Extended sump fastener corrosion issue

[guzziv7fan]

Put on one of those extended sump from Guzzi Power.com.

Have noticed corrosion issue with fasteners.

Removed them one at a time, bead blasted and re-painted and then installed with Permatex anti seize.

I guess they were not plated rather just painted with some cheap paint of some type.

I even had corrosion on the large one that holds up the oil filter.

In a short time they were already welding themselves into the engine casing. Dissimilar metals galvanic thing going on because they are not properly plated hardware which should have been considered for this type application.

[Kev m]

I've noticed that... but I've not worried about it.

I coated the bolts (with antiseize I think or maybe Loctite, I forget) when I installed them.

And the heads aren't gonna stick significantly if I ever need to remove them, it's just the threads I'd care about.

[drlapo]

I'll check mine, I did use antiseize  on installation

[pete mcgee]

Change them for stainless steel fasteners, refit with anti sieze and forget about the rust issue.

[Kev m]

Pull one out and see if you used antiseize or not. You don't want those things welding themselves into that engine.

Nah, I KNOW I coated them with something...either Loctite or Antiseize...both would do the same job.

I might have used a high temp Antiseize... I just forget which it was.

[boatdetective]

It can't be galvanic. Steel is more noble than the aluminum, so the sump itself would act as an anode for the bolt. However, the exposed heads would oxidize even if they are cad plated, i would guess.  If you were RK with your own Dr. Frankenstein plating tank, and if you lived in Sitka Alaska and were totally snowed in, and if you are the type who would do a Capt. Science project for the Sir Edmund Hillary excuse (because it's there), then you could custom electroplate your fasteners.

[rodekyll]

It's not too difficult to 'lectroplate zinc to a steel bolt, although I'd think that the zinc chromate (aircraft) primer would provide the galvanic fix for less hassle.  It's what we put between steel and aluminum on Cessnas, and what I'm putting between aluminum panels and the steel trim on the trike.

I'm a little confused about the issue though.  The case studs are all uncoated, regular (high strength) steel.  They don't corrode.