The resin used in MDF is a toned down (but still the same chemical) version of the urea formaldehyde resin that caused a big stir about 15 or 20 years ago because people were getting sick in newly built homes. The culprit there was particle board and OSB (oriented strand board). They’ve since re-formulated the glue to release less formaldehyde gas and cure it more before shipping.
The appeal of this resin is that besides being very strong and economical, it will sit for hours (even days) in a plywood lay-up or particleboard/mdf mixture, but can be cured in a few minutes with a microwave curing system.
As you pointed out Carl, even the dust is nasty stuff and deserves more respect than it seems like it deserves. It seems like plain old fine wood dust, but carries the binder (the UF Resin) with it right into your lungs. Burning it does the same thing.
Years ago I used to “not make a big deal” about spraying cars and handling chemicals (“you’re only immortal for a limited time”- Gold star if you can tell me who said that, but hurry).
The rule used to be “If you can smell it, it’s causing harm”
Then a fellow who I used to race with died from spraying Isocyanate hardened auto paint which was quite new at the time. (son of a body shop owner). You can’t smell Isocynates, but they will kill you.
Anyway since, I’m a fanatic about quality respirators, Heavy duty exhaust fans, interlock switches etc. You can’t buy new a new body, trust me I know.
Sorry to run on about safety, it’s a boring, downer kind of subject, but Laser art shouldn’t be fatal, and there’s many ways the little blue box can hurt or kill you. Just like the innocent appearing sawdust, nothing SEEMS real dangerous there, but you have un guarded laser light waiting to blind you, exposed unguarded mains voltage, exposed unguarded 15kv, and of course most of us will try lasering almost anything once. Many seemingly safe material release some very nasty byproducts when lasered.
Sorry again for repeating warnings you probably have heard before, but I constantly field questions from people running lasers vented into the room, poking around the high voltage section with a meter rated at 600v and so on. SOME new users don’t do any real research on what they just bought.
Every now and then a crafter buys K40 expecting a Cricut that cuts all sorts of new stuff expecting to plug it and and go. They show up here, usually a couple of times a year. I worry about the ones that don’t find our community. Better bad news than serious injury, fire or worse.
As nice as the K40 is, it’s analogous to selling a car with no seatbelts, emergency brake or door latches. That leaks gas.
It CAN be made into a safe, useful tool, but used out of the box, it’s asking for trouble.
Scott