Rust removal laser

[macona]

You can tell by the sound it is q-switched.

You dont want a polygon mirror, a galvo and a 1D f-theta lens to focus it. The mirror will be a dielectric coated mirror specific to the wavelength. Honestly, that's all the easy part. The big-ass fiber laser is the expensive part. 200w is really where the smaller units start with the larger units being around 1kw.

I would in no way use Pepsi and elbow grease. Use something that works like electrolytic rust removal or media blasting.

[javanam]

@VDX mine diode laser is similar like that you posted in the yt video.
What lens you have used for this laser ?
I have 3 diode laser like that and a 6kw disk laser but without galvo head i have only the laser-fiber-chiller

I want to remove rust from inside a 1000lt air tank that has a narrow human door but all conventional methods(angle grinder wire brush/sandblasting) i have tried failed for various reasons (mostly dust)
so iam searching the laser method...

[VDX]

... my fokussing enses for the diodes are "random finds" or orderd by Thorlabs for NIR and 50mm FL, so not suited for galvos, or rotating polygon-mirrors.

For a rotating polygon setup you could by chance search for old laser-printers -- some (ye older, the better) have two glass lenses shaped for a 1-axis f-theta optic and coated (or not coated) for the NIR-diode, so should work with the 975nm-diodes too ...

Viktor

[macona]

Before you go through the trouble of derusting an air tank you should have the tank checked ultrasonically. There is a name for rusty air tanks.... bombs.

[preston135]

phosphiric acid.

it's the special ingredient of coke. (that removes rust)
and also a dominant ingredient to etching primer.

i've done lots of metal/coachwork over the years.

there may be a new found way to remove rust with lasers and whatnot.... but i still use oxy acetylene majority of the time for my welding purposes. i'm quite "oldschool"
although i will use electric for panels/sheets. i always use gas on chasis ect.
but phosphoric acid works. it did in the past and still will in the future.

if youre running anything over 8-10 bar get it checked out professionaly.
tapping around it (empty) with a little hammer. listen for a tone change where the rusty point is. usually the bottom. you'll notice if the degridation is really bad.

[javanam]

I have checked the tank with ultrasounds & made pressure test with water @ 21bar/1hour -> success .

Phosphoric acid & rust converters with tanic acid does not work because inside is rust and old primer half-half so acids do not work on the top of old paint.
Needs mechanical or laser cleaning.
The best solution is water-sand blasting but this machine is 3000bar and very expensive (> 100k euros).

Im searching for laser rust removal..

[preston135]

I have checked the tank with ultrasounds & made pressure test with water @ 21bar/1hour -> success .

Phosphoric acid & rust converters with tanic acid does not work because inside is rust and old primer half-half so acids do not work on the top of old paint.
Needs mechanical or laser cleaning.
The best solution is water-sand blasting but this machine is 3000bar and very expensive (> 100k euros).

Im searching for laser rust removal..

i think using a laser for rust removal is expensive.

get some b/a and sand/bead blast it... very cheap. do it in segments., let the dust settle.


with regard to the laser i would guess a fanning optic/crystal would work better than a galvo.
it only needs to do one thing. fan with consistency.

[kecked]

i think using a laser for rust removal is expensive.

get some b/a and sand/bead blast it... very cheap. do it in segments., let the dust settle.


with regard to the laser i would guess a fanning optic/crystal would work better than a galvo.
it only needs to do one thing. fan with consistency.

I thought cyl or such myself but that’s actually dumb. You want to concentrate the energy not spread it out. You need to move the focused beam on the surface.

if you get this working please come back and let use know. It would be very handy.

[macona]

i think using a laser for rust removal is expensive.

get some b/a and sand/bead blast it... very cheap. do it in segments., let the dust settle.


with regard to the laser i would guess a fanning optic/crystal would work better than a galvo.
it only needs to do one thing. fan with consistency.

No, with a lens or other dispersive optic you kill the energy density which is needed for the process. I suppose if you had a big enough laser but at those kind of power levels you are going to have optics issues.With a galvo you can set you scan width for the job to have a bit more flexibility.

On the tank if it tests good with ultrasonic then why not just use a rust converter and paint and leave it as is?

[preston135]

indeed... i never thaught about the concentration of the beam.
but if a beam is blowing out the mirrors...how else?

polished tungsten?