Epoxy based Filler Primer?

Discussion in 'Materials' started by mcollins07, Nov 16, 2010.

  1. mcollins07
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    mcollins07 Senior Member

    Last night we began working on an Elvstrom Trapeze dingy, which I’ve shown on another thread.

    http://www.boatdesign.net/forums/sailboats/16-day-sailor-identity-35453.html

    First we pressure washed and scrubbed to remove any dirt and oils that might be on her. The hull has some slight pitting. We began wet sanding (220 grit) with a longboard and found the hull to be pretty fair except in one region near the automatic balers. The amount of fairing required seems to be little enough that mixing epoxy with microballoons might be overkill. I would like to try some type of epoxy based filler primer.

    The hull is polyester fg and we intend to use an epoxy paint. Local availability of products is rather limited. So, convenience and availability may also determine which product we use.

    Is there such a thing as an epoxy based filler primer which would spray on with liberal thickness and sand easily? And still be a respectable water barrier. Would the polyurethane based filler primers be compatible with this system?

    I’d appreciate your recommendations and suggestions.

    ~ Michael
     
  2. GG
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    GG offshore artie

  3. Steve W
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    Steve W Senior Member

    i agree with GG on the duratec products. What epoxy paint do you plan on using? i am not familiar with any epoxy top coats commonly used in the marine industry,they are all polyester or acrylic urethanes (just like in the automotive industry) applied over epoxy primers.You mention availability locally but just about every town has autobody supply shops that can sell you high build epoxy primers but they should be sealed with a regular epoxy primer.It sounds to me that you probably dont need a high build,just a bit of fill/fairing in local areas before priming,then spray with an automobile acrylic urethane such as Nason Fullthane or PPG Concept or similar.
    Steve.
     
  4. mcollins07
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    mcollins07 Senior Member

    thanks for you suggestions and the link.

    I am currently rethinking this and looking for a supplier of microballons.
     
  5. mcollins07
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    mcollins07 Senior Member

  6. GG
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    GG offshore artie

    Hey guy i have no mention of this product and to tell you the truth...... has anybody really seen this product mentioned before ? Hey guy , i really have a hard time using anything that was made for everything when it comes to using it for marine applications . Steve .................you ?
     
  7. PAR
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    PAR Yacht Designer/Builder

    I'm not sure of the formulation differences between PC-7 and PC-11, but if PC-7 is an indication, you can use PC-11 but only as a structural adhesive and certainly not as a surfacing compound. Who ever gave you the advise on PC-11 shouldn't be given any further consideration in this regard.

    If you're in Texas, then call up or log onto www.duckworksmagazine.com. They sell the usual suspects, though I'd recommend Marinepoxy as the base resin system, if cost is your primary concern. Of course there are the "pre-mixes" that every seems to love paying several times as much for as the non-mixed raw materials, such as "Quick Fair" by System Three or the Duratec surfacer.
     
  8. sabahcat
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    sabahcat Senior Member

    Its a fair fibreglass hull, surely it doesn't need re-fairing.

    I would use amercoat cc24 high solids epoxy primer, rolled on and squeegeed in to fill pinholes.

    Whats left in the mix, let thicken (cure) and while still workable fill any notable gouges and pinholes that have been missed.

    Once you have sanded that back use another ameron product for topcoat. I use Amercoat 450 from memory
     
  9. michael pierzga
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    michael pierzga Senior Member

    Thats a great technique from Sabahcat.... "Whats left in the mix, let thicken (cure) " to make a very fine filler compound for filling surface scratches and dings. Takes quite a while to thicken so it will be around your workshop for an hour or so and it gets the most out of a pot of expensive primer
     
  10. mcollins07
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    mcollins07 Senior Member

    My cousin bought the PC-11 and applied it to the boat. His initial response is that PC-11 is too thick (viscous) to apply in thin layers. Says the consistency is almost as thick as that epoxy that comes in stick - the type that you cut a slice off and knead it, to mix it. We’ll find out in a day or so, if the PC-11 sands easily.

    Based on his description the PC-11 seems to be similar to Marine–Tex, which I have used as filler on very small jobs before and it worked fine. The Marine-Tex must be slightly thinner consistency, less viscous, than the PC-11 based on his description. Marine-Tex is rather expensive and you can not alter the consistency either.
    http://www.marinetex.com/marinetexepoxyputty.html

    For this project, cost is a consideration but we try to balance cost against a quick completion and good quality. Also, it is a chance to explore new products and techniques. Thus, we are trying what is available locally. Microballoons and epoxy resin would be my preference. Unfortunately, most of my supplies for this type of work are a 6 hour drive away.

    Sabahcat, I like the idea of using a squeegee, thanks. I’ll give that a try.

    Is Amercoat CC24 available in the USA?
     
  11. PAR
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    PAR Yacht Designer/Builder

    You're going to be pissed about the PC-11 coating. It's hard stuff and sanding will be like trying to fair a hunk of granite with sand paper. PC-11 is just like PC-7, though formulated for marine use. It's stone in a can.

    How much do you need? Mail order can have a quart of whatever at your door in a few days. The very last thing you want is a surfacing compound that's rock hard. You'll be sanding more hull then filler and making a lot of trouble for yourself.

    Amercoat CC24 is PPG's Austrailan product name. It's available in the USA, but under a different name and I didn't check the MSDS to compare the various products to see which was Amercoat CC24.

    What you need is a fairing compound, either in pre-mix, like Quick Fair or using your own mixture with your preferred resin.
     
  12. mcollins07
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    mcollins07 Senior Member


    That is scary. I'd like to have seen the stuff before he put it on, but I was not there and it is his boat. I'll let you know how it goes.

    I think microballons with epoxy will be my recommendation for any further fairing compound. I like being able to adjust the consitency.
     
  13. sabahcat
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    sabahcat Senior Member

    But does he really?
    The picture of the boat looks like a laser or similar, that has popped out of a mould with gelcoat on it.

    http://www.boatdesign.net/forums/at...612138-16-day-sailor-identity-daysailor03.jpg

    In reality, it probably could have got away with a good hit with oxalic acid, then a buff
    or maybe a wet and dry and a buff
    or at worst, primer and topcoat

    paint I use in Aust. available in the us from here http://ppgamercoatus.ppgpmc.com/products/

    In reality, as its only day sailed and polyester, I would be thinking of using some cheap car polyester car filler (for any deep spot fill) and then a cheap car type sandable high build primer and a car grade topcoat
    All available in smaller quantity from auto accessory stores
     
  14. mcollins07
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    mcollins07 Senior Member

    Sabahcat, It did come from a mould, and the hull is generally in very good condition. If it is gel coat on the surface is seems very thin. There is some pitting through the gel coat, maybe 1/8th to 1/32nd of an inch deep.
    Also, the hulls looks to have been repaired once before, which is a source of unfairness.

    My cousin and I both are perfectionist enough to want it faired as well as reasonably possible if we are going to do a repair.

    Thanks for the link.


    Well, it is a very nice day sailor. Might even race it in dinghy races eventaully. Much too nice to be putting cheap car polyester car filler in my opinion.

    I would not mind car grade topcoat perhaps, but we already have a marine grade epoxy. I'll probably suggest putting an automotive clear coat on top of the epoxy to provide UV protection.
     

  15. mcollins07
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    mcollins07 Senior Member

    PAR, you were exactly correct about the PC11. According to reports, the PC11 was too think to properly fill the holes, and it very hard to sand. Looks like we will be using a belt sander to get back to where we started.
     
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