Corten Steel Backlit Sign

[AGinVT]

Hello All,

My shop is taking on a sign build that we have not encountered before and I was hoping that I could get some expert advice on the fabrication.

The general outline of the project is a roughly 8'w x 4'h custom corten or weathering steel sign. We work with a local company that will cut the face for us, but then we need to determine the best way to mount the thing to the front of the building with a box for the LED's. I was thinking of having them use a 11ga (.125") sheet to have enough thickness to avoid any waves, but this adds some extra weight to the structure.

I have floated the idea of a SignComp aluminum box, but we have gotten kerf cut tops before and they are a bear to bend and never end up being the correct shape. We usually have to add an additional piece to form the proper shape. Our shop has taken on a lot of new avenues over the last 29 years, but metal fabrication is not one of them. We have made boxes out of pressure-treated lumber and ACM, but no sheet metal bending.

Any thoughts? Here is a very early mock up of the sign. It is meant to have a solid sheet of Lexan behind the face to make all of the elements glow white at night. Almost forgot, the other concern is discoloration of the Lexan. This is a steel that is meant to have surface rust and I imagine that rust will run as it gets wet. Not sure of the best may to prevent this or if just simply spacing the Lexan away from the steel and adding weep holes would do the trick.

Thank you in advance for any constructive advice.

 

[Z SIGNS]

Make a cloud sign

 

[Gino]

Seems like a really big job to tackle, especially with the kinda weight you're gonna encounter. Coding and engineering could be a problem. You'd most likely hafta use all thread and put braces on the inside walls of the building to make codes happy. Did ya think about just printing the background onto trans vinyl or direct print with possibly 2 or 3 hits ??

 

[Notarealsignguy]

Let it weather to get the rust coating on it and then spray a flattened automotive clear on it which should lock it in. The Corten will not only bleed onto the lexan but will be running down the face of the building and staining everything.

 

[ChaseO]

That would be incredibly heavy to sit a few inches away from the building. I know there is no rust like real rust, but I'm afraid that sheet of steel is going to be so heavy, as soon as it pick it up from whoever you cut it, you are going to start finding problems in your plans. And Notareal is right, the rust will run down everything if you don't seal it. I'd be looking into doing something with a faux finish.

 

[B.jurton]

So for UL, you will need to only 'decorate' the outer skin with rusted steel, they will not allow you to utilize that as part of your 'electrical enclosure'. At least in this way you can get some really thin gauge steel for the face, then just glue it to the actual sign. I'd make the aluminum face like a channel letter, a second smaller one to go on the wall, and probably add some angle at the top inside the can to support the extra weight of the steel face. Hardest part is working with someone else to cut the steel to match the aluminum, folks with plasma cutters think about offsets and kerfs differently than router folk.

 

[signheremd]

I second Gino, why not simply print the rust and do away with the extra weight and eliminate the rust bleeding?

 

[islanddogsignsllc]

There are some textured powdercoats that mimic rusted steel. They won't have same variations of natural rust but would allow you to use aluminum and elimiate all the rust staining issues.

 

[AGinVT]

I second Gino, why not simply print the rust and do away with the extra weight and eliminate the rust bleeding?

The client is really keyed in on the natural rust finish. Even the best faux will be faux in their eyes. We have done some fake marble finishes that have been passable, but I feel like rust would be a tough one to pull off.

 

[AGinVT]

So for UL, you will need to only 'decorate' the outer skin with rusted steel, they will not allow you to utilize that as part of your 'electrical enclosure'. At least in this way you can get some really thin gauge steel for the face, then just glue it to the actual sign. I'd make the aluminum face like a channel letter, a second smaller one to go on the wall, and probably add some angle at the top inside the can to support the extra weight of the steel face. Hardest part is working with someone else to cut the steel to match the aluminum, folks with plasma cutters think about offsets and kerfs differently than router folk.

Thank you. I like this approach. This was my first thought too. Basically create a lightbox with no vinyl (or white backlit vinyl to avoid Lexan yellowing or graying over time) and apply the steel face over the top. I think my .125" thickness may be a big leap and unnecessary. I think it would work out to about 160 lbs.

 

[AGinVT]

There are some textured powdercoats that mimic rusted steel. They won't have same variations of natural rust but would allow you to use aluminum and elimiate all the rust staining issues.

This is an interesting idea that I'll have to look into. I have seen some articles about accelerating the rusting process with a pre-treat of vinegar and then a mixture of hydrogen peroxide, white vinegar and salt. The client is looking to have this sign up by the beginning of March and I don't want to deal with months of dripping rust before it settles in.

 

[Notarealsignguy]

I would think finding a real thin gauge corten sheet would be difficult. It seems to more typical for structural steel and even then you don't see it very often.

 

[AGinVT]

I would think finding a real thin gauge corten sheet would be difficult. It seems to more typical for structural steel and even then you don't see it very often.

I would've thought so too, but my metal vendor tells me she can get most any gauge I want within a week or two. I guess it would be "weathering steel" which is supposed to be the generic version of corten and maybe why it is more available.

 

[JBurton]

So, in my super good internet education, it's my understanding that corten steel is treated so it eventually develops this appearance of rust, but isn't rust? If so it sounds like more of a 'reclaimed material' sort of project. Like, something a waterject could knock out of a piece that's been laying in the yard for years in a few minutes, problem is finding something old.
As far as trying to age it faster, I think that would be harder than vinegar and peroxide or whatever the recipe is for regular steel. I know it rapidly breaks down the top layer, but it seems like this stuff would give much more resistance in its nature alone, it's appearance of rust is not actual rust. But that's 2 minutes on google.

 

[AGinVT]

So, in my super good internet education, it's my understanding that corten steel is treated so it eventually develops this appearance of rust, but isn't rust? If so it sounds like more of a 'reclaimed material' sort of project. Like, something a waterject could knock out of a piece that's been laying in the yard for years in a few minutes, problem is finding something old.
As far as trying to age it faster, I think that would be harder than vinegar and peroxide or whatever the recipe is for regular steel. I know it rapidly breaks down the top layer, but it seems like this stuff would give much more resistance in its nature alone, it's appearance of rust is not actual rust. But that's 2 minutes on google.

Ha. I have been scrambling to educate myself on the material. Sounds like it develops the rust/patina only on the surface and acts like a protective layer. Found two products called Everbrite Instant Rust Accelerator and Everbrite Protective Coating. Supposed to create the patina and then seal it in. Definitely need to read a lot of reviews and conduct a test on a cutoff, but sounds promising. Darkens the rust, but looks kind of nice.

 

[Notarealsignguy]

Corten is an alloy that forms an oxidized layer on the surface which becomes its protective barrier. Like a self painting steel but the coating is rust.
Shipping containers used to be made from corten and painted but I was told they aren't anymore due to the cost.

 

[JBurton]

Corten is an alloy that forms an oxidized layer on the surface which becomes its protective barrier. Like a self painting steel but the coating is rust.
Shipping containers used to be made from corten and painted but I was told they aren't anymore due to the cost.

So that layer is rust? Wikipedia says it is and it isn't. Thanks internetz. Regardless, found a great pic of a rusted panel. Print it, stick it to a panel, route out the copy, weld together the shape, glue poly to the face, have some tequila. Oh, and stuff it full of LED's at some point in there.
Full size link: https://upload.wikimedia.org/wikipedia/commons/3/36/Rust-AH-2022.jpg
Sample:

 

[Notarealsignguy]

So that layer is rust? Wikipedia says it is and it isn't. Thanks internetz. Regardless, found a great pic of a rusted panel. Print it, stick it to a panel, route out the copy, weld together the shape, glue poly to the face, have some tequila. Oh, and stuff it full of LED's at some point in there.
Full size link: https://upload.wikimedia.org/wikipedia/commons/3/36/Rust-AH-2022.jpg
Sample:
View attachment 163682

Yes it's rust.
"in the case of weathering steel, things would work in a slightly different way. While the rusting process would definitely start off in the same way, the progression would be slightly different. This is because the alloying elements in the steel would produce a rust layer that would be stable and adhere to the base metal. This would then help to form a protective barrier that would prevent further access of moisture, oxygen, and pollutants. As such, you would be able to experience a corrosion rate at a much lower level than what you would normally find on ordinary structural steel."

 

[Greg Kelm]

Check out www.surfinchemical.com for various finishes. I used it on a project and turned out great. Process was easy and I used their clear coat to prevent further oxidation.

https://www.youtube.com/@surfinchemical895

 

[AGinVT]

So that layer is rust? Wikipedia says it is and it isn't. Thanks internetz. Regardless, found a great pic of a rusted panel. Print it, stick it to a panel, route out the copy, weld together the shape, glue poly to the face, have some tequila. Oh, and stuff it full of LED's at some point in there.
Full size link: https://upload.wikimedia.org/wikipedia/commons/3/36/Rust-AH-2022.jpg
Sample:
View attachment 163682

Ha. Thank you for the ideas and image. At a minimum, there is one part of this plan I think I will definitely be getting behind.