Secondary Butterflies

[Sherman Kaplan]

I am removing the secondary butterflies on my 73 TCS.  I have tapped the outside hole and want to make sure that using a standard zinc plated bolt is OK as the housing is aluminum.  I was planning on using blue loctite to hold it in place.

Also wondering if I need to do anything with the hole that is opposite the bolt.  Please see the attached picture where I have outlined it in red.   It is a blind hole so I don't think anything needs to be done, but thought I would double check.

Thanks,
Sherman

[BDA]

 I don't think you'll have any problems with zinc plated hardware in the aluminum casting. Taking a look at this site (https://galvanizeit.org/design-and-fabrication/design-considerations/dissimilar-metals-in-contact), the table in the middle of the page shows that zinc and aluminum have nearly the same anodic properties (metals that are further away from each other are more likely to permit galvanic corrosion). The blue Loctite will probably offer even more protection from galvanic corrosion.

I don't remember the details about that housing. It looks like that would be a difficult hole to fill with a bolt. If it is a blind hole, you could probably get away with ignoring it but if you want to do something about it, you might consider filling it in with epoxy.

[jbcollier]

+1 - fill with epoxy.

[Sherman Kaplan]

I was thinking of epoxy (JB Weld) but I was afraid of the consequences if it let go.

Sherman

[BDA]

You should rough up surface of the hole as much as you can before you apply the epoxy. I think it's highly unlikely that it will come out. A screwed in solution would be preferable but I don't think that's possible.

The only other solution I can think of is a neoprene stopper.

[Arizona]

I used epoxy. Still hanging in there after 40 years.