Haze I just can't stop

[Mark Ward]

I'm having a battle with some coloured acrylic. I've messed with settings but just can't seem to get the problem sorted.
I have attached a picture of some rastering on some purple acrylic and you will see the haze on it (I know there are otehr threads on this and I have searched them too).
I think the setting on this one are 40p 100s on an 80W machine, I have tried other settings but can't seem to get it haze free. Any suggested settings to try that might sort my problem as I've been eating through the acrylic this evening. The problem is less noticeable on the clear acrylic but really stands out on the coloured acrylic.marked-acrylic.jpg

[Mike Null]

I would lower the power to 30% and the resolution to 333.

Will it clean off?

[Rich Harman]

Are you are engraving bare acrylic, or with the protective covering on?

[Joe Pelonio]

Even 30 seems like way too much power for an 80 watt, that's about my setting with 45 Watts.
One "trick" is to apply transfer tape (or leave on the protective paper if it's paper not plastic, vector cut the letters, remove the paper letters without moving the material at all, then engrave. You shouldn't have to do it though. I will do that on finished wood that's not going to be sanded.

[Ross Moshinsky]

Acrylic normally engraves at about 20-25W and 80IPS. At 140ips you need about 35-45W to keep that ratio. So with that said, I don't think your settings are wrong. You might be able to go with less power, but you won't get much depth on your engraving. It's worth looking at, but I just don't see your settings being off (assuming your DPI is 400-600).

I'd look at exhaust first. You may need more air flow. The other thing I'd look at is if Novus 1/2 will clean things up for you. A quick spray or polish may solve your problem. It will be a lot less labor intensive than masking, which is also a viable option to fix the problem.

[Frank Corker]

Joe's analysis is spot on. Transfer tape will stop the hazing too.

[Clark Pace]

Hi. Yes transfer tape will help, but if you are doing a photo it's not the best idea. I normally use 11% - %15 percent power on my machine and 400mm speed. My machine is a 50 watt Shenhui and a 50 watt x700 redsail.

[Kev Williams]

bah humbug on transfer tape-- I've tried it and the burnt glue residue is worse than the sooty haze. And I hate the weeding too.

Here's what I do... I have a can of plain old paste wax, or sometimes I use Raindance car wax-- I smear on a liberal dose, not mountains of wax but the surface is entirely covered-- engrave as usual, then take the plate to the work sink, get the water warm, rinse off what will rinse off, then scrub with a kitchen brush and some Dawn dish soap. Rinse well, then with a dry towel wipe it dry. Rowmark RED is my worst enemy, and this trick works great...

On other colors that don't soot up so bad I use Brillianize or Novus #1 plastic polish, or even Pledge or some other kitchen wax before engraving. The soot comes off any slick surface better than bare acrylic--

and finally, if some stubborn remnants remain, alcohol or mineral spirits usually works (I prefer spirits)

[Joe Pelonio]

bah humbug on transfer tape-- I've tried it and the burnt glue residue is worse than the sooty haze. And I hate the weeding too.

There is no residue when you vector cut the transfer tape, that's why I do it rather than engrave through it which does leave a mess. I would not try it with a photo. Weeding is not a big problem with good tweezers, and is really quick and easy if you are used to weeding vinyl lettering (a lot easier).

[Kev Williams]

Ok-- I should've said I don't use xfer tape for RASTER engraving, which is what Mark's doing -- I DO use xfer tape for vector cutting. It's also okay on some woods for rastering. But to raster thru it on laminate just doesn't work for me..

[Scott Shepherd]

Looks to me like you are engraving with the air assist on. Is that true? If so, turn off the air assist when engraving.

I agree with Kev, I've never had much luck rastering through transfer tape. Vector cutting through it, I do it daily. Rastering, not so much.

[Mike Null]

I raster through transfer tape when I'm going to be color filling wood items. No problems. (wood has to have a finish) Weeding is not an issue with transfer tape as it can be removed easily with a squeegee or plastic razor blade.

I do not use transfer tape on plastics.

[walter hofmann]

hi there
scott is dead on I never use air assist for all engraving even with wood it just blows the engraving residue right in the engraving. I did change the cone air assit to the outside nozzle like the epilog systems and if I get to much smoke I turn it on but the nozzle a bit down wards this just blows the smok away but nothing in the engraving
greetings
waltfl

[Mark Ward]

Thanks so much all of you for the replies, top people!
I've just been down having a play and accidently cut the shape without any engraving and it turns out it is the cutting that has left the marks which I just hadn't thought would be the case at all.
Power 70, speed 0.75 and 5000 PPI/Hz

I've had a go with application tape, it can work OK sometimes but it can be a right pain, especially when the middle circle on a letter needs to be pulled off which isn't good on small items that we may be doing in bulks of 100 at a time.

Also, yes air assist is on, I'll turn it off and see if that makes any difference on the cut too.

As I am still quite a noobie to the laser world, do I take it some of you would use the "cut" option on a very fast speed to engrave on the markings rather than just rastering it on?

[Mike Null]

I am not one of those.