Stop Laser Scorching without Masking or Sanding

This over here is a horribly scorched laser engraving where I've done basically everything wrong. And this

over here is a nice scorch-free laser engraving where I've done everything right. And very importantly, I haven't

right. And very importantly, I haven't used any masking or sanding to get the results that you see here. But here's

the thing. Preventing scorching

basically boils down to getting four settings to play nicely together, which I'll be honest is not easy if you don't know how to go about it. The good news is I've already spent months figuring this out and turning it into a process.

Yes, that's right. You heard me correctly. I did spend months on this,

correctly. I did spend months on this, but that's because that I knew that it would save me about 30% of the hands-on labor time that I was putting into producing my most profitable laser product. And so, I had a business reason

product. And so, I had a business reason to want to be able to do this. And in

this video, I'll walk you through the steps of my process using some real samples like these so that you can see how each of the four settings build upon each other to help you eliminate scorching for your next laser project so that you don't have to spend months

dinking around with it like I did. Oh,

and I should also mention that I'll be explaining the studs for both diode and CO2 lasers. So, with all that said,

CO2 lasers. So, with all that said, let's go ahead and get started. The

first thing you need to know is that getting rid of scorching for engravings and getting rid of scorching for cuts is actually a totally different ballgame.

So, I'm going to start by walking through the process for engravings, and then we'll come back later and do cuts.

And one of the first things you'll need to get right for perfect engravings is your air assist, which you've probably heard of. But, if you ask me, aist is

heard of. But, if you ask me, aist is one of the single most underrated and misunderstood parts of laser engraving.

So, let's get into these samples that we have here in front of us. So, first of all, we've got a couple of different rows and columns going on here with these samples that I'm showing. So, the

triangles on top are all done on a CO2 laser. And then on the bottom, all of

laser. And then on the bottom, all of these samples were done on a diode laser. This is important because it kind

laser. This is important because it kind of illustrates one of the uh differences in how air assists might show up when you're actually doing your engraving.

So, anyway, to kind of get into this in more detail, we also have uh columns of different air assist settings here. So

on the far left hand side over here we have air assist completely off. So no

air assist is being used for either of these two engravings. And then here in the middle we have air assist set to like a very low setting which you can do if you have like a a an an air compressor or some sort of pump that

you're able to adjust to a certain PSI.

Then you can adjust this just to a low setting like 2 or 3 PSI or if you have like a small pump that came with your laser. Um that's usually going to be a

laser. Um that's usually going to be a pretty low PSI as well. Then over here we have a assist set to a very high setting. So that's going to be anything

setting. So that's going to be anything 10, 15, 20 PSI or even higher. That's

going to be what I would consider a a high setting for your air assist. So

that's what's going on here. But now

let's talk about which of these options you actually want to use given your situation and the type of laser you have. Let's start up here by talking

have. Let's start up here by talking about CO2 laser specifically. Now, for a CO2 laser, I would not recommend going completely off with the air assist because that is likely to cause problems

over the long run with a buildup in things on the lens of your laser. And

so, it's usually going to be better to run at a low PSI setting. So, somewhere

around 2 PSI for the air assist if you're able to control it in that way.

Um, or otherwise, if you just have like a small built-in pump, it's very likely running at something in this ballpark anyway. And so you want a low air assist

anyway. And so you want a low air assist setting if you're running a CO2 laser.

You can run it at a very high air assist. And if you have a really nice

assist. And if you have a really nice CO2 laser, then you might still get clean results. But oftent times,

clean results. But oftent times, depending on the machine that you have, you'll actually get much sloppier engravings if you have the air assist on high when you're doing an engraving. And

you can see that in our diode laser example here. So, of all of the samples,

example here. So, of all of the samples, the messiest looking one is the air assist at a high, this in this case 20 PSI setting on the diode laser. And so,

I would typically avoid this entirely for engravings and stick to one of these two options. Okay? And so, for a CO2

two options. Okay? And so, for a CO2 laser, this is what I would do just based on my experience and doing a bunch of this, I would go with a low 2ish PSI setting for a CO2 laser. And then on a

diode laser, it it kind of depends a little bit on how you feel about your machine. So, when I run engravings on a

machine. So, when I run engravings on a diode laser, I go air assist completely off. So, I I don't run the air assist at

off. So, I I don't run the air assist at all, especially if I'm doing like a really detailed engraving like a photo engraving or something like that, just because, as you can see, hopefully in this sample, um, this is running at 4

PSI. And even still, you just get a tiny

PSI. And even still, you just get a tiny bit more scorching around the edges of the text compared with what you get over here on this perfect sample. And so if I'm running a diode laser, I typically will run it with no air assist at all

when it comes to the engraving. As I

said before, a cut is a totally different story. Um, but when it comes

different story. Um, but when it comes to running a diode laser versus a CO2 laser, this is typically what I'm going with. I'm going with no air assist at

with. I'm going with no air assist at all for the engraving on a diode laser.

And on a CO2, I'm going with the air assist set to a low setting. Now, with a diode laser, I should mention that you can have the same problem that you would have with a CO2 laser where it makes your lens dirty and you would have to

replace it or have some issue over the long run. Um, but I've done this a lot

long run. Um, but I've done this a lot and I have yet to have to replace my lens on my diode laser. And so, it seems to be less of an issue with a diode laser for some reason compared with a

CO2. So, if you want to be really safe,

CO2. So, if you want to be really safe, then kind of do the same thing for both.

Um, but if you want to do it exactly like I do, then you can do it this way.

Now, the next thing that we need to dial in to make sure that we're getting the perfect engravings that we want is the power and speed settings. Because power

and speed is going to determine the darkness as well as the depth of the engravings that we're going to get. And

so, as a result, this is actually a bit of a subjective game depending on the particular type of engraving that you want for the project that you're working for. So, for example, we might actually

for. So, for example, we might actually want a nice lighter engraving like this that's more on the surface. In other

words, not as deep as some of these other options for a given project.

However, for this example, I've just labeled it as bad because we might for a different project instead prefer something like this that's a little bit deeper and a little bit darker without going all the way over here, which is an

even higher power/ lower speed option on the right hand side. So, I won't go into any more detail on this particular part of power and speed settings because I have some free templates that you can use to test for this and find the settings that you want. You can get

those for free on my email newsletter if you want to do that. And I also have a separate deep dive video that goes into a lot of detail step by step and how to do the power and speed settings for your project. And so I'll put a link at the

project. And so I'll put a link at the end of this video to that video if you want to go check that out later. But

there is a little bit of a bonus tip that I want to talk about that I think often gets missed in uh other videos and other tutorials online, including my own in the past. And so let's talk about how

power and speed changes when it comes to line instead of fill engravings. Now, if

we compare what we have here on the left line engraving with what we have on the right, there is very clearly a huge difference in the amount of scorching that we get here on the right. But the

only thing that has actually changed here is a setting called minimum power.

And so the maximum power, which is what we typically set when doing our power and speed settings, and our speed is actually identical between the two of these. And the only thing that has

these. And the only thing that has changed is a setting called minimum power. Now, not every laser will have

power. Now, not every laser will have the minimum power setting available. And

so I'm going to jump over here into LightBurn real quick and show you how you can actually tell if this is something that you're able to dial in for your laser. So in LightBurn, what we're going to do is we're going to go to the layer that our text is on. So in

this case, it's on this blue layer, and we're going to double click on that. And

that's going to open up this cut settings editor for us. And what we're looking for is this minimum power input box right here. So some lasers will have this displayed in LightBurn. In other

lasers, this input box will be hidden.

Now, this is actually really interesting because this is a little trick that you can use to figure out if you have a laser that is what's called a DSP controller laser or a G-codebased laser.

And this could be useful for other things as well, like determining what LightBurn license you need, but that's a whole story for another time. for this

particular situation. The reason that we care about this is because if you have this input box available, then that actually unlocks a new set of tests that you can do to dial in nicer and less

scorched line engravings. And so, let's jump back over to the sample camera and we'll talk about that in more detail.

So, long story short, just to put this in a neat little bow here, the difference between the super scorch line engraving here on the right hand side and the nice neat looking one on the lefth hand side is that the minimum

power setting in LightBurn for this one here on the right is simply far too high. And so, for this one, we've just

high. And so, for this one, we've just optimized it and done some additional testing to kind of find the sweet spot for what we want for that minimum power setting. And you can actually run a

setting. And you can actually run a whole test for this as well. So, for

example, here is an example of one that I have. This actually is also available

I have. This actually is also available as a template inside of that uh that LightBurn starter kit that I talked about previously that you can get for free on my email newsletter. But any

case, what you do here is you basically run the same power and speed settings.

So all of these uh different triangles are set to different uh different minimum powers, but the same speed and max power. And then you can see like up

max power. And then you can see like up here with the minimum power set to 30%, you have scorching at the corners, but all the way down here at 5% there's not really any scorching. Maybe the uh the corners are a little bit darker than the

lines, but it looks a lot nicer. And you

could go in this case even down a little bit more, which is what I did for this sample. I believe I ran this at 4%

sample. I believe I ran this at 4% minimum power. And uh I should also

minimum power. And uh I should also mention that this is specific usually to CO2 lasers. And if you have a glass tube

CO2 lasers. And if you have a glass tube CO2 laser, then you're probably going to be stopping at around 10% because I happen to have a metal tube CO2 laser, which can run uh typically at lower

minimum power settings. And uh basically what happens for a a glass tube CO2 laser is if you go kind of below the minimum power that it can run at, it basically just stops firing and you start to get like gaps in the corners

and things like that. So anyway, long story short, you can run an extra test to dial in nicer line engravings, which can be really useful for certain types of projects. So there's one more

of projects. So there's one more ingredient for our nice perfect engravings that we're going for here that I want to talk about before we move on to laser cutting, and that is focus.

Okay? Okay. And so what I have here on the left is an example of an engraving done out of focus. And then the only thing we've changed from going from the left to the right sample is that this one over here on the right is now in

focus. And one difference that you'll

focus. And one difference that you'll notice that I think is pretty clear between the two is that on the left, if you look really closely to the edges, so if you look at the edge here on the F, there's there's basically a rounded

edge. It's almost like a bevel along the

edge. It's almost like a bevel along the edges of your engraving. Whereas if you look at the infocus version, it's like way straighter. So, if you look at the

way straighter. So, if you look at the edge of this eye, it's like super super straight and stark when you go around the corners. Now, this is interesting to

the corners. Now, this is interesting to mention as well because you might have a project or an application where you actually think it would look nice to have a bit of a rounded sort of beveled edge on the engraving and so you could

actually intentionally put your laser a little bit out of focus if you wanted that type of result. Um, but that's a little bit of an aside. If you want to have like a standard nicel looking engraving, then you need to make sure that you remember to put your laser in

focus. So, now it's time to shift gears

focus. So, now it's time to shift gears and talk about laser cutting because, as I said before, it's basically a different ballgame when it comes to dialing in the settings for eliminating scorching on a cut compared with an engraving, which is what we've been

talking about up to this point. Okay.

And so, you can see here on the left, we have a really dirty uh cut edge here where I've basically done the settings and things wrong. And over here on the right, we have a nice clean cut that basically has no noticeable uh scorching

around the edges. And so, that's what we're going for. And the first thing I want to talk about in this case is a category that we have yet to talk about, which is airflow. So, let's get into these four different samples of airflow

to figure out what exactly we want to use to get those nice clean cuts. So,

let me begin by just explaining what I mean by airflow and then we'll kind of go through each of these samples and compare the different methods. So, first

of all, what do we mean by airflow?

Well, airflow, just to give like a really simple example, is if I'm going to laser cut this piece. Okay, I'm

talking about the airspace that is underneath it when I'm running the laser. Okay, so just for example, if I

laser. Okay, so just for example, if I had a just a spoiler board, like a a piece of wood immediately under this and I'm going to try to cut it out directly on top of that spoiler board. This is

what I would call no airflow. Okay? And

then there are a few different methods of airflow. Honeycomb is one that you

of airflow. Honeycomb is one that you might have might have heard of and I'll put a little B-roll on screen of what a honeycomb looks like for anybody that's not familiar. And so this is a a

not familiar. And so this is a a different method. A third method is a a

different method. A third method is a a knive bed which is kind of like a honeycomb. It's just a a different

honeycomb. It's just a a different different shape, basically a different approach, but it's the same idea that creates a different amount of air flow on the bottom. And then there is another one which I call DIY setup. Okay. And uh

I'm going to flip each of these over so that we can kind of see the difference that this makes when it comes to how clean the cuts coming out on the other side. So it probably won't surprise you

side. So it probably won't surprise you to learn that the no airflow solution is going to be uh by far the worst. So you

can see that's super dark and scorched.

Um and it looks really bad. That's just

a really really bad one. Uh next up is honeycomb. Now honeycomb is obviously a

honeycomb. Now honeycomb is obviously a dramatic improvement. Like this is way

dramatic improvement. Like this is way way better than a no airflow solution.

Um, however, you will notice that there are tiny little uh scorch marks all along the edge, little black marks that go all along the edge of the cut, and that is from the laser basically running over the uh the little filaments that

make up the honeycomb bed. And there's

just a little bit of flashback that's going to cause those dark marks. Now,

the next one up here is basically what I think is kind of the 80% solution, and this is the one that I personally like to use most of the time when I'm doing a new project. And this is using a a knife

new project. And this is using a a knife bed. Okay? And so a knife bed is the

bed. Okay? And so a knife bed is the same idea as a honeycomb. It's just a little bit different approach to it. So

it's long knives like you can see in the B-roll here on screen instead of the the honeycomb which is sort of a mesh version of it here. So anyway, the reason that I like the knife bed is if you flip this over and compare the two

here, uh basically with the honeycomb, you're getting like basically a really frequent little small dark mark on the edge. Whereas with a a knife bed, you

edge. Whereas with a a knife bed, you still get a couple of dark marks. Um but

there's not as many of them. It's

basically just a significantly smaller number of those dark marks on the back when it comes to using a knife bed. And

so this is my usual preference for sort of the 80% solution. However, if you want a completely clean, no scorch marks, no little dark black marks at all on the back of your laser cut job, um

then what you're going to need to use is what's called a DIY setup. Now, in a video that I made about this in the past, I called this a jerryrigged solution. And I got a lot of comments

solution. And I got a lot of comments from people making fun of me and telling me, "Oh, it's jerryrigg." And so now I'm just going to call it DIY setup. So

anyway, uh basically what this is, and you can see the results here. It's super clean.

There are no dark marks at all. You

might see these two little marks. Uh

those are not scorch marks. That's just

part of the wood grain. Um but anyway, it's a perfectly clean cut all the way around. And the way that you would get

around. And the way that you would get this is basically um let me just give you a simple example here. Um, if you were trying to cut this out of, let's say, this piece of wood, then you would basically prop it up on like the corners

for example, so that there's basically nothing underneath where you're going to be doing the cut. And so, I'm just going to pull in some blocks to just give a a really simple example here. So, right

now, um, I'm kind of propping this this piece of wood here up. And, uh, if I put this like so, there's actually nothing there there's no uh, like knives.

There's nothing immediately below this cutout that I'm about to do, which is what allows you to get this nice clean cut without having any uh flashback on the edges or anything like that. And so

this is the DIY setup if you want like truly perfect cut results. It takes a little bit more effort to set it up, which is why I like that knife bed is sort of the 80% solution. Um, but if you're doing something over and over and

over again, you could set up your own jig in order to do this consistently if you're kind of trying to batch process something. So anyway, that is the DIY

something. So anyway, that is the DIY setup version for airflow. But to get these perfect laser cuts, you also need to make sure all of the other three ingredients are also dialed in. So we

again need to talk about air assist here. So what I'm basically showing now

here. So what I'm basically showing now is three different uh settings basically of air assist. You have off or no air assist at all. And uh you can see that this is really scorched on the back. But

very importantly, this can also cause flameups. And so this is definitely one

flameups. And so this is definitely one that you want to avoid. Do not run a laser cut job without air assist on.

Okay, so that's the one on the left. And

then the one in the middle is basically using a small pump or a built-in air assist on its max. Um, which is often going to probably be in the ballpark of around 2 or 3 PSI. And so for that, you

get a lot better results because you're not you're not getting the flame up or at least you're a lot less likely to get a flame up issue. But obviously, there's still a lot of scorching that you can see here along the edges. And so the

next thing that we have is running an external air. So having like an air

external air. So having like an air compressor where you can feed in 20 PSI or even higher and that is going to give you way cleaner results. And so this is where air assist really makes a huge

difference for getting cleaner laser cuts. Now here we still have a little

cuts. Now here we still have a little bit of scorching but I believe this was run on a honeycomb. And so the honeycomb bed kind of explains uh why we have that. And so if we wanted our truly

that. And so if we wanted our truly clean engravings here or or cuts rather here, we would both use a DIY setup and air assist on a high setting, which is going to be anything in the ballpark of

15 PSI and up depending on what you have available and what type of laser setup that you're running. So the next thing we have here is our power and speed settings. Now, this is very important

settings. Now, this is very important for doing a nice clean laser cut. And so

this is something that you'll need to make sure you have dialed in as well, because if you don't get this quite right, you might have a situation where the uh cut actually doesn't go all the way through. Like you can see this one

way through. Like you can see this one right here. It's not quite right and it

right here. It's not quite right and it didn't cut all the way out. And if this were to happen, we may very well have to just entirely run that project again so that it will actually be able to to pop it out. Or you might get something in

it out. Or you might get something in between where um it'll come out but it gets some like uh tags and things on the edge. So it's not very clean on the

edge. So it's not very clean on the edge. Uh but what you want is something

edge. Uh but what you want is something more like this. And I I got it kind of dirty on the front. I like dropped it in something or something like that. But

the but the cut is what we're looking at. And the cut is nice and clean.

at. And the cut is nice and clean.

There's no tags and it cut all the way through which is what we're going for.

And uh to get this sort of setting to kind of figure out what it's going to be for your laser, we'll again be using something like a test card like this.

This is a cut test compared to the engrave test uh that we looked at earlier. If you're not sure how to use

earlier. If you're not sure how to use these, if this is something that is over your head, um I do have a again a deep dive video that goes into how to use uh these sorts of things in more detail and

also how to importantly read the tests, which is something that um is kind of often overlooked. And so if you need to

often overlooked. And so if you need to understand how to set one of these up, run them and read them so that you know what settings to use for your laser.

I'll put a link to that video at the end of this one. So anyway, we can move on from this to the next thing. And the

next thing we need to talk about for getting nice clean laser cuts is having your laser in focus. So when you have your laser in focus, you're a lot more likely to get a nice clean edge on your cuts compared to if you have your laser

out of focus, which will be this example over here, where you're far more likely to have a sort of dark uh wide cut lines. You can see this this cut line is

lines. You can see this this cut line is pretty wide around here. Um, but even more importantly, it has not cut out all the way. So, it's kind of clinging on

the way. So, it's kind of clinging on there with some tags. And so, this is an issue that you can have as well if your laser is not focused quite correctly.

And so, this is another situation where just like with the engraving, it's really important to make sure that you're remembering to uh get your laser properly focus before running a job like this. But, up to this point in the

this. But, up to this point in the video, we've been talking about laser engravings and laser cuts separately.

But what you'll probably know is that these two things are often going to go together inside of the same laser project. And as a result, we need to dig

project. And as a result, we need to dig deeper to understand how we're actually going to manage the changes that occur between an engraving and a cut to make sure that we get both a high-quality

engraving and a high-quality cut within the same project, even though some of these settings are going to change a little bit when that shift happens. So,

let's start with the easy win. For any

laser project where we have both a cut and an engraving, we can usually actually use the exact same focus and the exact same airflow solution. So, we

won't really need to change these at all, even when we have both a cut and an engrave in the same project. However,

when we change to power and speed, now we're going to have things changing up a little bit. But, this one's pretty

little bit. But, this one's pretty simple, and I think you'll already probably be familiar with some of these steps, but I'll just kind of give you a quick summary here. So over here in LightBurn, just as a simple example, if we have one of these uh triangle cutouts

like this, we can have our text engraving on one layer with its own settings. And then we can have the red

settings. And then we can have the red cutout on a separate layer with its own settings. So that I think will be pretty

settings. So that I think will be pretty straightforward and you'll understand that the power and speed settings are going to need need to be different depending on if you're cutting through the material or just engraving on the surface. Now, things get a little bit

surface. Now, things get a little bit more interesting and nuanced when we go to the air assist because remember we want for our optimized engravings and cuts, we actually want a pretty different setting for the air assist.

And so, if we're using both of those on the same project, we need to make some little changes to make that possible.

So, just as a quick reminder, when it comes to getting nice clean engravings and cuts with the air assist, typically what I'm going to do is I'm going to have the engraving, so our blue portion here set such that it either has no air

assist at all, which is what I would typically do for a diode laser, or it has like a very low pressure air assist on, which is what I would do for a CO2 laser. And again, that would be in the

laser. And again, that would be in the ballpark of 2 PSI. And that is also going to be similar to what you'll often get with a small built-in pump with something like a desktop CO2 laser. But

then when it comes to doing a cut, regardless if I'm using a diode or a CO2 laser, I'm always going to run a high pressure air assist for that cut to get those nice clean cut lines. And for me,

that's typically going to be somewhere between 10 and 25 PSI. So somewhere in the ballpark of 15 PSI is usually what I'll run. So now I'll just quickly share

I'll run. So now I'll just quickly share with you the three methods I personally have used in the past when switching the air assist from a low engrave setting to a high cut setting. Okay, so the first

one is going to be probably the the worst solution overall, but it is something that gets the job done. And

that is in the early days when I first started doing this, I had my air assist set up to connect to my air compressor, which was for an open frame diode laser like you see here. And basically what I would do is I would just keep an eye on

the job and when I could tell that it was switching from the engrave to the cut, I would just simply go over to my air compressor and turn the air pressure way up. Now, that does work, but is

way up. Now, that does work, but is probably not the best and most strategic way of going about this. And so, a probably better way of doing it is simply to run your layers separately.

Okay? So, if you have an engraving and a cut to-do, you could just turn off the cut, run the engraving on your low air assist setting and then switch to the higher air assist setting and run the

cut job by itself. So, you're basically just splitting your project into an engrave job and a cut job so that you can change the air assist in between.

And the third and nicest approach is when you have a laser like this one actually behind me, which is an AON Mirror 9S, where it has a built-in air assist switcher. So, inside this

assist switcher. So, inside this machine, there is a built-in pump that runs around 2 to 3 psi, which is right in that range where I like to run my engravings. But, it also has a a

engravings. But, it also has a a connection where it can switch between the built-in pump and an external feed for an external air compressor. And

basically, if you look in LightBurn, what this allows me to do is it allows me to specify which air assist pump to use. based on this toggle. So, just to

use. based on this toggle. So, just to give you this example here, if I was running this job on this laser behind me, then I could have the air assist use the built-in smaller pressure air assist

pump by having this toggle off just as you see here. And then I could have it switch when it's going to the cut portion by having the air toggle on. And

that's just switching it to my external air pump, which I can have on an air compressor, which is set to a much higher PSI. Now, obviously, not every

higher PSI. Now, obviously, not every laser is going to have a built-in switcher like this, but the good news is you don't need it. You can do these things as long as you're able to use an external air compressor because then you can change the settings to your heart's

content for your air assist. But I

should mention on that note that not every laser has the ability to feed in an external air compressor because some of them just have a built-in closed system for air assist. And as a little bit of a tangent, that's one of the

reasons that I personally would not buy today any laser that does not allow me to feed in an external air compressor because doing that the ability to feed in your external air compressor makes

the um steps that we've been walking through in this video a lot easier when it comes to reducing or eliminating your scorching so that you don't have to do extra sanding and masking. And so that's a little bit of an aside, but hopefully

that will be helpful to some folks out there. So, that in a nutshell is how you

there. So, that in a nutshell is how you optimize for nice clean cuts and engravings that don't need masking or sanding. And as I mentioned earlier in

sanding. And as I mentioned earlier in this video, if you need extra help with doing test grids like some of the ones we've talked about through this video, then I have a deep dive video here on YouTube that you can go and watch that talks about exactly that. And I'll put a

little link card to it somewhere here on screen. So, you can jump over there and

screen. So, you can jump over there and check that out if you'd like to. Thanks

for watching and I hope to see you in the next video. Bye now.