Newbie = Hull painting advise needed

[FrankyB]

Hello - I purchased a '89 Fourwinns 315 vista that I planned to paint and modernize the look of the boat by painting the hull a dark blue. After failing to find someone to paint the boat at a budget that I could afford, I decided to undertake this project alone. I have gotten myself in a pickle many times along the way but have learned immensely. I now need some guidance on how to get some deep scratches out of the paint that I inflicted while sanding. Here are the notables: ​I used Epihanes monourethane paint. Primed it using their primer, than rolled and tipped 3 coats of the finish, sanding in between but not liking the finished look. Re-sanded the boat and elected to learn how to spay the boat, spraying 3 coats of the finish. This paint is a very "sensitive" paint to any moisture in the air or drop in temperature, and takes a long time to cure. What I was left with was some nicely painted areas and some that resulted in a lot of "orange peel." I've wet sanded the finished coat using a DA sander and a lot of 1000 and 1500 grit paper and then used the 3M method of buffing the finish to a mirror like surface. Pictures forthcoming.

Here is my dilemma, I lost my patience on some heavy orange peel areas using a lot of 1000/1500 g paper that I decided to try wet sanding it using 800g. The 800g did flatten out the orange peel but left some deep scratch marks that using 1000/1500g will not take out. Should I continue trying to get them out with the 1000/1500g paper or do I need to re-sand this area with the 800g to get it consistent and then re-sand with the 1000/1500g? I don't want to create more problems than I already have...thanks for your help. Frank

 

[ondarvr]

Wet sanding by hand is more aggressive than with a DA when using the same grit paper, so hand sanding scratches will be deeper and more difficult to remove. You just need to continue sanding until the scratches are gone without inflicting more damage.

 

[gm280]

Sure wish you provided some pictures. It is really hard to see what the "deep scratches" looks like without any pictures to go by. At this stage your only option is to use the 1000 grit and wet sand until one of two things happen. First you remove the "deep scratches" and then finish polishing to a nice finish. The second option is wet sand until you sand through thereby making you reshoot that area without orange peel.

Painting is a finicky business and there are no one-way options to accomplish things some times. You have to improvise to get things done like you want. And every situation has to be tailored to its needs to work. JMHO!

Need pictures for better suggestions and ideas. At least I need to see pictures for that! :noidea:

 

[FrankyB]

No Title

This is so weird as I did attach pictures and saw them on the post earlier....hmmm....here they come again. I'll post a pic of the "deep scratches" tomorrow once back at the boat.

 

[gm280]

FrankyB, the orange peel actually looks like there was something on the surface that didn't allow the paint to stick. It looks like there was some wax, oil or silicone or something that didn't work with the paint. Did you wash the surface down with either Acetone or Lacquer thinner before painting?

 

[Woodonglass]

I agree about the prep work. Glad to hear your used their primer but even so as you said conditions always dictate results. Soooo many variables will dictate the outcome. If you follow the exact mix ratio's of the MFG and the conditions are optimum for painting and curing and the Prep is done correctly then you should expect satisfactory results. Any variance from those conditions will/could cause changes in the outcome. What Spray equipment did you use. Was it properly filtered to ensure no contaminants were introduced into the paint at the time of spraying??

 

[FrankyB]

FrankyB, the orange peel actually looks like there was something on the surface that didn't allow the paint to stick. It looks like there was some wax, oil or silicone or something that didn't work with the paint. Did you wash the surface down with either Acetone or Lacquer thinner before painting?

Yes, followed paint manufacturer's directions. They stated to use a cleaner before sanding and then denatured alcohol between sanding/coats. This has been primed and followed by 5 coats top coat (3 rolled/tipped, 2 sprayed). My conditions were not perfect as I sprayed outside. I used a HVLP gun and did use filters though not commercial quality.

Given where I am at, can I still wet sand these down? Note picture 4 or 5 that has the mirror reflection. That surface looked the same with orange peel until I sanded it flat and then buffed it out. Appreciate the help from all of you!
Frank

 

[gm280]

Yes, followed paint manufacturer's directions. They stated to use a cleaner before sanding and then denatured alcohol between sanding/coats. This has been primed and followed by 5 coats top coat (3 rolled/tipped, 2 sprayed). My conditions were not perfect as I sprayed outside. I used a HVLP gun and did use filters though not commercial quality.

Given where I am at, can I still wet sand these down? Note picture 4 or 5 that has the mirror reflection. That surface looked the same with orange peel until I sanded it flat and then buffed it out. Appreciate the help from all of you!
Frank

FrankyB, At this stage of the paint project, I'd say yes, do keep wet sanding to see if you can flatten the surface before sanding through. What else can you do then try? If you sand through, shoot another coat. JMHO!

 

[Woodonglass]

What kind of Gun? What Nozzle Size? What Paint/Reducer Ratio?

 

[harleyman1975]

Keep on sanding. I knock the orange peel or dry spray down with 800 on a D/A and I do it dry. If the paper starts to ball up with little balls of paint stop and put on a new piece! (otherwise you'll get pig tails) If it happens right a way then it is not fully cured. (a new piece of paper should last at least 3-4 minutes before it starts to ball up. Next I dry sand with 1000 followed by 1500 dry then I go to 3000 wet and a final buff with Meguires diamond 2X. 3m and Norton (and I'm sure there are others) both make dry sanding paper.

 

[FrankyB]

Woodonglass - i'll have to look at the gun and the nozzle.....I do recall that I purchased the exact nozzle the manufacturer advised and I shot it at 20 psi (trigger wide open). I used a 15% reducer (manufacturer's advise and product). I'm leaving town in the morning for a week so I won't have the other info until I return home.

 

[FrankyB]

Thanks Harleyman, I may end up going that route on the other side of the boat. Ondrvr struck a chord when he said hand sanding is more aggressive than using a DA. SO....I tried block wet sanding with 1000g today and it is both taking out the orange peel and the deeper 800g scratches. What a smile that brought to my face! What I also found interesting is the grit on the 1000g wet/dry sheets also felt grittier than the grit on the 1000g 3M round 5" hookit. They also seem to last longer. Maybe Its the placebo effect and I wanted it to feel that way ..lol. Just happy its turning towards the better!!
Frank

 

[Woodonglass]

20 psi seems a bit low. Kind of hard to get proper atomization at the low pressure.

 

[FrankyB]

My bad - should have been 40 psi

 

[Woodonglass]

Ahhh, OK, that's more like it!!! Orange Peel has a lot of causes. You're getting good advice as to how to deal with it.

 

[gm280]

FrankyB, the reason wet sanding works so well is because the water helps wash off everything you sand off. Dry sanding can plug paper a lot quicker. But water washes off want you sand and therefore the sandpaper goes a longer way. So there is a difference when using wet sanding vs dry sanding with the exact same grit. JMHO!

And when you were spray painting, you stated you use 40psi. Was that at the compressor, or at the inlet of the spray gun? If at the compressor, you may need to up the pressure a little more, because by the time it gets to the inlet at the gun, it is a lot less. You can buy a inline gun regulator for a few bucks and set it at the gun for a better pressure regulation. It does make a difference. JMHO!