Painting Scratches out of Yamaha Lower Unit

Green Mountain Grady

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Hi All,
Last season I wrapped a mooring cable around my lower unit and left some scratches in my new engine. Nothing too deep or bad but I wanted to repaint them before we put it back in the water. Any recommendations on prep and paint? Wet sand with what grit? Where did you find pain to match? Appreciate your feedback! Everybody stay healthy and practice good social distancing on your Grady!
 

wrxhoon

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Paint will cover 600 grit. Depending on how deep the scratches you can start with say 80 to 120 then progress to 320 and finally 600.
As I'm not in USA I can recommend brand of paint but I would use acrylic paint two pack is better lasting but harder to use and more toxic.
In any case use a mask when spraying outside or in a very well ventilated area if inside.
First you spray etch primer then the colour. You can go to any automotive shop give them a part of the engine and they should be able to colour match.
 

Ky Grady

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Hoon has you covered on sanding. Here's what I used for paint. Picked up both from my Yamaha dealer.

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seasick

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I am pretty sure that Zinc Chromate has been banned in many states, NY being one. It has been determined to be toxic and a carcinogen by the EPA. Or did I dream that?
 

wspitler

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Seasick, I believe you are correct about zinc chromate, but it is still sold here in FL. We used it exclusively on the aluminum in aircraft. I believe they still do as I see newly manufactured aircraft being test flown as "green."
 

seasick

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Yes, it is still allowed on aircraft but is not sold to the public in many states. That stuff really worked; The substitutes (zinc phosphate is one) , not as well.
For those who are thinking " Gee, I will just order from a company in Florida", they are not allowed legally to ship to areas that ban its use.
 

Ky Grady

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I picked that up in SC back in '17, it may be unavailable now, haven't checked.
 

ScottyCee

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As a former industrial hygienist at Boeing, I highly recommend NOT breathing the zinc chromate. Hexavalent chromium will really tear you up. Supply air respirators were required whenever that was used in the paint shops.

And yes, it works wonders on parts!
 

seasick

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As a former industrial hygienist at Boeing, I highly recommend NOT breathing the zinc chromate. Hexavalent chromium will really tear you up. Supply air respirators were required whenever that was used in the paint shops.

And yes, it works wonders on parts!
Good advice. I wonder what it says on the aerosol cans being sold as mentioned in some states. Probably the generic " use in a well ventilated area"
 

Fishtales

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That spray stuff never seems to last long on the lower units.
 

Legend

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Colorite.com sells the exact match for engines year. Mine is a 2017 and the color to order is 1585335658919.png They sell spray cans, touch up pens and touch up bottles of paint. I used a clear spray top coat and it matches perfectly.
 

SkunkBoat

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FYI....there are at least three different Yamaha BlueGray Metallic /DarkBlueish Gray..
I had all three of of them..third time was the charm...
Gave a box of spray cans to the new owner.
 

seasick

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That's pretty funny. I was never able to get a color match for mu 2001 yami without going to a body shop for a color match. So I picked some color, who knows what it was and just painted the mounting bracket and skeg with it. Heck, I don't see colors all that well normally.
 

wrxhoon

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You can never get a professional job with spray cans however it can be satisfactory for most people. Spay gun will give you a much better job, if done by an experienced sprayer you shouldn't be able to tell it was painted.
As far as colour goes, it's never going to be exactly the same even if it is colour matched by a pro but it will be close . Spay the repaired part of the leg ( obviously the lower part in this case) then blend further up , finally spray clear over the top cut back with 1200 if acrylic 1800 for two pack buff and polish and you will never know it was painted until you run in the mud/sand again.

Is it worth doing it like that? Depends how fussy you are I guess .For most guys I think not.
 

Ky Grady

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I painted from lower cowling down so at least it's all the same color. The side panels are a little off in shade but it's a satisfactory match for me. I had to get something on mine from boat living in Florida and hitting the sand bottom and lower unit being sandblasted to bare metal.
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