Dust Collector Modifications (Separator/Filter) Questions

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Forum topic by seabiscuit posted 11-21-2011 06:14 PM 4142 views 1 time favorited 6 replies Add to Favorites Watch
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95 posts in 2420 days

11-21-2011 06:14 PM

I have the HF 2HP Dust Collector (don’t we all?) and have read a lot of forums about all the modifications people have made. I know that I need something to filter down below the 5 micron level (I’ve been using the basic filter bag since I bought it), and am looking for some advice.

People suggest the Wynn 35A ($109 + $20 shipping) due to increased air flow and a filtering of 0.50 microns. Is it that much better than the $35 Big Horn, 1 micron bag?

I have my shop in an upstairs bedroom next to my master bedroom. It is about 15’x15’ (not huge) and I am using a air purifier that changes out the air in the room about 5-6 times an hour down to 0.5 microns (has a HEPA filter).

Do I need the Wynn if I already have the purifier? I haven’t noticed an inadequacy in terms of suction, so I don’t know if the increased air flow and 0.5 micron is really worth the extra money…

Also, lots of people talk about Thein separators. I’ve looked at lots of pictures and realize they appear to be space hogs. Is there any way to achieve a similar setup (I believe the point of it is to keep most of the dust out of the filter in the first place to keep it from clogging?) INSIDE the dust collector itself? That way I don’t have a huge garbage pail and a bunch of extra tubing hogging up all my space. Also, are there places to buy this stuff at a reasonable price or is it all hand made?

Any advice would be appreciated.

6 replies so far

View Manitario's profile


2630 posts in 2879 days

#1 posted 11-21-2011 06:33 PM

An air purifier is great to catch residual dust, but really, it is not designed to do the work that your main DC should be doing. The Wynn canister is great, partially because it filters down to 0.3 microns, but also because the large surface area of the pleated filter allows your DC to run efficiently. A bag filter has a comparatively small surface area which will reduce the efficiency of the DC anytime you get a small amount of dust on the inside of the bag. A Thein separator work well, but besides it being a space hog, it also is an airflow hog, meaning it reduces the CFM of your DC. The new Jet DC has an internal baffle between the lower and upper bags that acts the same way as the Thein, without killing your CFM. If you search on LJ’s, I’ve seen a couple of guys that have built a similar internal baffle into their DC.

-- Sometimes the creative process requires foul language. -- Charles Neil

View fussy's profile


980 posts in 3047 days

#2 posted 11-22-2011 01:39 AM

I have to agree and disagree with Manitario. The Wynn is definately worth it for all the above mentioned reasons. The Thein separator is NOT a space hog. Go to to see how to add the baffle of the Thein separator to your HF dc. I and thousands of others have done this with no loss of cfm, no filter plugging, and next to no cost. Takes about two hours or less. It keeps the filter clean. I’ve had this setup for several years (2?), have blown my filter out only once, and got less than a cup of dust. Everything else goes in the bag.

Perhaps DBHost will weigh in here and put your mind at rest. He’s one of the BIGDAWG oldtimers on Phil’s site and knows whereof he speaks. Are you out there DB?


-- Steve in KY. 44 years so far with my lovely bride. Think I'll keep her.

View DannyB's profile


46 posts in 3418 days

#3 posted 11-22-2011 04:10 AM

I completely agree with Steve.
I also use a HF DC with an internal thien baffle (and a Wynn filter). As fussy says, no CFM loss, no filter plugging, etc. This took roughly 15 minutes to build with 1/4” MDF. In order to install it, rather than drill holes in the DC, i actually placed pieces of angle iron on the bottom of of the baffle, drilled holes in that, just put 10 inch bolts through the normal mounting holes for the lower support and through the angle iron. It holds it just just fine, no destructive modifications to HFDC necessary :)

My recollection is that Paul’s view was that the vortex on the new Jet was nowhere near as good as the baffle (in fact, IIRC, he said he had tried a similar shape at one point).

View PurpLev's profile


8535 posts in 3645 days

#4 posted 11-22-2011 04:21 AM

FYI, the reason for the huge external gabage pail on the thien SEPARATOR ( as opposed to the thien baffle) is to convert your 1-stage DC into a 2-stage DC. your HF DC as it is now is a 1-stage DC meaning that the all parts sucked in are passing through the impeller which in the long run (and depending what you suck) could shorten the life of the impeller and motor. a 2-stage DC separates the larger/heavier parts from the fine dust and dumps the heavier stuff before it passes through the impeller resulting in only the fine dust passing the impeller to the filter thus nothing impacts the impeller prolonging the life of the DC unit. This also makes it easier to empty it since the majority of chips is left in the external garbage pail so you don’t have to remove reattach the plastic bag on the DC as much (which is a hassle).

however, a separator WILL reduce your CFM.

the thien baffle on the other hand uses the same idea of the separator but built into the DC housing, which although helps keep larger parts from getting into the filter, still have it pass through the impeller

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View Viking's profile


880 posts in 3192 days

#5 posted 11-22-2011 08:17 AM

We used the Wynn 35 Nano filter cartridge on the HF dust Collector but, have a simple 30 gallon trash can pre-separator that collects the lion’s share of whatever goes through it. We have, in 2 years, never had to empty the lower bag on the DC. For increased portability, we installed the DC and the PS on same deck with casters.

The Nano filter almost completely eliminated finer layer of dust we found on everything in the shop when we had the original bag filter.

Good Luck!

-- Rick Gustafson - Lost Creek Ranch - Colorado County, Texas

View ksSlim's profile


1275 posts in 2886 days

#6 posted 11-22-2011 08:21 AM

What Viking said.

-- Sawdust and shavings are therapeutic

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