Should I Use Anti Seize On Turbo Bolts?

[Pgitug]

I am replacing my exhaust mixing elbow as a PM on my 2002 Cummins 330hp. I soaked the four bolts with penetrating oil for three days and they did break loose. So On reassembly I am thinking of using nickel anti seize on the four exhaust side bolts. Is this a good idea?

 

[sunchaser]

I am replacing my exhaust mixing elbow as a PM on my 2002 Cummins 330hp. I soaked the four bolts with penetrating oil for three days and they did break loose. So On reassembly I am thinking of using nickel anti seize on the four exhaust side bolts. Is this a good idea?

Loc tite makes several high temperature anti seize products, one with nickel I've seen used is #771.

 

[Lepke]

I use a anti seize compound on anything exposed to high temps, water, or when threads may corrode. Usually copper or nickel based, but don't really see a difference. I follow manufacturers recommendation if known.

 

[kchace]

I use anti-seize on pretty much everything except special bolts (like head bolts) which I treat exactly by the book. One thing to keep in mind with bolts that need to be torqued to a specific number is you need to use the part of the torque table for "lubricated threads".

Ken

 

[SoWhat]

I'm with Ken on this one. Anti-seize on everything. Next owner will thank me.
If the original bolt was a grade 2 I replace it with a grade 5.

 

[Northern Spy]

To the original poster. If you use anti-seize, do not use copper, use nickel, with a high solids content. Loctite 771 or JetLube Nikal would be my recommendation.

There are some newer metal free calcium fluoride compounds out there, but I have no experience with them.

We stick with the two nickel based ones I mentioned above because tests prove that the torque coefficient remains the same after 24 hours, alowing us to hot torque the fasteners again when at operating temperatures.

 

[Northern Spy]

I'm with Ken on this one. Anti-seize on everything. Next owner will thank me.
If the original bolt was a grade 2 I replace it with a grade 5.

That only works if you take advantage of the higher tensile strength afforded by the upgrade. You may actually be decreasing the clamping force provided unless you are increasing the torque to ensure proper preload.

A SAE grade 5 bolt has over one and a half times the tensile strength as a grade 2. A grade 8 has twice the tensile strength.

So generally speaking, increasing the bolt strength, and the preload is a good thing. Most of the bolts on a boat are non-critical. But if you find yourself reaching for a torque wrench on a more controlled joint assembly, (like an engine) it is probably best to use the manufacturers recommended studs, nuts, and bolts and the torque spec provided.

 

[Xsbank]

Cummins Workshop Manual.

 

[knuckelbuster]

This may sound strange but in the days of working on large reciprocating engines we used Milk of Magnesia on all bolts on hot exhaust related parts. From my experience most never-seize compounds dry out and cause additional seizure during removal events. Cheap also.

 

[Northern Spy]

This may sound strange but in the days of working on large reciprocating engines we used Milk of Magnesia on all bolts on hot exhaust related parts. From my experience most never-seize compounds dry out and cause additional seizure during removal events. Cheap also.

Milk of Magnesia is definitely an old school anti-seize that works. Particularly good for stainless to stainless to prevent galling.

All anti-seize dries out. It's a colloidal mix that leaves a coating of graphite, copper, or nickel (or magnesium).

The difference is in the torque coefficient or nut factor (k). In the commercially prepared anti-seize it is known and required torque can be calculated accurately for tensile preload.

EDIT I just checked my reference material for milk of magnesia testing. Unfortunately, the results on break out torque are pretty dismal. Warren Brown (The modern guru of fasteners and joints) tested it and presented a paper on it to ASME in 2006.

Interesting that it is one of the series of papers that led to our use of Loctite 771 and JetLube Nikal. Warren Brown wrote our bolted joints manual and is a member of several ASME committees on flanges and bolted joints.

 

[Larry M]

Spy: I just looked at my can of neverseez and it contains 7-13% copper as per the MSD. Why do you not use copper containing products?

 

[Northern Spy]

Spy: I just looked at my can of neverseez and it contains 7-13% copper as per the MSD. Why do you not use copper containing products?

Molybdenum and copper based anti-seize have a lower break out torque for disassembly for low temperature assembly low; so it's actually better!

At high temperatures copper didn't fare well. Even at temperatures lower than the ratings.

Most of the assemblies we work with require the higher temperature requirement of nickel.

 

[Larry M]

Molybdenum and copper based anti-seize have a lower break out torque for disassembly for low temperature assembly low; so it's actually better!

At high temperatures copper didn't fare well. Even at temperatures lower than the ratings.

Most of the assemblies we work with require the higher temperature requirement of nickel.

Thanks. I never realized there were so many different types of anti-seize for various applications. This is a good thread.

 

[Northern Spy]

I should be honest in saying that anti-seize doesn't always work. We still have to cut off a certain percentage of the studs and nuts. SAY 5-10%

Much of the benefit is gained by using it as a lubricant in order to torque and re-torque when hot.

I'm working on my ASME Qualified Bolting Specialist currently. One of the largest maintenance cost savings to date has been increasing our bolted joint integrity on site.

 

[RT Firefly]

Greetings,
Mr. LM. "...anti-seize...thread." Good one.

 

[Xsbank]

My anti-sieze, which I have started using when I have stainless fasteners in aluminium, contains aluminum. Haven't had it long enough to give results yet, but crevice corrosion and galling are a big issue for me.

 

[Ski in NC]

The mixer bolts on that Cummins screw into a water jacketed turbo. They don't get that hot. But the slots leave the thread gaps exposed so it is good to put something like grease or antiseize on them. I just use a touch of grease.

Ground off and extracted a good number of those. Yuk.

 

[Northern Spy]

The mixer bolts on that Cummins screw into a water jacketed turbo. They don't get that hot. But the slots leave the thread gaps exposed so it is good to put something like grease or antiseize on them. I just use a touch of grease.

Ground off and extracted a good number of those. Yuk.

And there you have it. As usual RTFM.

Real world experience is hard to beat. Thanks Ski!

 

[Pgitug]

I just finished some research on this. The discharge temperatures of your turbo can reach 1900 degrees. The ONLY anti seize that can withstand those temperatures is NICKEL.
Like Permatex #77134.
Copper burns up at 1800 degrees.
Aluminum burns up at 1600 degrees.
FYI
[emoji41]

 

[Ski in NC]

The turbine out temp on a 6B 330 will NOT reach 1900F.

And the bolts screw into a water jacket. Not exposed to exhaust gas temp. Threads might hit 250F, bolt head a little hotter depending on mixer design.

 

[diver dave]

Aluminum burns up at 1600 degrees.
FYI
[emoji41]

gosh, I wonder how outboards even exist.
Exposure to hot things (gas) is different from the temperature of the piece that has that exposure.

 

[psneeld]

passed to me by an engine guy....


..... if the OP's turbine outlet temperature reached 1900F or 1038C he would have a lot more to worry about than getting the bolts out of the turbo. In addition, the turbo inlet temperature would be even hotter than the outlet temperature.

I suspect he was looking at some figures for a gasoline engine operating at full load.

 

[Lucky Chucky]

Agreed with Ski on 250F temp.

 

[LarryM]

The turbine out temp on a 6B 330 will NOT reach 1900F.

And the bolts screw into a water jacket. Not exposed to exhaust gas temp. Threads might hit 250F, bolt head a little hotter depending on mixer design.

Again, Ski is right on. 905°F is max turbine outlet temp. per Cummins on a CPL 1975 330.
I think the highest I've ever seen on any 6 Series marine Cummins is around 1000°F

 

[Pgitug]

The turbine out temp on a 6B 330 will NOT reach 1900F.

And the bolts screw into a water jacket. Not exposed to exhaust gas temp. Threads might hit 250F, bolt head a little hotter depending on mixer design.

I do not see a water jacket for these bolts. But you may be right. The paint where the bolts go into the housing is not burnt. Just where the bolt heads are resting. Interesting. [emoji848]

 

[Maerin]

The banjo fitting that the arrow points to connects to the turbo jacket, it's a coolant line. So the turbo is water cooled. The bolts are threaded into the jacket. The paint on the turbo is barely discolored.

I frequently shoot temps on the exhaust and the turbo, NO WAY it's even close to 1900F. More like 200F, closer to 350-400 at the flange which sees exhaust gas.

 

[Pgitug]

The banjo fitting that the arrow points to connects to the turbo jacket, it's a coolant line. So the turbo is water cooled. The bolts are threaded into the jacket. The paint on the turbo is barely discolored.

I frequently shoot temps on the exhaust and the turbo, NO WAY it's even close to 1900F. More like 200F, closer to 350-400 at the flange which sees exhaust gas.

Understand better. [emoji106]

 

[Pgitug]

Well the high temp Anti Seize has arrived. Appears to be able to withstand much higher temps than I need, but it’s the same price as the lesser temp products so what the heck.

 

[Baker]

I read threads like this and realize just how little I know!!!