Corrosion questions

I have a 2002 MFS25A. The engine is primarily used in salt water and I thoroughly wash and flush and wash after each use. I have noticed some "paint bubbling" where the control cables exit the lower cowling (where the shifter would be if it were tiller). There is obviously corrosion below the paint. Also, the big piece of iron or steel that connects the top of the engine to the steering tube at the top is rusting badly around those 2 large studs and nuts.

I have already cleaned and treated the area around the top of the steering tube with POR 15. Should I remove the paint where it is bubbling around the lower cowl and treat that area with some zinc primer and touch up paint? Or just leave it? It's going to look like hell if I try and repair it.

Also, I ordered a can of touch up paint from Tohatsu and the color is off. It appears to be a shade or 2 lighter than mine like on the earlier 2 strokes lighter silver color. The early 4 strokes were almost a charcoal color. I have ordered paint from Moeller as well and had the same problem. The paint is metallic. But, just too light (not dark enough).

Regarding zincs. There is one on the bottom of the tilt bracket on the transom, one on the lower unit and one on the block. Should I remove all of these clean the area to bare metal where they meet and re-install? It seems they are not doing their job?

Also, a while back, I removed the lower unit to replace the water pump and oil. When I did, I sanded, primed and re-painted the entire lower unit. It looks great, but now I'm worried about corrosion on that as well. Should I remove the zinc steering tab and sand some paint off the lower unit underneath the tab? Or is the bolt a good enough connection to the zinc (metal to metal)?

You can clean, prep, prime, and re-paint the blistered area of the lower cowl. Personally, I use a 2-part etch, such as West System 860 to prepare aluminum alloy for primer.

There are currently three different paint colors available from Tohatsu America. The 2006 and newer newer "midnight black is actually called "aquamarine blue", and is available either as an aerosol or in a "nail polish" bottle. There are two different greys; one is for Nissan (only), and the other is for Tohatsu/Nissan: [h=5]TOHATSU/NISSAN SILVER/GRAY SPRAY PAINT[/h]

Description12 oz. spray can

Touch-up paint - Silver/Gray.

Matches Nissan "silver/gray" color for model years 2000~2006.
Matches Tohatsu "silver/gray" color for model years 1992~2006
Part #: 3B7723260M
List Price (MSRP): $17.75

and


[h=5]NISSAN CHARCOAL GRAY SPRAY PAINT[/h]

Description12 oz. spray can

Touch-up paint - Nissan Charcoal Gray

Matches Nissan "charcoal/gray" color from model years 1992~2000.
Part #: 99998D701M
List Price (MSRP): $17.75


The really-old blue from the 1980's has been discontinued.

As long as the fasteners for the anodes are clean, that should be enough conductivity.

Thanks for the input. I'll go ahead and tackle that corrosion bubble then.

Yea, I ordered a can of that Precision color from Tohatsu, part #3B7723260M. There is a little bit of it left. It has too much silver in it and not enough charcoal. Even though the years match the paint code, the color is off. It is more silver than charcoal. The Moeller version is the same but even a shade lighter. The Precision color is closer, but still not a match.

Adding cigarette ashes will darken paint if sprayed into paper cup and applied with a brush,wet sanding between coats