Preview: How to Use Epoxy, Part 4 – Prepping & Painting Over Fiberglass and Dynel

43 Responses So Far to “How to Use Epoxy, Part 4 – Prepping & Painting Over Fiberglass and Dynel”

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  Gustavo Haedo says:

  Eric: Newbie here and thank you for the vids. I was under the impression when talking 1008 or 1708 glass that the chop strand piece was supposed to touch the surface for better traction. I guess I learned something new

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  Steve Grube says:

  Eric,

  Outstanding video series. Well done, man! Easily the best videos out there on this subject. I learned so much.

  I’m nervous about an upcoming epoxy/fiberglass project on the hull of my first stitch-and-glue single hander. Yes, preparation and attention to detail is EVERYTHING in working with epoxy. It ain’t exactly Elmer’s Glue!

  You speak from great experience and therefore with authority. And I would also compliment the cameraman. Nicely lighted and photographed, with great angles on all shots. Excellent voice quality. And, especially, a HUGE thank you for NOT overdubbing your videos with ridiculous music played way too loudly, the plague of nearly all YouTube videos. Congratulations!

  Cheers and a Happy and Prosperous New Year to All at Off Center Harbor.

  Steve

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  Sean McCambridge says:

  Can you say more about timing the paint? In the video, it seems like you sand and paint while still in B stage and before full cure. I’ve had trouble with enamels staying wet over hard epoxy (three days in warm weather). Is there a way to “hot coat” enamel over B stage epoxy, or am I misunderstanding the video? Thanks!

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  John McGrath says:

  Eric, this was a great series, did you ever do a part 5?

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    Nate Rooks says:

    Hi John – you can find Part 5 here: https://www.offcenterharbor.com/videos/use-epoxy-part-5-practical-applications/

    If you like this, I’d definitely recommend checking out our 11-part series “Mastering Epoxy with Russell Brown.”

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  Jerry Zitterkopf says:

  Eric,
  I’m days away from using Xynole to sheath a Devlin Design Song Wren 21 which I understand is a material similar to Dynel. If you have used Xynole, I would appreciate any tips you might have that are peculiar to Xynole or things you did not cover in your discussion of coating and priming Dynel. Really a helpful series that I personally appreciated very much. Thank you.

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  Tom Arntzen says:

  Great video. Have you had any experience with applying Interlux Brightsides polyurethane directly over top of sanded clear epoxy? I just glass clothed and epoxied my 20 x 6 cabin top. I have used that paint on lots of topsides areas on my wooden boat. It sticks real well. I am trying to avoid donning the full space suit to apply Interlux’s recommended 2 part primer, Which I hear is very toxic. Thanks

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  Bill Theurkauf says:

  I realize this is an older video, but hoping Eric can answer a technical question. I’ve just covered my cabin top with dynel set in epoxy and was planning on using 2-part Awlgrip primer, as suggested in the video. The Awlgrip instructions do not cover dynel, but for new fiberglass set in epoxy, they recommend sanding with 30/60 grit to a uniform dull finish. Pretty clearly NOT what I want to do. Any specific tips on priming with 2-part primer?

  Thanks,
  Bill

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    Eric Blake says:

    Bill, good question. We typically have two part primer ready to roll onto the surface after the epoxy has semi-cured or reached B stage and roll it on shortly after applying the dynell. If time doesn’t allow or in your case where are you have already done the dynel work we would wash the surface of the dynel with hot water and a Scotch-Brite pad to clean it of any amean blush that may have come to the surface, and to scuff up any shine for better adhesion. Once this is dry applying two part primer or single part primer can happen. I hope this helps. Best, Eric

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      Bill Theurkauf says:

      Very helpful!, and thanks for the quick reply. I already forged ahead and primed at the B stage, s feeling better about my decision. My concern was that Awlgrip didn’t spell out this option.

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  Jeffrey Wright says:

  Great series!. What would be your suggestions if after putting down the initial e
  poxy and then the fill coat USING peel ply, if you wanted to finish with varnish, what would be the next step? Put a 3rd coat of 105/207 on then lightly sand it and then varnish?

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  William McCaffrey says:

  Nice series. One thing I think you should consider adding is the use of vacuum forming with peel-ply both on surfaces and in part making using a form or mold. Years ago when I first got started using epoxy-glass I couldn’t find much material to study – this series would have helped a lot. Just a thought anyway.

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  Harvey Kail says:

  Thanks so much for this series. I am planning to build a Goat Island Skiff with Okuome ply and the plans suggest basically coating the entire boat with three coats of epoxy followed by varnish or paint. You suggest that varnish over epoxy is not necessarily a long-term solution. Any further thoughts on varnishing epoxy-coated ply? Thanks.

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  Alex Jerrim says:

  Just came across this series of videos. Great information and well done. Thank you.

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  David Spensley says:

  Great series. Is it possible to use the peel ply cloth again say on smaller bits

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  William Fanning says:

  Thanks so much Eric and OCH ! In days of yore how in the bleeding h… would we be able to find valuable info such as this? I live four hours from the nearest body of water where there are few, if any, boats that get this kind of re-fitting anyway. Now we’re going to undertake a new cabin top on my Folkboat with what you have given us! #lookingforpart5

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  Grant E. Nelson says:

  Great Videos! Thanks. Lots of good questions and I am happy to see they get replies!
  Question: Video 4 saysat the end, ‘continued in Part 5’. Will there be a part 5?

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    Steve Stone says:

    Hi Grant. Yes, it’s nearing completion and will be released soon.

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  Andy Dorvillier says:

  Eric,very informative and helpful I want a perfectly fair surface to coat with a two part paint. Can you describe the sequence of fairing compound,sanding epoxy primer, post curing( even if out in the sun) and re fairing in preparation for final finish. I know that’s a lot but the test panels are far from topside quality that many of us may be looking for.
  I want the keys to the kingdom!
  Thank you.

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  David Badion says:

  Do you not recommend spraying paint?

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  Thomas Head says:

  Blake what’s the best way to not fill the weave on the Dynel when painting? I understand the reasoning with using a two part paint, it’s more durable, but it normally takes mutlitple coats to cover. How many coats of two part paint do you typically apply? Best techniques? Do you prefer a specific two part brand? Why paint a prime coat, won’t it just fill the weave even more so? Thanks.

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    Eric Blake says:

    All good questions Thomas.
    The best way not to fill the weave is not to fill the weave. We typically use Awl Grip and by applying the paint within 72 hours of laying the cloth with West Syatem 105/207 we roll on two coats of finish color as evenly as possible, and really strech the paint out.

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  Mark Roesner says:

  What about the blush, I thought you had to get rid of it with water before sanding, or you would sand it into the epoxy and then the paint won’t stick because of the wax in it?

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    Eric Blake says:

    Hello Mark,
    Epoxy’s have come along way over the last few years with regard to blush. We are using a low blush epoxy. All epoxy’s do blush, the West System 105/207 I am using here it is very minimal. I find that if I am not using peel ply where the blush comes through the peel ply and is removed when the peel ply is ripped off, the blush is removed by sanding. I have stopped using older formulas of epoxy because of the serious blush issues that you hear so much about and you bring up here.

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  christopher Dewitt says:

  Great series. Thank you. I especially like the seal ply. What is the correct spelling of “seal ply” or who sells it? I have searched the net for it however cannot find it. I probably have not the correct spelling. Again thanks.

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    Eric Blake says:

    Hey Christopher
    It’s Peel Ply or release fabric. We get it through a commercial composite outfit.
    You should be able to source it online for sure.

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  John Simlett says:

  The spec for my boat-build calls for, 8oz WR cloth in epoxy resin. Can you just confirm that’s the same(ish) as the 10oz first sample you produced?

  This epoxy series, I found on Day 1 of membership, and confirms membership was money well spent.

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    Eric Blake says:

    Hey John,
    Thanks for your comment.
    8oz is just the weight of the cloth per square yard. 8oz and the 10oz cloth I am using are so similar I would have a hard time telling them apart without looking at the spec on the roll.

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      John Simlett says:

      Thanks Eric

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  Paul Robillard says:

  Great videos! Can’t wait for #5.

  These vdeos are definitely meeting a need on the use of composite materials in boatbuilding.

  Keep them coming!

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  Charles Koucky says:

  How do you finish the second half of the Dynel center seam joint?

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    Eric Blake says:

    Hey Charles,
    The second half of the Dynel seam is made by waiting until the following day, and running tape 3/4″ on the dynel seam you just cut, this gives you an overlap and a look that would be similar to how canvas used to be seamed together. Lay out your fabric on the other half of your deck, wait till the epoxy B stages and knife it just like the first half. I will explain this in a final part 5 of the series shoeing some of these techniques in process.

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  Patrick Daniels says:

  Great stuff and timely as we make repair to our dinghy fleet at the club. Nice work!

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  Robert Hauser says:

  Nice tips, they would have saved me a lot of learning the hard way over the years. One thing though is painting as quickly as you suggest has caused me some issues with (one part polyurethane) not hardening quickly. Has anyone else had the issue. By the way I use the cabinet scrapers a lot on some jobs.

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  David Jeffery says:

  Excellent series. Now, please show us how to lay fiberglas down on a surface with hard radius curves, nasty angles, and other places where the cloth wants to bunch, wrinkle, pucker, and otherwise not want to fit smoothly.

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    David Jeffery says:

    A good part of answering my own questions about laying fiberglass, etc., over non-flat surfaces were answered by going back to review the series on building the Fox decked canoe. The ever patient and calm Bill Thomas shows how it is done (calmly and patiently). Also Geoff Kerr’s series on the Caledonia Yawl is helpful as are many other videos.

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  Ken Sloan says:

  Great series. Exactly the kind of hands on demos that us non-pros hunger for!

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  Jim Gallagher says:

  Very Helpful. Nicely done…simple clear and effective. Thanks, eric

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  David Heal says:

  What about first applying a coat of epoxy to the bare plywood surface, then laying on the cloth, and then wetting out the top surface as you showed in the video? I realize that this technique might be a bit awkward if using large sheets of fiberglass covering large areas.

  • 

    Eric Blake says:

    David,
    Some people would only ever do it that way.
    I like to lay out the cloth and properly wet through it, being mindfull to come back after 10-15 minutes and look for any dry spots that may be created from the plywood absorbing the epoxy once it was wet out. There are many ways to skin a cat.

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  Paul Fitzgerald says:

  Parts 3 and 4 are useful, thank you..
  I generally avoid sanding epoxy and use a sharp cabinet scraper where I can, do you guys use them?

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    Mark Nowlan says:

    Classic…cabinet scraper…great uncle of mine, cool old guy, amazing woodworker, when i asked why he didn’t sand that…. he looked at me like I had horns growing out of my head…”the guy that invented sandpaper should be strung up”!! LOL Why couldn’t you use a cabinet scraper? is it a risk of taking too much off? or is because there’s potential for it to be too smooth? Thanks for asking that Paul…

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      Eric Blake says:

      Hey Guys,
      Some people use cabinet scrapers for sure. I find that if a cabinet scraper is sharp enough to cut epoxy, it will probably remove more than necessary. Many thin coats, evenly applied shouldn’t take much sanding to make it ready for paint and I have better control with a sanding block than a cabinet scraper. That’s just me.