Which materials for my build? Cores, fiberglass, Resins, etc...

Discussion in 'Boat Yard Basics' started by kooker, Jun 9, 2014.

  1. kooker

    kooker I Love microskiff.com!

    I've been procrastinating pretty bad lately and finally decided to make a trip out to Fiberglass Coatings in St. Pete for some scouting. All I can say is these guys are awesome. Talked to a gentleman named Pat and he literally knew everything there was to know about fiberglass. So much so that I was lost numerous times in our conversation. Anyway, here's what I'm looking to do:

    14 ft Mitchell

    - Floor
    - Front and Rear Decks
    - Gunnel Caps (I think that's what they're called)
    - New transom.

    Something that looks very similar to this:


    Materials we discussed:

    Diab type60/type 80: Can I use this material for the decks and bulkheads? If so, I'd use 1708 Biaxle correct?

    Poly Umac?


    For the floor I was thinking about making glassed foam stringers and not sure what material for the actual floor itself. What lb. density foam would be best and what type of fiberglass to seal them?

    Basically I want to get a better understanding of what exactly I need to buy and not go there and buy unnecessary things and wrong amounts. I live 45 Minutes away from this place and making multiple trips isn't very efficient with the Hemi.

    So many questions.....
  2. gillz

    gillz Well-Known Member

    My $0.02;
    Consider how long much life do you want to give this hull and how soon do you want to be fishing. If you want it to last 5-6 years, the least cost, and on the water soon, go with good exterior plywood and vynilester resin and knock it out.

    If you want something your going to pass down (not get your $ back on)
    Use Nidacore for your Decks and Floor laminated with Polyester Resin and 1308 Glass. My experience is that 12oz Biaxial is good for decks, some folks say more some less, 1308 Bia worked for me. Nidacore is cheaper than the Diab products and will do the job on horizontal non-structural parts. Use Epoxy to bond them to the boat though, not the polyester resin. Use Divinycell H45 (Diab 45) for Bulkheads and vertical structure, Nidacore doesn't have enough strength on end. If it's an old school solid fiberglass hull that was very thick, it may not need "stringers" that weren't already there. If your replacing existing stringers or just feel they are needed, use at least 8lb two part foam, but 16lb is better. It sets rock hard and very strong. Use 2lb foam for flotation, if you feel the need to not sink in a emergent situation. If your going the "no rot" route you could also do your transom out of poured 16lb foam or some of the higher density Diab product.
    Check some online resources for your material too. I'm not saying anything negative about Fiberglass Coating, I've bought from them when I didn't want to wait for something to be shipped, but I've come to the conclusion that I'll waste more on gas and wasted time driving to get my materials then just ordering them and having them delivered to my door. Here are some of the  places I've used;
    http://www.carbonfiberglass.com/ (illstreet composites)
    http://www.compositesone.com/ (bought my NidaCore from them wholesale, wholesaler not online)
    http://www.uscomposites.com/ (Foam)
    Hope this helps.

  3. kooker

    kooker I Love microskiff.com!

    Gillz, PM Sent
  4. I use Raka for all my materials.

    I used marine grade 3/4" plywood(doubled up) for my transom in my RiverHawk B-60. It will outlast the boat.

    I'm about to rebuild the rear deck but haven't settled on what deck material I'll be using. I was somewhat concerned using nidacore (or the like) when fastening seat pedestal deck plates to it. I feel that it would pull out.

    Is the 1308 strong enough for that?

    Another thing I've read is that when using nidacore more glass and resin are needed which could offset the weight savings of using a lightweight core material.

    Just .02 worth...
  5. gillz

    gillz Well-Known Member

    SuperDave..The NidaCore will not hold screws without adding some kind of reinforcement ie; Marine ply, aluminum plate..etc. Also true is that the weight savings is not dramatic. My experience has been that laminated properly with a good resin to glass ratio you might save 15 to 20% on weight. If your lamination is resin rich, you could get really close to the same weight as plywood.
  6. 10-4.

    I was just put pulling some measurements for my rear deck but still can't decide if I should use this 3/4" M grade plywood or go get a sheet of 1/2"

    I weighed the left over 3/4" sheet and it came in at 55lbs. Now I wouldn't use all of this of course.

    I will say I'm getting pretty pumped about my little build up. It's been a long time since I've gotten back on it.
  7. tomahawk

    tomahawk Well-Known Member

    The decks in my boat are all 1/2" meranti as per the design. They will be glassed with biax, however, the plans don't call for them to be glassed. You can buy a 1/4" sheet for $40 and laminate two pieces together or a sheet of 1/2" is $70-90.