What to paint the lower unit of outboard with?

[bost0nwh@ler]

I painted my engine about a year ago, but the lower unit paint fell off. Is there a special paint to apply before you do a 2 part paint? I want to make sure this new paint is gonna hold up...

 

[GT1000000]

Re: What to paint the lower unit of outboard with?

Clean and prep the lower by removing any and all paint, preferably get it to bare aluminum...either by sanding or using a chemical type stripper...be careful not to damage any of the seals...
Then use a good quality Zinc Chromate primer under your choice of primer and paint...preferably good quality marine paint, but others have used everything from rattle can sprays to Rustoleum with hardener with very good results...
The secret to a solid finish is the prep...

 

[bost0nwh@ler]

Re: What to paint the lower unit of outboard with?

Ok thank you! Is the Zinc Chromate colored? Should I sand after applying that also? I am going to use mercury's OEM Paint. Do you know if they make silver OEM paint high gloss.

 

[ezmobee]

Re: What to paint the lower unit of outboard with?

Zinc Chromate is usually greenish. You only need a light dusting of the stuff and really only on the bare aluminum. I kinda disagree with my esteemed colleague GT100000 above on the stripping it down to bare aluminum. I'd just sand it thoroughly and feather out any chipped spots (unless the existing paint job is a total mess with cracking and peeling). I was able to find zinc chromate by Duplicolor at Pep-Boys pretty reasonably in a rattle can.

 

[gm280]

Re: What to paint the lower unit of outboard with?

GT1000000 is absolutely correct. I’ve seen his handy work and he knows what he is doing and I don’t hand out complements to just anybody’s work. Take the old paint off all the way to the bare metal. That can be accomplished with sanding, paint stripper, or I sand blasted mine. Then use Zinc Chromate as your first coat. I bought my Zinc Chromate at our NAPA auto parts store. It is a little pricey (around $13 for one spray can) but it is the best undercoat before your normal primer coat. Lightly spray the Zinc Chromate on and then spray your primer coat of the same manufacture of your top colored coat to make sure all the produces are compatible. I used different paints then GT1000000 did but it seems any quality catalyst type paint will work. Catalyst paint is any paint the uses a hardener additive to it. So in essence it is a two part type paint. I used PPG Shop Line produces (automotive) with a Catalyst Clear coats on top of the base coat. But others have used Rustoleum with hardener as well with great results. There seems to be no one way is best with painting an outboard... But just using a rattle can without any hardener will not stay as long as paint with hardener additive... Hope this helps you out some...

 

[bost0nwh@ler]

Re: What to paint the lower unit of outboard with?

I appreciate the feedback. The reason I am asking is because my previous paint job did not hold up well in the water. I will do this on the job and post some pictures when I am finished.

 

[zool]

Re: What to paint the lower unit of outboard with?

Im refinishing my volvo drives with the oem paint, then applying clear antifoul to the lower and intermediate...if you're in salt, might be a consideration for you.

Aquagard Alumi-Koat Spray Paint

 

[pauloman]

Re: What to paint the lower unit of outboard with?

use an aluminum filled mcu coating like Aluthane (google aluthane) - then enamel or poly on top.

 

[GT1000000]

Re: What to paint the lower unit of outboard with?

Zinc Chromate is usually greenish. You only need a light dusting of the stuff and really only on the bare aluminum. I kinda disagree with my esteemed colleague GT100000 above on the stripping it down to bare aluminum. I'd just sand it thoroughly and feather out any chipped spots (unless the existing paint job is a total mess with cracking and peeling). I was able to find zinc chromate by Duplicolor at Pep-Boys pretty reasonably in a rattle can.

I did forget to add that stripping all the way down to bare metal was assuming { and we all know what assuming can make out of us...} that the previous paint job was totally carpped...

EZ is absolutely correct, if the paint that is left on there is well adhered and not in terrible condition, you can just feather out the surface and apply a light dusting of the Zinc Chromate Primer to just the bare aluminum surfaces...

I will add that my personal preference is to use a good primer over the entire prepped surface to seal everything underneath and give a solid color foundation for your top coat...a good filler type primer can also be used to help fill any minor imperfections, sand and topcoat...

 

[Woodonglass]

Re: What to paint the lower unit of outboard with?

This ^^^ is good solid sound advice. As was stated before it's ALL about the Prep. Any Painter worth his salt will tell you to ALWAYS use primer. That's why they make it, to work in conjunction with the paint to ensure a proper chemical bond.

 

[Bwana Don]

Re: What to paint the lower unit of outboard with?

Moeller Marine Zinc Chromate Spray Primer from Wholesale Marine

Good price here for ZC spray cans. If it was mine I would strip it bare. Then do the washing, 50/50 water white vinegar, zin chromate, primer and finally color coat.

 

[Whalersailor18]

Re: What to paint the lower unit of outboard with?

It is imposible to replicate the factory finish that comes on the units. That finish is the most durable and best finish for the drive and in my opinion worth leaving alone if undamaged. Merc recommends that you spot sand and feather any areas that may be damaged or where corrosion from electrolysis has occurred. To each their own though, but why remove the best finish your outdrive is ever going to have and replace it with a rattle can finish?

 

[Pdevito]

I have 2 coats zinc primer.3 coats mercury black.2 coats mercury clear coat. Can i put vs721 on lower unit to help with algae?

 

[Chris1956]

Gee, that VS721 is pricey. Does it work better than antifouling paint suitable for aluminum?