On Wed, 18 Oct 2017 09:16:32 -0500
"Paul K. Dickman" wrote:

"Arjun Sharma" wrote in message
...
Hi there. I bought a bunch of big aluminum screws to help secure an aluminum
pergola I'm building
(https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1)

I'd like to remove the zinc plating to reduce galvanic corrosion (I'll
probably anodize the screws). I Googled it and found a couple tutorials
around using citric acid and another using another type of acid. However,
when I went to the hardware store, they had nothing of the sort.

Any suggestions for the best way to go about this (or where to get a strong
enough acid) ? Thanks!

I think you have a bigger problem. I don't think you have aluminum screws.
I have never heard of aluminum lag screws (it seems like an extremely poor
application for aluminum) and can see no good reason why they would be zinc
plated (I am not sure it is even possible).
I can see a good reason why normal steel lag screws would be zinc plated.
When I search for the part number, sku, or upc code, it comes up as Zinc
Plated Steel Grade 2 everywhere except the amazon page.

I think someone goofed when they were writing the specs. If you look a
bit farther down the page:

"Product description

Zinc Plated Steel Grade 2 - Manufacturer: Hodell-Natco Industries."

I've got some small aluminum wood screws that were used to fasten my
storm windows to the trim. They are maybe a #8 and 1/2 inch long. It
doesn't take a lot of torque to twist the head off with a slotted
screwdriver...

I would use some Anti-seize like:

https://www.amazon.com/Dynatex-49550...dp/B009XE8AEM/

https://www.amazon.com/dp/B000FW7VGE/

generously on the threads or a thick grease, like wheel bearing. I've
had good results through the years using either of them...

--
Leon Fisk
Grand Rapids MI/Zone 5b
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