Fir is pretty commonly available around the country. Spruce needs to be nailed down a bit, as there are a few different subgenus available. The more common white and black spruces are pretty commonly available.
     

  15. Nick.K
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    Nick.K Senior Member

    Yes, I tried it once for joinery, never again! About as durable as white sliced bread and unstable too, also quite heavy and water stains badly. Many "marine" or exterior plywoods sold here are poplar inside, a less suitable timber is hard to imagine.
     
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