CP16 Rudder Bracket

[dontpanic]

The cast aluminum rudder bracket on my 81CP16 had a lot of surface corrosion. I wire brushed it and sanded it and it now looks like brand new shiny aluminum.  My plant is to use Rustoleum Aluminum Primer and a Rustoleum top coat.

Does anyone know what color the original rudder bracket was. I think it was black, but not sure if it should be flat black or gloss?

A small question, but I would like some thoughts.

Thanks

Don't Panic

[skip1930]

Don't know. Guessing Factory-Flat Black. What ever was in the 'rattle can' that day.
Some will say semi gloss. After one season ... back to flat.

The one on my boat was hand sanded, Industrial sprayed-washed, rinsed, applied an aluminum conversion coat, rinsed, R/O water rinsed, dried and de-gassed, cooled the casting, applied a Hammertone Grey powder coat and baked at a temperature lower then the dry temperature.
Hammertones are available in liquids too. I would hit it again with a clear polyester for UV protection.

Note the bronze shoulder bushings, face to face. Drill the casting for 1/2 inch. Drop in two 1/2 inch dia. x 3/4 inch long x 3/8 inch bore bushings face to face.

Note the off set mast for easy access for going below deck.

And: It was harder then heck to heat and beat with a rubber hammer this casting off the transom after removing the [4] 1/4-20 bolts and nuts. The darn thing was spot sealed at the drilled holes with factory 3-M 5200 slow set sealer/adhesive. I heated the casting and area with a paint stripping gun and a helpful wife.

skip.

[dontpanic]

Skip your rudder castings look great not to mention how great your boat looks. I tried to get a nearby powder coating company to do the job but they wouldn't touch it for some reason.

The off set mast is a good idea as well.

Don't Panic

[nies]

Original rudder and bracket was flat black...................nies

[MacGyver]

Don't Panic,
In my opinion, and from jobs I have done including the 19's rudder casting, I took and got it completely cleaned up, then wiped it down with a solvent I had on hand, and let it sit in the warm sun. I then sprayed a can of etching primer on to the surface. It has a acid built in that etches the aluminum and causes a solid bond. if the can is in the heat for a little bit it will flow easier when sprayed. Be sure to mix the can extremely well.

After this has dried, which in my case was about an hour...... I took and sprayed a high quality paint (rustoleum probably) spray paint Gloss Black on the whole thing, being extra sure my coverage was even and covering all the primer.

It has held up 2 years flawlessly. Looks awesome even though some shine is gone.

Easy project, and the sun really helped to make for a nice finished product.

Mac

[dontpanic]

Thanks for the replies. Hopefully the weather will cooperate tomorrow and I can move forward. I think I will use flat black after the etching primer.

Don't Panic

[wes]

Don't Panic - if you search for "powder coating" on the home page of this form, you'll find several useful threads. Cast aluminum is very difficult to powder coat because it tends to outgas under the heat of the coating process, which makes the finish bubble up. There are some special strategies that powder coating shops can use to reduce this, if they are familiar with them. A google search on "powder coating cast aluminum" will make you the expert you never wanted to be.

I had mine powder coated gloss black (just the pintle and gudgeon, not the rudder blade) and although it did bubble a little, it looks great from any normal distance.

Wes

[dontpanic]

Wes: that clears up some of the powder coating question.

Thanks

[skip1930]

Prevent out gassing. --> Industrial sprayed-washed, rinsed, applied an aluminum conversion coat, rinsed, R/O water rinsed, dried and de-gassed, cooled the casting, applied a Hammertone Grey powder coat and baked [cured] at a temperature lower then the dry temperature. <--

Dry hot. Cure cool. The 'pot marks' are imperfections in the casting, exasperated by wax in the detents.


Having build many industrial powder coat lines, kindly remember that the paint job is no better then what's under it. In this case it's the conversion coat atop the aluminum. And if were talking steal or iron then zinc or iron phosphate coatings of approximately 300 milligrams per square foot is an acceptable coating.

Side Bar: What do you think is the one item that is most protected from weather? That's hot, cold, UV ... well think of electric transformers on telephone poles. Well, 13 stage pickle/zinc phos washer, two electrodeposition epoxy polyester coats, one or two powder coats. Generally years of weather proofing. Made this sketch back in 1977 while on the phone with a prospect for an e-coat tank.

skip.