damage / cleaning after slate engraving ?

[Jani Pedersen]

Hi,

I've just bought in a pile of slate coasters to engrave, sat and read through all of the threads I could find on here and now have a case of cold feet !

I'm worried now that the dust from the slate could potentially cause damage to the laser, and that I could scratch the lens and mirrors while wiping them afterwards.

My main question is, if I sprayed them with lacquer first, would this vastly reduce the amount of dust ?

I have a dust extractor .... tube hangs out of the window, but nothing that collects dust etc.

Am I likely to cause damage to my baby epilog ?

Thanks a lot.

[Mike Null]

I haven't engraved slate but I can't imagine that it will do damage to anything providing you have an adequate exhaust system. I'm not a fan of dust collectors when you have the option to exhaust outside.

Just follow the Epilog directions for cleaning your optics and you should be fine.

[Dan Hintz]

What Mike said... except I don't think Mike realizes the use of a dust collector doesn't necessarily mean you're actually collecting anything (most of us just use them as a source of vacuum).

[Jani Pedersen]

Thanks guys. I'll go for it., one last question - surely lacquer would create a fire hazard ? I found some varnish spray and was tempted, but fear of fire is massive - and made me question the idea of using spray lacquer pre rastering.

[Dan Hintz]

It's a fire hazard if still wet, as that means the volatiles are still off-gassing.

[Jani Pedersen]

Thanks Dan.

[Robert Walters]

If sand/grit were to get on the lens, I'd dip the lens into (cleaning) liquid a few times to loosen/remove the deposit(s), but not wipe it till the partials were gone.

[Gary Hair]

Thanks guys. I'll go for it., one last question - surely lacquer would create a fire hazard ? I found some varnish spray and was tempted, but fear of fire is massive - and made me question the idea of using spray lacquer pre rastering.

Almost everything you can laser is flammable, with the exception of granite, slate, marble, etc. If you have enough airflow and use air assist then you'll have a hard time getting anything to actually catch fire. You'll find that most fires happen when someone is cutting wood or acrylic and step away - fires know better than to start while you are watching...

Gary

[Rodne Gold]

Does slate engrave via fracturing or like marble , by leaching colour? You run more risk engraving glass , which does fracture and is generally harder and sharper than slate if slate does indeed fracture. Lots of us do glass and have no issues.
A thin layer of varnish has , imo, almost no chance of catching alight

[Dee Gallo]

This sample club from Epilog uses slate to make coasters : http://www.epiloglaser.com/sc_slate_coasters.htm

Might be of some help to you!

[Jani Pedersen]

I saw those Dee, I am such a scaredy cat though - I figured they'd be so sure of themselves and what they were doing, and knew how to overcome any issues before they arose. I was all set to just go ahead and then searched through the forum and started to develope a mild sweat / panic lol.

I don't have any lacquer, I do however have varnish .... is that considered the same ? Another dumb question !!

:D

[Dee Gallo]

Not a dumb question! Technically, lacquer is a TYPE of varnish. Varnish is simply a protective finish put on a surface like wood. There are a bunch of types:




1 Violin (http://en.wikipedia.org/wiki/Varnish#Violin)
2 Resin (http://en.wikipedia.org/wiki/Varnish#Resin_2)
3 Shellac (http://en.wikipedia.org/wiki/Varnish#Shellac)
4 Alkyd (http://en.wikipedia.org/wiki/Varnish#Alkyd)
5 Spar varnish (http://en.wikipedia.org/wiki/Varnish#Spar_varnish)
6 Drying Oils (http://en.wikipedia.org/wiki/Varnish#Drying_Oils)
7 Polyurethane (http://en.wikipedia.org/wiki/Varnish#Polyurethane)
8 Lacquer (http://en.wikipedia.org/wiki/Varnish#Lacquer)
9 Acrylic (http://en.wikipedia.org/wiki/Varnish#Acrylic)
10 Two-Part (http://en.wikipedia.org/wiki/Varnish#Two-Part)
11 Conversion (http://en.wikipedia.org/wiki/Varnish#Conversion)

Stone sealers are another discussion!

[Michael Hunter]

I don't think that laquer or varnish would make any difference to the amount of dust, as it would be vapourised instantly by the laser beam.

Where it may well help is with the contrast of the engraving - it will probably make the unlasered slate look darker and so highlight the engraving.

As Dan says, so long as the laquer is fully dry, the risk of fire is very small : certainly no worse than wood or acrylic.
If your exhaust is working efficiently then any possible dust damage and fire risk should be minimal.

[Michael Hunter]

Dee

If you mix up all the finishes you mention, you get a kind of snake oil which you can sell to yachty types for $500 or more per gallon (when sold in tiny tins).

It is the Holy Grail of boats - to get a finish which lasts for more than a few months in sun and salt water : everyone promises, no-one delivers but if it is expensive then "it must be good"!

[Robert Walters]

If you mix up all the finishes you mention, you get a kind of snake oil which you can sell to yachty types for $500 or more per gallon (when sold in tiny tins).

So, I can take all the lil remains in the bottom of each can that's useless, dump it all in shiny 1 pint tins for $500/each!

But, but, but...
What about my "Well, I might need just a lil bit for touch up down the road <time warp to 15 years later> as the stuff is just too darn expensive to throw out" rusty tin can collection?

[Dee Gallo]

Robert, if you wait long enough, it will all become the same inert useless stuff. Just shake it up to introduce enough air and you'll have a nice useless gel! Then you can sell it for $600.

:) dee

[Mike Null]

Dan

I've had a dust collector for many years but it's for my wood working machines. I don't like dust collectors as exhaust solutions for laser engravers as I am concerned about the possiblity of sparks, thus fire.

Maybe I'm too cautious but it's not gonna happen in my shop.

[Bill Cunningham]

Slate isn't much different than granite.. There is going to be dust, but if your vent is up to spec, it all (or most of it) goes out the exhaust. If in doubt you can use a little air gun to blow the dust off your lens and mirrors if any accumulates, before you clean them.. It's not so important with slate, but if your doing polished granite 'Wash' the engraving under flowing water to remove the dust from the stone, before you rub in any colouring or it will scratch the polished surface.