Glowforge Filter life for Proofgrade Draftboard vs Medium Proofgrade Plywood

Ok… I’m just using a bit of logic here. So I’m hoping if someone can help clarify

The following link shows lifetime for some of the proof grade materials.

First, it doesn’t show the life of draft board in the table, while I have read in multiple posts that draft board is just bad to use with the filter. Basically, all my draft boards are high risk for the Glowforge Filter (really disappointed). However, lots of particles from the cuts/engraves do make sense in limiting the life.

Second, the table shows Medium Proofgrade Plywood (1/8?) as 210 while Thick Proofgrade Plywood (1/4") is 1614. That’s a huge difference! I would assume thick would produce more particles in the cuts/engraves compared to Medium.

Third. What is the comparison between Plywood vs Draftboard. I think the table is a mistake or at least I hope it is. I’m hoping actual medium Plywood is performs close to Thick Plywood or better.

No, that is unfortunately accurate. Draftboard can clog a filter in as little as 10 hours, depending on how heavy the usage is. (It’s not the particles in it, it’s the glue holding the particles together. It goes airborne when heated and binds to the openings, narrowing the pore size, and clogging the filter so it can’t draw air.)

It’s best to vent Draftboard outside if you can. Also dodge any woods with a high resin content. (Padauk is as bad as Draftboard. Wenge will last forever - it throws nothing.)

The reason for the difference between Medium Plywood and Thick Ply is that the thick plywood is filled with basswood, not composite material. It keeps the weight down. So no glue buildup. The MDF fill in the medium plywoods will also clog a filter more quickly than hardwoods without glue. It’s a composite material too, but the thicker veneers on it keep it from going quite as quickly as draftboard.

All filters with pores that size (needed to capture odors and safely filter the smoke for breathing) have trouble with MDF style materials. It’s just the nature of the beast.

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tl;dr response - “medium” proofgrade plywood uses a “draftboard” (mdf) core, “thick” doesn’t.

You can purchase 1/8"ply from other sources that does not use mdf. Baltic birch is one popular and commonly available option.

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What Jules said! Glue doesn’t just clog the filter. It mucks up the entire inside of your machine, including everything that’s exposed, though more in the direction towards the exhaust. I wrote about this here (no, I don’t know why the link preview looks like that instead of the post itself).

I wasn’t aware of that about Padauk. I did know that Padauk dust can be toxic and is just as dangerous with a saw as with a laser. A shame, because it is gorgeous. I have a beautiful piece I’ve been saving for a special occasion. If you have a disposable mask handy that you’re not going to wear outside any more (or one with a disposable filter that you can clean afterwards), it’s a good idea to use it when working with Padauk.

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Because the post is not visible unless you are a member of failbook and the group.

Yes, of course. I’m not going to repost here, but the tl;dr version is: MDF, plywood, and fake plywood (actually MDF) all have glue. Avoid them.

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In my experience, oak is nearly as bad as MDFin mucking things up, but not for resins as much as particles which both throw in abundance. In the case of oak the water transport vessels in the wood do not burn nearly as easily as the rest and fly out as tiny fibers in the smoke. At one point when having other troubles with the exhaust I found what looked like black cotton balls made up of those fibers.

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A lot depends on what you are hoping to get for filter life. Eventually you hit the point where the carbon isn’t keeping up even if the hepa filter is still flowing. I’m pretty sure the numbers given are the technically safe numbers (no harmful gasses), not the point where there strong odors start appearing. Even with hardwood I was never able to get beyond 30 hours before the smell was too much.

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Wow… Thanks for the replies everyone. This is all great information! I put in the request to join the FB group so once I get access, I’ll read your post as well.

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That is great info! I cut almost exclusively maple and cherry (and some acrylic). They’re beautiful, cut nicely, take engraving well, etc. But it never occurred to me that oak would be bad.

I bought 3 4x8 sheets of 1/4 oak plywood,(out of looking through 40 sheets for minimum trash) and it is very strong for practical stuff but makes a real mess, The solid oak shows so much grain it does not engrave well for 3D stuff