Stand build - How to get an even paint coat?

[woodnaquanut]

I've never used the tinted but I assume it works like the clear. Those guns should work fine. I don't thin. I believe they recommend you don't thin because it's a complicated chemistry to get lacquer in water and thinning will mess it up.

Dry time is dependent on heat and humidity. With our bay area weather being all 'June gloom' right now it might take a couple of hours. I spray a light coat in one direction then right away spray another at 90 degrees to that. I have a hard time judging coverage with the clear.

I'm no expert so I always spray on a horizontal surface to prevent runs.

 

[davocean]

Practice on a scrap board to get the feel for how heavy you can lay on and dry time.
I agree w/ woodnaquanut, cross pattern.
Like most I do not have a spray booth, so I set up a plastic drop cloth overhead to keep dust from coming down, I even spray the ground w garden hose gently to wet down any dust below, and I spray first thing in the morning to avoid wind.
If you mess up it's not difficult to let dry, sand w/ 220 and do it again, sometimes that even makes a more perfect finish.
Tack cloth wipe before spraying to remove any dust.
Good luck.

 

[ThRoewer]

OK, I got the paint and already applied two layers. The paint is clearly better but the striping issue remains. I think the issue is my spray gun - it simply can't apply enough paint quickly enough in one pass.
I have to be about 4" off the surface to get the paint hit the surface wet, and then the spot is only 2-3" wide. I could probably still get an even coat if I had an robotic arm, but keeping the right distance and staying perfectly on track is nearly impossible.

Also, the compressor runs out of air after a while even though it's rated 4.0 cfm and the air gun 3.9 cfm.

I will try a 3rd coat later and if that doesn't work I'm out of ideas.

 

[davocean]

Your compressor tank may be too small to hold enough air volume.
sand w/ 220 and try a cross pattern, opposite direction of what you have been spraying to eliminate striping.
And yeah, you pretty much do want to try to replicate a robotic arm!

 

[thejuggernaut]

OK, I got the paint and already applied two layers. The paint is clearly better but the striping issue remains. I think the issue is my spray gun - it simply can't apply enough paint quickly enough in one pass.
I have to be about 4" off the surface to get the paint hit the surface wet, and then the spot is only 2-3" wide. I could probably still get an even coat if I had an robotic arm, but keeping the right distance and staying perfectly on track is nearly impossible.

Also, the compressor runs out of air after a while even though it's rated 4.0 cfm and the air gun 3.9 cfm.

I will try a 3rd coat later and if that doesn't work I'm out of ideas.

Which gun are you using. 1.3mm is pretty small for thicker paints.

 

[ThRoewer]

I think I already found the problem - the gun needs to be further off even if paint only hits the surface semi wet.
Since it's satin, as soon as the paint gets too wet the surface will be shiny. I probably would have been better off with glossy.

 

[PhreeBYrd]

In general, to get a very fine spray finish on wood, spray your initial coats with minimal thinning. This builds the finish film (either paint or a clear finish) as quickly as possible. After 3-4 coats, wet sand with 400 grit and then remove all residue from the sanding. Spray the final 2 or 3 coats thinned to the maximum (usually 50%, but no more). Thinning the final coats allows the surfaces to wet much more quickly and uniformly, and with most finishing materials, minimizes orange peel and flashing. Spray tip size is very important. The thinned coats should use a smaller tip orifice, which will allow better atomization and reduce the possibility of runs or sags. Too small an orifice, even with some thinned materials, will cause flashing. Make sure your tip sizes are as recommended by the manufacturers of your spray equipment and finish material... or try several tips until you find the one that works best for each coat.

In the best case, heavy material sprayed through too small a tip causes the material to dry before it flows out on the surface, resulting in orange peel or blotchiness. In the worst case, the finish will sputter, resulting in a complete mess.

You might need to do a final polishing after all of the finish has cured. Polishing will remove any minor patchiness you find in the finish.

And as a general rule, gloss is much better for a first rate finish than satin. You can always reduce a gloss sheen, but you can never polish up a satin or semi-gloss sheen beyond a certain point.

And a lot of variables come into play that no amount of advice can address. Air/fluid mix ratio, air pressure, tip pressure, orifice size and type, and your spraying technique all interplay with each other. Sometimes it just takes a lot of practice to find what works best for you and for your equipment and materials. Don't give up. Keep practicing and making small adjustments to your settings and technique. You'll get there.

 

[woodnaquanut]

I agree with everything PhreeBYrd said except the thinning. IIRC, you are NOT supposed to thin the Target Coating product.

To get my technique dialed in I sprayed water on cardboard. That way I could see the pattern, flow amounts and my overlap. It takes practice to get the settings correct. Try adjusting the flow and pressure to get a better spread. Also work on keeping the gun perpendicular to the surface and moving it at a steady pace. It might help to sing 'Mr. Roboto' to yourself while spraying!

 

[38bill]

About two years ago I painted a stand I made for my BC29 using the same paint (Rustoleum Satin Black oil) and I couldn't be happier with the results. I thinned it with acetone per Rustoleums instructions and sprayed it with a home grade HVLP gun. Built up the coats with sanding in between and then after the final coat and super fine sanding I rubbed it out with 0000 steel wool. Dont try to get a super smooth final coat, let the final sanding and rub out do that. I did mine outside in the sun to help it dry faster. It also helps if you can spray the surfaces while they are horizontal so the paint doesn't run. Don't get to worried over bugs in the final finish as they should sand and rub out.

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[ThRoewer]

I didn't thin the Target Coating paint since it is already optimized for spray application (the Rustoleum isn't).
What I like most about Target is that it dries very fast to the touch.
I'm getting ready to do another coat and hope this one can be the final one.

I've practiced with water, but since water has a very different viscosity than the paint it doesn't do too much good. So I usually try a few lines on a piece of Styrofoam.

The only other question is if I should add a clear coat or just let it be good with the Target Coting finish. I'm a bit worried about scratch resistance.

 

[ThRoewer]

OK, last coat came down pretty even. This time I sprayed from a larger distance so the surface never got "wet". That was the mistake before: to close.

Only downside is that the surface turned out slightly rough this way. I'm not sure if I want to sand it smooth and add another layer.

Also, will this coating be enough or should I add a clear protective coat?

 

[PhreeBYrd]

I didn't thin the Target Coating paint since it is already optimized for spray application (the Rustoleum isn't).
.
(snippage)
.
The only other question is if I should add a clear coat or just let it be good with the Target Coting finish. I'm a bit worried about scratch resistance.

No finishing product is ever or can ever be perfectly optimized. Equipment, weather conditions, project conditions are all infinitely variable. The best the manufacturer can do is to try to find the optimum solution for the largest possible percentage of its customer base.

From Target Coatings EM6000 data sheet:
"3. EMTECH™ Lacquer can be sprayed without reducing with
water or Target SA5 Spray Retarder. However, additions of
SA5 Retarder may be required to slow-down the system if
the lacquer is drying too quickly during high temperature applications.

4. Reduce EMTECH™ Lacquer upwards of 50% with water if lacquer
is to be used as a pre-stain sealer or tie-coat between
stain or dye coats to prevent color bleed. Using EMTECH™
EM1000 Universal Sanding Sealer will also work as a pre-
stain sealer or intermediate coat prior to using EM6000."

Clearly, Target does not prohibit thinning or even advise against thinning their products (if they did, they probably would be the first to do so). The full EM6000 Tech Data Sheet is here:
http://targetcoatings.com/wp-content/uploads/2014/10/TC_TechDataSheet_EM6000_R3.pdf

The fact that they make a proprietary spray reducer should be evidence enough that Target Coatings is aware that the standard product viscosity is not always ideal. And for what it's worth, spray reducers for waterborne finishes are typically simply distilled water with a small amount of surfactant added to promote flowout.

As for durability, the cured product is extremely tough and hard. Spraying a coat or two of clear finish over the top of the tinted coats will indeed add much depth to the finish and will protect the tinted coats underneath. If you decide to go this route, use only the same Target product in the untinted, gloss version. Their post-catalyzing cross-linker additive is probably not necessary, but it's another option for maximizing finish durability.

 

[PhreeBYrd]

OK, last coat came down pretty even. This time I sprayed from a larger distance so the surface never got "wet". That was the mistake before: to close.

Only downside is that the surface turned out slightly rough this way. I'm not sure if I want to sand it smooth and add another layer.

Also, will this coating be enough or should I add a clear protective coat?

This is what I referred to in a prior post as "flash". You sprayed too too lightly, from too great a distance, or at the wrong fluid viscosity.

This coat must be sanded away and the piece re-sprayed.

When you're spraying correctly, the surface will be wet, but not so thick that the coating sags or runs.

 

[ThRoewer]

OK, I sanded it and tried another more wet coat and it turned out stripy and uneven again. The paint is clearly too thick and dries way too fast.

I need to get this damn thing done, ideally this weekend, so getting their retarder would likely take too long.
What else could be used to thin the color and delay the drying?

 

[PhreeBYrd]

Although there may be additional issues, it does sound as though the material is flashing at the edges of your spray application, which can leave an uneven sheen. I assume you're using a fan spray tip. A cone tip might alleviate the issue. I need to go back through the thread to see what kind of spraying gear you're using. From the Target tech docs, this finish, like many other high-quality waterborne finishes, is not well-suited for a traditional spraying (low volume, high pressure) setup. Usually an HVLP spraying setup is far superior and recommended.

You could try turning the gun's air control down as much as you can without getting sputters. If you can switch to a cone tip, even better. Be warned that reducing the gun's air reduces it's ability to atomize, so if you go too far, you'll be in trouble.

You can use pure (distilled) water for reducing. It will most definitely slow the drying and improve flowout. I'd start by reducing 10-15% and see how that works. You can safely reduce to around 50/50, with some cautions.

Now, this is important:
If you feel like you've sprayed a thick enough finish film, you can stop spraying and just start polishing. A good polishing will absolutely remove the streaking you're seeing entirely. You want to do this by hand, not with some buffing machine, and you want to use the correct polishing materials (pumice, rotten stone, and thick felt pads). Automotive polishes may or may not work well and cannot be recommended. You need to let the finish cure for at least a week before you polish.

FWIW, the best finishes simply cannot be achieved without some polishing.

 

[ThRoewer]

OK, the last thinned coat came on even and has dried/cured now for a week.
So I think I'm ready for polishing. Which polishing products would be recommended and in which order?

 

[ThRoewer]

I tried to polish it:

1. wet sanded with 800 grit
2. wet sanded with 1000 grit
3. rubbed with 0000 steelwool and wax
4. polished with a polishing pad

The result was a surface that was very smooth to the touch but still looked shitty in strong light. The slightly rough "as sprayed" finish for sure looked better and more even.

I'm also not sure the Target Coatings paint is really suitable for saltwater by itself as even tap water leaves marks that can't be wiped off with a dry towel or even a wet one. So I tried 92% Isopropanol and guess what - it dissolved the paint surface :headwalls:

If I had not put so much effort and sunk so much money into it (let alone the completely messed up balcony) I would just scrap it.

I don't know what to do anymore...

 

[woodnaquanut]

I'm sorry you are having so many issues with this. I used the same product (in the clear version) for my kitchen cabinets, fireplace, mantel and tank stand. It's been bullet proof for me.

I've never tried to polish it. All my sanding was before the last coat. If you are trying for a very high gloss finish, I'd put on more coats, make sure each coat is thick enough (3 mils recommended) and wait a week or more before polishing.

Did you stir the product before spraying?

Did you let it cure before trying to polish? It reaches full hardness several days (100 hours) after final application.

Check out http://targetcoatings.com/wp-content/uploads/2014/10/TC_TechDataSheet_EM6000_R3.pdf for more info. The tests were done 14 days after application.

There is a product, CL100 Cross-Linker, that adds resistance to alcohol but since you probably don't use that around your tank, I don't think it's needed.

 

[ericarenee]

You do know Green (newly treated) Marine plywood will likely not hold paint and should be painted with epoxy or latex base paint if i Remember Correctly.

 

[ThRoewer]

I stirred it before use and let it dry/cure for a week.
I think this paint isn't meant for polishing - their instruction only ever speak of sanding before the final coat but nothing about it after.
The data sheet says that it will recover from denatured alcohol but the sanded film clearly didn't.

But even the top surface I didn't sand or polish was irreversibly stained by soap water that I let dry on it overnight.

Since saltwater is highly corrosive it will probably be a good idea to add the CL100. I only wish they had all those things listed on the actual product page so I could have ordered it all together. I feel their website isn't very well structured to find things you may need additionally.