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#1
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David,
In my experience, the chalk that I think you are describing is due to UV exposure (the sun). Epoxy coatings should be covered with several coats of UV resistant varnish. I think that Epiphanes has some of the highest resistance. The chalkiness is not just on the surface but all the way through the epoxy. If this is just on the deck and other exposed surfaces that have no structural strength value, just sand with 220 grit and paint it. If you want to finish the wood bright, you are going to have to sand down to wood and recoat with epoxy and then apply 4 or more coats of varnish. Charles |
#2
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Ervin, are you speaking to epoxy resin as opposed to epoxy paint? It is
understood that epoxy resin needs to be protected from uv. However David said his epoxy paint is getting chalky. I have experienced the same thing w/ Poly Poxy, which surprised me. I thought the pigment protected the epoxy. I can't see covering white epoxy paint w/ varnish. "Ervin Charles" wrote in message ... David, In my experience, the chalk that I think you are describing is due to UV exposure (the sun). Epoxy coatings should be covered with several coats of UV resistant varnish. I think that Epiphanes has some of the highest resistance. The chalkiness is not just on the surface but all the way through the epoxy. If this is just on the deck and other exposed surfaces that have no structural strength value, just sand with 220 grit and paint it. If you want to finish the wood bright, you are going to have to sand down to wood and recoat with epoxy and then apply 4 or more coats of varnish. Charles |
#3
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epoxy chalk
Hi all
anyone know the best way to remove the chalkeness that forms on epoxy paint over time, as i wish to to put the top finishing coat of paint on now. David |
#4
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Garland Gray II wrote:
Ervin, are you speaking to epoxy resin as opposed to epoxy paint? It is understood that epoxy resin needs to be protected from uv. However David said his epoxy paint is getting chalky. I have experienced the same thing w/ Poly Poxy, which surprised me. I thought the pigment protected the epoxy. I can't see covering white epoxy paint w/ varnish. The pigment protects the underlying finish, but it can't protect the surface. The good news is that a light sanding to remove the UV damaged surface is probably all that's necessary prior to painting. Paint it with something other than epoxy and you won't have the same problem again. |
#5
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sorry i should have been more specfic its the hull and deck on a 45' steel
boat i primed it with epoxy grey primer 12 months ago now i want to put the top coat of white polyurathane paint on but first i have to remove the chalkiness as you say caused by uv. i dont like to sand it as i may sand through the primer and was hopeing there was something i could wash it with thanks david |
#6
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david wrote:
sorry i should have been more specfic its the hull and deck on a 45' steel boat i primed it with epoxy grey primer 12 months ago now i want to put the top coat of white polyurathane paint on but first i have to remove the chalkiness as you say caused by uv. i dont like to sand it as i may sand through the primer and was hopeing there was something i could wash it with thanks I don't think you have much choice other than to sand. The chalky material is UV degraded epoxy that must be removed completely before paint. Otherwise, you're putting paint over a weak surface that will likely result in a poor bond. Think about it this way, you can either sand it now and possibly have to re-prime, or you can paint over it, end up with a bad and/or flaking finish and have to sand/scrape all of it off and do it all over again. Which would you prefer? When it comes to painting, preparation is key. |
#7
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Brian Nystrom wrote:
david wrote: sorry i should have been more specfic its the hull and deck on a 45' steel boat i primed it with epoxy grey primer 12 months ago now i want to put the top coat of white polyurathane paint on but first i have to remove the chalkiness as you say caused by uv. i dont like to sand it as i may sand through the primer and was hopeing there was something i could wash it with thanks -------------------- most modern epoxies don't chalk much anymore (but they do still yellow and loss their gloss). Used to be that chalking epoxies were called 'self cleaning' paint water tanks etc would have the dirty 'chalk' washed off when it rained - that said, I suppose you could waterjet the surface clean. I wonder if you'll find the post chalked surface as smooth as the pre chalked surface?? In not might affect the gloss of your 2 part poly. paul oman progressive epoxy polymers |
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