I made a dozen test burns, all about 1 to 2 in. in size. The last 4 or 5 looked really good so I went for the gusto. My first full size etching and it looks like doggie stink !!! As you can see it has dark shaded areas (3) and I have no idea what went wrong. Does anyone know what I did wrong? After I peeled off the paper covering I washed the acrylic in warm soapy water and cleaned it real well. ( At least I thought I cleaned it real well).
Randy
I’m not sure if you talking about the image itself or the clear background…
It would help if you clarify your process… Is the Ortur laser visible light?
Are you leaving the covering on both sides?
Hello Jack: I peel the paper off both sides and then I wash the acrylic with warm soapy water, rinse off real good and then wipe dry with a micro cloth. I then lay a piece of black card stock paper down and focus the laser to that. Then I lay the acrylic down on top of the paper and go for it. After being up all night and still up right now thinking about this, I think I I know what might have happened, maybe!!! I noticed that after I made the burn I had black paper stuck, (melted) to the acrylic. I had to peel the paper off the acrylic in the areas that are darkened and then washed with windex. I’m thinking that I may have burned the image a little to hot, (or a lot to hot) and black ink molecules from the paper melted into the acrylic. ( I’m just guessing ) I using my Orze laser rig. Or is short for Ortur and Ze is short for the Zeus laser module head I bought. I made the burn at 2000 mm/m and 15% power. ( laser head is 15w opt. output) Now I;m thinking either more speed or back of the power. Back to testing again!
Randy
Edit update: the dark spots are in the image itself. All 3 spots run vertically bottom to top of image, one runs through the front of the rear wheel, the second goes through the front wheel and the third is in the area of the opening to the wagon cover. And then I made the mistake of using paper towels to wash off the black paper and I scratched up the acrylic badly !! (Funny thing is that my last 4 or 5 test burns turned out really good. The test burns were only an inch or two in size. Using a super bright pen light I check the test burns from behind, from front and from the edges of the acrylic looking for defects and see none.)
Part of the issue is the use of an indirect method. You will lose resolution.
Don’t forget when you burn something, gas is usually released, this has to go somewhere.
Have you tried just burning the backing before you peel it off? Or applying something dark tot he backing so it absorbs better.
Reverse the image and apply it to the back with the original backing paper…
The only issue doing it this way is that you have to peel each little part out individually…
Acrylic shows aberration in it’s clarity if the debris sticks to it… It’s worse with a co2, as it effects the acrylic directly creating a vaporized cloud of acrylic… tends to stick.
I see what you are talking about… I don’t think I can be of much help… I usually use the co2 for this not the led… You add an extra or more variables when you do something indirectly…
Good luck… maybe some other will chime it…
ok thank you
Randy
It sounds like you are focusing on the underside of the acrylic (if I understand your focus process. What focal length lens do you have? a 2 inch? I would try to focus on the top surface of the acrylic.
Focusing on the acrylic will give you a larger spot by the time it gets to the material that reacts with the beam…
He should be focusing on the whatever the material is that’s affected by the laser.
His laser will go through clear acrylic, it’s visible light…
I use Kit Scratch Out to remove fine scratches in my acrylic work. Just place a small amount on a cotton cloth, and most of the fine scratches will disappear. Find it in the automotive section.
AHHHHHHHHHHHHHHHH my mistake. My brain is in CO2
I have tried just about every way to do acrylic with a diode. I have had best luck with the method you are using. I also have had the exact same issue test come out fine then I go do a piece and it doesnt work. to light or it burns. I can have a real nice visible in LED burn in a test 2 inch by 1 inch filled, go to do a piece and suddenly it burns as soon as it start or it pops instantly, if I do not get any of those issues I get the very same that you mention where the poster board burn to the acrylic and I have to scrub it off. I fell like I am almost polishing the the burn away while I’m taking the paper off the back. I have had ok luck with just using construction paper instead of poster board since it burns the paper away but the burns are very light and do not show up well in the LED base.
For what it is worth yours looks a lot better than any of mine.
I’m going to try that – thankyou
Randy
James: I have been sitting in front of the Utube TV watching everything on lasers and acrylic, I found some lady , ( I have never seen before). She was using Tempera paint, mixing ratio of 1 part paint to 2 parts water, pour in plant spray bottle, (for finer mist) and spray paint the bottom of acrylic, (painted side down). Her work looked really good. She never said what type of laser or specs and I forgot to write down her name. I’m going to give that a try, hope it works for me !!!
Randy
No it does not, I say they look the same only my scratch marks run Vert. and yours look Horz. We ought to join forces, start selling on ebay – one time limited run of 500 units desk lamps “WITH” high light reflecting lines for enhanced viewing. Your choice of Horz. or Vert. lines. No extra charge for finger prints!
Randy
As a side note, don’t use glass cleaners on acrylic. They contain ammonia and will fog the acrylic. It’s best to use plastic cleaners or rubbing alcohol.
I recently read a long thread on here about alcohol being problematic in the long run creating cracks in acrylic. I talked with an engineer at work and he is thinking that may be my issue with my tests. most of my test are on pieces of acrylic that I had use part of and cleaned with alcohol and a magic eraser, both, from what I have heard are bad. then I used the unsed parts of the acrylic to run test on. this “may” be the reason I have test that are not reproducible. but it still do not answer all my questions since i have two test on fresh acrylic that I was not able to reproduce, now I came close not like other where the test was great and the next time it was a chard and burn mess. so I am going to go back to the my best results method of tempera paint on bottom of acrylic focusing on the bottom. I think I need to stick to one method and fine tune it instead of chasing my tail trying everything under the sun. new acrylic should be delivered today.
This is absolutely pathetic. Why would you waste a piece of acrylic? I mean, seriously, you could have chosen A&M, Nebraska or another school but Oklahoma? 
Looks cool but I’m from Nebraska originally and have lived in Texas since 1995. Still hate the Longhorns though.
Ever tried acetone? I haven’t tried it on acrylic yet but works wonderful on Polar cups.
Acrylic condiment containers… I used the one on the right to hold isopropyl alcohol to clean a part for less than 15 minutes… In the next few days it started showing cracks… It is getting much worse over time…
Alcohol is a solvent for acrylic.
Don’t know if this will help, but, I am doing a few acrylic etchings and they seem to do well. I stumbled across a suggestion to cut acrylic on wet (very damp) paper towels. I never clean prior to cutting and only remove the front covering of the acrylic. The backing comes off very easily after cutting on the paper towels. I have a thunder nova 35/100 and used a laser for the first time in September 2022. Here were my first efforts. I did purchase my first designs, but am now designing my own. Also - The best cleaner out there for acrylic (IMO) is novus - available from amazon or tons of other vendors.
Very nice work! 
