Special paste

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Tweedle dumb

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I know there is a special paste to use on stainless screws into aluminum masts, but it seems to be sold in huge quantities.

Are there any general household items that will do the same job? e.g.vaseline?
 
Presumably you mean Duralec.
Huge quantities? It's about the size of a tube of toothpaste.
Lanolin or possibly Vaseline can usefully isolate fasteners in different metals, but only relatively short-term: i.e. bits that routinely come apart every few months.
 
If you can use monel rivets you dont need duralac even quite small gauge are very strong also any mounting surfaces can be protected with a gasket I use wide plastic tape.
 
As vyv_cox, Force 4 do a similar tube for a similar price. It will probably last you a lifetime with enough left over for your kids.

If you are bedding a plate, or similar, a suitable gasket will do the job as will any robust paint system or mastic. You would still have the problem of the fasteners. Most grease would either dry and/or wash out, in the end. I think a good marine grease would last a long time though, though this is surmise. Duralac itself dries brittle over time but seems to continue doing the business.

When stuck, (he-he) I have used contact adhesive on screws but offer no guarantee. Bone idle riggers often use nothing, which they seem to get away with as long as it is at the top of the mast rather than the, saline, bottom.

In the end it is probably best, and easiest, to bite the bullet.
 
Tweedle dumb said:
I know there is a special paste to use on stainless screws into aluminum masts, but it seems to be sold in huge quantities.

Are there any general household items that will do the same job? e.g.vaseline?
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The answer is no, just bite the bullet and buy some Tefgel. Yes it seems expensive but in a few years time when you come to undo he fittings you will understand why you spent the money.

Yoda
 
yoda said:
The answer is no, just bite the bullet and buy some Tefgel. Yes it seems expensive but in a few years time when you come to undo he fittings you will understand why you spent the money.

Yoda
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Not disputing that Tefgel works, I have never used it. However, reading their literature makes it clear that it is only a sealant to prevent the ingress of water. It may well be a very good one but it offers no chemical action. Duralac does, it inhibits the corrosion reaction and is also a sealant. It would seem that aircraft construction continues to use Duralac, according to many internet sources.
 
yoda said:
The answer is no, just bite the bullet and buy some Tefgel. Yes it seems expensive but in a few years time when you come to undo he fittings you will understand why you spent the money.

Yoda
Click to expand...

vyv_cox said:
Not disputing that Tefgel works, I have never used it. However, reading their literature makes it clear that it is only a sealant to prevent the ingress of water. It may well be a very good one but it offers no chemical action. Duralac does, it inhibits the corrosion reaction and is also a sealant. It would seem that aircraft construction continues to use Duralac, according to many internet sources.
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Tef-Gel is a good choice for sealing closely fitting joints. Duralac is probably a better choice for not so close fitting joints.
 
vyv_cox said:
Not disputing that Tefgel works, I have never used it. However, reading their literature makes it clear that it is only a sealant to prevent the ingress of water. It may well be a very good one but it offers no chemical action. Duralac does, it inhibits the corrosion reaction and is also a sealant. It would seem that aircraft construction continues to use Duralac, according to many internet sources.
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An interesting subject for a long term test. The riggers down here seem to use Tefgel, hence my answer.
 
vyv_cox said:
Not disputing that Tefgel works, I have never used it. However, reading their literature makes it clear that it is only a sealant to prevent the ingress of water. It may well be a very good one but it offers no chemical action. Duralac does, it inhibits the corrosion reaction and is also a sealant. It would seem that aircraft construction continues to use Duralac, according to many internet sources.
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When I left the aircraft industry (2010) we still used Duralac or JC5A on aircraft, a coating on all bolts, and also between any panels that were jointed together. I'm unclear on any difference between the two they were both yellow. On the newer aircraft we used a liquid rubber that set after a few hours.

I'd use Duralac personally.
 
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I wouldn't go near Copaslip either, there are enough different metals on a mast already without adding another one... funnily enough i've just used my Duralec again today, refixing a mast fitting... I've had the tube 10 years, and have maybe used 5% of it thus far.
 
According to the data sheet, Duralac only has a 2 year shelf life when stored at below 20°C. But I would think that relates to the fluidity as the barium chromate wouldn't evaporate.
 
ghostlymoron said:
According to the data sheet, Duralac only has a 2 year shelf life when stored at below 20°C. But I would think that relates to the fluidity as the barium chromate wouldn't evaporate.
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I have a tube of Duralac which I bought about 2 years ago. I have no current use for it so the OP is welcome to it if you can wait until my next visit to my boat (within the next 4 weeks). I'll put it in the post with pleasure. I'd prefer someone to get use out of it rather than it be fed to the skip
 
Reading the relative literature it appears that Tefgel (PTFE in a stable medium) is intended for a different purpose to Duralac (barium chromate).
Both are very expensive, but the latter is the one always used in the aircraft industry for joints between two metals far apart on the galvanic scale.
I quite frequently use monel rivets - very strong, very expensive and obviates the formation of Al hydroxides to jam up stainless/aluminium joins. The drawback is that you can, apparently, get local. electrolytic weakening on the aluminium around the hole.
Barum chromate jointing compounds are produced by a number of people, Ryland Llewlleyn's Duralac appears to be the one sold in smallest packaging (115ml), sufficient to insulate fixings on a normal sized aluminium hull and enough to last a yachtie his lifetime and allow it to be passed on to his offspring.
 
Phoenix of Hamble said:
I wouldn't go near Copaslip either, there are enough different metals on a mast already without adding another one... funnily enough i've just used my Duralec again today, refixing a mast fitting... I've had the tube 10 years, and have maybe used 5% of it thus far.
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Copaslip seems to work very well on stainless-alloy parts on motorcycles, such as stainless bolts into alloy threads.
On my bike, every fastener on alloy gets either copaslip or Loctite. (Using the names generically).

For bedding ss fittings onto alloy masts, there is no substitute for Duralac IMHO.
 
My tube of Duralac must be at least twelve years old. I first bought it when I was fitting home-made stainless mast steps on my previous boat. What I do every pre-season is to 'massage' the tube gently so as to prevent the oily goo separating from the yellow stuff. Last used before the summer of last year when fitting the wand of a new mast-head wind unit.
 
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