Inert Gas / Air assist

[Eric Ucci]

We've been told by others with laser cutters that if you substitute an inert gas (specifically argon) for your usual shop air air assist that you can eliminate charring on some materials. We're considering experimenting with nitrogen as it is a much cheaper inert alternate. Does anyone have any experience with this? Any dangers? I considered this earlier, however, I assumed that the lack of O2 would hinder cutting. I'm told that with many fabrics it eliminates charred edges. I'm eager to give it a try with a variety of materials (most importantly acrylic and plywood) and see the results.
Any input would be greatly appreciated.

Thanks

Eric
Shenhui SH-1490 150w reci
Shenhui SH-690 60w

[Tom Schulze]

I don't have any info for you, but I am very intrigued to here the results. keep us informed.

[Nick Foley]

Along similar lines, I wonder if a focused jet of pure oxygen would allow cutting thicker materials...

[Mark Sipes]

Nick.... Here is your answer......http://www.instructables.com/id/CO2-...s-sheet-metal/

[Ernie Balch]

I had good experience with a helium shield gas on a Tripled YAG UV laser for micro machining flex circuits. The smoke blasted far away from the substrate and allowed the exhaust nozzle to remove the particles.

[Bruce Boone]

I will be using nitrogen assist gas on my fiber cutting laser. Trials with it did fine in titanium after initial trials used argon. It's much cleaner than the oily compressed air I could supply and I'll be using 250 psi, which is a bit more than my 90 psi compressor can handle. Air worked well in trials, but unless you have the crazy industrial air cleaning equipment like the research facility I was at, it will be wet and oily which is not good for optics. I was told that I could substitute nitrogen for the argon I use in my welding laser also, so I'll probably end up getting full size tanks of nitrogen and supplying both lasers with it.

[Art Anderson]

I've added CO2 to the air assist in order to keep the flaring down on the "no odor" rubber when making stamps. If I don't use it, the edges of fine lines and letters will essentially burn or bubble from the flare-up. While I have used it on wood, I don't think the benefits are worth it, especially if you take the time to dial in your settings. I've not tried it with fabrics.

[Rodne Gold]

Iv'e used nitrogen , works well for keeping discolouration on paper in check and supresses all flaming , you still get char on wood and on leather. The real way to minimise char is to have a LOT of power , 250 watts or so , the power density of a small spot and a powerful tube just vaporises the wood/leather and have very little heat affected zones. Think of a BIC lighter burning a hole in paper vs a small solder blowtorch , both will do the job but the lighters hole is gonna be messy....Downside is that engraving using the high powered stuff is too "clean" , ppl seem to like the burnt effect when lasering wood , I often see plaques etc with the resin and smoke stains uncleaned and the customers seem to ooh and ahhh over it...

[Michael Hunter]

I often see plaques etc with the resin and smoke stains uncleaned and the customers seem to ooh and ahhh over it...

Weird isn't it!
I get through lots of application tape because I HATE to see smoke marks on wood.
Last Christmas I did a load of little plywood promotional tags and warned the customer that there might be *some* smoke marking - she said not to protect the wood at all and wanted them as smokey as possible.
No accounting for taste.

[Glen Monaghan]

Last Christmas I did a load of little plywood promotional tags and warned the customer that there might be *some* smoke marking - she said not to protect the wood at all and wanted them as smokey as possible.

maybe that's what is known as "shabby chic"?

[Michael Hunter]

I suppose that that is what she thought - I saw it as "poorly done".