 |
|
.. CLICK HERE TO GOOGLE SEARCH OUR ENTIRE WEB SITE FOR KEY TERMS/WORDS .. |
Return to Progressive's boating site
Return to Progressive's commercial site
Your Host and Tour Guide:
Paul Oman, MS, MBA - Progressive Epoxy Polymers, Inc.
Member: NACE (National Assoc. of Corrosion Engineers), SSPC (Soc. of Protective Coatings)
"Professionals helping Professionals"
|
|
.. CLICK HERE TO GOOGLE SEARCH OUR ENTIRE WEB SITE FOR KEY TERMS/WORDS .. |
------------------------------------
Fisheyes - Craters In Epoxy Surfaces
Fisheyes are where a coating pulls away from the underlying surface creating 'holes' or craters in the topcoat
that go down to the bottom coating. They sometimes happen under certain conditions with epoxies. Two part polys
(LPU) coatings are especially sensitive to fisheyes. Almost always they are caused by surface contamination, oil
or wax, even in minute amounts. They can sometimes be caused by surface tension issues. Our Bio Clear 8100 (tm)
tabletop epoxy is a good example. If applied too thin over a very smooth surface it will fisheye. Some epoxies
will fisheye more easily than others. Some of it is chemistry but also thickness and fillers come into play.
The bad news is that when epoxies fisheye due to surface contamination there is no simple fix. Solvent washing
will not fix the problem. Presumably the solvents just move the wax / contaminants around. More epoxy doesn't help,
the fisheyes/craters just telegraph through the new layers of epoxy. I don't have an exact fix for fisheyes in
epoxy. It happens rarely and never seems to happen when I intentionally try to product it. My best fix ideas are:
1) sand down / remove all the fisheyes so the remaining level is flat. Then recoat. That MAY work.
2) 'Seal' the surface with traditional oil based spar varnish (which is getting hard to find in may areas of the country) then apply the topcoat of epoxy. I think that MAY work.
A leading cause of oil surface contamination affecting epoxies has to do with oil based stains used on wood. It
takes the 'oil' in the stains several weeks to dry or evaporate away so that it doesn't potently cause fisheyes
in any epoxy coat applied on it. It has happened to me (using our Low V epoxy) and I have had others report it
happening (using our marine epoxies, I think) but I have not been able to duplicate it when I wanted to test some
possible ways to 'fix' the fisheyes.
I have had reports of our Premium No Blush Marine epoxy fisheyeing over our solvent thinned epoxy sealer, ESP 155
which was applied to a raw wood surface. After some tests I speculate that the solvent thinned ESP 155 epoxy took
oils from the wood/subsurface to the top surface of the ESP155 (without having the thin ESP 155 fisheye itself).
But when the ESP 155 was topcoated with our Premium No Blush epoxy the Premium epoxy did fisheye. Interestingly
I didn't get any fisheyes when 1) using our Basic No Blush epoxy on top of the ESP 155, 2) when I used several
coats of the ESP 155 under the Premium No Blush epoxy, 3) When I repeated the tests using glass instead of wood
under the ESP 155.
------------------------
Reports of Premium No Blush epoxy fisheyeing when applied over ESP 155
- see fisheye.html .
Reports of alkyd enamel drying issues when applied over ESP 155 - see enamel.html .
###
Knowledge is Power - We like informed consumers!
Learn the basics of epoxy at our educational EPOXY 101 page - Click Here.
Finally, email us back with your questions or comments before you buy - EMAIL HERE
Understanding The Difference Between Floor Paints, Wall Paints, and Basic Marine Type Resins/Epoxies -- CLICK HERE