Metal corrosion on spars

A

alanmacack

New Member
Does anybody have any tips for stopping any spread of corrosion on Laser Masts – or any alloy masts, for that matter. Mine only have slight patches round a few of the fitting rivets and I don’t want them to get any worse. Perhaps there’s a “magic” solution, if only hot soapy water, that will remove the surface deposits but then what can any one suggest to cover and neutralise the areas and to get under the fittins to where the rivets penetrate. WD40, primer, metal paints ???? ... any ideas?

Thanks,

[FONT=&quot]Alan[/FONT]
 
It used to be clean it sand it rinse it with the appropriate thinner ( see paint label) and cover it with zinc chromate primerand a good paint.

I need to do a little research for best systems today.

Meanwhile....

If you have corrosion issues:
Consider it a given that you will be end for ending your top section.

Take off EVERY fitting on every tube and look under it. The corrosion UNDER a gooseneck fitting can be extensive and this mostly fresh water sailor has managed to break two bottom sections by allowing inch ling cracks to develop under the gooseneck fitting. ( Whoopie!! It is really easy to examine a freshly broken section to see which parts were corroded and cracked a long while ago and what tore that day..Phooey!!)

Both times, I came back from big breeze events, rigged my boat for a light wind ride and had the mast fold over on a light air run. The compression of the vang was not there to protect the gooseneck area cracks and they simply ripped apart. Had I only taken a look, I may have been able to have a welder touch up the cracks and end for end the bottom section with the old gooseneck holes aft and up high.

Ed Adams once won the NA masters champs witrh an old end for ended bottom section. He certainly didn't seem to be suffering from lack of mast performance.

Anyway...visit the Courtalaids Coatings website and see what they have to say about aluminum mast coatings and corrosion protection.

I am going sailing in 20 minutes so I don't have time to do it right now.

J-22 Midwinters start friday and we are actually going to try to practice.

Ravi thinks we ought to roll our gybes better. It is blowing 25. This will be interesting
 
One thing to think about is that Steel/stainless rivets will corrode the aluminum masts. Anywhere you can, you should use aluminum rivets, but there are some places (like the vang tang, etc.) that have to be stainless due to the amount of load put on it.
 
Clive is right on the Duralac paste - I have a rather old 'ex worlds lower section' that has absolutely no problems at the gooseneck because of this treatment while others in the club have had failure with newer sections.

a further consideration is probably wheter you use stainless or 'monel' fasteners, the latter ar probably nearly as strong but don't seem to react to aluminium as much (even though the fittings themselves ar stainless - slightly different stainless in the fasteners might be a contributing factor setting up a battery effect?)

Silicone adhesive sealant like Silastic* 732 can potentially handle the dissimilar metal barriet problems really well over a long period, unfortunately before cure it seems to lubricate rivet style fasteners too much while pulling the rivet to get good seating unless you have an industrial press/tool. - fine for bolted fittings though.

A stop gap (suggested unexpectedly by my daughter) that appears to be able to inhibit or slow down the process is to clean off all loose oxidisation and paint the area with clear nail varnish. not a complete solutio0n if there are serious electrolytic problems, but seems to retard minor corrosion growth if checked around once per season.

GL
 
There is a product called Lanocote which comes in a spray or thick gel-like form that prevents corrosion between different metals. Just dip the ss rivet in it before riveting and you are all set. Lanocote is made from sheep lanoline so its a little smelly but I here our Kiwi bretheren like the stuff :p
 
I use a strange silicone spray which i spray over all the rivets so the water never sticks to it and it just runs off - probably like the nail varnish trick which is probably much cheaper!
 
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