Painting Epoxy

Discussion in 'Materials' started by Dhutch, Dec 22, 2009.

  1. Dhutch
    Joined: Oct 2008
    Posts: 83
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    Location: Cheshire UK

    Dhutch Junior Member

    I have a an epoxy sheathed peice of ply i want to paint.
    - Its actaully a lift off roof for a boat rather than a hull but simular constuction to date.

    I made it about five years ago and used westsystems epoxy colouring the final layer over the sheathing with there pigment.

    This worked well and gave good self coloured finish in white. I always ment to paint it afterwards but life being what it was didnt.

    Now ive just had the roof off the boat again and done some running repairs to it and want to freashen it up a bit, to cover the repairs and to bring back the shine thats been lost by the exposed epoxy degrading.

    I plan to flat it all off and take off a thin layer of epoxy without exposing the glass sheathing but what paint would i be best using.

    Would a onepot polyerthene such as international brightside do the job? I would two pack it but its cost and effort verses finish?
    - The boats a steam boat, so being able to clean oil/soot/etc of it forever would be great.



    Daniel
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Sand all the dead epoxy off, until you're down into good resin. Apply a fresh coat if you think you've thinned it down enough to warrant it (like hitting some cloth). The two part solvent based polyurethanes will offer the best and hardest finish, but you have to accept the smack in the mouth when you buy it. Next up will be the water based two part polyurethanes for hardness, though the shine is about the same as the single part polyurethanes. The single part polyurethanes will be next on the list for durability and hardness. These will be much easy to apply then the two part paints and easier on the wallet too. These paints have improved so much in the last few years that you can get nearly flawless finishes with a brush. The paints left on the list will be less hard and will have less shine, but if you want to low ball it, get the best porch and deck acrylic enamel you can find. It will not be as hard, but the shine will be close and it'll probably be the cheapest too.
     
  3. missinginaction
    Joined: Aug 2007
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    Location: New York

    missinginaction Senior Member

    Well Dhutch you certainly won't go wrong following PAR's advise. Wow, you're pushing 5000 posts PAR, impressive!

    Dhutch, I'm an amateur compared to PAR, I thought I'd cover my experience with Interlux Perfection (2 part polyurethane) as a first time user. I'm restoring a 73 Silverton Sedan. I chose the 2 part poly paint because of it's durability. I was a bit put off by it's cost but decided to give it a try anyway.

    I'm glad I did.

    You will find lots of preparation and application information at www.yachtpaint.com

    Quite a few amateurs at the club where I keep my boat thought I was crazy to use a 2 part paint. They all said that it was hard to apply, that it was prone to runs, that they hated it. I found that the reason that they had so much trouble was that they failed to follow the manufacturers instructions.

    You will need to prime the surface using the recommended Epoxy Primecoat. Follow the instructions to the letter and you will get a prime coat that looks almost as good as a finish coat. But primer is not UV stable so you'll need to apply the finish coat of course.

    2 part paints need to be thinned and mixed carefully. It's not rocket science, my 11 year old son can do it but you need to pay attention to what you are doing. You're supposed to let the paint sit for 20 minutes or so (they call this "induction time"), I'm not sure why this is required but the instructions said to wait....so I waited. The properly thinned and mixed product is very thin (low viscosity). Don't be fooled by this. The paint covers very well. Put on a THIN coat according to manufacturers instructions and you will be very pleased. I used a thin 1/8" chemical resistant foam roller and had great results. You can just roll the paint if using light colors but the darker pigments need to be rolled and "tipped". Apply your second coat during the time window specified and you're done! Again if you just do what they tell you it comes out great.

    That's my opinion FWIW. I'll post a couple of pictures of the finished surfaces I've done. The cockpit photo is Perfection over properly prepped gelcoat, the cabin wall on the left is fiberglass over plywood. The second shot is just a ply section that I did in the garage prior to installing on the boat.

    I'm sure you know this but I'll say it anyway - The more time you spend getting a really good substrate the better the painted surface will look. 80% prepping and 20% painting is about right.

    One last thing, use a good canister type respirator. It can't be good to breathe this stuff.

    Good Luck,

    MIA
     

    Attached Files:

  4. apex1

    apex1 Guest

    Nice Job MIA!
     
  5. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    MIA is one our success stories. Yes, it is possible to use the fancy paints and get good results, in fact all the paints have under gone huge transformations in recent years.

    The waterborne LPU's which first had limited stick, but were very hard, now are "fixed" and rival sprayed solvent LPU's even if hand applied. The single part poly's which for decades where soft and "sensitive" over certain surfaces, now are hard, shinny, buffable and "lay down" with the best of them. Even the acrylics rival the poly's in hardness, gloss retention and durability.

    There's a lot of reasons for this, but mostly boils down to changes made in the USA's EPA requirements in the early 1990's to force down VOC's and other "issues" associated with paints and coatings. The first attempts at these products were less then perfect in some cases, but they've had 10 to 15 years to "figure it out" and now some really good stuff is available.

    Painting is 90% surface prep and 10% actual brush in hand time anyway, so pick a product that fits you budget and it'll probably do a great job for you.
     
  6. Dhutch
    Joined: Oct 2008
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    Location: Cheshire UK

    Dhutch Junior Member

    Ok, very interesting reading.

    Sounds like you can ultimatly paint anything you like on epoxy, which does supprised me too much given its both relativly intert and hard/stiff. And hence its then a case of using the right paint for the finish, which is a polyurethene and in many ways might as well be a nice hard one given the substate in question. (unlike a unshethed thin ply boat, where you want a nice flexable paint to avoid cracking).

    Interlux is International and perfection is the two-pot that our local marina shop sells so would be what i would be using. Whats the shelf life of that if i did 'invest' in a tin of it? I dont like not using something on cost if its the right thing but even for me £40 for a 750ml tin is a tiny bit steep if it will only do one 5ft*6ft pannel!

    Im hoping i'll hit sound epoxy sooner rather than later (ie hitting cloth) but we shall see. I took the roof section home today and its drying out in the hall ready for repair as we speak.

    All good fun. Spent the last two days moving the boat back to its winter moorings through the iced over canal. At just over 10 miles in nearly two days it was slow progress even by narrowboat terms!


    Here are some photos of making the roof and when it was new 5 years ago. linky




    Cheers, Daniel.
     
  7. apex1

    apex1 Guest

    Why would you "overdo" it with a 2 component PU? Vessels like yours have a "rugged" character and a roof looking like a private jet wing does´nt fit imho.
    A single pot PU will do a very good job on that roof and not cost you arm or legs.

    Regards
    Richard
     
  8. Dhutch
    Joined: Oct 2008
    Posts: 83
    Likes: 1, Points: 0, Legacy Rep: 22
    Location: Cheshire UK

    Dhutch Junior Member

    Well i think you proberbly right, but a decent slice of it would be in order to have a play with a new (to me) material. But also the reason its come back as well as having been broken a bit in a few places is because the matte finish that the degraded epoxy has left after the first year is nigh on imposable to clean.
    The boat is a steam boat so soot falls on it and everyones hands are fairly permantly covered in a thin layer of steamoil and grime. Im not too worried about it looking overly pristean and out of place for very long eather really as it will only be a matter of time before its scratch and scraped and then some one will drop the funnel on it again and another five years later it will be back in workshop again being stuch back together again till next time! :)
    I also though i might put a tiny splash of yellow the paint too just to take the edge of it, unless i can get some 'old english' type white shade.


    Photos of damage (roof currently drying in hallway) http://img444.imageshack.us/gal.php?g=dscn9583.jpg

    Daniel
     

  9. apex1

    apex1 Guest

    Look at my avatar, I know what you are talking!
    Outdoor housepaint is your friend! Acrylic enamel. Cheap and does the trick.

    Regards
    Richard
     
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