Leaving Grady drive unfinished.

[vitamin sea II]

I have searched and read lots of threads about how to refinish my aluminum Grady drive bracket.
One thing I haven’t seen discussed is the possibility of cleaning it up and leaving it unfinished.
I have had the boat for about 4 years and the previous owner painted the bottom half of the bracket with copper based bottom paint. It is flaking off and I’m getting some oxidation.
Has anyone just left the bracket unfinished? It is used exclusively in salt water.

Thanks

 

[seasick]

Copper paint and aluminum is a no-no. It's asking for trouble. I wouldn't leave the bracket unfinished since it will may get growth and/or barnacles. In addition it may act as a sacrificial anode depending on the alloy and the waters you boat in. I would clean it up by scraping/sanding as needed and either apply an epoxy primer and then the appropriate paint for the water conditions. You probably could also apply something like Interlux 33 ( I think that's the name) which is an anti-fouling paint that is suitable for aluminum surfaces.
The fact that the paint was ok for 4 years tells me that the bracket was painted/coated so that the aluminum was insulated from the copper.

 

[vitamin sea II]

I should’ve noted that the vessel is no longer wet slipped. Thanks for the reply. As far as acting as a sacrificial anode, wouldn’t that be true as well for boats made entirely out of aluminum?

 

[seasick]

I should’ve noted that the vessel is no longer wet slipped. Thanks for the reply. As far as acting as a sacrificial anode, wouldn’t that be true as well for boats made entirely out of aluminum?

To a degree yes, but there are other factors. The type of sacrificial anodes makes a difference. You want the anodes to react before the hull. In your case the bracket may be more reactive than the current anodes. I don't know but brought it up as something to check.
Also note that aluminum hulls if used in salt water and even in brackish water need to be 'bottom' painted.
If your boat is not kept in the water, the issue will be greatly reduced but the bracket if left uncoated should be rinsed after every outing if used in salt or brackish waters

 

[Halfhitch]

Vitamin, when I lived in the NW, I owned a couple of different inboard aluminum boats. I think bare aluminum looks good and can be kept looking good with a little care. If your bracket is not pitted too badly, you can bring it back fairly easily follow any of the YouTube videos on polishing aluminum using varying grades of abrasives. The same polisher you use for your fiberglass will provide the muscle. Once you get it looking premo, be sure to install a couple of magnesium anodes on the bottom, out of sight and tape over them. Then apply 2 coats of Sharkhide protectant. Amazing stuff and easy to apply. Don't fall for the cheaper imitations. Then remove the tape before spashing