Painting acrylic then Lasering

[kyna cass]

Does anyone know the results of painting (black )on clear extruded acrylic. Then lasering your design on top of the black paint so it shows through clear where lasered
Has anyone tried this
What would a suitable paint be
Thanks in advance

[Joe Pelonio]

You are better off using cast. Extruded when engraved leaves more of a muddy appearance, with ridges, rather than remaining clear and frosty.
I do it all the time, though usually in reverse on the back, but I always use cast. Krylon Fusion works fine though if it won't be handled regular Krylon or even rolled on latex paint works.

[kyna cass]

My local plastic shop dosnt normally carry cast acrylic thats why I was wondering if I could get away with using extruded with some sort of paint spray I could laser through.
The owner of our plastic shop says our local Trophy business only buys extruded. hmmmm

[Scott Shepherd]

I do the clear extruded a couple times a month. It can either be engraved and then another color put down, or you can put metal against it to show a metal finish.

If you use the different colors, you'll end up with an image that's all painted and it's subsurface, so you can't scratch the image off from the front. It really does make a very nice looking product.

I tend to use Krylong H2O paint for the backside.

[kyna cass]

Scott
Do you mean you are paint filling the acrylic after you have lasered through a mask Im not understanding

[Scott Shepherd]

Paint the backside, say white. Engrave the backside, spray the recently engraved area with a new color, say blue. When you look from the front, you'll see the solid white and the blue. It'll be from the backside so you'll have 1/8" or however thick it is of clear on the front. It really makes for a nice look. After I do several colors on the back, I usually spray black over the entire back. It doesn't do anything, but it does prevent someone from looking at the back and seeing how it was done. Sure, they can figure it out, but when you look at it, see all the colors, turn it over and it's all black, it's a bit of a puzzle to understand how it was done.

[kyna cass]

Thank you
I understand now . I`m gonna give it a whirl !

[Scott Shepherd]

The goal is to get it as clear as you can. Use a lower frequency if you have an Epilog or a low PPI if you have a ULS. I think 200-250PPI gets it pretty clear. Also, low power. Probably will take 2-3 passes to get through the paint (make sure you use several coats or the secondary colors will bleed through the main color and show through the front).

[Bill Cunningham]

Sometimes extruded can give a nice effect.. Just don't hit it too hard, only use enough power to remove the paint.. This is a 5x7 that looks ok even up close..

[R. A. Mitchell]

If you use the different colors, you'll end up with an image that's all painted and it's subsurface, so you can't scratch the image off from the front. It really does make a very nice looking product.

I tend to use Krylong H2O paint for the backside.

Steve - I tried this process & was pretty happy except I used Krylon Fusion. The initial layer providing a back coating before engraving turned out very well, but the subsequent fills using different coatings in the engraved areas suffered from crazing. In this particular project, the crazing didn't hurt and actually added texture, but I'd like to be in better control.

Is the crazing because of the Krylon Fusion paint? If so, what's the next best recommended paint that won't cause crazing?

Rob

[Scott Shepherd]

Rob, several people on this forum swear by Fusion, but I just can't get it to work. It crazes for me as well. H2O from Krylon doesn't craze for me. It's the only product I have found that doesn't.

It's also a very odd paint. The color out the can is WAYYYYYY different than the color it dries to. I have a burgundy I use for a repeat job and out of the job it looks like it's purple. Only after several coats and drying does it turn a rich burgundy.

[Darryl Hazen]

Krylon Fusion is formulated to "bite" into plastics. It is specifically formulated for painting plastic surfaces that normal paint would not adhere to.

[Bill Cunningham]

Adding to what Darryl said, Fusion is a solvent base, and it's that base that reacts to acrylic that has been surface stressed by a laser. This is why you can coat the acrylic with fusion, 'then' laser it, but once the surface has been lasered and stressed, the addition of solvent (in the paint) will craze the plastic, so additional coats should not be fusion. Scott suggested H20, which will work fine for stressed acrylic. You will also find that putting a second coat of fusion on fusion on glass or plastic is fine, 'providing' you do it within about two hours. Past that, you may have to wait as long as two weeks before you can second coat it without it wrinkling. This is also true for many marine paints for use on metal...

[Ray Mighells]

I've done considerable playing around with painting the sub-strate then lasering and have posted quite a few pic in my Picture Trail albums of the results. Any time you use paint and/or multiple types of paint you should check out the compatibility of different types being used. Some of the solvent based paints have to be recoated within 2 hours, after 2 weeks, or maybe never. I have not found a paint that will bond to glossy surface ceramic or porcelien, polished marble or granite (paint the backs of these). All new efforts can be tested on waste prior to going for the gold. Some time ago we went thru a nice thread on doing photos. The atchd images I think came from Scott Shepard and the image was processed by Frank Corker. The left one is on Ivory acrylic, first painted flat black then lasered. The one on the right is engraved on poster paper. Many things are possible with these machines. I think the one on Ivory acrylic (Delvies $1.00 sqft) is the best one I have ever done. Frank did his magic on the image and I made a good guess on my machine settings. http://www.PictureTrail.com/razaxnstuff Scott, if you'd like these two pieces send me your address and I'll mail them to you.

[kyna cass]

Thanks everyone for sharing your knowledge. I love this idea of lasering on ivory acrylic . I'm going to give it a try this week. Ray, your engraving is absolutely beautiful ! Flashy website too ! Love your work . It inspires me !!)

[Mike Null]

Kyna

The early advice to use cast acrylic is very good. Putting any kind of chemical on extruded acrylic can cause crazing and usually does. There are many places to buy cast acrylic.