Rotostay aerofoil

Poignard

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My very old Rotostay system works fine but it's 10 years since it was last overhauled so I have decided it's time it had another overhaul and a new forestay. In order to remove the forestay the aerofoil has to be completely dismantled. The aluminium aerofoil is in sections with aluminium coupling pieces connecting each section. Getting the sections apart was quite difficult because the coupling pieces were seized into the sections of aerofoil. When I come to re-assemble it I want to coat the coupling pieces with something to make it easier to get apart next time [2017!]. I am considering using Duralac. Would this be ok or would grease be better?

BTW I have the original Rotostay installation instruction sheet but it doesn't say anything about putting anything on the coupling pieces when assembling but obviously something is needed.
 

jb2006

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What is Duralac?

I would have thought a lubricant with a high degree of water resistance/ repellency might be best - would that be a silicone base - lubricity of silicones isnt usually that great though?
 

john_morris_uk

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[ QUOTE ]
What is Duralac?

I would have thought a lubricant with a high degree of water resistance/ repellency might be best - would that be a silicone base - lubricity of silicones isnt usually that great though?

[/ QUOTE ] From the Silmid website:
[ QUOTE ]
DURALAC is an anti corrosive jointing compound for use between joints of
dissimilar metals.

DURALAC is a yellow paste prepared from an elastic varnish medium of low
moisture permiability, a corrosion inhibiting material barium chromate and an
inert filler. It conforms to specification DTD369B.

[/ QUOTE ]
 

PBooth

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My ( brand new) rotostay has foil sections bonded together with loctite ( can't remember which grade). As I was assembling it I was thinking "I hope that I don't have to sepparate this"

Peter
 

Poignard

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I wish you good luck when you do! [Perhaps Rotostay hope you will just buy a new one].

On the insructions for my old Rotostay the only mention of loctite is for the screws, which makes sense. Whatever the couplers did, or didn't, have on them, the sections of aerofoil had to be pulled apart using a winch after heating them up! In future I'm going to dismantle the thing every couple of years just to make sure everything is kept free of corrosion.
 

Talbot

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I use Quicksilver general grease with teflon on both the sliders, and the actual bearing races. I reckon its far superior to anything else, and a disassemble every 5 years is adequate. The place that normally gives the most trouble is the foil to furling drum connection. The water coming down the inside of the foil causes corrossion with the stainless .
 

Poignard

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[ QUOTE ]
The place that normally gives the most trouble is the foil to furling drum connection.

[/ QUOTE ]

I've not had any trouble with that because I lift the foil a few times each year to keep it free, as advised by Rotostay but, as you say, it would be trouble to get apart if neglected. As mentioned previously, the only problem I had was with the coupling pieces joining each length of aerofoil. A problem I want to avoid in future.
 

Poignard

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According to the manufacturer's website, Duralac is barium chromate paste. About £12 a tube from Seateach, Emsworth, last time I bought some. Enough to last several lifetimes.
 
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