Unpainted mast after stripping the paint - What Happens?

[atoll]

Originally Posted by Thumbs Up

Seven liters to paint a mast?

65ft mast roughly 12"x 8" section ,2-3 coats spray painted outdoors

[roverhi]

Lefiel is an American Company in Santa Fe Springs, CA. Bought my painted mast for the Westsail from them. The story I got was they went to paint because the anodizing companies in California with tanks large enough to anodize a 40' mast section were shut down by the CA and Fed EPA. This was back in the '70s so things may have changed.

In any event paint sucks big time!!! It will blister and bubble and look bad after a few years especially if you have wire halyards. Repainting the masts is very expensive because of all the hand sanding needed to clean up the corrosion in little nooks and crannies and fair in the paint where it's not adhering properly. No need to strip the paint as the paint is doing it's job where it's still adhering properly. Watched a boat next to me repaint there mast. They spent many days doing all the prep work and a few hours actually spraying the mast with primer and paint.

If I still had a painted mast would strip the paint off and leave it bare. The extrusion is a marine alloy just like the 'naked' aluminum boats out there. It will oxidize into a rough gray finish that will protect the underlying metal and all will be fine. While you are at it, remove all the dissimilar metal hardware and insulate under it and use TefGel, Silver Never Seize, etc on the fasteners when reassembling.

The anodized mast on my now 48 year old boat is doing just fine. The aluminum colored anodizing is still holding up with a smooth finish and largely free of any discoloration.

[Jim Cate]

If I still had a painted mast would strip the paint off and leave it bare. The extrusion is a marine alloy just like the 'naked' aluminum boats out there.

May be a bit of confusion here... The alloys used for plating aluminium boats are 5000 series and most masts are 6061 or similar. These alloys are quite different in corrosion resistance and in strength. The 6000 series are not nearly as corrosion resistant.

However, bare masts do survive, and there are plenty of them around to prove this. But there is another solution to the problem. We built a new mast for our previous boat after being dismasted. The spar builder (Sparmaster then of Wynnum Qld), knowing that we were fiscally distressed at the time said a proper paint job would add some 3-4 thousand to the price. But if we would come in and do some hand sanding on the extrusion they could coat it with a Tectyl clear coat that would protect it quite well... for 75 dollars. Not a hard decision!

Process was sanding off all the mill scale and then doing what they called "train sanding". We hand held 120 grit paper and started at one end of the tube and walked its full length, never lifting the paper... over and over until there were kinda uniform grooves running from top to bottom. Took 4 of us a couple of hours on a 55 foot tube. They then gave it an acid etch prep and simply sprayed the Tectyl on and let it dry.

The appearance was quite attractive to us. Maintained it's silvery colour and in any low angle light, kinda glowed. Very distinctive! It was quite durable but could be dinged up. The beauty of it was that then spot sanding to remove the damaged film and simply wiping on some more Tectyl with a rag made an unnoticeable repair.

When we sold the boat 8 years later it was still corrosion free. A little duller in appearance, and with some corrosion around s/s attachments, but such that a fairly hard nosed surveyor made favourable comments about it.

So, Dave, there are other options!

Jim

[maxingout]

Originally Posted by Jim Cate

May be a bit of confusion here... The alloys used for plating aluminium boats are 5000 series and most masts are 6061 or similar. These alloys are quite different in corrosion resistance and in strength. The 6000 series are not nearly as corrosion resistant.

However, bare masts do survive, and there are plenty of them around to prove this. But there is another solution to the problem. We built a new mast for our previous boat after being dismasted. The spar builder (Sparmaster then of Wynnum Qld), knowing that we were fiscally distressed at the time said a proper paint job would add some 3-4 thousand to the price. But if we would come in and do some hand sanding on the extrusion they could coat it with a Tectyl clear coat that would protect it quite well... for 75 dollars. Not a hard decision!

Process was sanding off all the mill scale and then doing what they called "train sanding". We hand held 120 grit paper and started at one end of the tube and walked its full length, never lifting the paper... over and over until there were kinda uniform grooves running from top to bottom. Took 4 of us a couple of hours on a 55 foot tube. They then gave it an acid etch prep and simply sprayed the Tectyl on and let it dry.

The appearance was quite attractive to us. Maintained it's silvery colour and in any low angle light, kinda glowed. Very distinctive! It was quite durable but could be dinged up. The beauty of it was that then spot sanding to remove the damaged film and simply wiping on some more Tectyl with a rag made an unnoticeable repair.

When we sold the boat 8 years later it was still corrosion free. A little duller in appearance, and with some corrosion around s/s attachments, but such that a fairly hard nosed surveyor made favourable comments about it.

So, Dave, there are other options!

Jim

I have never heard of this treatment, and it sounds interesting.

Sometimes paint jobs don't last very long which would be really discouraging to have to do it again a couple of years later. I will do some internet research on the Tectyl.

[Seaslug Caravan]

Dave, in answer to your question. The best thing for aluminium mast longevity if you cant anodise it is leave it unpainted.

My first boat had a painted mast and I will never repeat this error.

My present unanodised mast is approximately 20 years old and has had no paint/treatment.
It is still in perfect condition. Used exclusively in warm salt water conditions.

Aluminium forms a protective oxide when exposed to air. This protects it from further corrosion. Dissimilar metals/fittings attached to the mast still require a Duralac style bedding compound, as they would for a painted mast.

All that is achieved by painting other than a pretty colour is any chip, scratch or small failure in the paint , that allows water to enter, will start a corrosive process that traps the acids produced and cause this....



Picking off the paint/corroded mess and exposing the aluminium is the only way to halt this process.
Google is your friend.
There is a lot of misinformation out there for you to wade through. From experience NO PAINT IS GOOD.

Many bare aluminium boats/dinghys' in Australia will attest to that.

I stripped all the powder coating finish from my aluminium cast anchor winch casing when it started to bubble seven years ago and its still perfect.

Read.....http://www.cruisingworld.com/how/bare-better

[Terra Nova]

Originally Posted by Seaslug Caravan

...any chip, scratch or small failure in the paint , that allows water to enter, will start a corrosive process that traps the acids produced and cause this....



...

Not true.

That condition is caused by dissimilar metals and improper installation.

[Seaslug Caravan]

Originally Posted by Terra Nova

Not true.

That condition is caused by dissimilar metals and improper installation.

[GordMay]

I suspect LeFiell used 6061 Al for their mast extrusions. Should be good unpainted, with all the usual cautions/caveats.

LeFiell Manufacturing Company
13700 Firestone Blvd
Santa Fe Springs, CA 90670 USA
Tel: (800) 451-5971.....FAX (800) 373-3361
Short List of materials we can handle:
Aluminum Grades 7075, 2024 & 6061
➥ Materials
➥ Cruising Mast & Boom Assemblies

See also ➥ http://www.cruisersforum.com/forums/...em-118845.html

[Viking Sailor]

Originally Posted by GordMay

I suspect LeFiell used 6061 Al for their mast extrusions. Should be good unpainted, with all the usual cautions/caveats.

LeFiell Manufacturing Company
13700 Firestone Blvd
Santa Fe Springs, CA 90670 USA
Tel: (800) 451-5971.....FAX (800) 373-3361
Short List of materials we can handle:
Aluminum Grades 7075, 2024 & 6061
➥ Materials
➥ Cruising Mast & Boom Assemblies

See also ➥ http://www.cruisersforum.com/forums/...em-118845.html

Good luck in contacting LeFiell. I was interested in getting a tabernacle for my mast and spent 2 week calling them and leaving message after message. No response, none, never picked up the phone or called back.

My mast is about 40 years old and repainted once many years ago. Used Pettit EZ-poxy paint. Still look OK. None of the problems noted above. YMMV...

[noelex 77]

It depends on the grade of aluminium used, but if it is one of the 6 series such as 6061 (which it is likely to be), long term it is generally better not painted, although these grades of aluminium are not as corrosion resistant as the 5 series. The best treatment is anodising, but this is not practical on an older mast.

Try and isolate the dissimilar metals as much as possible.

[Sailorbob8599]

Leaving your aluminum mast/boom bare might be ok for longevity, but what might it do to your sails?

[Cheechako]

Originally Posted by Sailorbob8599

Leaving your aluminum mast/boom bare might be ok for longevity, but what might it do to your sails?

Good point, it does give off some grey powder. Although not sure the sails contact the mast that much. But maybe so on a small sloop.

[roverhi]

Originally Posted by Sailorbob8599

Leaving your aluminum mast/boom bare might be ok for longevity, but what might it do to your sails?

Probably nothing as your sails usually don't touch the mast unless you have an internal bolt rope attachment. Even then doubt it would be a problem. Sails are way more likely to come in contact with the rigging.

[Wulf]

Originally Posted by GordMay

I suspect LeFiell used 6061 Al for their mast extrusions. Should be good unpainted, with all the usual cautions/caveats.

LeFiell Manufacturing Company
13700 Firestone Blvd
Santa Fe Springs, CA 90670 USA
Tel: (800) 451-5971.....FAX (800) 373-3361
Short List of materials we can handle:
Aluminum Grades 7075, 2024 & 6061
➥ Materials
➥ Cruising Mast & Boom Assemblies

See also ➥ http://www.cruisersforum.com/forums/...em-118845.html

Might have better luck contacting the marine division directly.
LeFiell Marine Products (562)921-3411 or fax at (562)926-1714 or email at marine@lefiell.com

[Viking Sailor]

Originally Posted by Wulf

Might have better luck contacting the marine division directly.
LeFiell Marine Products (562)921-3411 or fax at (562)926-1714 or email at marine@lefiell.com

Update on contacting LeFiell - They have closed the marine div. I will try emailing them to see if there are parts available somewhere.