Best Epoxy for *Hand* Layup??

Discussion in 'Materials' started by CatBuilder, Nov 25, 2010.

  1. michael pierzga
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    michael pierzga Senior Member

    I just witnessed a French gang of boatbuilders reskin the bottom of a 20 meter cat after grounding damage. . It was SP resin on triaxial cloth, but more importantly they employed the wet out table method refered to above. The table was Two full size sheets of plastic laminate covered plywood. They impregrated on the plastic sheet covered table, pvc pipe rolled, laminated ,peel plied ...upside down !! It was a two man gang , they worked fast and the work was very clean looking, very presice...very little fairing required.
     
  2. CatBuilder

    CatBuilder Previous Member

    Yes, I was thinking last night that I would be making my own sort of "pre pregs" on a table, then rolling them up and laying them out on the hull.

    I guess you're all right... just about any epoxy can work if I do it that way. Should save some money, especially using the System Three General Purpose Epoxy I already have on hand.

    PAR: Some questions...

    You say I'm "screwed"... that scares me a little. :) Do you mean my boat has no chance of coming out structurally sound, or do you mean it's difficult to work in FL? I see you're in FL. What do you do? I am surrounded by boat builders and NA's here (many are in St Augustine). They build Sea Rays and Hunters not too far away. Okay, maybe those guys are screwed too! Explains a lot! ;)

    Seriously, though... are you saying I have no hope of having my laminates come out well?

    Regarding using nylon from a fabric store: My designer said this is a huge mistake. He says in his literature that the nylon isn't manufactured to be free of contaminants and these contaminants can cause problems with bonding. I don't mind spending a bit on peel ply if it's going to help me.

    Question: If I don't use peel ply and just use bog to start fairing right away, as was suggested before, wouldn't that save a step? I mean, if I'm going to blush anyway or something, wouldn't it be best to have to sand the bog layer since you have to sand it anyway to fair?
     
  3. Steve W
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    Steve W Senior Member

    Bogging as you go as suggested by Sabahcat is a common way of finishing your layup and works particularly well where working time is limited due to high temps and you are working by yourself or short handed or you only have a couple of hours available, as you can lay your first couple of runs of the first layer then start your second layer (staggered overlaps of course) and then procede along as far as you want and then peel ply the overlaps where you stop for the day.






    ,then bog the work you have completed, next day you can peel the peel ply and continue on with minimal prep.This allows you to work at a comparitivley leisurely pace without too much stress.
    Steve.
     
  4. CatBuilder

    CatBuilder Previous Member

    Thank you, Steve. That is exactly how I was thinking of doing this layup because I am short handed and want to work efficiently. It's good to hear it can be done.
     
  5. War Whoop
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    War Whoop Senior Member

    If you mechanize a little and explore the hardener systems you may have time to get a bag on it.
     
  6. PAR
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    PAR Yacht Designer/Builder

    In context is usually best don't you think? Maybe working in 95% humidity and temperatures in the 90's most of the year is your idea of fairly good conditions, but I'd say it's a fairly "screwed" set of conditions to work in. Don't get me wrong, I've done it for years and until I A/C's my shop, I couldn't appreciate how bad I had it. Actually, I knew how bad it was.

    You can do a fine job of it, but don't compare your situation with the Florida based polyester builders, that have clean molds, sufficient crew size to manage large layups and most importantly well developed set of procedures to insure a consistent level of laminate production.

    As I and others have hinted, this is a technique issue(s) and one you can address, though working solo or short handed, in the Florida heat is going to bring additional issues.

    The nylon used in ripstop is the same (nearly sterile) nylon used in peel ply. The process of making and weaving the stuff leaves it quite clean, though I don't imagine most designers have been to textile mills to see this process in action, it is pretty amazing. I can get it locally from less then 3 bucks a yard. In fact, most ripstop can be had uncoated or coated with a variety of things (silicone, wax, etc.). I use the uncoated stuff. Your designer is correct in that the coated stuff will likely contaminate the laminate.

    Yep, if you're fairing directly after the layup, just get started at the same time and lock down the condition of the layup with peel ply, though under these conditions, adding more work, short handed sounds like wishful thinking.

    When I was working outside, I just assumed there was going to be a blush, mostly because I know a lot more about the chemistry, then most and those "non-blushing" formulas, are more marketing hype then anything working in the conditions you are.

    Steve has a good point, have you looked into bagging?
     
  7. CatBuilder

    CatBuilder Previous Member

    Thanks for expanding on your post, PAR. I wasn't quite sure what you meant. Additional comments in red.


     
  8. michael pierzga
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    michael pierzga Senior Member

    Catbuilder. You will be purchasing a huge amount of chemicals and disposables for your project. Its best to put together a bill of materials and solicit comment and estimates from local suppliers. The main consideration for any project is "Technical Support ". You will need plenty during the build. Be sure that your chosen system and supplier comes with technical advice and on site visit supervision. If youre in Florida, you have access to several first class suppliers ....seek their guidance.
     
  9. Herman
    Joined: Oct 2004
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    Herman Senior Member

    Indeed, find help in your suppliers. Make a list of what you need, and negotiate a good discount. Peelply should not cost more than 1,2-1,4 usd / sq yd.

    Your suppliers will also be able to direct you to a small team (2 people) to help you with laminating. This phase of the project should not cost more than a couple of days.

    Applying bog over the laminate is a good idea in general, but when laminating alone, and as a relative beginner, I would not do it for the reason to be able to check and verify the laminate during and after cure.

    Also do not use too thin a resin, as you will experience drainage and dry spots in the top part.
     
  10. War Whoop
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    War Whoop Senior Member

    Catbuilder ,Par is right here is some ripstop nylon it works fine "the green", I used it to finish this boat.Let's see it is 2 AM and I have 36 feet to laminate and get a bag on by myself before I can stop for the evening.


    [​IMG]
     
  11. CatBuilder

    CatBuilder Previous Member

    Ok, all the advice is well taken. Thanks.

    I'm not sure which of my threads to put this in now, since I have 3 going, but I just found out from my designer I cannot layup the triaxial athwartships and must lay it up fore and aft to keep the fibers intact in the proper direction.

    This presents a whole new range of hell.

    Between a materials bill that has increased by $30K switching to foam/glass and now that I cannot layup the boat myself due to laying up for and aft, I am afraid this is slipping out of my financial ability.

    I can't hire people to work on the boat *and* pay $30K over budget for the Corecell, epoxy and glass.

    I may be getting close to "check mate" on this, even after driving 1900Km (1200 miles) to my build site this week to get started. I am at least in "check" if I can't figure out how to reduce these costs and make the project possible for a one man build with only a small bit of hiring.

    Damn.
     
  12. sabahcat
    Joined: Dec 2008
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    sabahcat Senior Member

    Get a house where you can build in the back yard

    Build a cat from Paulownia or cedar using half the glass weights you will for foam and be able to do the drops athwartships

    Will be $30k plus in front and will only need occasional help
     
  13. CatBuilder

    CatBuilder Previous Member

    Man, I wish I could just afford a boat. This is getting very tiring. I've been starting to build a boat for 9 months now. What about a female mold? Would that help me in laying up the longitudinal glass strips?
     
  14. sabahcat
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    sabahcat Senior Member

    LOL
    If only they were so cheap in Australia. Median house price here is 4 x that
    But, I save about $300/week on the cost of shed rental
    And only walk 15 steps to work

    Most reputable designers of multi's should already have stock plans for strip plank

    Plans are cheap for older designs

    As an example plans for a Simpson 11.88m cost $1500
    And are designed for strip plank with ply bulkheads and furniture.
    http://boatcraft.com.au/Shop/index.php?main_page=index&cPath=32_33

    My current build's hulls are modified simpson 15's
    And I had a 9 stretched to 10 before that, so clearly like the designs


    Standard strip plank sandwich
    Been in use with great success since the 80's

    You can get an idea of how the build is done in these pictures

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     

  15. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Make sure you get the un-coated, un-waterproof, un-water resistant, un-waxed or un-siliconed ripstop. You can usually tell by the price, with the un-coated stuff being the cheapest. War Whoop is down in your area (I'm assuming) see where and what he's getting.

    I'm inclined to agree in that building with these types of laminates and cores tends to be a lot more costly then plane 'ol strip planked with abrasion sheathings.
     
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