G 052112A3 hot bolt paste

@spike I don't do silver plate unfortunately; I was thinking about this one over the weekend. Melting point of silver solder is about 750C, silver is a bit higher at around 900C. Why doesn't the silver solder the nut onto the stud? I assume exhaust temperatures get up there?
 
This picture is slightly out of focus but you can see the problem I've been having with nuts corroded onto studs. If hot bolt paste was applied in the factory it has long since given up.

Albert 6.jpg


I wanted the EGR feed pipe out of the way but when I got 12mm 6 sided socket on the nuts and a 3/8 breaker they were solid. I could feel if I pulled harder something would yield. The socket may have gone, perhaps the 1/4 extension or most likely the stud would have broken off. I've now got access to get Oxy on the job.

This is the grease I've been using on exhaust studs, because I have it on the shelf. It is sold for glow plug threads and tolerates 1400C. Thoughts for use on exhausts?

Albert 5.jpg


Also anybody got a product sold for the job, a cheaper alternative to the VAG paste?
 
The easiest way to remove a seized nut is a nut splitter, if there's sufficient access.

RAB
 
philward said:
I’ve never got one to work. Could be I bought rubbish splitters. Got a link to some decent ones?
Click to expand...
These should be good:

www.toolden.co.uk

Teng Tools NS02 Nut Splitter Set (2 Pieces)

Shop for Teng Tools NS02 Nut Splitter Set (2 Pieces) online at Toolden. Free UK Delivery over £50. 0% Interest Finance Available.
www.toolden.co.uk www.toolden.co.uk

If you can afford it, buy Facom:

RS PRO Nut Splitter For Nut Sizes Up → 9/16 in Withworth, 5/8 in BSF, 1 in AF in | RS

uk.rs-online.com uk.rs-online.com

289.M8 | Facom Nut Splitter For Nut Sizes M2 to M8 | RS

uk.rs-online.com uk.rs-online.com

RAB
 
Yes @RAB looking at the price of those tools I had cheep and natsy splitters. They broke and the nuts had a dents in them.

I'll probably get a set but not for this job, access is restricted and the nuts are flange nuts, they must be more difficult to split?
 
philward said:
I'll probably get a set but not for this job, access is restricted and the nuts are flange nuts, they must be more difficult to split?
Click to expand...
Yes, they might be more difficult but if you can split most of the nut, it should loosen anyway. You should be able to cut through the flange. Try to preserve the studs!

RAB
 
As an alternative to a nut splitter a Dremel or equivalent tool with a thin cutting disc can be used to carefully slice through nuts.
 
philward said:
I don't have a Dremel unfortunately and I suspect the access would be difficult, Ill post what I do.
Click to expand...
Get the plumbers mats in there

Albert 9.jpg


Fire up the oxy

Albert 10.jpg


Heat to cherry red, trying not to melt it. That's the easy one done

Albert 11.jpg


5 minutes later job done, will tidy studs with a die nut.

Albert 12.jpg
 
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This is how I got to where I did with this matter.

Melting point of zinc 420 C, silver 960 C, copper 1080 C

Diesel exhaust temperature 500 - 700 C

Petrol exhaust temperature (difficult to find due to range of applications from family to race car) up to 800 C

So I concluded, zinc plating on studs and nuts is pointless, it will melt and and could make the fasteners more difficult to remove. Corrosion protection will be gone after the first drive. Silver plating is good. I also answered my own question to @spike , it does not solder the fasteners together because it doesn't melt. Copper melts at a higher temperature than silver and is cheaper so I bought copper plated nuts.

I bought FEBI 26712 ceramic grease after breaking 2 out of 6 glow plugs on a V6. The mobile guy who drilled out what was left without destroying the threads or getting swarf in the engine recommended it. Not had a glow plug stick since. Never thought to get the data sheet, thank you @Mark Adams . I've had problems with galvanic corrosion of threads around my A2 so I don't want to encourage electron flow between steel and alloy. I'll use this grease where hot steel components screw into alloy.

For steel on steel or iron hot components I bought Locktite LB 8008 (good for up to 980 C). It looks like a refined version of copper grease that you get at any motor-factors. I'm not entirely sure the refined LB 8008 will perform better than the gunky mess in my copper grease pot. Time will tell.

Facom nut splitters on my wish list, I get things eventually.

I'll continue to resist a Dremel, came close several times but for fine high speed cutting or grinding I have a die grinder.

Thank you all for your contributions.
 
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philward said:
This is how I got to where I did with this matter.

Melting point of zinc 420 C, silver 960 C, copper 1080 C

Diesel exhaust temperature 500 - 700 C

Petrol exhaust temperature (difficult to find due to range of applications from family to race car) up to 800 C

So I concluded, zinc plating on studs and nuts is pointless, it will melt and and could make the fasteners more difficult to remove. Corrosion protection will be gone after the first drive. Silver plating is good. I also answered my own question to @spike , it does not solder the fasteners together because it doesn't melt. Copper melts at a higher temperature than silver and is cheaper so I bought copper plated nuts.

I bought FEBI 26712 ceramic grease after breaking 2 out of 6 glow plugs on a V6. The mobile guy who drilled out what was left without destroying the threads or getting swarf in the engine recommended it. Not had a glow plug stick since. Never thought to get the data sheet, thank you @Mark Adams . I've had problems with galvanic corrosion of threads around my A2 so I don't want to encourage electron flow between steel and alloy. I'll use this grease where hot steel components screw into alloy.

For steel on steel or iron hot components I bought Locktite LB 8008 (good for up to 980 C). It looks like a refined version of copper grease that you get at any motor-factors. I'm not entirely sure the refined LB 8008 will perform better than the gunky mess in my copper grease pot. Time will tell.

Facom nut splitters on my wish list, I get things eventually.

I'll continue to resist a Dremel, came close several times but for fine high
A68C3BF8-DE7E-4F47-9975-65CEDCE073D6.png
speed cutting or grinding I have a die grinder.

Thank you all for your contributions.
Click to expand...
Hi Phill,
I found the small tin of grease in the garage see below:
A0159132-BF65-4CD2-B027-E45DDC8ADB90.jpeg
E0E18168-2CC5-427D-9CEB-D2F5384DD3D8.jpeg

A68C3BF8-DE7E-4F47-9975-65CEDCE073D6.png

Just an example of how it’s used, this came from a
UR Quattro maintenance store
after the car was sold.
 
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@kp 115 Interesting, I’ve not found Audi G5 grease for sale anywhere. On eBay Febi 26712 is listed as an alternative. I have a tub of that and it looks nothing like your G5. G5 looks like a thicker version of Loctite LB 8008. I’ll slap some of that on the studs.
 
philward said:
@kp 115 Interesting, I’ve not found Audi G5 grease for sale anywhere. On eBay Febi 26712 is listed as an alternative. I have a tub of that and it looks nothing like your G5. G5 looks like a thicker version of Loctite LB 8008. I’ll slap some of that on the studs.
Click to expand...
Hi philward,
I’ve had it since the late 90’s
So I doubt it’s still available
Turbo rob or Quattro corner on eBay may have some.
No connection with either seller
Cheers
Keith.
 
philward said:
So I concluded, zinc plating on studs and nuts is pointless, it will melt and and could make the fasteners more difficult to remove. Corrosion protection will be gone after the first drive. Silver plating is good. I also answered my own question to @spike , it does not solder the fasteners together because it doesn't melt. Copper melts at a higher temperature than silver and is cheaper so I bought copper plated nuts.
Click to expand...
When I bought the correct new nuts from VW for the exhaust manifold/turbocharger, they were always copper plated.

RAB
 
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