Engraving bamboo on CO2

[Ignas Kaz]

Is there an actual way to make bamboo engraving dark ?
Tried fast with lots of power, slow with little power, in focus, out of focus to varying degrees…and the combinations in between. But no matter what i do the engraving just washes off under water while in cleanup stage, So i’m just left with engraved depth but not much colour… To be clear i’m not looking for paint filling/staining the engraving tips, just trying to figure out if its just wood itself that is not conducive to engraving on CO2 lasers ? (also to avoid unnecessary steps in production)…
Machine is 80W CO2, so diode wisdom may not apply.

[Pete Cyr]

If you apply 2-3 clear coats of lacquer or shellac, then engrave, then use either brown or black "liquid" shoe polish slathered over the engraving you will get the result you are looking for.

After slathering the liquid shoe polish you must immediately wipe off all you can with clean rag/paper towels - recommend testing before you do.
The picture attached is done on cherry with black liquid "KIWI" shoe polish - the stuff I use is in a plastic bottle with a foam applicator pad

Injury.jpg

kiwi polish.png

[Ignas Kaz]

Not keen on "finishing" it with anything. Especially as i see shoe polish not exactly food safe (yeah, afraid to get sued by dumb people).
In general i want to know if bamboo can be engraved dark without any additional finishing. And to exclude steps in production...

[Pete Cyr]

Just so we are clear I am NOT telling you how to do your job.

For food safe I can only recommend 20% pwr - 20-30 mm/sec.
It will burn deeper and give a darker burn but bamboo is very hard and is difficult to get a good char.
I assume this is a cutting board so cutting deeper may not be your choice as it tends to create a place where food can be trapped if not cleaned well.
it is not an easy product to get a dark burn in.

As far a food safe - I know lots of folks over here that regularly put their foot in their mouth daily while wearing polished shoes and they seem to be ok - health wise - not so much in other ways

[Gene Uselman]

You could try LaserBond 100- not sure about foodsafe but I would think it would be burnt away- or black epoxy resin.

[Ignas Kaz]

so, this is effectively what i can do to bamboo without messing with filling/staining...
Engraved at 250mmps ~20-30% power and way out of focus (~7-8mm down from normal on 2" lens)...

[Pete Cyr]

That looks really good for bamboo

[Ignas Kaz]

It does, in comparison to what i see most. Mostly inconsistencies in colour because of stripey nature of panels. So i went way out of focus to see just what happens. Most of the colour washed off, but at least consistency is there... I was kind of hoping i'm missing something and it is possible to get darker burn on it...

[Gene Uselman]

A deeper burn always looks darker in my experience- maybe followed by your out of focus pass? As Pete sez these are not going to be used as functional cutting boards in my estimation.

[Ignas Kaz]

Burn is not that deep in above example, maybe half a millimeter to a millimeter (grain variation). I will be trying to do a deep hog out of material just to see what happens. However i see that bamboo being so stringy will still retain the "grain" in the engraving. And i also think the deeper i hog the more pronounced said "grain" will be...