Anti seize on prop bolts?

[bernth1961]

When re-pitching my Sensenic GA last weekend, 2 of the bolts seized. I had to cut the bolt heads to get the hub off. Bolts could not be moved, lugs in the prop extension rotated when I used extensive force.

From Sensenic I got (in writing) that they do not recommend anti seize.

However, by phone, I got some additional (unofficial) information, besides what I got in writing: "We love anti seize, although a mechanics will not like it. If you use it, consider lowering the torque by 5-10% due to the lubrication effect, the blades will be safely in place. We test our aluminum hubs extensively, often the bolts breaks before the hub"

Considering:
1) This must happen when we have -14 Deg C (5 F) in the hangar, making the work less attractive.
2) If this happened to one of the inner bolts, the bolt head would have to be drilled out which may or may not ruin my prop hub($$$). Difficult with my resources.
3) Lugs in my extension are stainless, prone to galling.

I'm considering using anti seize with my metal hub, but stay with dry threads whenever I'm installing the wood prop (risk of over torque).

Any thoughs?

 

[swjohnsey]

From memory I think the torque reduction using anti-sieze is more like 20 - 30%.

 

[PilotjohnS]

My opinion

If steel bolts are going into stainless, I would use anti-seize without question.

It is my understanding, that when stainless steel is tapped, little burrs fold over. It is these burrs that catch the bolt when it is removed. Easy in, hard out. So I don't think one can tell during assembly if the bolt would seize coming out; it isn't like bad threads can be detected during assembly, like on steel-steel interfaces.

In my opinion, any threads in stainless should be heli-coiled to avoid problems with seizing JMHO YMMV

 

[BillL]

If steel bolts are going into stainless, I would use anti-seize without question.

It is my understanding, that when stainless steel is tapped, little burrs fold over. It is these burrs that catch the bolt when it is removed. Easy in, hard out. So I don't think one can tell during assembly if the bolt would seize coming out; it isn't like bad threads can be detected during assembly, like on steel-steel interfaces.

In my opinion, any threads in stainless should be heli-coiled to avoid problems with seizing JMHO YMMV

Stainless, in general, is well known for galling, but does depend on the alloy. Some are just worse than others, 400 series is less-bad. I would add the anti-seize and reduce the torque appropriately.

 

[bernth1961]

Thanks for your input gent's.

Seems as if I'm on the right track. Anti-seize it will be on this prop in the future.

/Bernth