Outboard cowl paint help

sms986

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It's that time of year. I'm going over my boat and repairing everything that needs attention. This year I decided to redo my cowl. 99 Merc 90hp. I've got it stripped down to the glass and I'm repairing a few cracks and stuff. What kind of paint and primer should I be using for this? I am notoriously bad at rattle can painting and I want to make sure this paint doesn't scrape off with my fingernails. Doing all the proper prep work and I want to make sure I get the right paints to match the job. Any recommendations on what to get or what to avoid? Thanks!
 

Scott Danforth

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It's that time of year. I'm going over my boat and repairing everything that needs attention. This year I decided to redo my cowl. 99 Merc 90hp. I've got it stripped down to the glass and I'm repairing a few cracks and stuff. What kind of paint and primer should I be using for this? I am notoriously bad at rattle can painting and I want to make sure this paint doesn't scrape off with my fingernails. Doing all the proper prep work and I want to make sure I get the right paints to match the job. Any recommendations on what to get or what to avoid? Thanks!
get a primer and paint with a hardener.

rattle can paint is just solvent dry paint and not a catalyzed paint.

merc phantom black is just PPG Black. same as GM Tuxedo black and Rustoleum black.

I would get a quart of rustoleum, a bit of urethane hardener (from tractor supply and spray it with a $20 harbor freight spray gun. total job about $80
 

sms986

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Awesome! I have a spray gun but I'll get the paint and stuff from TSC. Thank you!
 

sms986

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Well I have no clue what I did wrong here. Mixed paint, catalyst, and a bit of acetone and it came out horrible. Absolutely horrible. I'm no expert with a spray gun, but I've definitely never had any issues this bad. IMG_20220421_192206877.jpg
 

Scott Danforth

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what gun are you using?
what tip?
looks like the gun was not set right, not enough air
 

sms986

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Central pneumatic hvlp. Had a wide fan (almost as wide as it could go), air turned all the way up at the bottom of the gun, and I messed with the fluid knob on a practice sheet which made no difference on the orange peel part. Had the air pressure up to 30psi spraying (max on the gun is 29) and made no real difference.
 

sms986

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What makes absolutely no sense to me is this. I sprayed the cowl and the back handle with the same batch of paint and at the same settings. Did the cowl then moved right over to the handle. The results are WILDLY different. I also sanded the cowl down today with 800 grit and tried again with a bit more acetone to thin. Same thing.
 

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merc850

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Maybe Acetone is not the proper thinner, I've always used Lacquer thinner.
 

Scott Danforth

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Central pneumatic hvlp. Had a wide fan (almost as wide as it could go), air turned all the way up at the bottom of the gun, and I messed with the fluid knob on a practice sheet which made no difference on the orange peel part. Had the air pressure up to 30psi spraying (max on the gun is 29) and made no real difference.
i use the Harbor Freight "purple" gun often. just used it moments ago with my drive. (rustoleum, hardener and acetone to thin)

turn your pressure up to 45psi. you need more air.

what type of compressor do you have?
 

Faztbullet

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Did you use a chemical stripper? Did you neutralize it before painting?
 

sms986

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@Scott Danforth you were right. I actually went up to 55psi spraying pressure in the end. I also switched from acetone to mineral spirits thinking maybe in the hot sun some of the paint was drying too fast. I sanded it down a bit yesterday, mixed up another batch, and sprayed it on. Still have a little bit of the previous coat texture showing through, but it looks much better and good enough for me. Only reason I'm painting it in the first place is because I re-glassed a 7"x4" chunk missing from the back of the cowl. Thanks for the help though! I didn't think it would turn out to be this big of a headache, but I'm a tiny bit wiser now.

@Faztbullet no, I sanded the whole thing dry and by hand...took hours.
 

Scott Danforth

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BTW, the harbor freight guns wear out fast. if you leave the tips in solvent, the inner tip will rust

Here was my spray yesterday. with the sun/temp at 88, it was kicking quick.
0424221400-1-jpg.359366
 

sms986

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@Scott Danforth I have no issue with buying cheap stuff and tossing it when it goes lol. That Looks really good though!

Here's my cowl all done up.
 

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