Paint versus powder coating

[bluedog225]

I’ve got some iron timber washers I’d like to mount in an outdoor location. Once installed, they will be permanent. Removing to recoat will not be an option without breaking into the wall.

Is there a consensus on rust prevention over literally decades? A good prep and paint job or powder coating? Or do I need to spend the money and get them hot-dipped?

Thanks

 

[Juneaudave]

You might consider Por-15. That stuff is pretty tough.

 

[jack stand]

Pretty piece of q/s oak!
Cast-forged steel seems to "flash over" with minor surface rust and stop without constant wetting/drying which would eat the timbers long before the cast (might be forged) steel would fall.
I think a coat of red rustoleum oil based primer is all you'll ever need.

 

[rlitman]

Galvanizing is the gold standard for a good reason, because it protects, even when scratched through.

Any other surface finish will trap water eventually, potentially accelerating corrosion, but I do agree with jack stand in that the wood is more likely to fail before a good paint system. I'd definitely not powdercoat, because you're sure to compromise the finish during installation. At least with paint, you can touch it up when installed.

 

[CraigStu]

I am pretty sure that I have seen that POR-15 is not safe from UV. So it needs a UV safe paint over it.

 

[bluedog225]

Thanks all. The timber washer will be mounted on a galvanized and painted sheet metal surface. I’m hearing that powder coating will not be ideal.

I’ve never tried to get something hot dipped. There is a place in San Antonio. I’ll look into it. There are some other brackets and things that I’d like to have done.

 

[Zeke]

Those are sold plated. As expensive as they may seem, you might end up spending less.

 

[nolimits76]

We build bridges and frequently drive H-piles, pipe piles and steel casings in the ground. Depending on the state we are working in, the DOT requires we use galvanizing or Tnemec coatings.

 

[bluedog225]

Those are sold plated. As expensive as they may seem, you might end up spending less.

You just saved me some headache. Thanks!

 

[bluedog225]

I’ve gotta know; why are some of them notched?

 

[nadogail]

Hot Dipped Galvanized is the Gold Standard for Rust Protection.

 

[Zeke]

Hot Dipped Galvanized is the Gold Standard for Rust Protection.

Actually gold is the gold standard. Gold plated bridge bolts, maybe in Saudi Arabia.

 

[jack stand]

I’ve gotta know; why are some of them notched?

I believe for driving a couple of nails to preventing rotating when tightening with a lock washer.

 

[isb cornbinder]

I have been able to buy those plates in stainless steel. I sold our sailboat 25 years ago and I have not been to the marina since.

 

[rlitman]

I have been able to buy those plates in stainless steel. I sold our sailboat 25 years ago and I have not been to the marina since.

I wouldn't mix stainless washers with steel nuts and bolts, but if you really want to go all stainless, then sure, have at it.
Stainless washers for unistrut/kindorf are similarly sized and readily available too, though square.

 

[Zeke]

I believe for driving a couple of nails to preventing rotating when tightening with a lock washer.

Then what's the hole for? So, actually if you look it up, the keyhole notch is for driving a nail or wedge in after tightening the nut, kinda like an external cotter key. I would think some square cut nails would be ideal for this.

 

[nolimits76]

Actually gold is the gold standard. Gold plated bridge bolts, maybe in Saudi Arabia.

LOL @Zeke, we haven’t built any bridges in Saudi but that sounds about on par. Got a chance to go work there a few years back. The pay is insanely great and a fun fact is they do (or used to) have a majority portion of big crane rentals in that area. They push the envelope on their builds.

On a realistic note, gold is a weak metal. Although it depends what is it alloyed with as it can gain strength that way.

In my experience HDG is great for certain elements. A washer may be okay. But my field guys want electro galvanized nuts & bolts as things remain easier to thread.

We use mostly stainless steel bolts, nuts & washers on pier caps to secure the bearing assemblies that bridge beams set on.

Lastly for pedestrian handrails located on bridge, retaining walls, etc we commonly see galvanized metal or galvanized + powder coat for black or whatever color the DOT feels like requiring, lol.

 

[bluedog225]

Maybe the keyhole for hanging the thing, then mark the hole and drill, then notches to keep from rotating? The keyhole notch still seems odd. Who cares about orientation.