Stainless steel bolts into aluminum threads?

So I have this aluminum Frankland quickchange center housing that I'm cleaning up and getting ready to ***emble.

A friend of mine is going to bead blast it for me, and we got to talking about how I want it to look, and the subject of fasteners came up.

I told him I want the center section to have the cast aluminum look, with all stainless nuts and bolts.

He's adamant that I should never install stainless bolts into aluminum threads, even if I were to use anti-seize.

Anybody have definitive answers on the subject?

Thanks - Karl

 

I'd listen to him. I'd also be real careful to get every last bit of gl*** out of the holes and everywhere else after blasting it.

 

What is his reasoning ?? Anti sieze it and go ! At least I would..

 

Anti seize and go for it, this comes from a background of outboards they are mostly all ally with stainless. It may sound funny but when connecting rigging (ally spreaders) with stainless pins a common practice is to coat with blue lock***e which isolates the metals

 

I work on filling machines where aluminum and stainless have come in contact. Then you add moisture in and watch out . Ive seen it bow 1/2" alum. plate. Now think how it will keep that bolt or stud in its grips forever. Sure theres guy's that do it, I say no.

 

he is most likely thinking like this

http://www.bssa.org.uk/topics.php?article=89

have seen this topic before, but have not had trouble with stainless fasteners and aluminum intakes, both threaded and non threaded intake holes.

hell ask him... he may not know or he just might educate you

 

Well now I have seen both scenarios mentioned: stainless hardware in alloy casting on marine parts with no problem, but also marine parts where the stainless and aluminum have corroded (the aluminum builds up a white deposit that deforms the aluminum). So perhaps it matters what alloys are used? I am sure someone will chime in with the right scientific/engineering info.

 

Thats exactly what I'm talking about 3 replies back.

 

Yes, I've seen it too and that prompted my reply.

 

My old halibrand has stainless bolts to hold the rear cover on, no problems whatsoever.

 

Have run SS bolts in aluminum heads (intake, header bolts, carbs, alum rods, etc) with no issues at all for over 20 hrs. Anti seize and go.

 

As an alternative, why not use proper sized carbon steel studs with stainless acorn nuts? If you go this route still use antisieze.
Another alternative would be salt water marine hardware made of Monell, it's damned expensive though. You can get it through high end marine supply companys.

 

Most of the problems I have seen with the buildup ruining parts or so frozen that they cant be budged takes imersion in salt water often heat and most importantly improperly ***embled. An example is a friends boat trailer, yes it was rinsed off after each use. In five years it went from a new trailer to one requiring a rebuild. The trailer was ***embled with a combination of ally, galvanized steel, and stainless. The galvanized steel and ally caused the greatest problem, the stainless was bad but not nearly as bad, it will probably last another year or two. On the other side is the boat motor which also has a combination of ally and stainless with no sign of corosion.

 

Well, that BSA page made a lot of sense. From what I read there, exposure to moisture and salt was the biggest issue.

 

actually stainless steel with Aluminum is ok, ferrous metal fasteners would oxidize to the aluminum, stainless prevents it

 

As I poorly tried to show an example that done correctly there is little to no problem done incorrectly protected steel degrades faster than stainless.