PTFE tape for dissimilar metals?

[Yeoman_24]

I’m finally putting my 1970’s Cobra Whiltock steering pedestal back together after full strip down to replace bearings and to get it sandblasted and powder coated. What a bloody labour of love it has been!

Embracing more modern materials I’ve been making gaskets from 3mm closed cell neoprene sheet rather than using sticky sealants.

I wondered about using PTFE plumbing tape on the threads of stainless machine bolts going into aluminium threads rather than Duralac. I thought the PTFE would keep the metals apart & create a more waterproof seal. Thoughts please?

 

[RichardS]

I wouldn't use PTFE tape on non-tapered fittings unless these are hoses carrying liquid or gas, and even then, it's not ideal.

I would use aluminium grease or, if I didn't have any, copper grease. Either of those will ensure easy removal next time.

I don't use Duralac but that will achieve the same result, I believe.

Richard

 

[LadyInBed]

My experience of using Duralac isn't great, it does its job but with time it hardens and makes bolts difficult to get out. Also if you happen to spill any on wood it's a real sod to get off, maybe I just don't know what the correct solvent is for it.

 

[gertha]

TefGel is one of the up to date products for preventing Electrolisis .
PTFE tape is for preventing fluids gas leaking; but it will not prevent metal to metal contact in your join , it will fill the gaps rather than separate the metals.
It is the metal to metal contact where the reaction happens.
Duralac is a bit 20th Centaurus, there are better products on the market .

 

[lw395]

I've never heard of anyone recommending ptfe tape for stainless screws in ali.
I sometimes use a PTFE loaded grease.
Copper grease or variations thereof is a proven way, but it's very messy sometimes.
Alternatively, a weak Loctite type nut grade thread threadlock is a good answer in many places.
I use duralac between components and where I suspect grease will get washed out.

 

[lw395]

TefGel is one of the up to date products for preventing Electrolisis .
PTFE tape is for preventing fluids gas leaking; but it will not prevent metal to metal contact in your join , it will fill the gaps rather than separate the metals.
It is the metal to metal contact where the reaction happens.
Duralac is a bit 20th Centaurus, there are better products on the market .

Tefgel is not gap filling.
It's one of those products that some people talk up well beyond what the makers recommend. It is good for threads and bits that mate tightly together IMHO, but it's really just a nice PTFE grease.

What other than Duralac fills gaps and prevents electrolysis?

 

[Poignard]

Tefgel is not gap filling.
It's one of those products that some people talk up well beyond what the makers recommend. It is good for threads and bits that mate tightly together IMHO, but it's really just a nice PTFE grease.

What other than Duralac fills gaps and prevents electrolysis?

.

There is a new and supposedly improved version of Duralac: Duralac Green.

http://www.llewellyn-ryland.co.uk/downloads/DuralacGreen.pdf

I haven't tried it, still having plenty left in the tube of yellow Duralac I bought 20 years ago.

 

[vic008]

Bought a small tin of Duralac, used a bit, then a year later, open tin to find it all dried out and no good.

 

[vyv_cox]

Bought a small tin of Duralac, used a bit, then a year later, open tin to find it all dried out and no good.

It is available in a tube nowadays, presumably giving a longer life. I had a large dollop of it wrapped up in polythene that lasted many years.

 

[Daverw]

+1 for tube wrapped in poly bag as it gets a bit sticky as well.