alternative to duralac?

[ashh]

need to put a few stainless screws into some ally on the boat, would that white thread sealant tape (wrapped around the thread) that plumbers use do the same thing as duralac? or can I just dab the screws in some grease before fitting them? I only have a few screws to fit and dont want to fork out $$ for something (duralac) that I only need a few drops of....if I can make do with what I have in the shed....
thoughts? :)

[revs57]

Hi Ash,

The issue as you're aware is the capacity of a material to isolate the stainless from the alloy to minimise corrosion...I'm not sure Teflon Thread tape would really cut it...and I don't think grease would either as it breaks down over time. Stag jointing compound is another compound you could use or perhaps some other gasket cement compounds like copper cote or theres another that is brown and tacky but I can't remember its name... I'd stay away from sika or silicone as they dont have corrosion/oxidization/electrolysis resistent properties

Cheers

Rhys

[Dan5]

Hey mate don't use copper cote it is actually corosive to ally and will exelerate the process(maybe nickle anti seize would do?).Duralac is the go $25 a tube from whitty's there are other jointing paste's but they are about the same price,duralac definatly work's and $25 buck's is cheaper than repair's 12 month's down the track.Good luck Dan.

[blaze]

and remember if you use self tapping screws nothing will work as the screw cuts into the alli when putting it in. You need to use threaded bolts and nyloc nuts for it to work.
cheers
blaze

[dnej]

Lanolin grease works well.I use it regularly.It self heals
David

[mromanis]

If you do use Duralac be very careful about getting any directly on your skin, and be very thorough with you clean up. Whilst it is very good gear for what it is intended for, it contains known carcinogen compounds. In some countries it is restricted for sale to non professionals because of this.
If in doubt check the US EPA site for reference to Duralac. For some reason it has not come under the same scrutiny here, same for MDF dust particles.

[SCOTTYGC]

If you do use Duralac be very careful about getting any directly on your skin, and be very thorough with you clean up. Whilst it is very good gear for what it is intended for, it contains known carcinogen compounds. In some countries it is restricted for sale to non professionals because of this.
If in doubt check the US EPA site for reference to Duralac. For some reason it has not come under the same scrutiny here, same for MDF dust particles.

OH BUGGER

I was useing some of this the other day after it had been in the shed for awhile The end had gone hard and it was only coming out slowly

I gave it a good hard squeeze and the end of the tube popped out and it was everywhere Bloody hard stuff to get off your leg and also the carpet

Turps seemed to work the best in the cleanup

[ashh]

thanks for tips guys, appreciated ;)



in the end I managed to get away with using aluminium rivets

[Dan5]

Just to make it difficult were they ally rivet's with s/s pins or ally rivet's with steel pin's?HaHa ya can't win mate!!Dan.....

[ashh]

dont think they are ss but they arent steel either, the ones I used are what we use at work in box gutters and sumps, a bit of silicone over each end of the rivet should keep the moisture out and they are under the flase floor so no need for it to look too pretty.......I guess time will tell ay, bloody salt water lol

[sempre]

Still use lanolin grease with alloy rivets.
It cant hurt.

[saurian]

Ashh, silicon causes corrosion to. Sikaflex marine is ok.
Nothing seems to replace duralec, Don't know where you guys got this lanolin grease idea from ???
Ta

[finga]

I've used the Lanolin grease for years too.
It seems to simply make a waterproof seal that doesn't allow anything in to allow the corrosion to start.
Great on things like electrical terminals and those tags that light bulbs sit in on the trailer lights etc.
And you don't have to re-apply the Lanolin grease after a screw has been taken out and put back in.

Does anybody know if the duralac works on the insulating principle or the conduction principle??

The only reason I ask is I've also used a conducting paste I used to use on power lines where-ever we joined ali-ali overhead wires. It is basically a conducting pasty grease so the contact area is as large as possible and with the lowest resistance possible and there was never any corrosion under the greasy grey crap. It was called alumox or something like that.

[saurian]

Finga , not sure on principle of duralec, but lanolin grease for electrical contacts fine . I thought duralec was neautral as such ?????
But would'nt think lanolin grease for dissimilar metals would be at all appropriate, what happens in really hot weather , wouldn't grease thin or run , allowing possible contact between dissimilar bits ???
I would'nt use it , sikaflex or duralec for me.....
Ta

[disorderly]

Yeah I'm surprised that you find the lanolin grease so effective, too, finga.I bought some to smear on some rust areas on the boat trailer but find that in the hot weather it seems to liquify.
hey saurian, did you catch anything the other day?

Scott

[saurian]

Sw winds , freezing cold ,sloppy to lumpy and got enough for a feed but thats all..
Then ended up doing another dog clutch, just after she has been fixed.
Somethings wrong but no-one wants to say what !!!
But I really needed to get out and I enjoyed it heaps, the salt in the hair etc.....
But this rain , 3 weeks and lucky to have 24 hrs without some more, just sending me nuts. Tassy weather in queensland sucks ......
Ta

[disorderly]

You should try living up this way,120 wet days this year so far.Sux

[saurian]

Yeh , orderly , seems like I'm living up your way without being there.
Looked up there to buy in the last 6 months and then Ingham/Tully flooded
twice I think, put me off big time.
Anyway , raining again lol .....
Ta

[cormorant]

I've used the Lanolin grease for years too.
It seems to simply make a waterproof seal that doesn't allow anything in to allow the corrosion to start.
Great on things like electrical terminals and those tags that light bulbs sit in on the trailer lights etc.
And you don't have to re-apply the Lanolin grease after a screw has been taken out and put back in.

Does anybody know if the duralac works on the insulating principle or the conduction principle??

The only reason I ask is I've also used a conducting paste I used to use on power lines where-ever we joined ali-ali overhead wires. It is basically a conducting pasty grease so the contact area is as large as possible and with the lowest resistance possible and there was never any corrosion under the greasy grey crap. It was called alumox or something like that.


Hi I understood Duralac to work in 2 ways . First was as a physical barrier and second was also as a barrier but by neutralised / conversion layer on surface of both metals. I would say it is non conductive at a guess

[dnej]

Lanolin grease has always been there still, when I have had to dismantle two surfaces.
I dont have any trouble, with it leaking out, betwen two surfaces, that are tightly joined.
I am extremely happy with the use of it.
It is also great ,for sealing timber joints.
Each to his own I suppose.
David

[harlequin]

hi ashh the rivets you used i think you will almost definitely find they have a steel stem and will cause galvanic corrosion even if you use sealant over the top or if they are blind the salt will absorb atmospheric moisture hydrophilic. get a rare earth magnet and place it over the rivet to confirm if it has any ferrous material present also nickel based conpounds as well as copper can not be used . galvanic scale too far apart. cormorant is right duralac is a surface conversion compound of barium chromate highly toxic absorbed through the skin or orally if you eat after using it wear gloves nitrile rubber it si by far the best compound to use and has no rivals just use ppe good luck

[Wear the fox hat]

Ash,
You will still get electrolysis with aluminium rivets, as different grades of aluminium will react. You will still need to use duralac.

Blaze,
Duralac works with self tapping screws, just tap the thread with the screw, take it out, apply the duralac & re-insert the screw. Did this 3 years ago with all fittings on my boat & still no problems.

WTFH