Spraying Epifanes

Anything that doesn't fit into the other Physical Systems categories
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GeoffSchultz
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Spraying Epifanes

Post by GeoffSchultz »

Has anyone had any luck spraying Epifanes varnish? I've been using an HVLP to spray both the high gloss and rubbed effect varnish and am getting "orange peel".

-- Geoff
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1997 Freedom 40/40
http://www.GeoffSchultz.org

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THATBOATGUY
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Re: Spraying Epifanes

Post by THATBOATGUY »

When you figure it out I'd love to add it to my bag of tricks. When everything is right it makes a great finish.

George
George and Kerri Huffman S/V Marquesa Freedom 40 CC CK Sail MarquesaImage

katorpus
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Re: Spraying Epifanes

Post by katorpus »

The air has to be totally dry. If there's no drier on the compressor downstream of the tank, that's likely your problem.

Compressor oil can also play heck with the finish.

I have a friend who has had great luck using an airbrush setup...less overspray, great control, easy to lay on proper coats...tiny oil-less compressor...less equipment to clean up.

You can buy the whole setup for not-much at Harbor Freight (not spam here, I own no interest, and a lot of their stuff is cheaply made junk, but it's a good place to buy light-use tools that you might not otherwise lay out the bucks for).

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GeoffSchultz
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Re: Spraying Epifanes

Post by GeoffSchultz »

This is an HVLP and there are no compressor tanks. It has a 4 stage turbine and runs at 6-8 PSI.

-- Geoff
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1997 Freedom 40/40
http://www.GeoffSchultz.org

katorpus
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Re: Spraying Epifanes

Post by katorpus »

Wet air in...wet air out

And maybe the atomization process is driving off too many of the volatiles in the varnish

And maybe the atomization is foaming the varnish...the same thing can happen with brushed varnish if you shake it instead of stirring

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GeoffSchultz
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Re: Spraying Epifanes

Post by GeoffSchultz »

Considering that I'm spraying this in New England in February, I don't think that wet air is the issue. Freedom used to spray Epifanes and the finish was wonderful. I suspect that my major issue is viscosity, but I was hoping to find someone who has done this and come up with a "factory finish" result.

-- Geoff
BlueJacket
1997 Freedom 40/40
http://www.GeoffSchultz.org

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Castaway
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Re: Spraying Epifanes

Post by Castaway »

Sometimes you can get "orange peel" effect from too thick coatings; water in the air supply is more likely to leave randomly spread 'holes' in the finish. We had that problem when the boat was spray painted last year, and it all had to be re-done. Try moving the spray gun faster to get a thinner coating, or using a lower flow rate from the turbine. Viscosity is critical, so it would be worth actually measuring it, and adjusting any thinners used.


Good luck.
Gerald Freshwater,
s/y 'Castaway', (UK F35 cat ketch, centreboard, 1987)
Lerwick Boating Club
Shetland Isles, Scotland

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GeoffSchultz
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Re: Spraying Epifanes

Post by GeoffSchultz »

I am thinning it with Epifanes thinner for spraying. I just suspect that I have to thin it a lot more than I have been.

Based upon some info that I just found, using a viscosity DIN cup with a 4 mm hole, it should take 20-24 seconds to drain. It appears that they're suggesting a 15-20% thinning.

Now, my HVLP suggests that using the viscosity cup provided, which is equivalent to Zahn #2 (which is a 2 mm hole????), it should take 18-24 seconds for the cup to drain to obtain a usable viscosity.

On Wikipedia, I found the following formulas for viscosity:

* Zahn Cup #2: ν = 3.5(t - 14)
* Zahn Cup #4: ν = 14.8(t - 5)

Using an average of 22 seconds for the 4 mm hole, that places the viscosity at 251.6.

Using an average of 21 seconds to achieve the recommended viscosity for the HVLP sprayer, that would place the viscosity at 24.5.

That's basically a factor of 10 apart! I don't know if viscosity is linear or logarithmic, but clearly they're a long way apart, and I don't understand the differences.

Any help in understanding this would be appreciated.

-- Geoff
BlueJacket
1997 Freedom 40/40
http://www.GeoffSchultz.org

katorpus
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Re: Spraying Epifanes

Post by katorpus »

Geoff

Maybe this (and the associated links) will help

http://www.flexoexchange.com/gorilla/ce ... conds.html


Where are you spraying this in New England in February? Obviously, the temperature of the product and the surface being sprayed are critical here. Have you moved your boat indoors?

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GeoffSchultz
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Re: Spraying Epifanes

Post by GeoffSchultz »

I talked to the "experts" at Apollo (who makes the HVLP sprayer) and they suggested that I go to a 2 mm tip and a different air cap (which directs the air at the liquid exiting the tip). They also suggested that I thin the Epafanes until I got 45 seconds thru their viscosity cup. The parts are on order from CA, so I'll let you know once I get them and try them.

-- Geoff
BlueJacket
1997 Freedom 40/40
http://www.GeoffSchultz.org

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