# Why Are Aluminum Mast Painted?



## casey1999 (Oct 18, 2010)

Why are aluminum mast painted? 

If you answer to protect from corrosion, then why is the inside of the mast not painted? The interior would get salt spray from all the holes in the mast and would not get the benefit of a rain shower or wash down. Now if the mast is anodized, I could see how that could provide good corrosion protection- and look good for a long time. Paint seems to be just a maintenance problem.

My mast is painted, and needs to be repainted. Should I just strip the paint and leave as bare aluminum?


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## ericb760 (Apr 11, 2012)

casey1999 said:


> Why are aluminum mast painted?


Because they look pretty?


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## casey1999 (Oct 18, 2010)

ericb760 said:


> Because they look pretty?


Ok, since I do not care about looks, I should just strip all the paint from the mast and leave as bare aluminun?

Actually, I think bare aluminum looks better that paint, if paint is there just to look "pretty". I like function over looks, and if a bare aluminum mast functions as well as a "pretty" painted aluminum mast, I would go bare.


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## jvlassak (Oct 1, 2009)

Painting aluminum doesn't make a whole lot of sense IMHO. When paint starts to delaminate, water gets underneath and the aluminum corrodes with little chance of the native oxide reforming. I prefer anodization.

I suppose paint looks good and if the prep is well done, it can last quite a while, but still... I just had to redo the boom and part of the mast, not a fun job.


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## GeorgeB (Dec 30, 2004)

Casy, have you looked down the inside of your mast? Have you seen corrosion? How many "holes" do you have? Don't know who built your mast (Charleston? Selden?) but chances are there is some sort of protective coating on it which would be sufficient for the inside (at least when the mast was built.) The exterior of the mast really gets weathered and should be annodized or painted. Scatches in either should be touched up. Stripping the paint would also strip any annodization. Repainting the mast is your cheapest and most effective option. If you have a lot of "holes", I'd tap them and screw in a short shank screw in them (after bedding). Not only do holes weaken the structure, but like you said, can introduce salt spray/fog corrosion into the interior of the mast.


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## Rhapsody-NS27 (Apr 8, 2012)

I have seen some boats that have bare poles. I believe many are painted to give them a clean finished look for those new boats. I actually plan on repainting mine someday.


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## casey1999 (Oct 18, 2010)

GeorgeB said:


> Casy, have you looked down the inside of your mast? Have you seen corrosion? How many "holes" do you have? Don't know who built your mast (Charleston? Selden?) but chances are there is some sort of protective coating on it which would be sufficient for the inside (at least when the mast was built.) The exterior of the mast really gets weathered and should be annodized or painted. Scatches in either should be touched up. Stripping the paint would also strip any annodization. Repainting the mast is your cheapest and most effective option. If you have a lot of "holes", I'd tap them and screw in a short shank screw in them (after bedding). Not only do holes weaken the structure, but like you said, can introduce salt spray/fog corrosion into the interior of the mast.


I have looked inside my mast as best I can and see no corrosion. The mast is deck stepped and I can inspect the inside of the base- no corrosion issues. I also have interior haylards (total of 7)- which means quite a few holes (actually slots) both at the top, middle and base of mast. the mast also appears to have many holes (about 1/8 inch diameter) along the first 1/3 of the mast track- I am thinking this might be fore a storm tri sail mast track that was never fitted.

As far as the make of the mast, I am not sure, the mast was first stepped in Australia in 1978. There is no name plate or number I can find on the mast. The exterior was originally painted and then painted one time. There are a few areas under the paint where corrosion has formed- nothing significant.


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## Skipper Jer (Aug 26, 2008)

There is an anodizing process that imparts color to the metal. So you can have your mast anodized and the looks of painted too. 

Daniel, check out AAA Custom Anodizing & Metal Finishing. They are in Piney Flats TN and have a tank 39 feet long. I'm not connected with them at all but they did anodize the spreaders and will do some electro polishing on some stainless steel parts for me.


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## Dave_E (Aug 7, 2013)

Here's to your question. There ARE manufacturers that sold every boat they made with a painted mast. I know, I own one. Allmand boats were sold with white masts. There were many San Juans (Clarks) sold with "matching or contrasting painted masts".

Then comes the refurbishment... as stated it's easier for us DIY'rs to clean and paint as not many of us have the facilities to completely strip and dunk a mast in solution etc.. I just got done refitting my mast which included a sanding, treating and repainting. Turned out beatiful.  If you scuff your paint and it mostly holds... paint it. I don't think you'll be happy with the way it will look after you've sanded all the paint off of it. You'll have sanding marks and swirls etc.. Now you could spend months sanding all the paint off and hand sanding down with finer grits to give you that new bare aluminum mast look... but that isn't going to happen - you want to use your boat! 

PM me if you want good particulars on how to do it.

Dave


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## Rhapsody-NS27 (Apr 8, 2012)

Captainmeme said:


> There is an anodizing process that imparts color to the metal. So you can have your mast anodized and the looks of painted too.
> 
> Daniel, check out AAA Custom Anodizing & Metal Finishing. They are in Piney Flats TN and have a tank 39 feet long. I'm not connected with them at all but they did anodize the spreaders and will do some electro polishing on some stainless steel parts for me.


Thanks, I'll look into it. I was thinking to repaint to a bright Yellow. Figured it would be a good way to stand out at an achorage. 

I think I need to have my spreaders taken care of. The ends are not looking too well to me.


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## jzk (Feb 25, 2008)

To add weight aloft.



casey1999 said:


> Why are aluminum mast painted?
> 
> If you answer to protect from corrosion, then why is the inside of the mast not painted? The interior would get salt spray from all the holes in the mast and would not get the benefit of a rain shower or wash down. Now if the mast is anodized, I could see how that could provide good corrosion protection- and look good for a long time. Paint seems to be just a maintenance problem.
> 
> My mast is painted, and needs to be repainted. Should I just strip the paint and leave as bare aluminum?


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## GeorgeB (Dec 30, 2004)

I like the look of red hulls, not sure about red masts. Call me a traditionalist, but if it was me, and the stick was pulled for maintenance anyways, I’d be (light) sanding, priming and painting white. Not sure that I like big, open exposed slots on my spars. Have you considered putting in halyard exit plates to “fill – in” those open slots? Harking and others make these plates. Is the corrosion you see near screws or rivets? Without seeing your boat, I’d guess you have a little galvanic corrosion going on under the paint. I would clean up/sand. Then prime with aluminum primer and then paint the top coat. Tap and screw in “plugs” for your trysail hole pattern. You might want to drill a tiny weep hole at the base of your mast (rear side). My guess is you have accumulated a lot of water in it since the last time the stick was pulled.


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## casey1999 (Oct 18, 2010)

GeorgeB said:


> I like the look of red hulls, not sure about red masts. Call me a traditionalist, but if it was me, and the stick was pulled for maintenance anyways, I'd be (light) sanding, priming and painting white. Not sure that I like big, open exposed slots on my spars. Have you considered putting in halyard exit plates to "fill - in" those open slots? Harking and others make these plates. Is the corrosion you see near screws or rivets? Without seeing your boat, I'd guess you have a little galvanic corrosion going on under the paint. I would clean up/sand. Then prime with aluminum primer and then paint the top coat. Tap and screw in "plugs" for your trysail hole pattern. You might want to drill a tiny weep hole at the base of your mast (rear side). My guess is you have accumulated a lot of water in it since the last time the stick was pulled.


Agree, If I paint, the mast will probably be white or maybe platnium. Some corrosion near rivets and some under the paint where the paint bond broke and water gets under the paint and cannot be washed away. As far as the base of the mast- there is actuall about a 2 inch by two inch hole in the base that allows water to drain out. During wash downs I actually shoot the water right into the mast (through the halyard exits) to rinse it out.


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## Dave_E (Aug 7, 2013)

Maybe it's just me... but this painted mast and boom, just makes this boat "pop".


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## Faster (Sep 13, 2005)

Most 'bare' aluminum masts are in fact clear anodized.. Aluminum will oxidize to a stable outer layer, but it's usually fairly rough/dusty when you rub or touch it. An example of that could be the rough, pimply surface on a below decks aluminum backing plate that didn't quite stay dry.


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## casey1999 (Oct 18, 2010)

Faster said:


> Most 'bare' aluminum masts are in fact clear anodized.. Aluminum will oxidize to a stable outer layer, but it's usually fairly rough/dusty when you rub or touch it. An example of that could be the rough, pimply surface on a below decks aluminum backing plate that didn't quite stay dry.


My mast base tabernacle is a fabricated from aluminum. Never was painted. Can be seen in the pic. It is like you say rough, but has developed a tough protective skin.


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## Geoff54 (Oct 30, 2011)

The corrosion resistance of aluminum varies tremendously, depending on the specific alloy. Think about a cheap generic bracket (Home Depot style) that develops the white pox in a few months, and compare that with the hull on an Ovni, which just forms a nice protective layer of dull gray oxidization. I don’t know but I would bet that the extrusions that are used for most spars aren’t anything special. 

BTW, all that fancy colored anodizing, starts out as clear and then gets a dip in the dye tank. At least that’s what I was told by the company that used to do all our anodizing. That’s why it fades, and red is the worst.


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## casey1999 (Oct 18, 2010)

Geoff54 said:


> The corrosion resistance of aluminum varies tremendously, depending on the specific alloy. Think about a cheap generic bracket (Home Depot style) that develops the white pox in a few months, and compare that with the hull on an Ovni, which just forms a nice protective layer of dull gray oxidization. I don't know but I would bet that the extrusions that are used for most spars aren't anything special.
> 
> BTW, all that fancy colored anodizing, starts out as clear and then gets a dip in the dye tank. At least that's what I was told by the company that used to do all our anodizing. That's why it fades, and red is the worst.


Just did a quick search and found some interesting information:
Boatbuilding In Metal

Also, marine aluminum alloy would be 5000 or 6000:
Aluminum Alloys

I have check selden website and cannot find what aluminum alloy they use.


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## ambianceack (Aug 27, 2006)

I cannot really answer your question but I just repainted my 35 year old 50 ft mast this spring. Last year I was seeing a lot of corrosion and minor pitting around all the stainless steel screws and stainless hardware (e.g., around the winches, halyard plate covers, boom attachment, shroud attachments, etc.) so I labeled everything and removed all the hardware, which was no easy task. I used an impact driver, heat, penetrating oil and a lot of patience to get all the old frozen fastners off. I then sanded all the paint with a 50 grit sandpaper on a Festool Rotex RO 150 with vacuum, a wire wheel via a Makita electric drill in the recessed track and a dremel via wire wheel in the track too, and of course some hand sanding. Added three coats of Interlux gray barrier paint as the primer and three coats of White epifanes 2-part polyurethane via the roll and tip method. Came out okay looks even better from 30-feet  Added many new fastners prepped with forespars lanocote, in fact with all the stainless steel I added a thin coat of the Lanocote. I painted the mast to help slow the corrosion process, it seemed like the thing to do, probably wasn't. Moreover my boat is in the same harbor as the Secretary of State's so I thought I'd spruce her up a bit giver her that Bristol look. My Catalina 22 and Oday javelin have anodized masts, never been painted and never will as long as I own them and both are probably 40 years old or more and look great.


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## Stumble (Feb 2, 2012)

Selden currently uses 6082 alloy. 6061 is the somewhat traditional alloy because it is a primary alloy in aircraft building but has 3-4 times the copper as 6082. The extra copper makes 6061 a lot more suseptable to corrosion.

A lot of class societies have disallowed 6061 because of the corrosion problem, but this is a relatively recent change (10 years or so). So what alloy any particular boat has is a bit of an open question.


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## tommays (Sep 9, 2008)

i like seeing myself in the shine


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## Minnewaska (Feb 21, 2010)

I think a white painted mast is one of the classiest things one can do to improve the look of their boat.

However, you have to be one of those boaters that likes top coating brightwork, waxing your hull more than once per year, etc. Once painted, always painted. 

I do like my boat to be maintained properly and that means I can't have everything. I sanded off some of the brightwork and will never paint the mast. Poorly maintained paint or brightwork look much worse than none at all. I have enough to do to keep her in the shape I want her in.


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## pdqaltair (Nov 14, 2008)

^^ Exactly.

I've had both (2 each). The shine isn't worth it. But then again, I don't sail for dock apeal. Some do.


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## Multihullgirl (Dec 2, 2010)

Why are aluminum mast painted?

1.Against corrosion
2.For looks
---

If you answer to protect from corrosion, then why is the inside of the mast not painted? The interior would get salt spray from all the holes in the mast and would not get the benefit of a rain shower or wash down. Now if the mast is anodized, I could see how that could provide good corrosion protection- and look good for a long time. Paint seems to be just a maintenance problem.

1. Some masts are painted in and out, but the inside of a mast doesn't get the wear that the outside does and thus can oxidize in peace
2. It's friggin' expensive to anodize most anything, and a 50 foot stick would be REALLY expensive. Much cheaper to paint, and that's likely the main reasons why mfg paint masts.
3. Good paint, well painted isn't that much of a maintenance problem
___

My mast is painted, and needs to be repainted. Should I just strip the paint and leave as bare aluminum?

No, unless you have a lot of time and patience and are willing to take the chance of a good oxidation layer may or not form.

___

One way to do it is to sand the mast and then literally IMMEDIATELY get a primer coat of paint on. If you can't do that, then after sanding you want to get a coat of zinc chromate primer on (the yellow stuff.) After your prime, if you use a good two-part polyurethane like AwlGrip or Imron, and do the job well, you'll have a quite durable paint.

--Use anti-seize on all threads and other thru-fasteners, such as rivets. I use the Permatex silver stuff. TefGel is another good choice
--Install fasteners with a coating of caulking as an insulator (BoatLife LifeCaulk is a good choice, or 4200)
--As a backing for bigger fittings, you can also install anti-corrosion insulation pads. These are commercially available from Sparcraft with nice sticky back, but I bought thin sheets of ABS plastic from McMaster-Carr (ABS WHT .020x60x6 size is what I use) and cut to size


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## casey1999 (Oct 18, 2010)

Multihullgirl,
Good advice. I will be pulling the stick in a few months. Some of the paint is in good shape, other areas have been worn down to bare aluminum. I will not strip the entire mast, only the areas that are bad, then prime and paint.

Is it ok to prime with zinc chromate in areas were the existing two part paint is in good shape?

I do like the thought of anodizing. Sailed on this boat Evohe over 20 years ago and had a chance to see her a few years back. After many miles at see including circumnavigatioins and a run through the northwest passage the masts (from Protor Mast Southhampton England) still looked brand new- and this was a working boat. Evohe was built in 1979:
Evohe yacht charter: charter sailing vessel for scientific, documentary filming and diving expeditions to remote locations - recent expeditions include Subantarctic, south Pacific, and northwest passage - specifications


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## tommays (Sep 9, 2008)

The J24 mast was easy to keep that nice 

There is NOT ENOUGH money in the world to do anything bit leave the Cal 29 mast its nasty carefree bare self


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## Multihullgirl (Dec 2, 2010)

We patched our mast in order to deliver the boat down here. It was pretty bad, big flaked off areas, etc. What we did was sand the worst spots to metal, applied zinc chromate to the bare spots, and then painted with Rustoleum (matte finish, that's all they had in Callao, VA, ha ha)

We just had it professionally stripped and painted a couple weeks ago, and the Rustoleum had held up pretty well over the last couple years, although it looked dingy from the matte finish. Pleasantly surprised


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## jvlassak (Oct 1, 2009)

casey1999 said:


> Multihullgirl,
> 
> Is it ok to prime with zinc chromate in areas were the existing two part paint is in good shape?
> 
> [/url]


You don't want to use a self-etching primer on areas with paint as the adhesion will not be very good - use it on bare metal only.


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## hellosailor (Apr 11, 2006)

1. Aesthetics. Paint is pretty.
2. Navigation. Honest. "Go to the boat with the white mast" as opposed to the black one or all the silver ones.
3. And most important of all...the econazis have made anodizing into an unacceptable industry. All your mast needs is anodizing, but good luck finding anyplace that still does anodizing because of all the ecological compliance issues. But they ARE allowed to paint.

If you left aluminum bare, most alloys would form a protective layer of white aluminum oxide powder. Which would rub off at every chance, leaving you with a really ratty looking mast very quickly.


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## christian.hess (Sep 18, 2013)

ive seen a lot of bare masts and like them, my only complaint is the slight rough surface and maybe its me but the dust is dark colored and rubs off dark not white, maybe its white initially...

at least on the bare masts I have touched...

I have contemplated sanding off all the paint and leaving mine bare on my boat but without a yard to take the mast off thats going to be too much work aloft...

maybe some touchup paint and roll on will be better...


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## hellosailor (Apr 11, 2006)

Christian-
I think the "bare" masts are still clear anodized from the factory. Dark dust is dust and dirt from the air, same that you'd find on a parked car. Aluminum oxide is white. Leave a block or bar of "pure" aluminum (or any of the wrong alloys) sitting in your cockpit for even a week, and you'll find the salt air leaves it covered with a white oxide powder. Of course, if you leave it outside that will also have the dark dust from the air hiding it.(G) But I've seen aluminum electrical boxes, engine pulleys, etc. down below in the salon go white within a week. A lot depends on the alloy.


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## christian.hess (Sep 18, 2013)

hmmmmmmmmmmmmmmmm I know what yo are saying but maybe Im seeing it differently
Ive had anodized gold masts and clear coated masts as well as bare masts and wood, painted etc...

what I have noticed is the best overall clear winner hands down was the anodized mast(go figure) and the worst was the painted mast...

in any case

the masts Im familiar with clearly had dark stuff rubbing off it even after cleaning it and washing it down...not the typical white stuff that appears especially around fittings and or dissimilar metals

Im specifically talking about the rough surface bare masts that have been sanded down...

maybe just maybe its that these masts have been taken PAST the clear coat initially applied...

maybe thats why I see it differently

its similar to hwat happens to magnesium engine cases or alloy wheels...its not white powder that you see when bare but a very dark ashy like oxidation

my motorcycle cases showed the same symtoms(after compromising the clear coat)

anywhoo


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## hellosailor (Apr 11, 2006)

dunno, but I think we basically agree: Stuff that sits outside or gets exposed to the elements? Gets crud on it. Black crud, white crud...

Reminds me of what Chairman Mao once said: "Black cat, white cat, all same. Catch mice."


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## christian.hess (Sep 18, 2013)

jajaja yup...


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## Daveinet (Jun 10, 2010)

A combination of dirt and oxidation will stain your white boat really bad. The oxidation powder gives the dirt something to stick to, so the dirt builds up, turning the powder black. The paint is there to prevent the black streaks from running down your boat any time it rains. Paint is smooth an not as porous, so the dirt does not cling to the mast as easy. This means the dirt washes off, rather than building up and creating black streaks.


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## Minnewaska (Feb 21, 2010)

Daveinet said:


> A combination of dirt and oxidation will stain your white boat really bad. The oxidation powder gives the dirt something to stick to, so the dirt builds up, turning the powder black. The paint is there to prevent the black streaks from running down your boat any time it rains. Paint is smooth an not as porous, so the dirt does not cling to the mast as easy. This means the dirt washes off, rather than building up and creating black streaks.


This sounds more like a problem with acid rain or soot. We get no streaking here.


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## Rockter (Sep 11, 2006)

If it is not anodised beneath the paint - and I doubt if it would be - then I really would keep painting it. Bare aluminium will corrode something shocking.


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