Any Suggestions on Reducing or Eliminating Soot?

[rebeltaz]

Keeping with my love of silver coins, my girlfriend and my astrological signs:

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BUT.... HOW CAN I ELIMINATE OR at least REDUCE SOOT?

This is straight off the laser:

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This is after sanding:

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The edges are so bad that I have to wipe them down several times with a paper towel or else black soot is all over my hands.

[JimNM]

Good ventilation into and out of the work space, and make sure there is cross ventilation from inlet across the work to the outlet.

Faster passes
Lower power
Better focus

Season to taste. Two passes at 75% power will leave less soot than a slower single pass at 100% power.

Also, use a layer of thin masking tape over the engrave area - any soot left will settle on the tape and leave your wood much cleaner.

[rebeltaz]

Good ventilation into and out of the work space, and make sure there is cross ventilation from inlet across the work to the outlet.

Faster passes
Lower power
Better focus

Season to taste. Two passes at 75% power will leave less soot than a slower single pass at 100% power.

Also, use a layer of thin masking tape over the engrave area - any soot left will settle on the tape and leave your wood much cleaner.

On the cuts, I'm doing 400mm/min @ 75% power 2 passes.

Focus... I'm using their little acrylic focus block, but... ¯\_(ツ)_/¯

As for ventilation, it's in a open air room with an exhaust fan sitting directly behind it I guess I could use an enclosure for a more negative pressure situation.

I have used the masking tape before. I may have to go back to doing that, pain that it is.

I appreciate it!

[Gillman]

Wood type? If you are using plywood, it will have more than most hardwoods. I made a ribbon caddy for the wife today, and was reminded that plywood has the dustier sooty edges that then move to the surfaces when handling. Never have the same issues when working with my maple boards.

[rebeltaz]

Wood type? If you are using plywood, it will have more than most hardwoods. I made a ribbon caddy for the wife today, and was reminded that plywood has the dustier sooty edges that then move to the surfaces when handling. Never have the same issues when working with my maple boards.

It's supposed to be baltic birtch, from Amazon so who knows. I'll see if I can't find another wood type and try that.

[Beeyobee]

An enclosure will make a big difference, in my experience. Without an enclosure, you're just kind of sucking smoke away in a somewhat random manner. With a well-designed enclosure, you get better airflow across your work piece, pulling more smoke away and reducing soot.

[JimNM]

For cutting all the way through, be sure to allow for gas and soot to have an exit from underneath, as well as from above. Simple spacer to hold the work piece off the surface by 1/8" (~3.2mm) would be perfect. My metal cutting surface has ridges built in that allows air to flow through the channels between -note, it does not work nearly as well when not aligned to air flow. The small details all make a difference, and those differences add up.

Not having the laser in an enclosure is a HUGE red flag for me. Not only to contain and evac smoke and pollutants, but also to reduce the risk to my eyes and everyone else's from incidental laser exposure. Yes, you can lock yourself in the room with the laser to keep the kids and pets out... but what about the neighbor across the yard that may eat a reflection through your window? Not trying to beat you up, but a simple enclosure will pay for itself many times over.

[rebeltaz]

For cutting all the way through, be sure to allow for gas and soot to have an exit from underneath, as well as from above. Simple spacer to hold the work piece off the surface by 1/8" (~3.2mm) would be perfect. My metal cutting surface has ridges built in that allows air to flow through the channels between -note, it does not work nearly as well when not aligned to air flow. The small details all make a difference, and those differences add up.

I do use a honeycomb grid.

Not having the laser in an enclosure is a HUGE red flag for me. Not only to contain and evac smoke and pollutants, but also to reduce the risk to my eyes and everyone else's from incidental laser exposure. Yes, you can lock yourself in the room with the laser to keep the kids and pets out... but what about the neighbor across the yard that may eat a reflection through your window? Not trying to beat you up, but a simple enclosure will pay for itself many times over.

lol... So in this room, the only window is permanently covered with white foam board insulation, with the exception of the six inch slot at the bottom, where a board is installed with a 4" hole for the vent hose. Nothing is getting out that way.

Plus... nearest neighbor is at least three acres away. We're not all city folk

Also, when I am engraving, I leave the room (after expelling the cat), shut the door and monitor the machine on a wifi camera.

I'm not knocking the enclosure. I am sure that it would help with the lingering smoke and smell that takes a while to evacuating, but from a "safety" perspective... nah. For my use case scenario, that would do nothing.... ¯\_(ツ)_/¯

[JimNM]

'Nuff said about your safety

The lingering smoke will deposit ash and soot on every surface. If you are in a certain state on the west coast, those things can cause cancer My main product is now Yeti type tumblers that I burn the coating off of. The burned paint ash is very reactive in my throat and lungs. Even though I engrave in my 2-car garage with considerable natural ventillation, I vent my work to the exterior through a filter.

The second most popular product from my shop is earrings - those are made from a wood product that has a masking tape layer from the vendor. That can be a real pain when trying to "weed" the leftover tape bits off the small and sometimes delicate parts. I feel your pain.

Explore the three variables I gave you in my first post - go to extremes to find the balance that works for you.

I suggest you use a ramp test to verify your best laser focus

Remember that when cutting all the way through a piece of wood, subtract half the thickness from your focus height. A 8mm thick wood that has the laser focused on the surface, can be way out of focus when you reach the bottom edge of the cut.

Have fun, let us know how you get along with your projects (don't forget your safety squint!)

[JimNM]

Honeycomb does not help, if you don't have a downdraft or a cross draft built in under the piece. You need direct air flow to carry the smoke and debris away from the cut. Just sitting on top of a honeycomb makes the airflow worse.