whitening marble

[Nigel Morgan]

Hello,

Have just engraved a tile bought from Laserbits, one went in the bin when experimenting, I have now used up my second, not a very white engraving at all, though nice detail if it were. Read the threads regarding "armour" must try it next time, for now I need to whiten the tile a bit, will white colour fill do this, or any other tips would be apreciated.

[Bill Cunningham]

I always do marble twice.. The second pass seems to clean of some of the collected crud from the first pass, and also seems to bleach it somewhat.. I run the second pass at the same power, but higher speed and it always brightens it up quite a bit.. Now keep in mind, the marble I use is standard, absoloute black 'floor tile' marble (about $15.00 each Canadian).. I have never tried the laserbits stuff..

Granite on the other hand will never brighten up. The beam has no bleaching effect on granite. It's simply removing the polished surface.. I think the reason the armour all seems to work, is because it cleans and darkens the polished surface, thereby providing more contrast when etched..

[Frank Corker]

Nigel this is another option if you are finding that everything is too dark, believe me I thought I was going to make a HUGE mistake when I tried it, but it worked for me.

Do your etching. White acrylic paint smeared all across the item you have etched, leave it about two minutes and then I took a piece of leather, put methalated spirit on the backing (not the smooth bit), rub like crazy. I found that the white came off the main surface and stayed inside the etching!

That was granite by the way. The reason why I did it in the first place was not because I didn't get a good result, I just forgot to put the writing on ( duh ) and when I engraved after I couldn't see it. I took the chance and put the acrylic paint on and the result was brilliant as you can see. The white paint incidently is smeared across the whole image and not just the writing.

[Ashton Waters]

I just made a really dumb mistake while lasering a marble tile and I'm really glad I did. I was experimenting with one of the tiles from Laserbits and instead of the reccomended settings of 30% speed and 100% power, I put it 100% speed and 30% power. It worked great It left the art work standing out great from the black background. No other whitening needed and it was done with the first pass. Now I just need to remember to invert the photo next time so I don't get a negative image.

Ashton

[Shane Silcox]

Frank-

That pic looks really nice for granite. Did you use Photograv for the processing?

[Frank Corker]

Yes photograv - 100 speed 44 power 300 dpi.

[Ray Rouleau]

I have the same problem with material I had purchsed thru Laser Sketch, they sugest 49% power vs 100% speed (35 watt Helix) but I'm unable to achieve anything close to a crisp white image. I know when I bought my machine they had an image of Beckham with material bought from "Jon Ko". Has anyone used material from them? Does it actually make a difference?