Ear Savers First Batch

Here is my first batch of “ear savers” for our local fire and EMT houses. I’ll also take some to the hospital.

Cut on .125” cast plastic [acrylic, sorry] purchased on Amazon.

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Make sure you know what that plastic is before you use it. Some types of plastic release dangerous fumes that the GF can’t control and others will destroy your Glowforge. If you don’t know exactly what that material is, don’t use it anymore until you know it is laser safe.

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Thanks. What specs should I need to know?

Those look really great and I love the color!

I was a bit confused when you said “cast plastic” too because those terms don’t normally go together and the plastic part is probably what caught @ben1 eye as well . Could you have meant “cast acrylic” perhaps? Acrylic and plastic are very different things and as long as the material says it’s acrylic, you’re good to go.

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You need to start with the material type. Plastic is a pretty generic term. If it is acrylic, like most of the Amazon products look like, you are fine. If it is PVC, or Kydex, which is a similar material, you may be in trouble as laser cutting PVC will destroy your machine and your lungs.

There are literally hundreds of different types of plastics. If you don’t know what it is, don’t cut it.

At the very least, you should start with a Material Safety Data Sheet, or MSDS, sometimes called an SDS. Look for the combustion products. If they contain anything like hydrochloric acid, chlorine gas, or anything else you don’t think you want to breathe, you shouldn’t use it. Chlorine is the most common dangerous byproduct though.

Do some research into laser safety and choosing laser safe materials. There is a lot of material available with a little effort.

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Yes, sorry, it was cast acrylic.

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Thank you, Ben1.

Yes acrylic is fine. But making an observation…

There are two things that are unequally important when using unknown materials. Damage to your health, and/or the risk of completely destroying the laser unit. I say these two risks are unequal because the mindset of people are different.

Coming from a rural area I see two completely different types of people. As an example there are a significant number of folks that live like the hippies of old, keep a complete stock of herbal medicines, might be vegans, or exercise regularly. Their health is paramount. Things, not so much. Another example might be small farmers who work in dangerous conditions, use pesticides, climb and fell large trees, and work around dangerous machinery. Health is only important after they are sick. But these folks might have tractors that are decades old because they keep every joint greased and oiled beyond what I might consider necessary or normal. (I still use my deceased grandfather’s 1947 Farmall tractor to mow grass)

Tell me that my health is at risk and I will try to be careful. But tell me that I might destroy the GF after a single use of PVC and I will spend days researching the MSDS and performing a flame test for Chlorine. Many will hear the guaranteed loss of $5000 louder.

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Well, what is done is done. I won’t use the acrylic I purchased on Amazon (luckily I only have one sheet remaining).

Do you all have suggestions on where I can buy proof grade acrylic? The GF store is sold out on all big sheets and I’m not interested in buying the small size cuts of acrylic.

Thanks.

Amazon acrylic is usually labeled as Cast or not. If it’s not labeled, the seller will usually tell you (or someone has likely already asked). Cast acrylic is just about the same from every vendor - pretty sure most of it is made by Chemcast. You’ll see their logo on the paper masking.

Acrylic is acrylic, it’s fine. Use what you can get. People were just reacting to “plastic”, as it could have been some other kind of plastic, like PVC, which would be exceedingly dangerous.

In my experience, Proofgrade acrylic isn’t particularly special compared to cast acrylic I can get from other places. Wood is a different story.

And before someone corrects “acrylic is acrylic”, yes there is a difference between cast acrylic and extruded acrylic. Not in terms of composition or safety, but the way it’s made affects how it behaves in the laser: in particular, how stinky it is, how the cut edges and engraves look, and how it behaves when stressed or exposed to solvents.

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This is what I had purchased:

Looks like it’s probably extruded acrylic from the comments & answers to the questions in the listing. It came with plastic masking didn’t it? That’s usually a sign it’s extruded.

It’s smelly and you want to be careful to keep an eye on it so it doesn’t catch fire but it’s okay. I don’t use extruded because of that (and it doesn’t engrave with the nice frosty contrast cast acrylic does).

It actually had paper masking.

That means cast acrylic and it is perfectly safe. You just need to be careful in the future when you are considering materials.

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