Outboard Painting

JimS123

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I do all my painting in the Winter, inside, with a temp of ~70 F. "Outside" can be a chore. Even a very slight breeze screws things up.
 

cprodave

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I do all my painting in the Winter, inside, with a temp of ~70 F. "Outside" can be a chore. Even a very slight breeze screws things up.
I am going to hold off any spray painting until warmer weather, then do it outside when wind is calm. I have only 2 or 3 small jobs to paint. However if i ever broaden into more extensive painting, it is good to know what precautions I should take. Thanks.
 

cprodave

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Update: i stopped by my nearest/reputable marine supply store last week. They are unable to buy/stock zinc chromate any more--can order zinc phosphate, though. Apparently paints containing hexavalent chromium are now banned/unavailable.
Which leads to this question: would Ospho Coat facilitate adhesion of normal rattle can paint to my aluminum props (and aluminum engine blocks)? I do realize that Ospho has no zinc...but i have a bottle of Ospho sitting around from previous project. Would be nice to put this bottle to good use, avoid another soray can sitting on the shelf (I have limited storage space, my wife keeps reminding me.)
 

dingbat

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The zinc based primer is to protect the aluminum in case the coating is compromised.

If you don’t use zinc for its sacrificial properties then any primer will do. Used Rustoleum primer and paint on my aluminum props for years.

A good sanding, then primer and paint will do
 

ahicks

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I'd like to find a process that is gas proof, without spending a fortune in time and money. I've found the Dupli Color paint colors I need to allow touch up, but even if it's been applied carefully and dried for weeks or months, it will lift if you get any gas on it. Not a big deal for many I suppose, but I like to drain the carbs prior to putting a motor away, and that's going to wet the lower unit at the very least....
 

JimS123

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While the zinc rich primers offer a certain amount of corrosion resistance, the main reason for their use on aluminum is to ensure that the paint sticks. I haven't been able to buy chromate in years in my state, so I'm not surprised you can't find it either.

Go to an Auto Parts store and buy their acid-etching auto primer. It's an outboard guy's second best choice.

No rattle can paint is gas proof. Some are gasoline resistant. My best luck has been with Dupli-Color ceramic auto engine paint. Spill gas and wipe it right up and you're OK. Just don't let it sit there too long. Adding hardner or using epoxy is what's needed for gas proof.
 

gm280

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Use quality automotive type paints with a hardener mix. It will be gas and oil proof...period!
 

ahicks

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Thanks guys, but the suggestions are going a bit beyond the "touch up paint" concept. We'll just keep going with what we have. I thought maybe I had missed something....

What about hitting a touched up surface with clear urethane to fuel proof it?
 

JimS123

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Thanks guys, but the suggestions are going a bit beyond the "touch up paint" concept. We'll just keep going with what we have. I thought maybe I had missed something....

What about hitting a touched up surface with clear urethane to fuel proof it?
If you are referring to suggestions to use a hardened paint, and of course having to buy professional spray equipment, I understand.

If you are looking for cheap, quick and dirty, just go to Wallyworld and buy a $4.99 can of spray paint that is the closest match. If there is a spot that is down to bare metal, pre-prime it with the Wally primer made for all metals.

If you want it to last a little longer, buy auto store Duplicolor acid etching primer. If you want the color to match, IBoats sells outboard engine matching colors.

Clear urethane will fuel proof it, but you'll need hardener, professional equipment, etc.

An old Engineering professor once told me: "You can have it fast, you can have it cheap, or you can have it good. Or, pick 2, but you can't have all 3".
 

gm280

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I hear so many talk about "going cheap" when talking about paints and such. And so many also talk about not having the equipment to do "professional" painting jobs. Well a mere $20 or less HF touch up gun and a cheapie air source is really all anyone needs for touch ups. Then buy a pint of any color automotive paint you like with hardener and have at it. It really isn't that costly and will certainly do the job, if you want to... I can buy a pint of colored matches automotive paints and the hardener and make a touch up look flawless with very little effort and not much money involved. But anyone can always think of a reason to not do such things... And remember, the cheap air gun you buy will be there for future painting jobs, if you clean it up after painting. So it all is basically a one time purchase. JMHO
 

JimS123

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I hear so many talk about "going cheap" when talking about paints and such. And so many also talk about not having the equipment to do "professional" painting jobs. Well a mere $20 or less HF touch up gun and a cheapie air source is really all anyone needs for touch ups. Then buy a pint of any color automotive paint you like with hardener and have at it. It really isn't that costly and will certainly do the job, if you want to... I can buy a pint of colored matches automotive paints and the hardener and make a touch up look flawless with very little effort and not much money involved. But anyone can always think of a reason to not do such things... And remember, the cheap air gun you buy will be there for future painting jobs, if you clean it up after painting. So it all is basically a one time purchase. JMHO
I can't say I disagree with you, but no matter what subject you talk about someone will say its too expensive, while another will say its cheap.

Let's see, Gun for 20, lower priced compressor 80, hoses and fittings, 20, pint paint 40, 1/4 pint hardener 20....=....$180.00. Or, 2 cans wally @ 4.95 = $10 bucks.

We'll let the OP decide...
 

gm280

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I can't say I disagree with you, but no matter what subject you talk about someone will say its too expensive, while another will say its cheap.

Let's see, Gun for 20, lower priced compressor 80, hoses and fittings, 20, pint paint 40, 1/4 pint hardener 20....=....$180.00. Or, 2 cans wally @ 4.95 = $10 bucks.

We'll let the OP decide...
Harbor Freight small gun can be bought for $10 or even less with coupon. And while I don't have such a gun, I have read many reviews that claim they are pretty good. A pint of paint around maybe $15 to $20 dollars or even less if you go the Rust-Oleum or even store brand paints. Most people know of a friend or family member with a compressor with hoses. Hardener IDK the true cost off the top of my head. But you would use very little and left overs for the next project. So it really all depends on the individual if it cost too much or worth the deal. But that is how most people determined buying most anything. Owning a boat is a hobby, for the most part. You just have to figure in if it is worth it... Certainly not trying to talk or debate anyone about this, only offering a point of view.
 

ahicks

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Here, it's not about the expense so much as it is the time it takes to do a quality job. Maybe not "so many say" but this person has learned if you're going to do a quality job, you can't spray over poor prep work.

Even an inexpensive gun needs to be cleaned too....

I work on Honda's for the most part. Rustoleum can't get close to that fine metalic color even when judged from 50'.

Bottom line, I have the equipment to lay down decent paint work, and the experience, but I don't want to invest the time it takes to do one. Think priorities....
 

gm280

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Here, it's not about the expense so much as it is the time it takes to do a quality job. Maybe not "so many say" but this person has learned if you're going to do a quality job, you can't spray over poor prep work.

Even an inexpensive gun needs to be cleaned too....

I work on Honda's for the most part. Rustoleum can't get close to that fine metalic color even when judged from 50'.

Bottom line, I have the equipment to lay down decent paint work, and the experience, but I don't want to invest the time it takes to do one. Think priorities....
I can totally appreciate that...
 

ct1762@gmail.com

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Well i took pretty much everyones advice and the half dozen or so cowlings i've done this winter came out great. I did learn the power of sanding... getting that surface smooth, applying primer, sanding again gets the paint to pop. i tried clear coat, but it seems to me if the paint isn't really smooth, it will actually look worse than before (hazy). I did use clearcoat like regular spray paint to prevent runs, but ill try to go on thicker as an experiment.
 

gm280

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Well i took pretty much everyones advice and the half dozen or so cowlings i've done this winter came out great. I did learn the power of sanding... getting that surface smooth, applying primer, sanding again gets the paint to pop. i tried clear coat, but it seems to me if the paint isn't really smooth, it will actually look worse than before (hazy). I did use clearcoat like regular spray paint to prevent runs, but ill try to go on thicker as an experiment.
Seem YOU have now learned that if you want a very nice finish, you have to do the prep work to get that finish. The final top coat color is the easiest part. The prep is where all the work happens. If you can see it or feel it, it will show up in the final finish. Paint does not cover over any flaws and makes them go away. I've been there and sadly learned that lesson way way long ago. But once you understand that, you can work and rework the prep until it looks perfect. Then paint and if you want it to pop, clear coat and buff and polish the clear coat. Amazing to see how buffing and polishing makes an acceptable finish a show piece.
 

cprodave

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Seem YOU have now learned that if you want a very nice finish, you have to do the prep work to get that finish. The final top coat color is the easiest part. The prep is where all the work happens. If you can see it or feel it, it will show up in the final finish. Paint does not cover over any flaws and makes them go away. I've been there and sadly learned that lesson way way long ago. But once you understand that, you can work and rework the prep until it looks perfect. Then paint and if you want it to pop, clear coat and buff and polish the clear coat. Amazing to see how buffing and polishing makes an acceptable finish a show piece.
If i am painting an aluminum prop using either zinc phosphate bbn or Rustoleum self-etching primer do i need to sand down the entire prop to bare aluminum? There are some areas where the original paint is well adhered and almost impossible to sand off with SiC paper. I am trying to feather-out areas between bare aluminum and original paint.
 

JimS123

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If i am painting an aluminum prop using either zinc phosphate bbn or Rustoleum self-etching primer do i need to sand down the entire prop to bare aluminum? There are some areas where the original paint is well adhered and almost impossible to sand off with SiC paper. I am trying to feather-out areas between bare aluminum and original paint.
I'll second that about prep work. If you have original paint you won't need to etch prime that. The bare spots will need it, though.

The issue is the feathering. I have not been too successful in that regard. Any time I tried I always saw a hump after it was painted.

I never sand a prop until the end. Paint remover will take off the paint in a jiffy.

Rustoleum self-etching is good. I used chromate years ago when it was legal, but I never tried the zinc phosphate.
 

cprodave

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I'll second that about prep work. If you have original paint you won't need to etch prime that. The bare spots will need it, though.

The issue is the feathering. I have not been too successful in that regard. Any time I tried I always saw a hump after it was painted.

I never sand a prop until the end. Paint remover will take off the paint in a jiffy.

Rustoleum self-etching is good. I used chromate years ago when it was legal, but I never tried the zinc phosphate.
So to avoid leaving humps i will remove all original paint. Do you use paint stripper (like methylene chloride or newer less toxic formulas) or something different as a paint remover?
 
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