Bolt in floor?

[tony_h]

Have you seen any corrosion on the aluminum where your stainless bolts contact it?

How long has it been together like that?

Did you add the silicon to the bolts yourself?


Sorry for all the questions but I am about to put aluminum skin on my steel framed cabover truck bed camper and haven't found a solution for the bolts. In between the steel bracing and the aluminum I will use VHB tape.

I recently put a 1/4" aluminum plate on the bed my little steel-framed utility trailer. I tend to suffer from analysis paralysis and over thought galvanic corrosion. My cheap solution was to cover the steel really well with a Rustoleum primer/paint, then put a PVC/foam seal (same used between campers and truck beds-cheap), use zinc-coated bolts and nylock nuts, nylon washers between the aluminum and foam (that was a pain) and finally dielectric grease on the threads and head of the bolts.

Overall, it wasn't difficult and, including cutting the aluminum to fit, took about 2 hours.

Time will tell, but my goal was to isolate the aluminum from any steel. I had a wood floor before, and I'm hoping never to have to worry about it again.

 

[ITTOG]

I recently put a 1/4" aluminum plate on the bed my little steel-framed utility trailer. I tend to suffer from analysis paralysis and over thought galvanic corrosion. My cheap solution was to cover the steel really well with a Rustoleum primer/paint, then put a PVC/foam seal (same used between campers and truck beds-cheap), use zinc-coated bolts and nylock nuts, nylon washers between the aluminum and foam (that was a pain) and finally dielectric grease on the threads and head of the bolts.

Overall, it wasn't difficult and, including cutting the aluminum to fit, took about 2 hours.

Time will tell, but my goal was to isolate the aluminum from any steel. I had a wood floor before, and I'm hoping never to have to worry about it again.

Any particular reason you used zinc coated bolts? I am no expert but according to the research I have done Zinc is more anodic/active than Aluminum. Therefore the zinc will corrode first. Does that mean the aluminum won't corrode until all of the zinc has corroded? Or will the zinc and aluminum corrode at the same time? I do not know the answer. Below is a link to the table that identifies zinc as more anodic than aluminum.

Corrosion Control - Galvanic Table

 

[tony_h]

Any particular reason you used zinc coated bolts? I am no expert but according to the research I have done Zinc is more anodic/active than Aluminum. Therefore the zinc will corrode first. Does that mean the aluminum won't corrode until all of the zinc has corroded? Or will the zinc and aluminum corrode at the same time? I do not know the answer. Below is a link to the table that identifies zinc as more anodic than aluminum.

Corrosion Control - Galvanic Table

I'm hoping the bolts corrode before the aluminum. I check it often and didn't want to chance the aluminum corroding. The bolts are easy to come by and replace. I'd also read the SS bolts could cause similar problems, so I went the cheaper route. It also seems that since the bolts are so much smaller than the amount of aluminum that those are sure to go first.

However, I'm also hoping that because the bolts are coated in dielectric grease and I'm using nylock nuts and nylon washers, most of contact between dissimilar metals is eliminated.

Like I said, we'll see...

 

[ITTOG]

I think your approach makes sense. I may do the same for some of my fasteners that aren't visible. . For the areas I need it to look pretty I will try the approach that @IdaSHO too. Given I am in a humid area, I will have plenty of moisture in the air (electrolyte, which is required) to test both.

Thanks for the info.


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