PDA

View Full Version : sanding glass after laser etching



Michael Vasiloff
11-23-2015, 4:33 PM
I tried to find a post on this, figuring it would likely exist but didn't have any luck. I am taking on more and more projects laser etching glass, and am having issues with the glass burrs that are left behind. Typically right now I spray the glass down with Windex or something similar and then wet sand with a 12,000 grit sandpaper or pad. It works ok, but doesn't seem like a viable option for a large group of items.

1. Does anyone have any other suggestions to smooth out the burrs (on about 500 round 3" disks).

2. Does anyone know where I can purchase 12,000 grit paper/pads in bulk (currently paying around $5 for a 2"x2" pad)

Any help or guidance is greatly appreciated and I apologize if there was an existing post on the topic.

Regards,
Mike

Gary Hair
11-23-2015, 6:18 PM
For that quantity I would use photo-resist and sandcarve them. I guarantee that they would take less time and will come out 1000% better than you can ever get with lasering, especially given the issues you are facing.

Kev Williams
11-23-2015, 6:38 PM
I've found that using any type of sandpaper or scotchbrite works great-- but they scratch the glass!

I use 0000 steel wool on my glass engraving. Couple of light buffs and done... and no scratches.

Scott Marquez
11-23-2015, 8:17 PM
Can you mask first, laser, then clean with an abrasive hand pad (they come in different colors for different grits)?
That will protect the surrounding area.
Scott

Craig Matheny
11-23-2015, 8:23 PM
I used brass 0000 woll works great never saw a scratch but them again it was always cheap glass no crystal.

Michael Vasiloff
11-24-2015, 9:59 AM
Thanks all!

I just ordered some steel and copper 0000 wool to try. Definitely less expensive so hopefully it does the job. Do you wet sand with this?

I love the idea of masking and sand blasting, however we are doing about 500 ornaments that are each "custom", so it would be a lot of labor to create a new mask for each one. We are using InDesign to create a "Mail Merge" technique and have a jig to do about 18 pieces at a time. This should help cut down on labor time for us.

I havent previously used any type of sand blasting/carving/etching techniques before, but that might be my next journey after doing some research on what types of equipment/materials I need to purchase to get started. We do a lot with Glass/Acrylic and I bet that would be a nice alternative. Do you think the liquid mask would hold up to sand blasting on glass?

Thanks for all the feedback
Mike

lee chitwood
11-24-2015, 10:45 AM
I use a small piece of 1/8" Acrylic on edge and give your item a brisk rub.

Dave Hutton
11-24-2015, 11:24 AM
Do you think the liquid mask would hold up to sand blasting on glass?

Thanks for all the feedback
Mike

Mike

You'd be amazed what will withstand sandblasting whilst still allowing the glass to be quite deeply marked. Bearing in mind the first masks were made from tissue paper glued onto the glass, the masks you'd produce with a uv exposure unit are really quite flimsy but the sand doesn't seem to affect it - just bouncing off. You can use masking tape/paper, thin vinyl type film etc.

You can of course use the laser to cut away a mask directly on the product, then sandblast (obviously increases your work, but easier than making a mask separately then applying/sandblasting in my opinion) and maybe quicker than lasering and then trying to sort out chips? Probably not ideal for curved glasses if you don't have a rotary attachment. There are films specially designed for doing just that, the liquid mask should work judging by what I've seen, but a bit more effort. Looks like you can also make a mask with the laser flat , then apply to the glass. Takes a bit of fiddling about to get the right settings etc but from initial experiments it'll work fine. That would be good for odd/large shaped items that won't work in the laser

As far as kit for sandblasting, you can 'get away' with an inexpensive blasting cabinet designed for cleaning car parts (along with a vacuum for keeping it clear) and a decent sized compressor - that's what I'm currently using. The 'proper' blasting cabinets look a lot better/cleaner/clearer but a fair bit more money. If I did more I'd have one of those - probably a Rayzist unit.

Good luck and good to see you are busy with it.

DJ

Joe Hillmann
11-24-2015, 12:37 PM
Try putting the glass in the fridge before you engrave them. I find that cold glass is less likely to have the little splinters in the engraving and have more of a nice frosted look.

Martin Boekers
11-24-2015, 1:19 PM
I use a hard bristle brush, it seems to work good. not sure what you are engraving but I find if you engrave through regular masking material
it leave a "Smother" engraving and it comes off easily with water...

Ross Moshinsky
11-24-2015, 5:29 PM
Once again, if you setup your laser, you can engrave glass and crystal with essentially no shards/chipping.

Martin Boekers
11-24-2015, 5:38 PM
Once again, if you setup your laser, you can engrave glass and crystal with essentially no shards/chipping.


Ross, I know you are good with glass, one Sat I spent the whole day making minute changes to speed, power and Freq and couldn't get to perform consistently.
Believe me I tried everything. My new 120 Watt does better than the 75 Watts, but it does have a 3" lens were the other 2 have 2" lenses... I find,
that glasses, mugs, and other items engrave differently... I even have drop outs at some parts, which I wrote of as inconsistence of the glass... If you could
share some of your expertise on this I'd greatly appreciate it. Some products I know longer carry because of consistency... Help!

David Somers
11-24-2015, 6:04 PM
Ross,

Would love to hear your experiences as well please. I was just looking at a laser shop's glass work near me and the laser engraved glass was good. Better than much of what I have seen. But the sand blasted glass was heads and tails above it. And far more flexible in the type of engraving you could do, the depth, layering, consistency and finish of the engraving. All aspects of it. And the time to do it didn't seem bad either, even for larger jobs. I should warn you I have little experience with glass but am very curious. This is one of those tasks on a laser that I hear such a wide range of results on.

Thanks for anything you feel you can share!!

Dave

Dave Hutton
11-24-2015, 6:33 PM
Once again, if you setup your laser, you can engrave glass and crystal with essentially no shards/chipping.

Agree with that - I've seen some glass at a recent demo and a nice smooth effect with quite good detail (also seen some really bad examples as well). It's a different finish I think, probably the average customer wouldn't know the difference, but sandblasting still gives a better effect I believe, much finer lines and smoothness are achievable and to do it its a much more 'hands on' type of thing, really nice effects can be achieved with different depths and 'colour'. Probably easier to cope with the varying types of glass available.
Having said that for every day work if I can do it with the laser I will :-)

Ross Moshinsky
11-24-2015, 11:22 PM
First, you can't exactly compare lasering and sandblasting. Sandblasting is going to give better overall results but there are plenty of downsides as well. There is a cost involved in making each mask. Ikonik masking for example is I believe about $8-10 per 10x12 sheet. You have to hand lay the mask, which may result in error. You can also blow out the masking when blasting fine art which will result in ruined pieces.

I've said my technique for doing glass/crystal more than once. 500-600dpi. 35W of power. Dial the speed to be around 50-60ips. I use soaking wet packing paper and full black color. If you have a really dense/black area, you may want to go to 80-90% black. I find I get very consistent results using this method. The only time I find I get chipping is when I'm out of focus. With a 2" lens, you have a decent tolerance but on tapered glasses and glasses with a good amount of curve, you're going to get inconsistent results. I can't say going to a 3"+ lens will help, but I'd be pessimistic as it will just result in an overall larger beam size which could just make the chipping happen even when in focus.

David Somers
11-24-2015, 11:31 PM
Thanks Ross!

I am back at my computer finally and did a search for your other posts on this and appreciate your repeating the info.

Dave

Dan Hintz
11-25-2015, 3:31 PM
I use a brown paper bag... sandpaper, stell wool, etc. are all too expensive and unnecessary. A few back-and-forths with a brown paper bag is all that's necessary to get rid of any loose particles. If you have to scrub hard or use a more aggressive substance, your settings need tweaking.

Craig Matheny
11-27-2015, 1:31 AM
Nope just rub the brass wool and it works great


Thanks all!

I just ordered some steel and copper 0000 wool to try. Definitely less expensive so hopefully it does the job. Do you wet sand with this?

I love the idea of masking and sand blasting, however we are doing about 500 ornaments that are each "custom", so it would be a lot of labor to create a new mask for each one. We are using InDesign to create a "Mail Merge" technique and have a jig to do about 18 pieces at a time. This should help cut down on labor time for us.

I havent previously used any type of sand blasting/carving/etching techniques before, but that might be my next journey after doing some research on what types of equipment/materials I need to purchase to get started. We do a lot with Glass/Acrylic and I bet that would be a nice alternative. Do you think the liquid mask would hold up to sand blasting on glass?

Thanks for all the feedback
Mike

Ron Hamilton
11-27-2015, 3:10 AM
Mike,
I use steel wool with good results. 70% black artwork also helps

Ron....