Dumb question: Is anti-seize ok for aluminum components?
I have an aluminum tranny mount that is apparently fused to the aluminum-alloy tranny. Don’t want that to happen again.
Sure!
I’d use an anti-seize compound that contains aluminum.
Tester
Yes it is. After all, many use it on spark plugs in aluminum cylinder heads.
Antiseize is perfectly safe for aluminum, and preventing the situation you described from recurring is an excellent application of it. I would recommend against using it anywhere with critical torque values, as its effect on torque readings could cause you to strip the threads in aluminum.
Anti-seize was developed with aluminum in mind. When you have steel and aluminum coming together, they can interact with a galvanic action and actually microweld to each other. This causes serious problems, especially with steel bolts and threaded spark plugs in aluminum parts like cylinder heads. The microwelding can cause the aluminum threads to rip out. Anti-seize prevents that. It has also proven very effective in high corrosive conditions with steel-on-steel, aluminum-to-aluminum, and many other applications. Use freely.
Yes…as many others have already stated.
Zinc Oxide anti-seize is made for aluminum. This is commonly sold in little tubes for spark plugs.
@keith since you mentioned it, as I am reading up on this topic - I have some Gardner-Bender Ox-Gard. It claims to be for aluminum (among other things). I was considering using that instead… but like I said, still reading… also, I don’t know if more than one metal is in this part.
See if you can find the MSDS for Ox-Gard on line. It might tell you a lot of what’s in it.
On the subject of aluminum and copper compatibility, I’ve read that a pre-1982 (mostly copper) penny dropped in the bilge of an aluminum boat will eat a 1/2" hole right through the aluminum, so aluminum boat owners are careful to keep copper away from their hulls.
But Permatex says their copper-containing anti-seize is recommended for use on spark plugs threaded into aluminum heads, so I guess it’s a different situation.
Interesting. I think I’ll leave a small chunk of copper wire on a piece of aluminum flashing out in the elements and see what happens.
And add a little salt to simulate seawater…
Permatex already makes a Nickle, Aluminum, and a Copper anti-seize.
Yosemite
All metals fall into one of five categories for “activity”. When two metals are in contact, the more active metal will corrode and while it is corroding, it protects the less active metal. Copper happens to be one of the least active metals, Aluminum is in the middle. The most active metals are Potassium and Sodium. Those metals are so active they will actually catch fire when exposed to air or water.
Zinc and Cadmium are a little less active and are often used to plate metal to provide a sacrificial coating. Zinc can be applied as a paste or a paint like product.
When you put and iron plug into an aluminum head, the aluminum will corrode while protecting the iron. You really don’t want this to happen. Manufacturers mostly now plate their spark plugs so that the plating sacrifices itself to protect the aluminum. Non plated plugs need to have the paste applied and the paste should not contain copper or aluminum or lithium.
The paste should also be applied to a plated plug that has been removed for inspection as the plating will not be there anymore.
Copper anti-seize is made for stainless steel on stainless steel applications or SS on mild steel. Aluminum anti-seize is for electrical applications such as low voltage power bushings. Lithium or cadmium plating is for mild steel on mild steel.
You want your anti-seize to be one class more active than the most active material it is applied to.
THanks @Keith; that was informative.
Yosemite
well I ve seen about a million copper tube aluminium fin coils for AC and radiators too, so don t hold your breathe. you don t want to run copper tubing thru your masonry without a plastic sleeve tho
wesw, you may see a lot of copper tube aluminum fin coils but have you ever seen an aluminum tube copper fin coil? You want the more active metal where it will do the least harm if it corrodes.
no never seen one of those… plenty of aluminium tube aluminium fins…
I wasn t disagreeing with anything you said keith. I just didn t want mountain to waste his retirement years watching the aliminium and copper in his experiment oxidize… 
LOL, thanks for the thought.
wesw, sorry about that. You are right about copper and masonry though. My brother in law bought a brand new house a couple of years ago that had copper pipe under the slab. It was not properly protected. It just cost him $18k to get it replumbed. PEX this time.