Mixed metals in a bolt set up (but not one that'll ever kill anyone)

A disclaimer first: fortunately, the mistake I am about to describe was made in a place that will be of no consequence to anyone other than me-- a private, indoor wall. Therefore, no other climbers were/will be harmed in the making of this film.

So, I put a pair of bolts w hangers into my basement climbing wall. Sort of an anchor spot for practicing rigging and various belay set ups and such (I've got kids who are/will be learning to climb, and I also like to brush up my own systems knowledge before big objectives and when it's been too long). I bought my first set of plated steel bolts and hangers (both Fixe) for this purpose. Everything else I have ever placed outside or have in my stash for future placement outside is stainless steel. Only the best when everyone else's a$$ is on the line.

Unfortunately, when it came time to place the set up, I grabbed the wrong hangers. I drilled through the 3/4 plywood, 1/2 inch of insulation, and into the concrete as far as I could go. Then I placed the 1/2" by 4 1/2" bolts with hangers. Once I finished tightening the bolts, I stool back to admire my work and saw my mistake. Now I have stainless steel hangers on plated steel bolts. I am loathe to take the bolts back out unless it is absolutely necessary, since it is not something I have ever done before, and I fear losing the expansion nut in the back of one of the holes, rendering them useless and forcing me to drill more holes in my wall.

Now, these bolts are for practice/demonstration purposes only, so 1) they will rarely hold weight, 2) the only people who will use them are me and my family and perhaps a couple of friends as nerdy about this stuff as I am, and 3) the furthest they could drop anyone is a few feet onto the pads at the base of the home woody. No harm, no foul.

Therefore, I am mostly just curious: in a dry, indoor setting, will galvanic corrosion still occur at all? Will it occur but at a slower rate without any moisture to facilitate the ion exchange? Is that how galvanic corrosion occurs? How long will it take in these near-laboratory conditions for the corrosion to significantly affect the holding strength of the bolt and/or hanger? Should I simply write back to everyone in a few dozen years when the bolt heads finally pop off? That might be like waiting for the answer to how many licks it takes to get to the center of a Tootsie Pop...

Oh, and just to get it out of the way: I'M GONNA DIE!!!!!

Wow, MP threads have really gotten this bad...

And, why not just swap out the hangers if you're so worried about it. Rawl 5-piece studs are removable and replaceable, that's the whole point of the bolt.

Ooookay, people. I thought I made it clear no one is worried here. I hoped to use this opportunity to learn something about how the chemical process works. This is not something most of us learn in school without a degree in metalurgy or materials engineering.

To get galvanic corrosion you need an electrical connection between the two metals and an electrolyte to transfer the ions. If there is no fluid then corrosion will not occur.

My anchor setup at home is 3/8" holes (?)in plywood with 5mm cord doubled to make a loop, and tied with a stopper knot, then fed through the hole from behind. I'm not sure why you needed bolts?

Didn't Josh explain that the bolts were plated, not the hangers? Why is everyone telling him to switch out the hangers? I confused.

Edit; oh, never mind I just read up on galvanized corrosion. Makes sense now.

Brendan Blanchard wrote:My anchor setup at home is 3/8" holes (?)in plywood with 5mm cord doubled to make a loop, and tied with a stopper knot, then fed through the hole from behind. I'm not sure why you needed bolts?

Josh wrote:Ain a dry, indoor setting, will galvanic corrosion still occur at all?

Thanks for the info, all. I appreciate the tutorial on the galvanic process. I'll switch out those hangers at some point, when I get around to it, but it sounds like there is no hurry...

As long as you do it sometime in the next 3-400 years its all good.