Hi all,Just wondering if anyone has come across this problem before.I have each of my panels done up in CAD, and have got a local sign shot to laser engrave and cut each one.First I take some white perspex. Sand it. Primer. 2 layers of Acrylic plastic paint.When its getting cut, the laser is buring the paint, and leaves nasty brown burn marks all over the panel.I am thinking of adding a coupl eof layers of topcoat to see if it will protect it.Any other ideas?CheersChris G.

I would say that the laser beam is too strong. You need to add extra layers of paint, and ask the shop to adjust the laser intensity so that it just burns the color and not the material beneath. You better prepare some small pieces for tests before applying the laser to the actual material.George DorkofikisAthens, Greecehttp://online.vatsimindicators.net/811520/1704.pnghttp://www.precisionmanuals.com/images/forum/betaimg.jpg

Sounds to me like they dont have a very good machine or they dont know what they're doing.If they high pressure cut the material you will lose about .015" of paint around the edges but you should'nt have any burn marks.Why are you painting before the laser cutting?What is the material you are cutting?If I can be of help send me a [email protected]

Hi Floyd,I am using 3mm white plexi.I am painting before so they can cut the text out for backlighting.I will get them to do a second test piece for me.ThanksChris

I definetly would suggest to have the panels cut first.Then sand , prime and paint them. Then laserengrave them.This is more troublesome for the shop, because everything needs to be good aligned (zero point of cutting must be the same as engraving)If you do cutting and engraving on the painted panels, you will see the white perspex there were it is cut. If you paint after cutting the paint will also get on the side of the panel.good luckNorbert

Currently they would charge me more for the panels if I was to do them twice, and I am unsure as to how accurate these guys can get.Living in Singapore I have to make do with what I can get, and there arn't too many places to go to.In regards to painting, I am masking carfeully and respraying after the cutting to cover the sides and holes.Will post some photos if it all goes well.Thanks Norbert.CheersChris G

Laser cutting plastics can be a bit of a pain in the buttthe machines have a metal grid for a table, and when the laser beam penatrates the plastic it hits the metal grids as it passes over them which causes sparks to damage the under side of the plastic, the metal grids are removable and depending on the machine they might be able to remove the table altogether and hold the part on a simple fixture. So there is no metal underneath the plastic.Also lexan is about the best type of plastic for laser cutting, comes out beutifull. It comes with a protective paper backing which protects the underside of the plastic most of the time... but the odd spark does get through. the best thing is to have no metal under the plastic ,but this might add alot to there setup time.Most sign shops use cnc routers this might be the way to go for your initial cutting. You should look into it , might be cheaperFloyd