David Thatcher wrote:

Timothy Rumbinas wrote:

I've had good success brushing on a coat of zinc chromate primer and then using a coat of "Hammerite" paint on bare aluminum. I don't know if if Hammerite is available in your area, but it is a glass-filled enamel that creates a very slick surface and is quite durable.

I have used Hammerite paint in quite a few different applications. It is a very tough paint but I am not sure whether it will survive long on the aluminum with the friction and rubbing from the sail battens and yard, unless there was soft fendering on all of these. Certainly you would need a very good priming system.

I would wet sand the masts, that way there is no dust and all the nasty stuff is continuously being washed away.

That's probably the best way to go about it. Good plan. You'll still need a protective coating, however. I've tried Hammerite and a coal-tar based barge epoxy. The coal-tar epoxy is remarkable stuff in some applications (notably steel), but never really hardens enough for use on a mast. Even after some years, it still remains slightly soft. I suppose this is a good thing on a barge hull. I would consider tacking a strip of HDPE to the mast where the battens and boom contact. You could calculate the width you'd need with any good CAD program. I recall seeing self-adhesive HDPE tape being offered., but I don't immediately recall where. I do know that it takes a very, very long time for any noticeable wear to occur between two HDPE surfaces. I commonly use it for sliding jigs and fixtures.

I've had good success brushing on a coat of zinc chromate primer and then using a coat of "Hammerite" paint on bare aluminum. I don't know if if Hammerite is available in your area, but it is a glass-filled enamel that creates a very slick surface and is quite durable. It also fills well and hides a multitude of sins. For "slick strips" I've used ultra-high density polyethylene. UHMD tends to be an expensive material, but I found a place that sells UHMD cutting boards for far less than I can buy the stuff in sheet form.

The difficulty with sanding aluminum -- or dealing with abrasion on untreated aluminum of any form, is that you will create a lot of aluminum oxide. Aluminum oxide is nasty stuff. 

There's some debate as to its toxicity. Some say it's relatively innocuous, and others claim it will make you want to run for president on the US Republican ticket. It creates a dark and very durable black stain on anything that it touches, and is practically impossible to remove. It's not soluble in water, nor any other compound that I've tried. It will eventually come off skin with forceful application of pumice soap, along with a few layers of hide.

I've not built my junk rig yet. This comes from doing a few masts on other boats, restoring a 1972 Land Rover, and doing a little work on a 1956 Cessna aircraft that had a mouse nest in the tail. Mouse pee is right up there with nitric acid for pure corrosion potential.

If you are going to sand your stick, please, get a very good dust mask, eye protection, gloves and some Tyvek suits. There's a barrier cream sold under the brand name "Liquid Gloves" here in the US. Despite the gloves moniker, you can use it on your face or any other exposed skin, and it makes it a little bit easier to get the oxide off.

David Tyler wrote:

And not anodised either, I assume? If not, and the surface is rougher than the brushed finish that is usual with these poles, then I would suggest that you use some fine abrasive on them first.

I wouldn't recommend bonding anything onto them. Some people have applied wax to bare aluminium with success, but it has to be reapplied frequently. A smooth anodised finish is much the best, but a well-prepared paint job or powder coating are also good.

It's the battens and yard that need the fendering applied, not the mast, and there have been many different solutions here. Plastic tubes, plastic strips screwed on, fire hose, glued-on foam, leather or Treadmaster, rope wrapped around the batten, or foam-under-webbing sewn to the sail pocket - many solutions. So long as the fender protects the batten and the mast, all will be well.

Thank you David.  Not they are not anodized either.  Yes, I think sanding them might be our best option.  Our battens are already prepared with a plastic rub strip that is screwed on.  Maybe we will just replace them with a thicker pad before we start voyaging.  I'm not sure what I'll use if we scrap the wooden battens for aluminum tubes.  First step is sanding.  Thanks again!

Greetings!  Our aluminum masts just arrived and they look amazing!  The masts are natural aluminum (not powder coated or painted).  The masts have been formed in such a way that they are pretty rough and will likely tear through our battens if not properly finished.  I'm thinking of bonding sheets of kevlar to the aluminum so our wooden battens are properly insulated.  Does anyone have any experience with materials to bond kevlar to aluminum?  Totally open to suggestions on this one.  Appreciate the input as always.