Does Polyester bond over vinylester??

Discussion in 'Boatbuilding' started by Edmundo Souto, Jun 26, 2013.

  1. Edmundo Souto
    Joined: May 2008
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    Edmundo Souto Junior Member

    Does anyone know if I can make a hull in vinylester resin and laminate the stringers and bulkheads with polyester resins??
  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    You could, but is would be silly. If you have vinylester and are able to laminate a hull and deck with it, using polyester makes no sense. The bonds will be much weaker and lessen the value of the boat.
  3. tunnels

    tunnels Previous Member

    What size is the boat ??
    In a real life situation you are better to do 2 outside skins of 450 csm resin rich with Vinylester then the rest of the lay up in polyester !!,
    then glass your stringers and bulkheads with Vinylester !!
    This is how most big boats would be done !!
    The 2 outside skins are for osmosis protection plus to slow the fibre glass print through to the outside gel coated surface !!
    The strings and bulkheads need just that extra bit of strength !!

    What are the details of the stringers?? wood or foam ?? and what glass you using and how are you going to use ?? :D

    Vinylester bonds better to polyester then polyester to Vinylester :confused:
  4. kapnD
    Joined: Jan 2003
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    kapnD Senior Member

    I have heard that polyester does not bond well to vinylester, and proper preperation is key to making that bond.
    What I cannot determine is the formula for said prep, is it simply roughing the surface for mechanical bond and wiping with acetone?
    While VE may be a stronger product with certain desirable characteristics, it is not always the best material for the job.
  5. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Polyester doesn't bond well to much of anything, including mechanically to itself. Polyester will bond sufficiently to vinylester, if the tabbing overlap is generous. This is the key to using lower modulus resins, like this - lots of surface area. To directly answer the question, yep, it'll bond, but use a wide overlap on the tabbing and make the tabbing sufficiently thick enough, to be effective.
  6. keysdisease
    Joined: Mar 2006
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    keysdisease Senior Member

    As this is a mechanical bond and not a chemical bond roughing the surface and wiping with acetone as well as PAR's recommendations about tabbing is as good as it will get.

    Not a good place to save a few dollars.
  7. redreuben
    Joined: Jan 2009
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    redreuben redreuben

    A vinyl ester skin with a polyester body has been standard practice in boats, swimming pools, spa baths etc for decades.
    So if that's what you want to do go for it.
    But the above advice is correct, VE is a better resin, your call.
  8. JCherubini2
    Joined: Jan 2014
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    JCherubini2 DianaOfBurlington

    Go with Gonzo

    I agree with Gonzo. :)
  9. GS Miller
    Joined: Oct 2016
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    GS Miller New Member

    achieving a bond

    I have used a product in the industrial fiberglass business called Derakane 8084. I have used it to achieve outstanding bonds with concrete, steel, wood, and other frp resins. It works great with any dissimilar resins. I have used it to bond just about all resins including epoxy. prep the surface you are wanting to bond to as normal by either sanding, blasting or chemical prep (acetone). If you are kind of doubting this product do a pull test with it. prepare a small area of the surface you are trying to bond with then do a lay up on it building a loop or something in your laminate to mechanically pull with. put an inline scale if numbers matter to you or just watch what happens to your laminate if I were a betting man I would say you are going to destroy your lamination before it comes loose! Seen it too many times! Good luck and I hope this helps!

  10. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    Since about 90% of the boats built in North America use a combination of VE and polyester you'll be fine. This combination has been the norm since blistering became an issue decades ago, it took a while for some companies to go with a VE skin and polyester for the rest, but after that the blister issue was reduced dramatically. In fact many of the skin resins are now a blend of VE and polyetser, they work very well together, and are completely compatible.

    The bond to the VE will be chemical unless it has cured completely, and some VE's stay tacky on the surface for an extended period of time, so it's even less of an issue.
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