J. Phil Thien's Projects

About 5 months ago I added a Thien baffle to my Harbor Freight DC. (Here's that story.) So far I've been really pleased with the addition of the baffle. I was getting very little buildup of fines on the pleated filter. Instead of removing and cleaning my filter every 3 weeks or so, I'd not seen the need at all since adding the baffle. I just whacked the sides of the filter from time to time, and gave it a shot of compressed air once every few weeks.Then, a couple or three weeks ago I noticed that the DC wasn't sucking the way it should. Sanding sessions at the lathe were dustier than normal, because the dust hood wasn't pulling in as much dust as it used to. I suspected the filter was getting clogged.

Last Saturday I finally had a chance to take it apart and see what was happening. Before I removed the plastic bag from the bottom of the DC, I whacked and blew on the filter more thoroughly than normal, and was amazed with the volume of very fine dust that fell out of the filter. (A good 6" to 8" deep in a new layer in the lower bag.) When I shook the filter (the whole DC, actually), even more stuff fell into the bag, falling off the top of the baffle through the slot around the outside edge. Something was up. This was dirtier than before adding the baffle.

To remove my filter, it's necessary to first remove the baffle...an overhead job if I want to avoid completely dismantling the DC to turn it upside down. I undid the three screws holding the baffle in place, and lowered it carefully to avoid dumping sanding dust all over myself. Here's what I found:



I guess that's what I get for using the 4" hose to clean up the mess after a turning session. You don't suppose that piece of edging for my foam floor mats might have caused the filter packing do you?   I was laughing so hard I had to take it inside and show my wife. I did check the impeller, and it seemed no worse for the experience. (I've sucked up a few solid chunks of wood or bark that alarmed me enough to open up the DC and have a look at the impeller.) No big surprise, but my DC is sucking mightily once again.

For the price I paid, I've been very pleased with my Harbor Freight dust collector. From the get-go I added a 0.5 micron pleated filter and a neutral vane to improve the performance. Here's the story on that part. However, every time I emptied the lower bag I had to remove the filter to clean all the embedded chips and sawdust from between the pleats of the filter. The solids were not staying in the lower bag like they were supposed to.

I'd read good things about Phil's baffle, so I decided to adapt it for my Harbor Freight DC. I wanted to see if it'd help my DC without a detached separator unit.

Here's the separator, removed from the DC and turned upside down...



The inside diameter of the separator is 19", so I needed to draw a 19" circle on the masonite. I don't have a compass that big, but I do have a nail, a pencil, and some scrap wood...





Then I needed another circle, 1 1/2" inside the first one. Same approach, just a different hole for the pencil...



Then I laid out the 120? part of the circle...



And got busy with the jigsaw...



Next, I needed some standoffs to hold the baffle in place. I used some 1 1/4" (as I recall) dowel material I picked up at the Borg. I had to play around a bit to figure out the angle to cut the ends to match the slope of the separator. I have no idea what the actual number ended up being, but it worked. I also drilled the holes in the end before cutting the angle...



Then I attached them with screws at roughly equal points around the separator...



And attached the baffle to the tops of the standoffs. (Actually, it's the bottom once the separator is turned right-side up.)



And a shot of the finished installation after putting the filter back on (but before attaching the lower bag). This is looking straight up into the bottom of the separator. I had to attach the filter before installing the baffle, since with the baffle in place, I could not reach the turnbuckles that hold the filter in place...



Before I added the separator, I could walk by my DC at any time, bang the sides of the filter, and see clouds of sawdust fall off the filter and into the lower bag. I have now been through two fillings of the lower bag since I added the baffle, and although I've not removed the baffle to check the condition of the filter, I get absolutely no dust falling now when I bang the sides of the filter. My DC seems to perform better, since the filter's not getting clogged, and emptying the lower bag (and cleaning the filter) is no longer the nasty chore it used to be. It will be a bit more work to remove the filter now, because I'll have to remove the baffle first, but based on what I'm seeing so far, I won't be needing to remove the filter any time soon.

I'm very impressed with how condensed the debris stream is when it drops into the lower bag. Previously, I could see the material swirl around the bag, but with the baffle, the spiraling stream of dust and chips looks like it's being shot out of a hose. I've also nearly filled the lower bag (12" to 18" from the top of the bag) with chips from my planer, and still saw no signs of chips going into the filter.

I'll give the Thien Baffle two thumbs up.  ;D

Thanks much, Phil.