obligatory obscure reference

Between making PPE and cranking up my Etsy sales I’ve learned  few things I’d like to share:

• Etching rubber stamps will clog your filter.  I knew etching would kick up a lot more dust, I just had no idea how much.  My pre-filter and my HEPA clogged after about 3 hours of etching.
• You need the HEPA filter.   Mine clogged just as I was finishing a cut, so I pulled it and ran just with the pre-filter and the charcoal.  Smoke came out of ventilator, enough that I needed to ventilate the studio by opening the garage door.  Except it was 20F outside.
• You either need two HEPA filters or a way to buy a replacement within an hour or two.  All of my clogged HEPA filters went from “pulling smoke just fine” to “completely clogged” in less than hour.  Maybe I could put some sort of wind-speed sensor in the hose but it’s easier  to order two HEPA filters and have a replacement on hand.
• HEPA quality varies by brand.  I didn’t keep records of cuts between filters, but one filter lasted a few months, another almost a year.  These were knock-off, mail-order brands, for the next filters I’m going to keep some simple notes on how many things I cut.  I already do this to track nitrogen usage and plan on tank replacement.
• There’s no inventory of HEPA filters that have overnight shipping as an option, at least within my budget.
• A better pre-filter would help, maybe use the fabric wraps we use on standalone HEPA filters?