What have I been cutting- lens film

[Tom Majewski]

Besides all the usual wood, plastic, granite, and cermark stuff I've always done, I narrowed it down to 2 new items.

I etched some dichroic glass. Small designs that were put into a kiln. Looked great when all done.

I've also been cutting an iron-on heat shrink film product for model airplane use called Monocote. I assumed it is polyester- can't find an MSDS sheet for it.

My lens has a film coating I can't clean off with regular lens cleaner. It's blotchy and I'm afraid to wipe it any harder. It almost lookes etched on. I'm thinking of soaking in acetone or vinagar for a while. My aircone was also coated with pure white ash, which washed off easily. That really puzzled me. Has anyone lasered any of these two items before?

Thanks,
Tom

[Tom Bull]

Doesn't seem likely to be the dichroic coating. That stuff is pretty darn thin, in the realm of 30 millionths of an inch. It's a bit surprising that it lasered off since it is metal. Were you doing a large amount of dichroic?

[Joe Pelonio]

When in doubt and no MSDS, I will contact the manufacturer or refuse the job. That film is a lot like sign vinyl, so may well contain PVC. I have cut it for the local RC airplane club members, but on the plotter.

Laser lenses have a gold coating, which keeps the beam from burning a hole in them. Soaking in any solvent may take that off and ruin it. When I had to replace a lens it was because the gold coating had deteriorated, and I cleaned it only with the liquid provided by Epilog (lens was 4 years old).

I'd call your manufacturer for help, and also to order new optics in case they cannot be cleaned.

On the other hand, if you are still on warranty, better not mention that you were cutting an undocumented film in case it invalidates the terms of the warranty!

[Larry Bratton]

Also, Epilog recommends that if you run out of lens cleaning solution, you can use Grain alcohol (Ethyl). It is readily available, and is clean and pure. I ran out of solution so I cleaned mine with some 100 proof Smirnoff and it worked just fine. I'm sure though that Epilog means the 190 proof stuff but the 100 got me by jussssssss fine. :)

[Tom Majewski]

Hmmm 100 proff vodka. Just happen to have some of that here.

I only did about 6 coin size pieces of dichroic. The coating etched off very easy at medium power.

Joe,way past warranty, and these jobs were my own ideas...no customer to turn down.

Using lens cleaning colution, how agressive with a swab could I get ?

It's working fine now, but from the look of it, I can only assume I'm down in power a few percent compared to an unblemished lens.

[Joe Pelonio]

I think the swab (Q-Tips) did mine in over time. on the new ones I have used only the lens tissues made for optics and had no scratching. Maybe try a swap with a tissue wrapped around it?

[Tom Bull]

Found this msds for film to cover model airplanes
http://www.phenix.bnl.gov/WWW/publish/donlynch/MPC%20N/Safety%20Review%206_22_06/MSDS-Super%20Monokote.pdf
says it is polyester.

[Tom Majewski]

Thanks Tom !

[Dan Hintz]

I use normal Q-Tips on mine without issue, I just make sure to swap gently until any particulate matter is gone. The coating on a lens (while it may appear to be gold in color) is an anti-reflective coating, but it's not actual gold.

[Mike Null]

I use Q tips or medical swabs on a wooden stick if I can find them. The cleaner supplied with both my lasers was acetone formulated for lens cleaning. (I believe that means no H2O)

I put a drop or two on the lens and swirl it around then gently clean with swab and repeat if necessary.

[Chuck Stone]

Also, Epilog recommends that if you run out of lens cleaning solution, you can use Grain alcohol (Ethyl). It is readily available, and is clean and pure. I ran out of solution so I cleaned mine with some 100 proof Smirnoff and it worked just fine. I'm sure though that Epilog means the 190 proof stuff but the 100 got me by jussssssss fine. :)

It may work fine, but there may be other things in it that can leave a
residue on the lens. They were probably thinking of Everclear or similar,
which is pretty cheap and not all that drinkable.
(some may say the same is true of the Smirnoff :p )

[Martin Boekers]

I would trying swabbing a couple times, as if there is any particulates attached to the lens You want to make sure they are "loose" any wipe away easily. If you "scrub" to hard you may scratch the lens.


Marty

[Martin Reynolds]

We cut a lot of PETG, also a polyester. It breaks down into a white gas that condenses into a fine white powder on everything. That sounds like your problem. Our lens cleans with a swab and lens cleaner. Some of the stuff that gets baked on to the laser bed, we clean with acetone so you might use acetone as Mike suggests.

Don't use any kind of acid (vinegar) or aggressive chemical cleaner (mean green, scrubbing bubbles and so on).