Aluminum mast/boom sections coat or leave unfinished?

[BAD ORCA]

I removed both the forward section of my boom that connects to the gooseneck and the aft piece that the control lines run through. The aluminum is still in good condition in spite of there being a moderate layer of surface oxidation. I plan to have new custom sheaves made and will sand blast both parts. The original coating looks like maybe powder coat, but the oxidation got under it and it now peels off in big pieces.

I am wondering if anyone has any long term experience with two part paint or urethane coating for bare cast aluminum? Has it held up well? Any recommendations? I am considering using Epifanes 2-part polyurethane with their epoxy primer coat first. I'm also considering just leaving the aluminum bare and waxing it every so often, but there will be places on the sections i wont be able to reach once they are installed, so not sure the latter approach would be best long term.

I know some people leave their aluminum masts uncoated and they get a nice protective layer that does well in the weather, but masts are probably much higher quality aluminum extrusions than these cast pieces. I'm wondering if anodizing might be an option? Any input or recommendations would be appreciated.

 

[Project_Mayhem]

I hate painted rigging because it always ends up looking beat up. Curious on anodizing to hear other's thoughts on anodizing

 

[dlochner]

I have used a 2 part polyurethane on aluminum hatch frames and steering pedestals. Follow the manufacturers precisely. It will probably require an etching primer, then an undercoating/primer, and then several coats of the 2 part paint. The paint itself is thinner than water and it is difficult to find brushes or rollers that can stand up to the solvents in the paint. Patience is a real virtue in its application.

My current boat has painted spars. Hall Spars used Awlgrip and I'm sure it looked great in the show room After 30 years, not so much. Repainting is a major expense if hired out and a lot of work DIY.

 

[Calif. Ted]

Some of the boat and car builders I knew used to be very fond of Cadmium plating, can be many colors from the weird yellow to black.
What is Cadmium Plating? Benefits of Cadmium Plating | Anoplate, Inc

 

[BAD ORCA]

Some of the boat and car builders I knew used to be very fond of Cadmium plating, can be many colors from the weird yellow to black.
What is Cadmium Plating? Benefits of Cadmium Plating | Anoplate, Inc

Interesting. I had not heard of this before. There is a place close to me in Van Nuys that does this. Might take a drive over and see if its something thats affordable.

 

[BAD ORCA]

I have used a 2 part polyurethane on aluminum hatch frames and steering pedestals. Follow the manufacturers precisely. It will probably require an etching primer, then an undercoating/primer, and then several coats of the 2 part paint. The paint itself is thinner than water and it is difficult to find brushes or rollers that can stand up to the solvents in the paint. Patience is a real virtue in its application.

My current boat has painted spars. Hall Spars used Awlgrip and I'm sure it looked great in the show room After 30 years, not so much. Repainting is a major expense if hired out and a lot of work DIY.

yeah agree. luckily i only have to do the two end pieces for now. i will eventually do mast and boom in a couple of years.

 

[dLj]

I'm not a fan of cadmium coatings for this kind of application. But to each their own...

Since you are just doing the end pieces, you might find an anodizer that can do the work for you at a reasonable price. I've never had good success doing DIY anodizing on larger pieces, but if you feel confident in the process, small pieces might be possible.

The difficulty with all coating systems on aluminum is making sure you do the initial surface prep correctly. Dave mentioned the etching primer - that is critical for all coating systems you may choose.

For those parts, I would have no problem leaving them without any coating.

dj

 

[BAD ORCA]

I'm not a fan of cadmium coatings for this kind of application. But to each their own...

Since you are just doing the end pieces, you might find an anodizer that can do the work for you at a reasonable price. I've never had good success doing DIY anodizing on larger pieces, but if you feel confident in the process, small pieces might be possible.

The difficulty with all coating systems on aluminum is making sure you do the initial surface prep correctly. Dave mentioned the etching primer - that is critical for all coating systems you may choose.

For those parts, I would have no problem leaving them without any coating.

dj

Thanks. Im going to sand blast them lightly and see what they look like without any coating. Epiphanes has an epoxy primer they recommend before painting. If i go this route i will be sure to prime them correctly.