Laser "etching" steel with low power laser !?

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Downunder35m
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Laser "etching" steel with low power laser !?

Post by Downunder35m »

Once you played enough with carboard and wood and despite knowing it really can't work you still try to engrave some metals....
Of course you don't want to invest into costly coating either, after all a can laser marking spray can cost in excess of 50 bucks in some places.

So what are the two main etchin or marking methods in use anyway?
A powerful fibre or CO2 laser does what your little diode laser does on wood - it is able to REMOVE the material and produces a true etching.
A low power laser needs some help to do anything at all.
Like those marking fluids, providing a print like quality that won't really come off easy and won't rub off.

For our little laser though we face a long list of problem when it comes to using chemicals on the surfaces we want to engrave.
Fumes are the least of the problem...
We don't want anything that causes corrosion, produces acid fumes or worse when the laser hits it...
I guess there is a reason these marking fluids are so expensive and we should just buy them - or not ?

I have done quite a bit of etching, mostly cirbuit boards and blades but also some gun restaurations.
Of course you pick up and try some of dirty tricks over the years...
Like making your own bluing solution or creating line etchings....
Bur what might work good enough on a laser, especially a rather weak one?
So far I have two candidates that show enough potential to be explored further:

Acid goo coatings...
Most acids, especiall once ho will damage steel, even stainless.
Buying some acid paste is easy enough, just go to your favourite supermarket and buy a jar of the cheapest mustard they have, I prefer the french mustard ;)
Smear a really thin layer onto the steel and then hit it with the laser at a very low spped and full power.
For a 5W model I recommend going as slow as 50mm/min with three or four passes.
On some steels a single pass is fine, so do some tests first please.
Key is of course to have a clean surface, no dirts, no smear...

Number two is still a work in progess - coffee ;)
sounds crazy but coffee actuall creates rather nice effects on carbon steel.
A dmascus blades comes out beautiful after a few hours of soaking in coffee.
Just don't use hot water to make it, use room temp water and let the stuff soak for a long while before filtering.
I also hang some paper towel strips in it for later use.
Getting a liquid to stay on a flat surface it hard, hence using paper strips to provide and hold the coffee in place.
Gum Arabic works well to create a paste, same for adding a bit of flour but I am still working on a mix that produces equal results every time.
It might even work if just a tiny amount of water used with the coffee powder to create a coffee paste but I have not tried this yet - need to get more coffee first as I don't really drink the stuff.
Exploring the works of the old inventors, mixng them up with a modern touch.
To tinker and create means to be alive.
Bringing the long lost back means history comes alive again.
liquidhandwash
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Joined: Thu Sep 17, 2020 5:28 am
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Re: Laser "etching" steel with low power laser !?

Post by liquidhandwash »

you can try this I do it with the students and get a great result.
https://www.instructables.com/Engravein ... er-Cutter/
Downunder35m
Posts: 484
Joined: Sun Aug 16, 2020 5:32 am
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Re: Laser "etching" steel with low power laser !?

Post by Downunder35m »

Electro etching is great fun indeed....
But right now I am more focussed on the "etching" or to be precise marking of those impossible materials.

My last electro etching project though was rather funny, funny enough to share...
A friend of mine ordered a bunch of vinyl stickers.
Just imagine the classic disability sticker you would find on car windscreens.
Same layout, same colors, just with a stick girl in front giving the guy a... well, let's say some pleasure ;)
He was really desperate to have this in metal, like in a trophy stand.
So he approched me one during a BBQ and siad:
"Hey, you know everything and do everything, can you make me metal emblem from this?" And handed me one of these stickers....
I made it sound really hard and complicated, with lots of even more complicated preparations involved.
I mean: You have to justify the payment in the form of a slab of beer somehow ;)
But all I really did was this:
Scan the sticker, vectorise it and then place it under my CO2 destroyer - made a lot of bad stink but was only for a minute or so.
Used his now cut out sticker as the mask and painted the rest.
Was a bit lazy so instead of a real electro etching with paying attention and all I just used hydrochloric acid with a good cup full of hydrogen peroxide in it.
Came back after about an hour and it was DEEP ;)

But since you make somany projects with the kids, how about the sponge etching and galvanising? ;)
I like it because it is quick and simple, especially if you have to galvanise a few little things at once.
Works great with masks as well.
For example, make a copper sulphite solution and wrap some cotton wool over a stiff enough wire or metal pin.
Instead of submerging the part you can now do very detailed work directly and even for different times in different areas.
Exploring the works of the old inventors, mixng them up with a modern touch.
To tinker and create means to be alive.
Bringing the long lost back means history comes alive again.
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