Spray painting

Can the Panel please advise ~FootyCat has developed an orange peel look when I put on another coat of grey primer!

I had previously primed her and as usual then discovered some blemishes I needed to attend to so this evening I did just that and sanded everything down with 180 then 220 and then 600 grit to achieve the desired feel.

I then wiped the hull down with a clean dry plain paper kitchen towel set up the spray area and gradually layered the first dusting that looked ok however when i came to do the next dusting the reaction took place

I have not experienced this before so looked in the FAQ section and could not find any thing there either.

What did I do wrong?
What do I do now?

I know i could leave the effect and give it a top coat of Tropical Orange and start playing the tin drums but I’m not sure what it would do the hydrodynamics

Rgds
AndyT

golf balls are dimpled…so it may help…:)if its on the deck surfaces consider it a non-skid surface for the hamsters… you hid e your boat

I used to get fish eyes (little bits of oil) and alligator, which is when the acetones in the clear coat spray would react the painted surface causing the paint to lift from the primer.

Gloss paint sprayed on a smooth surface (such as the body of a car) should also dry into a smooth surface. However, various factors can cause it to dry into a bumpy surface resembling the texture of an orange peel. The orange peel phenomenon can then be smoothed out with ultra-fine sandpaper, but it can be prevented altogether by changing the painting technique or the materials used. Orange peel is typically the result of improper painting technique, and is caused by the quick evaporation of thinner, incorrect spray gun setup (e.g., low air pressure or incorrect nozzle), spraying the paint at an angle other than perpendicular, or applying excessive paint.

I’d leave it try to sand/polish it out with some 2000 grit and water…

It usually happens when a cellulose acetate (acetone solvent) or 2-part polyurethane paint is applied over an enamel (white spirit based paint). With successive compatible layers it shouldn’t happen.

Stop buying your wife those paper towels with the hand lotion in it. :smiley:

Otherwise, remember to use wax & grease remover before painting anything.

In addition to Martin’s note, read the instructions on the paint can.

Some paints can be multicoated before 1 Hour - OR - AFTER 24 hours.

Orange peel can happen with most any paint (other than waterbased) as the hardeners/driers in the fresh coat attack the original coat which has not had time to fully harden.

Ihave eliminated this by spraying light coats many times - then allowing at least 3 days to dry/harden. I also found that clear coat has some thinners in it that seem more aggressive in attacking the first and subsequent paint layers. I’m shifting from clear coats that use thinners, to water based claer polyurethanes that even when brushed on have some nice, self-leveling properties.

Look for the toluenes as they seem the harshest of the bunch.

like dick Ive gone to the brush-on clears or gone to the extreme of pouring the clear on the part letting it drip some and then start rotating it so the drips and sags don’t appear. works well on rudders and keels, put em in a drill dip em and then turn the drill on a slow speed.

end up with a much thicker coat than you need, probably. but I’ve ruined more paint jobs with spray laquers than I can count. the soling hull can only be sanded so much before you break through…:scared:

Hi Andy,
If you had already sanded it with 400 grit or finer, adding more primer will leave the surface rougher than it would be after it was sanded with the 400 grit. Maybe there is a bit of undercoat attacking going on if there was insufficient drying time for the most recent coat of primer, maybe the first coat of paint was applied too dry resulting in a texturing effect, or maybe there was too much time elapsed between the first finish coat and the subsequent coat, and the paint didn’t flow out properly. If your finish coat is a lacquer, the temperature and humidity can also radically affect drying times. Orange peel is a frequent problem with spray cans, since you have no control over the ratio of solvent in the mix. When I used to paint with a spray gun, I found that adding more solvent to the mix with subsequent coats allowed them to “flow” out as the solvent flashed off (evaporated), resulting in a wet, glass-like look. The final coat was mostly solvent, and was applied just under the threshold of having it “run” (do not try this when applying lacquer over enamel). If the orange peeled paint is allowed to cure completely, you should be able to wet sand (just don’t break through to the primer) and re-coat. If it’s not too bad, you may be able to wet sand and then use rubbing compound without the re-coat, but there’s a greater chance of breaking through to the primer. Some enamels take a very long time to cure enough to be able to sand without the surface “gumming up”, wet sanding helps prevent this.

Good luck,
Bill Nielsen
Oakland Park, FL USA

With can spray paint the orange peel effect can come from not shaking the can long enough to mix the ingredients completely, in which case the lighter solvents will be released first. I double or triple the recommended shaking time printed on the can.

I wet sand my hulls with 600 grit anyway as gloss coats look nice but in theory don’t go as fast.

I switched to water based colors from autoaircolors.com with a 2 part acrylic enamel with PU hardener added over the top. The water based stuff was great to work with and dried within minutes with a hair dryer. It is a flat finish but is designed to have the clear over it anyway. A quart of automotive clear and hardener will last a dozen boats or so, wet sands and polishes out to a super smooth, glossy finish.

I repeat, I wet sand my hulls with 600 grit anyway as gloss coats look nice but in theory don’t go as fast.

The theory is that a non-gloss finish holds a layer of water against the hull which acts somewhat like a lubricant, breaking the surface tension of the water that flows by the hull thus reducing drag. One of the tricks that became outlawed in the America’s Cup was to apply a special film that performed the same function. I believe that it in turn was an attempt to emulate a dolphin’s skin. The dolphin evidently has striated muscles running diagonally under its skin. The effect is to allow the dolphin to swim faster than its body shape should allow.

I know it’s probably late in the process but here is a good article for those wanting a good paint job.

It’s from the SeaWind Newletter but both of us that wrote the article are sailing the Footy NCR

http://www.seawindrc.com/us-scoa/documents/SWE_10.pdf

It’s the tech article on page 5:zbeer: