Ortho vs. Vinylester

Discussion in 'Materials' started by We're Here, Aug 21, 2011.

  1. We're Here
    Joined: Aug 2007
    Posts: 43
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Gloucester

    We're Here Junior Member

    I'm in the spec'g stage of an under 30' lobsterboat build. The builder estimates that he'll use 65-gallons of resin in the hull layup. He recommends a "barrier coat" of vinylester but I'm wondering if the superior strength of vinylester (in comparison to conventional ortho layup resin) warrants having the entire hull layup done in vinylester?
     
  2. gonzo
    Joined: Aug 2002
    Posts: 15,623
    Likes: 1,109, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Unless you re-engineer the laminate for a resin with better elongation and adhesion properties, it is a waste of money.
     
  3. Herman
    Joined: Oct 2004
    Posts: 1,618
    Likes: 89, Points: 48, Legacy Rep: 1240
    Location: The Netherlands

    Herman Senior Member

    wtf is ortho resin doing in a boat? OK, it is cheap, but it is prone to blistering and water ingress. I would either specify a DCPD or a ISO-NPG, unless cost is the driving factor. But most DCPD is same price or even lower than ortho now anyhow. Just mind the secondary bonding, although that is seldomly a problem with DCPD (or better: DCPD blends) anymore.

    I would definately invite a supplier over to tell you more about the different resins, or at least read some spec sheets.
     
    1 person likes this.
  4. daiquiri
    Joined: May 2004
    Posts: 5,373
    Likes: 255, Points: 93, Legacy Rep: 3380
    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    I agree with this observation, but there are brands approved by Lloyd's for shipbuilding use (example: http://www.cfsnet.co.uk/acatalog/Lloyds_Cert_Nors_6343.pdf) hence (I guess) the designer's cost-oriented choice and the prescription of vinylester as just a moisture barrier.
    Cheers
     
    1 person likes this.
  5. Herman
    Joined: Oct 2004
    Posts: 1,618
    Likes: 89, Points: 48, Legacy Rep: 1240
    Location: The Netherlands

    Herman Senior Member

    Lloyds has little to do with what is best or at least in the direction of what is optimal. There are better performing resins than ortho ones on the list approved by Lloyds.
     

  6. Ilan Voyager
    Joined: May 2004
    Posts: 1,272
    Likes: 196, Points: 63, Legacy Rep: 758
    Location: Cancun Mexico

    Ilan Voyager Senior Member

    I do agree with Herman: Lloyds is not a good guideline for composite boats. And for polyester and yachts Lloyds is obsolete.
    Herman is right ortho has nothing to do on a boat. DCPD is a good choice and a lot of brands have a good balance price/strength/"workability"/durability.
    For a small lobster boat vinylester is overkill and does not justify its price. 65 gallons is just over a barrel, what's the size of the boat? 65 gallons is very grossly 255 kg of resin, a very rough calculation gives a hull around 400 kg for a classic hand layed mat/roving polyester.
     
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.