How To Steel N Brass

[Way-Barney]

Why do brass liners scratch the hardened steel of the tang on a folding knife, I would have thought that its the other way round.

 

[Natlek]

Why do brass liners scratch the hardened steel of the tang on a folding knife, I would have thought that its the other way round.

That is impossible , something else make scratches

 

[Ken H>]

Could it be a tad of grit gets caught between the brass 'n tang that actually does the scratching?

 

[Way-Barney]

so its lack of proper maintenance?

 

[Natlek]

Could it be a tad of grit gets caught between the brass 'n tang that actually does the scratching?

If it was new knife ...............depend on finish of steel it can be let call it *lose burr* that make scratches....brass will *catch* them and then they will make scratches .When I finish grinding bevels on knife /40 grit belt/ I use piece of scotch brite and with my thumb I sand bevels .I call it burr removing and believe me make BIG difference how finish look after that .

 

[Bill DeShivs]

Water can wear away stone. Because a material is softer, doesn't mean it can't wear a harder material.
Adding dirt/grit between the 2 accelerates this wear.
Until recently, a few scratches where the blade opens was expected. Then, makers started using thin washers or milling out liners to prevent it. It's a great idea-until those thin washers wear through, or the liner wears out because of insufficient surface area. When that happens, you have a knife that needs serious work.

 

[Richard338]

When I wanted to drill into a hardened ball bearing and was waiting for a carbide bit to arrive, I tried drilling by putting abrasive paste on the end of a brass rod. It does work, but the hole wasn't as clean and precise as I hoped.

 

[Way-Barney]

Water can wear away stone. Because a material is softer, doesn't mean it can't wear a harder material.
Adding dirt/grit between the 2 accelerates this wear.
Until recently, a few scratches where the blade opens was expected. Then, makers started using thin washers or milling out liners to prevent it. It's a great idea-until those thin washers wear through, or the liner wears out because of insufficient surface area. When that happens, you have a knife that needs serious work.

Hello Bill,

Is it not a step in the right direction?

 

[Bill DeShivs]

Hello Bill,

Is it not a step in the right direction?

If properly done with the right size (maximum diameter) washers it's OK.
Expecting tiny diameter, thin washers to hold up for any length of time is not a great idea.

 

[Way-Barney]

If properly done with the right size (maximum diameter) washers it's OK.
Expecting tiny diameter, thin washers to hold up for any length of time is not a great idea.

Thanks for your valued opinion.

What minimum thickness would you suggest?

 

[Bill DeShivs]

I don't really know, as I don't use them.

 

[Stacy E. Apelt - Bladesmith]

Just a note:
It is the dust that gets on the blade and liners that causes the scratches, not the brass itself. The soft brass plus the oil from the blade and maintenance traps the minute hard particles. Most dust is quartz based and will scratch steel.

As for water wearing away rocks, it is the minute particles of sand and minerals that does most of the wear. The other part is soluble minerals rock dissolving very slowly. This creates a fragile matrix which breaks away in minute pieces under the impact of moving water. Freeze/thaw cycles also contribute to the waer.
A good example is the Grand Canyon. It slowly eroded over millions of years as the water broke down the sandstone and the resulting muddy slurry wore away the rock.

One of my favorite places to see in New Hampshire as a boy was called "Glacier Bowl". Not much as far as spectacular, but a local tourist attraction. It was a large round bowl-shaped depression in solid granite. It was caused by a large boulder getting trapped under the glaciers as they melted, and moving around. As it slowly turned and rotated, it ground out the huge smooth bowl. Story was that when first discovered it had a large perfectly round several ton rock in the bottom. I wonder if it is still a local tourist attraction? It wasn't too far from Meriden, NH.

 

[Natlek]

A good example is the Grand Canyon. It slowly eroded over millions of years as the water broke down the sandstone and the resulting muddy slurry wore away the rock.

There is a theory that says that everything happened very quickly . In short ... The shores of some giant lake gave way ... . .

 

[Stacy E. Apelt - Bladesmith]

The space-laser beams cut the Grand Canyon when the aliens drained Lake Agassiz to steal earth's water.

Seriously, you are right. It was "sudden" in geological terms.

80 million years ago the giant lake Agassiz drained down what is now the Mississippi River.
65 million years ago, as the land rose due to continental plate movement, the Rocky Mountains started to form.
The Colorado River formed to carry the Rocky Mountain watershed to the Pacific Ocean.
Starting 35 million years, ago the Kaibab plateau rose in what is now Arizona. This slowly blocked the Colorado, forming a huge lake called Bidahochi, and a new river path south to the Gulf of Mexico.
As the plateau rose, at some point around 8-12 million years ago, the Colorado River cut through the plateau (most likely from underground river erosion) and a collapse of the plateau started. The lake drained in rapids that cut through the 1.8 Billion year old sedimentary rocks that formed the plateau, eroding the canyon we have today over 5 or 6 million years. It reached its current depth around 1.2 million years ago.
Once the river wore away the middle of the plateau, the course returned to its original path, forming the Gulf of California about 6 million years ago as it wound its way to the Pacific Ocean.
Many other long canyons formed as part of the draining of lake Bidahochi.

So, yes, it was fast once the water started flowing - 5 or 6 million years fast.

 

[Natlek]

The space-laser beams cut the Grand Canyon when the aliens drained Lake Agassiz to steal earth's water.

Seriously, you are right. It was "sudden" in geological terms.

80 million years ago the giant lake Agassiz drained down what is now the Mississippi River.
65 million years ago, as the land rose due to continental plate movement, the Rocky Mountains started to form.
The Colorado River formed to carry the Rocky Mountain watershed to the Pacific Ocean.
Starting 35 million years, ago the Kaibab plateau rose in what is now Arizona. This slowly blocked the Colorado, forming a huge lake called Bidahochi, and a new river path south to the Gulf of Mexico.
As the plateau rose, at some point around 8-12 million years ago, the Colorado River cut through the plateau (most likely from underground river erosion) and a collapse of the plateau started. The lake drained in rapids that cut through the 1.8 Billion year old sedimentary rocks that formed the plateau, eroding the canyon we have today over 5 or 6 million years. It reached its current depth around 1.2 million years ago.
Once the river wore away the middle of the plateau, the course returned to its original path, forming the Gulf of California about 6 million years ago as it wound its way to the Pacific Ocean.
Many other long canyons formed as part of the draining of lake Bidahochi.

So, yes, it was fast once the water started flowing - 5 or 6 million years fast.

I said one of theory

An Alternative theory was that the Grand Canyon was cut very rapidly as an large inland lake formed at the end of the last ice age was suddenly released cutting through the relatively soft layers of sediments formed during the ice ages.