properly painting aluminum

[Dave Hussey]

I haven't found any previous discussion on this subject so here goes:
What is the proper way to prepare, and finally paint aluminum, such as spars, spreaders, etc.
I recently had to find a replacement for my E27 boom (which has been an adventure in itself) It came from LeFiell, painted with a linear polyurethane (whatever that means) and there is no primer that I am aware of. It scratches with out much effort, revealing the mill finish aluminum beneath it. The inside of the boom is bare metal, and this worries me...are all new construction spars left unprotected from corrosion on their innards? LeFiell, and several spar riggers told me that their fabrications are not anodised. I looked into having my boom stripped and anodised inside and out, but no one in Seattle does that, and the cost of shipping anywhere is prohibitive so even if there is a plant that will do it, it's out of the question. So, how long can I hope my bare (inside) boom to last in salt water spray? How do you paint inside a boom?? How do you get paint to stick to aluminum? And while I'm on a roll, what are the next winning loto numbers going to be???

 

[chrism]

Sherwin-Williams has an aluminum paint that a lot of people use for their masts.

You can also use Awl-Grip, but this is a complicated way to beautify your mast. If you pay to have it done, the cost is comparable to that of a new mast.
This is incorrect... I read it on another board. Disregard it.

Don't know anything about the inside of the boom, sorry.

 

[Geoff Johnson]

I had mine Awlgripped and the cost was $3,000 which I believe is about 1/3 the cost of a new mast.

 

[Dave Hussey]

inside paint?

Three grand??? ouch... do they dip the whole spar to coat the inside?

 

[Chris Miller]

Local guys do it themselves...

A couple of local guys do it themselves- I think they awlgrip it using an hvlp sprayer. I build furniture and use an hvlp gun that I picked up for about $150. Awlgrip has an application guide at www.awlgrip.com which has recomendations for aluminum. I'm going to give painting ours a try this winter, so let me know how it goes!
I don't think the inside of our boom is currently painted...
Chris

 

[Geoff Johnson]

As they say, painting is 90 percent preparation. My mast was transported to Rhode Island (from New York), all the hardware was removed, the mast was stripped to bare metal and then primed and Awlgripped, and then rewired. (Actully the mast was transported and painted twice since my yard was not happy with the first paint job.) I don't think the inside of a mast is ever painted. I don't have the skill, time, patience, space or protective breathing gear (Awlgrip is toxic) to do it myself. $3000 is a lot of money, but if you do it every 15 years, the amortized cost is reasonable and will extend the life of the mast indefinitely.

 

[Mike Thomas]

Dave.

I just pained my spars this spring. Also did my last boat a few years ago.

On the first boat I sanded the spars with 150 grit to bare alum. Primed with Interlux Epoxy Barrier Kote and finished with Interthane Plus two part epoxy. Those spars were done in black. 4 years later the boat went to the scrap heap but I kept the mast and boom on the ground behind the shed. When I took them out 3 years after that (7 years total) they looked line new. I was amazed at the performance of the coating. We freeze in the winter and bake in the summer.

On this boat I just primed with Pre-kote and painted with Brightsides. On this one I had to do 4 coats of the Brightsides (wet sand in between coats) to get the finish I wanted. I should have done the two-part primer and topcoat again.

Both jobs done with brushes and look(ed) great.

In as far at the inside of the spars.. I don’t think it will be a problem.

Mike T
E-29 Babylon NY

 

[Dave Hussey]

paint

It just seems to go against chemistry, sea worthiness, and reason to leave unprotected bare aluminum to the elements... I guess I will just have to trust the current trend in manufacturing, taking care of the visible surfaces for the sake of eye-worthiness, and then sell it before it rots through from the inside, in 7 or 10 years :eek: Thanks for the tips on paint...sounds like the way to go.
Dave Hussey

 

[Chris Miller]

carbon would solve it!!

Well, you could just get a new carbon rig (I like the pretty ones that look like wood) and not worry about it :eek:

Ours has been out there for 18 years and is ok. What color are you going to paint it?
Chris

 

[Dave Hussey]

carbon

hmmm, maybe faux carbon...that way, it'd look like carbon, and in time I'd forget about the oxidation processess at work deep in the inner recesses of the spar...nah...I guess I'll just stay with the traditional sailboat-white

 

[Rocinante33]

Consider Powder coating?

Why don't you give some local powder coating shops a call to see if they can do it? It may be a good, viable, reasonable option. I will consider this with my boom over the winter, which needs it badly. Powder coating is very durable & resistant to the elements. They should be able to powder coat at least the inner end portion of a spar, too.

 

[ted_reshetiloff]

Dont you need an oven to powder coat? Would need to be one hell of an oven...