Leg day

[tjbnwi]

The legs weigh 65 pounds each. The owner has chosen to leave them with no finish whatsoever so ever. I did blue and oil the cut ends of the flat bar.

Set the top today, it is QSWO stained to match the other oak pieces in the kitchen.

A new bench and a coffee table is on the list.

Tom

 

[luvmytoolz]

Very nice! Bit dubious about the benefit of no finish on the legs myself, but awesome work, looks great!

 

[tjbnwi]

Very nice! Bit dubious about the benefit of no finish on the legs myself, but awesome work, looks great!

Strictly a looks preference.

Tom

 

[nclemmons]

Those look great, Tom!

 

[Packard]

No finish makes no sense. A coat of shellac + a couple of coats of clear is a more sensible solution. But no water-based finish in direct contact with the steel.

 

[Cheese]

I like the look of the legs a lot... ...and I also get the no finish thing, but at some juncture a decision should be made between aesthetics & practicality. I've been experimenting with some finishes to get the "black naked steel" look but with a smidgeon of additional protection.

 

[tjbnwi]

No finish makes no sense. A coat of shellac + a couple of coats of clear is a more sensible solution. But no water-based finish in direct contact with the steel.

View attachment 378920

Least of my worries.

DTM and the primer for it are both waterborne.

Tom

 

[onocoffee]

When I was a much younger person, I volunteered as a clerk at the First Circuit Court of Hawaii in Honolulu. The judge that I worked for oversaw one of the longer standing cases on the docket. Many years before, when they were building the Aloha Stadium (where the US NFL used to hold their Pro Bowl), the designers sold the state on the idea that the raw exposed steel structure would develop a natural weather-resistant "patina".

Most of us would call this "rust" - and you can imagine the rest.

 

[tjbnwi]

When I was a much younger person, I volunteered as a clerk at the First Circuit Court of Hawaii in Honolulu. The judge that I worked for oversaw one of the longer standing cases on the docket. Many years before, when they were building the Aloha Stadium (where the US NFL used to hold their Pro Bowl), the designers sold the state on the idea that the raw exposed steel structure would develop a natural weather-resistant "patina".

Most of us would call this "rust" - and you can imagine the rest.

Very different environment, this table is located in a high desert. I have about a ton of this alloy steel on the shelf years old with no rust on it, including the cut ends which have not been treated. I chose to blue and oil the cut ends on the bars due to water from washing the floor.

They did not use weathering steel on the stadium?

Tom

 

[rvieceli]

Apparently they did use Corten on the stadium but the salty environment caused the Corten to continue rusting.

https://alohastadium.hawaii.gov/wp-content/uploads/2019/01/2018-12-12-VOL-1-FINAL-Aloha-Stadium-2018-Corrosion-Review-Report-and-App-A-4.0.1.pdf

Ron

 

[tjbnwi]

Apparently they did use Corten on the stadium but the salty environment caused the Corten to continue rusting.

https://alohastadium.hawaii.gov/wp-content/uploads/2019/01/2018-12-12-VOL-1-FINAL-Aloha-Stadium-2018-Corrosion-Review-Report-and-App-A-4.0.1.pdf

Ron

TYhank you for the clarification.

Tom

 

[Packard]

TYhank you for the clarification.

Tom

Apparently they did use Corten on the stadium but the salty environment caused the Corten to continue rusting.

https://alohastadium.hawaii.gov/wp-content/uploads/2019/01/2018-12-12-VOL-1-FINAL-Aloha-Stadium-2018-Corrosion-Review-Report-and-App-A-4.0.1.pdf

Ron

Corten depends on a continuous layer of self-inhibiting rust. Anything that prevents that layer from forming will thwart the corrosion inhibiting qualities.

This from Google AI:

Corten steel is not very durable in coastal environments due to the salt in the air, which prevents the protective rust layer from forming and can lead to continuous corrosion. While the material needs wet and dry cycles to develop its protective patina, persistent salt spray from the ocean interferes with this process, causing the rust to be unstable and the steel to corrode and potentially fail over time.

I first saw Cor-Ten steel in the early 1970s. The rust is self-inhibiting. Once a full film of the rust forms, no additional rust will occur.

Its main use (that I have seen) is highway barriers. The main advantages over hot dipped galvanized barriers are lower cost, longer life, and a less-atttention-getting rust color vs. silver colored galvanized finish. Also, the hot-dip process involves a lot of heat, and that heat tends to soften the steel and make it less effective as a barrier as the heat partially anneals the high tensile steel.

It was originally a patent-protected process and spelled.”Cor-Ten”, which stood for High Tensile, Corrosion inhibiting. I guess the patent ran out and the spelling changed as a result.

Google AI writes:

Corten steel, or weathering steel, was developed in the 1930s by the U.S. Steel Corporation for use in railroad hopper cars. Trademarked as COR-TEN®, its name is a portmanteau of "CORrosion resistance" and "TENsile strength". Its use expanded to architecture and art beginning in the mid-20th century, with notable early architectural projects including the John Deere World Headquarters in 1964.

And here is my Google Search “History of Corten”:

Google Search

 

[Cheese]

Interesting report Ron...thanks for that.

So, I've learned 2 things about so called "non-corrosive metals" this week, COR-TEN should not be used in a coastal environment unless it's overcoated with a protective finish and even 316 stainless fasteners should not be used on wooden boats below the water line.

 

[tjbnwi]

I like the look of the legs a lot... ...and I also get the no finish thing, but at some juncture a decision should be made between aesthetics & practicality. I've been experimenting with some finishes to get the "black naked steel" look but with a smidgeon of additional protection.

Have you tried blueing?

This is what I use;

https://www.brownells.com/tools-cleaning/paint-metal-prep/metal-bluing/oxpho-blue/?srsltid=AfmBOorlyMMu9vaCLJGsiNx_7MTs9LLazILLOsew_RKn7CdA1qWsLw7ChGI

Make sure the metal is absolutely clean, I use Acetone, apply the blueing, wipe as needed, once dry apply a very light coat of oil.

Tom

 

[Packard]

Interesting report Ron...thanks for that.

So, I've learned 2 things about so called "non-corrosive metals" this week, COR-TEN should not be used in a coastal environment unless it's overcoated with a protective finish and even 316 stainless fasteners should not be used on wooden boats below the water line.

Also 400 series (which includes all the knife making stainless steels) should not be used on boats. The 400 series steels are magnetic and a magnet makes a good test for 400 series stainless steel. 400 series stainless steel will form small pockets of rust. Most flatware is made from 400 series stainless steel, but the small bits of rust will wash off in the dishwasher or with soapy water and a sponge.

 

[Packard]

Have you tried blueing?

This is what I use;

https://www.brownells.com/tools-cleaning/paint-metal-prep/metal-bluing/oxpho-blue/?srsltid=AfmBOorlyMMu9vaCLJGsiNx_7MTs9LLazILLOsew_RKn7CdA1qWsLw7ChGI

Make sure the metal is absolutely clean, I use Acetone, apply the blueing, wipe as needed, once dry apply a very light coat of oil.

Tom

Traditional gun bluing process involves high heat (about 600 degrees) and has a salt spray rating claimed from the low 20 hour range (which seems reasonable to me) to 96 hours (which is a Paul Bunyan tall tale). All the cold blueing I’ve read about is less effective. And the Brownells’ product does not list any salt spray rating claim. Worrisome. I would contact Brownells and ask what the salt spray rating is for their product.

This from Google AI:

There is no specific, standardized salt spray (ASTM B117) rating or hour count publicly available for Brownells Oxpho-Blue. This is typical for cold bluing products, which are generally intended for touch-ups and not for providing long-term, high-level corrosion protection like a professional hot blued or a modern painted finish.

Note: Salt Spray testing is done in a high temperature chamber with a high saline fog. The product is removed the chamber briefly every 2 hours and observed for rust. As soon as rust appears, the test is complete. This highly hostile environment accelerates the corrosion process. The hour rating give a relative (not absolute) rating for corrosion.

The standard test is ASTM B-117.

Some familiar metal’s ratings (approximate)

Nickel plating: 20 hours
Zinc plating with clear chromate 0.0003” thick: 90 hours
Pre-galvanized steel (“commercial quality” 40
Black oxide: less than 2 hours
Black oxide with oil: 95 hours
Black oxide with acrylic clear: 20 hours.

 

[peter halle]

I love the look of those legs, and have wondered about steel legs for a couple of tables on my horizon. Mine will have to have some sort of finish. With four Golden retrievers their noses and slobber would definitely cause corrosion.

Peter

 

[Packard]

I love the look of those legs, and have wondered about steel legs for a couple of tables on my horizon. Mine will have to have some sort of finish. With four Golden retrievers their noses and slobber would definitely cause corrosion.

Peter

A pricy, but durable finish is clear powder coating. You can get as much as 800 hours of salt spray rating for powder coating, though typically about 250 hours. Which is way more than zinc plating or any brush on finish. But note, that rubbing of shoe soles will wear through almost any finish over time. So the position of the legs can have a big impact on corrosion.

 

[tjbnwi]

Traditional gun bluing process involves high heat (about 600 degrees) and has a salt spray rating claimed from the low 20 hour range (which seems reasonable to me) to 96 hours (which is a Paul Bunyan tall tale). All the cold blueing I’ve read about is less effective. And the Brownells’ product does not list any salt spray rating claim. Worrisome. I would contact Brownells and ask what the salt spray rating is for their product.

This from Google AI:

There is no specific, standardized salt spray (ASTM B117) rating or hour count publicly available for Brownells Oxpho-Blue. This is typical for cold bluing products, which are generally intended for touch-ups and not for providing long-term, high-level corrosion protection like a professional hot blued or a modern painted finish.

Note: Salt Spray testing is done in a high temperature chamber with a high saline fog. The product is removed the chamber briefly every 2 hours and observed for rust. As soon as rust appears, the test is complete. This highly hostile environment accelerates the corrosion process. The hour rating give a relative (not absolute) rating for corrosion.

The standard test is ASTM B-117.

Some familiar metal’s ratings (approximate)

Nickel plating: 20 hours
Zinc plating with clear chromate 0.0003” thick: 90 hours
Pre-galvanized steel (“commercial quality” 40
Black oxide: less than 2 hours
Black oxide with oil: 95 hours
Black oxide with acrylic clear: 20 hours.

I replied to the post by Cheese. I do not believe he is near the coasts (Minnesota?). From his post he looking for a finish that is “decorative” with a blackish steel look.

If what I was working on would be in a salt spray environment blueing would not be a product I would use.

Tom