Why a anodized mast?

[danrochas]

This could be a dumb question but all the same... Why do I need to anodize a aluminum mast if I can leave a aluminum hull bare? Are the aluminum extrusions used to make the mast not marine grade? Why would there be more corrosion on the mast then everywhere else in the hull? Or is it "necessary" just because we want a white mast?
Thanks

Daniel

[danrochas]

Hey, nobody has any ideas?

[Suijin]

You don't "have" to anodize it. You can leave it bare and the natural oxidation will build up a barrier that prevents, or slows corrosion. I had a 40 year old Flying Scot that had an unanodized mast and it was fine, if somewhat unsightly. That said, anodizing or painting will provide maximum protection.

[HappyMdRSailor]

Daniel,

Bumping your thread to get more action....

I know NEXT TO ZERO about aluminum hulls... I would actually assume that they are anodized, or take on a corrosive barrier through passivization...

Sticks are anodized specifically for corrosion resistance... ANY corrosion of a mast is a critical thing to be avoided.... The forces created on a mast are a billion times more than the flat surface of a hull... Anodizing is usually the "natural greyish" color of aluminum... not white... but anodizing can be done in ANY color of the rainbow....

(note to self... investigate purple anodizing for sailorchic)

[roverhi]

So are masts anodized so they will look better over time or because it's actually needed?? Painting is a non starter for me after having owned a boat with a painted mast. Painting looks good for a few years then starts bubbling and flaking and looks like crap. Prep work to repaint eats up way more man hours than almost any other paint prep required on a boat.

If a mast could just be left unfinished and let the natural oxidation protect it, would be a big money saver. Personally like the look of unpainted aluminum hulls so appearance of unanodized mast wouldn't bother me.

[forsailbyowner]

I talked to the guy who built my mast in the morgan yard. He said they used concrete block seal and dipped the whole mast in it. He said he sees his work all the time 30 years later and it was a great idea.

[Jim Cate]

FWIW, the alloy used in masts is different than that used in hull plating... stronger, stiffer, but much less corrosion resistant. Anodizing or painting the mast has both aesthetic and corrosion resistance advantages, but is not necessary.

When we were dismasted in our previous boat, the sparbuilder offered us the choice of bare, proper paint or a urethane finish called "Tectyl"(sp?). The costs for painting were around 2K$, the Tectyl (if we did the simple prep work which mostly consisted of removing the mill scale and sanding the spar longitudinally) was 50$. Since we were "self insured", the decision was a no-brainer! The clear Tectyl over the longitudinal sanding marks was quite attractive and lasted until we sold the boat 9 years later. I would do that again in a flash!

Cheers,

Jim

[JPA Cate]

Just to add a bit to what Jim wrote, the appearance of that mast was clear and shiny: it was unique among the aluminum masts for its brightness. The Tectyl was clear and could be applied with a rag if you didn't have a paint brush.

Ann

[DoubleWhisky]

Tectyl is whole range of protective coats.

Daubert

Interesting which one did You use???

Best regards

Tomasz

[Jim Cate]

Originally Posted by DoubleWhisky

Tectyl is whole range of protective coats.

Daubert

Interesting which one did You use???

Best regards

Tomasz

G'Day Tomasz,

Well, that was in 1996, and I simply don't remember which variety of Tectyl it was. And sadly, Sparmaster (the builder) is no longer in business. Perhaps an inquiry to the Mfg would answer your question.

Sorry to be unable to help further.

Jim

[Cotemar]

I had a white painted aluminum mast and it was a piece o sheet. Every year I had to sand and paint a bad area and it scratched and marked easily. Just like having more exterior wood work. I sucks on such a high level.

Never again.

Anodized mast would be my 1st choice

[glenn.225]

An anodized mast has a superior finish that will last for years and years. They are very well protected and just look better than no coating. Mine is forty years old and still looks new.

[GRIT]

I had a mast that was not anodized, and after 20 years, it was fine. The only complaint I had was that if the sail rubbed up against it, repeatedly, on wet days, (mostly after a few hours of being reefed) it could stain the sail with a bit of blackish residue. I think that's the main reason folks anodize or paint their masts; cosmetics.

Cheers.
Paul.

[Cheechako]

many are not anodized. The only problem with bare aluminum is once it oxides over naturally, it gives off a grey residue on your hands, sails etc. Few large masts are anodized because the tanks require were not large enough to do them. So they are often painted.

[Helios]

Also consider the different manufacturing methods.
Aluminum masts and booms are extrusions made by a handful of manufacturers around the world. They produce a variety of sizes that are cut to size and shipped to boat builders world wide. It's relatively easy for the mast manufacturer's to set up an anodization line to accommodate the long but relatively low product volume extrusions. The manufacturer's also have large enough production quantities to make the expense of setting up the ano line worthwhile. They choose to anodize their products for the superior corrosion resistance, improved cosmetics, and ease of manufacturing in large volumes.

An aluminum boat on the other hand is sheet aluminum that is usually cut and welded together by boat manufactures world wide but with relatively low production volumes. Since the hulls are welded together they would need to be anodized post welding. A boat hull is huge and would take a massive anodization tank. Additionally the anno process has many different steps, each requiring a different chemical bath. So huge expensive tanks with tight environmental controls, and low production volumes.... It would be very difficult for the boat manufacturer to pay off this capital expenses. I'm sure many would love to have an anodize hull, but it's just not economical.

Thus for a boat hull you either have bare aluminum and deal with the oxidation, or paint/coat it.