Air Scrubber Purex XBase 400

[Philip Kulp]

Getting ready to lay out some money. Either VLS2.30 with the dealer recommended Purex Xbase 400, or, VLS3.50 with DH's DIY air filter. I am going to be working in a small 8x10 basement space, and want to be able to work with all suitable materials. I want to maintain a low profile, ie. not smell up the neighborhood, and of course protect me and the house. This is to be strictly a low production hobby operation with the idea that after I figure whats what turning it into a part-time business. Is getting an air scrubber really worth it? I'm seeing a lot of posts where people are basically taking whatever scrubber they are using and abandoning it in favor of outside vent. Found some good air assist advice here, using airbrush compressors (thanks!) hoping you can steer me away from any major mistakes with the scrubbers! The dealer says the expensive $500? secondary filter "lasts a long time". That makes me a little wary.

I can definitely build the DIY filter, is it good for all materials?

[Randy Digby]

I don't do wood, only plastic and anodized, so I can't speak to the odor produced when processing wood. I do know that with our closest neighbor (we are in a covenant restricted residential neighborhood) about 100 feet away that I could not run plastic without a scrubber. If I abandoned my scrubber, I would be out of business the first time my neighbor walked outside while the wind was right (or wrong!). Some folks could vent outside but use a scrubber to keep the warm air inside in winter and the cool air inside in summer. You just have to weigh your process and environment (where are the other people) and make your choices. The other posts here certainly helped me build my own scrubber for small bucks vs. the $4,000.00 commercial option.

[Philip Kulp]

Thanks Randy, I'm going to try Dan Hintz's DIY model. He happens to have a shop fairly nearby. Any advice on your homebuilt scrubber? Ok for acrylics too?

[Randy Digby]

I don't do acrylics but I don't see why it would not handle those fumes as well.

This is a test post of a pic before I waste my time posting several.
http://farm5.staticflickr.com/4153/4957242808_d4e0eed64a_z.jpg (http://www.flickr.com/photos/rmdigby/4957242808/)
_MG_9056 (http://www.flickr.com/photos/rmdigby/4957242808/)

[Randy Digby]

Here are a series of pics detailing my scrubber. I pull from the bottom of the scrubber, through the blower and then out a dryer vent. The blower is on the floor under the table that supports the laser and the scrubber. The first pic shows the inside of the scrubber. There is a 12" x 24" section of closet shelving with a layer of 1/4" hardware cloth to support the charcoal charge. The air inlet from the laser is top left on the scrubber.
http://farm5.staticflickr.com/4126/4957247982_553f5416fb_z.jpg (http://www.flickr.com/photos/rmdigby/4957247982/)
_MG_9055 (http://www.flickr.com/photos/rmdigby/4957247982/)

I then lay down a single thickness of cheesecloth. This holds the charcoal in place and makes it easy to remove the charcoal by pulling out the cheesecloth/charcoal bundle.
http://farm5.staticflickr.com/4149/4956657717_ddd191ddc2_z.jpg (http://www.flickr.com/photos/rmdigby/4956657717/)
_MG_9057 (http://www.flickr.com/photos/rmdigby/4956657717/)

The charcoal charge is added, about 2-1/2".
http://farm5.staticflickr.com/4094/4957252252_787e80f3b3_z.jpg (http://www.flickr.com/photos/rmdigby/4957252252/)
_MG_9058 (http://www.flickr.com/photos/rmdigby/4957252252/)

A 12" x 24" HVAC filter is placed over the top of the charcoal to act as a pre-filter. The loose cheese cloth is packed around the perimeter of the filter to seal it in place.
http://farm5.staticflickr.com/4121/4957244526_69546d6b27_z.jpg (http://www.flickr.com/photos/rmdigby/4957244526/)
_MG_9059 (http://www.flickr.com/photos/rmdigby/4957244526/)

The lid is held in place with four toggle clamps for toolless entry. Weather stripping is applied to seal the lid.
http://farm5.staticflickr.com/4137/4956653731_59c1a2c621_z.jpg (http://www.flickr.com/photos/rmdigby/4956653731/)
_MG_9060 (http://www.flickr.com/photos/rmdigby/4956653731/)

I use the top of the scrubber to hold a storage rack for material.
http://farm5.staticflickr.com/4127/4956661443_fe51c15760_z.jpg (http://www.flickr.com/photos/rmdigby/4956661443/)
_MG_9061 (http://www.flickr.com/photos/rmdigby/4956661443/)

There are a thousand ways to skin a cat, this is my method. I like Dan's method as well, I just had mine in the works when I discovered his design.

Hope this helps a little in your planning. Happy scrubbing!

[Dan Hintz]

One of these days I'll get around to more of a stacking design like Randy's, where every piece of the puzzle is a separate rack" that stack on top of the next. It may not look like a trashcan anymore, but that may not be such a bad thing ;)

[Randy Digby]

Dan, I guess we never get completely happy with some of our creations. If you look at my first pic above you can see a small block of MDF below the front toggle clamp. That covers the port for the removable filter from the first generation - it just plain didn't work. Then there was the HUGE HEPA filter - that just plain didn't work, either.

Back before I retired in 2007, I had access to a full blown machine shop where I was maintenance manager for a large plastics operation. I sure do miss milling machines, lathes, presses, brakes, TIG welders, etc. Now I operate in a world of MDF, circular saws and caulk! But, I sleep good at night :-)

[Rich Harman]

I'm not impressed with the performance of my scrubber. The first thing I cut using it was Delrin. Five minutes into the job and my eyes started burning. I am using a bed of charcoal that is 10" x 35" x 2" deep. It does greatly reduce the smoke and fumes, but not enough to enable me to vent it into the shop. I do feel better about venting it outside though and for that alone it is worth-while.

I may change my mind after re-doing the seals, maybe. I know the seals could be better but I am skeptical that it will make much difference. I can see it pulling all the smoke straight into the middle of the filter rather than around the sides where I could have done a better job sealing it.

[Randy Digby]

Rich, not knowing your set-up, I'll just grab at a few straws.

Is everything from the laser to the charcoal under negative pressure? If not, you will be extremely lucky to seal all possible points of leakage on the pressure side. If you are pulling negative pressure, a good seal is equally important so that no vacuum is lost, but leaks on the vacuum side are nearly impossible to locate.

Do you have enough air flow across the cutting table to you exhaust vent on the interior of the laser? My laser has a perforated grid across the back side of the inner cabinet for the exhaust fumes. I can take a piece of printer paper, suspend it from two corners and observe how good it is sucked up against the grid with the blower running. I have learned by experience how much "pull" the paper needs against it for the scrubber to work. Originally I had too much charcoal and my blower would not pull through it enough to give me the air flow I needed across the work table.

[Rich Harman]

Rich, not knowing your set-up, I'll just grab at a few straws.

Is everything from the laser to the charcoal under negative pressure?

Yes.



Do you have enough air flow across the cutting table to you exhaust vent on the interior of the laser?

If there is a reduction in airflow since installing the filter, it is not noticeable.

When exhausted to the outside (using the carbon), there is no problem with build-up of fumes or smoke. When exhausted to the inside, there is. Either fumes are getting sucked around the bed of carbon (leaks) or the carbon is not removing enough.

[Dan Hintz]

If you have a HEPA filter on yours like I do mine, you should see zero smoke in the room... unless you have a leak.

[Shawn Conklin]

I know this thread is kinda stale but wanted to chime in since I do have a Purex system and not too many other do.

I have the 400i. Its a digital version and has the pre filter and the dual hepa/carbon filter.

The machine is good looking, the air volume is measured and adjustable so you can adjust to suit the material.

I like everything about the system but the replacement costs. If you do a lot of acrylic cutting be prepared to replace the main filter ($500 of pain) more frequently. If I was venting into a shop or larger building I am sure it wouldn't be an issues but if we do a lot of acrylic the filter will start to allow some by after a few weeks. Not a lot but enough to notice in our 1000' office.

I would also say, regardless of age, that the filter has a hard time keeping up with cutting acrylic thicker then 1/4 inch. If you do cutting of 1/4 for more then an hour regardless of air flow you smell it.

Other then that though its great. And the build quality is that which you would want if you do shows or any onsite stuff. Can't really tow a hand made contraption into a mall or craft market :-)