CH 17 - white "speckles" under epoxy

I know it would be helpful if I posted a couple of pictures but i seem to be having trouble doing that right now.  This may be a matter of too much too late but here goes. I have finished epoxying and done a lot of sanding and have discovered that I have a multitude of pinprick sized white spots  - mainly on the deck near the hull deck joint and around the deck nails - that seem to be under the epoxy.  I assume  but am not sure that  this is a result of the fiberglass not being firmly secured to the wood (or, in the case of the nails, the nails not hammered flush to the wood.  At this point is there anything I can do to eliminate - or camouflage - the tiny spots?  


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RE: CH 17 - white "speckles" under epoxy

Hi Bruce, 

based on your description, there are two likely things that are happening.  sometimes white specks occur after sanding as epoxy dust fills little holes in the epoxy.  if you throw some denatured alcohol on a cloth and rub it over the speckles and the speckles disapear....then this is just dust on the surface and a fresh coat of expoxy after cleaning out dust-filled-divots will address the problem.

if it doesn't go away, then, as you suggested, the problem is under the epoxy.  this sometimes happens around corners and other irregularities when the glass lifts and a little air-bubble is formed and or the glass is not completely wetted out.    these ones, while not typically a problem structurally if the areas are small, cannot really be addressed without opening up the bubble and filling it with epoxy.  easy to do if the scope of the problem is limited....harder if you have a lot of this.

that said, a common paint theme on the Chesapeake line is to paint the hull and slight overlap onto the deck (typically one inch in from the actual edge).   if the bubbles are under a painted area....problem solved.

if that is not could just live with it and focus on paddling.   let us know what the diagnostic above shows and we can come up with some additional ideas and suggestions.



RE: CH 17 - white "speckles" under epoxy

+1 on everything that hspira says.  I would add that you are not building a piece of furniture.  It is a boat that you will run into logs and beat up on top of your car, so it will soon have more small cosmetic defects.  In any event, the large scale beauty of the boat will hide all the little imperfections.  


RE: CH 17 - white "speckles" under epoxy

   I've had some small patches of speckles that sound similar to what you describe appear on the bow of my NE dory and my Shearwater.  They are minor, and picking up on some words I first learned on the forum - I consider them a feature, not a blemish.  In all cases I attribute their development to oveheating. And the overheating to causing outgassing.  So maybe you have conditions that caused some outgassing - I read suggestions elsewhere on how to try to limit that.

Here is how I ended up with speckles.  On the dory they appeared several months after the boat was copleted.  It was one of our 105 degree Texas days with the boat in full sunlight with a plastic tarp over it, but the tarp was in direct contact with the breasthook on the bow.  Not sure how hot it got, but I'm betting in the "fry an egg" range.  On the Shearwater, again on a hot day, I got the speckles during the build - during the end-pour.  I knew that a cup full epoxy was going to cook hot and fast that day, just didn't guess that the heat was going to cause speckles.  Before doing the second end-pour I stood the nose of the kayak in a bucket of water and even swished it around a bit during the time the epoxy was cooking at it hotest.  That almost solved the problem - even then I got just a speck or two that you can see if you really look hard.  

Of course I'm kidding and think that there might be some structural concern for a totally speckled boat, but if it could be done uniformly over a whole boat it would look pretty cool, I think.  Maybe we should start mixing metal-flake into our epoxy (and painting flames on the hull sides)!  

RE: CH 17 - white "speckles" under epoxy


Thanks for the responses.  I was able to eliminate a lot of specks with denatured alcohol.  If I epoxy these areas though is there anything to do to avoid repetition of the problem?  As to the spots that are left, which tend to be larger and are indeed proximate to the hull deck seam and also some of the finishing nails on the deck, I had two thoughts - one suggestion from my local hardware store was to lightly tint some varnish and spot touch up these areas.  The other is to paint an inch - inch and a half border along the seam.  I am reluctant to paint the entire hull  - I’m not sure it is finished well enough that it would look decent painted.

I understand the observation that after one day on the water all the existing defects will get lost in the rounding.  However, for me, the attraction (and satisfaction) has been in the build and the learning experience.  I am considerably less agile that when  I actually stared the project and I’m not sure how much time it will spend on the water Whatever happens I am determined this will be the last winter of my build so wherever it is come spring I intend to declare it “launch ready” and move on.  N the meantime, I would like to make as good as I can.




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