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View Full Version : Color Fill vs LaserLights on Acrylic



Liesl Dexheimer
03-21-2010, 10:10 AM
I have a customer who would like a few 2" x 8" acrylic signs. I'm not sure what will be going on them just yet but I made up my own sample piece with black color fill as he would like black text (see attached photo). I used some black acrylic paint that I had but wasn't really happy with the way it came out. The paint chipped and certain spots are not covered in paint.

I kept the paper mask on when I engraved the piece, ran it at 25 speed, 100 power on my 35 watt laser. I had quite a bit of white smoke that I wiped off with a damp paper towel and I even used a soft toothbrush to try to get any remaining residue off but that didn't quite work.

I'm not sure if it would be easier using black LaserLights instead of paint filling. I'm guessing it will depend on the size of the text as well. If the text is too small than I will prob have to paint fill.

Any suggestions or tips regarding this type of project? Also, how much should I charge? Paint filling and applying LaserLights are somewhat labor intensive and I've never really had a job like this before. What is the going rate for something like this?

David Fairfield
03-21-2010, 10:30 AM
Not sure why you are getting the rough edges, but I would not sell a finished piece in that state. When I do plexi signs, I reverse the lettering in the graphic, and engrave from the back, through the paper mask. Spray the color on with a rattlecan then remove the mask. Should be zero chipping and a really crisp edge and a smooth front surface that collects no dust. Plus the letters look a little bit 3 dimensional through the plexi.

HTH
Dave

Liesl Dexheimer
03-21-2010, 10:39 AM
I definitely would not sell this piece. That's why I was wondering how I could get it to come out right.

I did reverse engrave the piece and then painted it with the mask on. I'm wondering if I either went to deep when I engraved it or maybe it's the paint. I used Folk Art acrylic paint and applied two coats.

David Fairfield
03-21-2010, 11:05 AM
I think the paint might be part of the problem. That craft store acrylic stuff is good for wood and paper, but it doesn't really bite into the resin and plastic the way enamel does. Also brush paint can seep underneath a mask. Try a spray can of Krylon, or similar, and see what you get.

Dave

Liesl Dexheimer
03-21-2010, 11:16 AM
Ok, thanks for the suggestion. I was actually thinking about buying some Krylon Fusion in black (I currently have red & blue...maybe I'll try those out first).

Rodne Gold
03-21-2010, 12:15 PM
You might be having a problem with the perspex stress cracking where its lasered cos of the paint solvents , use a water based paint. I'm not sure what your acrylic paint contains as a solvent.

Ron Chapellaz
03-21-2010, 12:58 PM
I have just started to dabble in acrylic as well and have the same result as Liesl. I used the same settings as Liesl 25 speed, 100 power on my 35 watt laser. I lasered the text 2X. The 1st pass I found there was residue from the mask that stayed on the acrylic, which is why I did the 2nd pass. I did 2 coats with Krylon Fusion for plastic spray paint which I was told should work. I applied the 2nd coat 1 hour after the 1st, let it dry another hour and then removed the mask. The spray paint had bubbles in it and migrated under the mask as well. This was my very first piece and all looked well until I removed the mask.

Any suggestions for Liesl and I??

Ron Chapellaz
03-21-2010, 1:03 PM
Oh, forgot to mention the properties of the spray...

Contains Acetone, propane, toluene, butane, petroleum distillates, xylene and methyl isobutyl ketone.

FYI Liesl I tried the red and the black so far...with the same result as you. Actually yours looks nicer than mine :)

David Fairfield
03-21-2010, 1:23 PM
Odd, I've never had this problem and I've even done signs and badges with very fine detail. They always come out sharp.

If you blast the spray paint on heavy and at close range you will have a problem. Just dust it on so it dries a second after it hits, and it won't bubble or seep.

Or it might be the paper backing. Try replacing the paper backing with a masking tape. If you don't need a clear field, try burning through a layer of paint, then applying a second color. If that doesn't work I don't know what will.

Dave

Rodne Gold
03-21-2010, 1:25 PM
With those solvents you almost sure to have issues.
We flood fill the engraving with automotive paint , undiluted.
We scrape the excess off with a piece of straight card
Let the paint dry.
Twist a small square of pex in a lint free rag so the rag is stretched tight over it , moisten it with methylated spirits and wipe off the excess - I use no masks.

Liesl Dexheimer
03-21-2010, 5:21 PM
How much do you charge for paint filling, especially a 2" x 8" piece. I have no idea what to quote...

Rodne Gold
03-22-2010, 12:13 AM
10-15x material cost , smaller more fiddly stuff to the 15x end of the scale. It's worth your while to tackle this job as "school fees" in terms of paint filling. You might even turn a profit on it.

Martin Boekers
03-22-2010, 10:33 AM
I've used Fusion for a number of jobs, I have some samples still in the shop about 8 months old with no sign of it attacking the Plex.

How long should it be before I can safely say it wont have a future effect?

The main problem with Fusion for me is how long it retains the "fresh spray" odor.

Marty

Chris DeGerolamo
03-22-2010, 10:39 AM
I'd use masking tape on the "back"...apply it then I use a post it pad to smooth it out and get rid of the bubbles. vector cut out the tape around the letters or raster through it. spray with krylon fusion (black) and let it dry. remove the remaining tape. done.

Scott Shepherd
03-22-2010, 11:18 AM
I fought the same issue too many times before giving up on that process. I do some back painting now, but it's all done with what I consider, more "proper" techniques/tools.

I cut paint mask with a plotter, apply, and then use an automotive acrylic type paint.

For the most part, the letter edges are crisp and sharp. Every once in a while I'll get something that lifts, but that tends to be from too much paint, not cleaning the surface properly before painting, or something like that. It's almost always my fault, in lack of prep when it doesn't go right.

I know that doesn't help your situation, but I do have far less issues now than ever before.

Ross Moshinsky
03-22-2010, 11:22 AM
I don't like painting. In my opinion it's too time consuming and hard to get right. If you get it wrong, it's hard to fix the mistake.

Why not just apply black vinyl on the back of the acrylic? Or, cut some black plastic and insert that into the acrylic? Both will achieve the same result. It will cost a bit more in materials but save a lot of time.

Every time I attempt to paint, I'm frustrated by the result. I know I can do it, but is it really worth the time and the effort when so many options are out there that look just as nice and don't cause me a headache?

Liesl Dexheimer
03-22-2010, 1:41 PM
Well I think I'm going to give up on color filling. I tried another piece with blue Krylon Fusion spray paint. I also change the settings slightly, 100 power, 30 speed. It still didn't come out right. Ugh! I cut out letters using LaserLights and applied them on the acrylic instead, came out much better. Now I'm trying to figure out what to charge...

Dan Hintz
03-22-2010, 2:38 PM
Liesl,

Are you sure any dust from the engraving process was removed from the etched area? The paint will attach itself to any junk left over and eventually fall out.

Viktor Voroncov
03-22-2010, 2:59 PM
In this case vinyl letters will be cheaper than LaserLights. And with vinyl will be possibility apply from back side of acryl if necessary.
But be honest, I always have quality problems when working with paints :( May be my hands grew slightly not from proper place :)

Liesl Dexheimer
03-22-2010, 7:34 PM
Liesl,

Are you sure any dust from the engraving process was removed from the etched area? The paint will attach itself to any junk left over and eventually fall out.

I can't guarantee it but I did use a vacuum with a brush attached to it and went over it a few times. I also used a damp paper towel and tried to clean out any remaining residue. It looked clean but after I spray painted it and let it dry, it the paint in the letters appeared to be cracked.

I have a feeling paint-filling isn't all it's "cracked" up to be, lol!

I wish I could use vinyl letters but we aren't a sign shop and don't have a vinyl plotter. :(

Rodne Gold
03-23-2010, 3:19 AM
Paint filling is a snap if you use a flood fill method without a mask , however large area paint filling is not quite as easy and you have started off with a large area fill.
The key is to use methylated spirits as clean up as it does not ruin the sheen of the paint in large letters and wont scoop away the paint in the middle like thinners will,
You can also try black gilders paste (like rub n buff) and use turps to remove excess , this will also work.
Best acrylic for back filling is extruded and not cast as it engraves clear and not frosted

Jeremy Brown
03-23-2010, 6:56 AM
I do alot of color filling with spray paints/airbrush. I have tried using actual color fill from lasterbits and I hate the results.

Like everyone has said above, making sure the surface is clean from dust is a must.

When I engrave and plant to paint fill. I use the Green painter's tape (scotch brand). I mask the entire engraving area and make sure its pressed firmly down(textured material) and engrave through the paint and into the material. The tape also allows me to do a very light engraving on the tape only to make sure I have everything positioned.

after painting I remove the tape and clean up with a dry tooth brush

Our machine is mostly used for engraving things into radio housings, so 80 percent of the time, I am engraving into plastic and paint filling.



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John Noell
04-14-2010, 11:32 PM
With those solvents you almost sure to have issues.
We flood fill the engraving with automotive paint , undiluted. Rodney, is your automotive paint water-based? (We don't have any of that here.) When I flooded the engraving with our automotive paint I got stress cracks. :(

Rodne Gold
04-15-2010, 6:58 AM
I use water based for clear acrylic and normal for coloured when filling , I use mainly cast so stress cracking is not so much of an issue.
I often do this as well if I need colour and small reverse frosted engraving : Apply coloured vinyl and kiss cut with the laser , engrave the frosted bits and weed away the vinyl for the "colour" fill.