Air filter and Proofgrade materials

Looking for clarification: The advice is not to use the (delayed) air filter with MDF because of the potential to clog it up, and Proofgrade Draftboard has been cited as such a material. Are the other Proofgrade materials safe to use with the filter in this sense? I’m thinking in particular of the hardwood-laminated plywoods (e.g. Medium Maple Plywood). Thanks!

You want to avoid things that make really fine dust (like the draftboard and MDF) because of clogging.

The filter handles wood smoke really well.

Your mileage may vary :slight_smile:

Things I’ve read -

  • Run the filter at full speed always
  • Run the filter for 15 minutes after you’re done
    Both these things help with moving the particulates deep into the filter so that the filter lasts longer…

Just things I’ve read. I have no working knowledge of the compact filter…

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Thanks, both. What I’m really trying to get at is whether the Proofgrade laminated “hardwood plywoods”–the ones that have a veneer of hardwood on each side–are also things to avoid. To me, they look like they are basically MDF in the middle. Are they to be avoided in the same way as draftboard, or is this an engineered wood product that somehow avoids creating a high-particulate smoke?

I use all of the Proofgrade materials with my filter other than Draftboard.

I’ve given up using draftboard for the most part.


They are indeed MDF in the middle. You can use them but they will clog your filter faster than straight wood but a little slower than draftboard. Engraving is particularly bad.


Both of those seem to run contrary to the manual, to some degree, I believe.

I thought the manual said run only as fast as needed to keep the smoke at bay, and then to run for 1:1 empty for the same amount of time that you worked. So, work for 2 hours, let it run for two hours. At least, that was @dan’s advice.


I would agree that if you’re running a 1 hour job, run the fan for 1 hour more. But with HEPA type filters, running on the highest speed provides the best ‘cleaning’ and if you are not running fast enough, you’re going to clog the front layer of the filter too fast… which kill the filter prematurely. Done this in my cigar room before… so the filter runs on 4 (max) constantly.

When the exhaust fan died on my old machine, I bought a Vivosun in line fan to make up for it. It did not do a very good job alone, but when I finally got the new machine and the exhaust fan was working, the two together rip away the smoke very much faster, and as a result there is far less buildup of gunk than before. If I could have the 500 cfm fan running there might not be enough to clean.

Now of course if the smoke and smells are not in the machine they will be in the filter and if there is a washable prefilter it will also gather less with a higher volume of air and at some point the fumes may go so fast through the activated charcoal that they are not well absorbed, but short of that I will still want as much air movement as I can get.

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