Harbor Freight Dust Collector Upgrades Cost More Than You Think: Wynn, Rikon, Thien vs. Grizzly HEPA

We've all been there. You're halfway through ripping a sheet of plywood, the kids start asking what's for dinner, and you notice that fine, ghostly film of dust settling on everything in the shop that isn't a tool. It's the moment every Harbor Freight 2 HP dust collector owner eventually faces: this machine is pulling chips, but is it pulling the stuff that actually matters?

The forums have a standard answer, and it's a good one. Instead of replacing the collector, you upgrade it piece by piece: a Thien baffle separator, a Wynn cartridge filter, a beefier impeller, maybe a remote. I've seen finished builds like this praised all over the woodworking internet. The question I wanted to answer is how that stack really stacks up, dollar for dollar, against something like Grizzly's HEPA cyclones. The honest answer is more interesting than either camp's sales pitch.

The Base Machine, and One Honest Caveat

The unit everyone modifies is the Harbor Freight / Central Machinery 70-gallon 2 HP Heavy Duty dust collector, Item 97869. Harbor Freight's own coupon materials have listed it at an Inside Track Club price of $199.99 with a 1550 CFM rating. I'll be upfront: I couldn't verify Harbor Freight's current pricing for this piece, because their product pages wouldn't load when I researched this. So treat $200 as the historical baseline, not today's sticker. Check the current price before you budget.

It ships with a 5-micron collection bag, which is the weak link the whole upgrade path exists to replace.

Upgrade One: The Thien Baffle, Free Plans, Honest Trade-Off

The Thien baffle is a drop-in separator lid you build yourself from plywood and a trash can, based on plans published by its inventor, J. Phil Thien, at jpthien.com. He developed it after testing three commercial cyclone lids and finding they all let big chips through and suffered "scrubbing," meaning they re-entrained settled debris once the bin was more than about a quarter full. His design uses a specific geometry: a 1.125-inch drop slot, formed by reducing 240 degrees of the baffle by 2.25 inches, with the rest matching the can's inner diameter. He says the design scales well and that he has modded single-stage collectors with it so cartridge filters stay cleaner, longer.

A well-documented build on LumberJocks used a 31-gallon trash can with a Thien baffle and a 15-foot run of 4-inch pipe to a table saw. The verdict on separation: excellent. After months of use, only a couple of cupfuls of dust ever reached the collection bag.

But here's the part the forum highlight reels skip. That same builder reports that most of that performance gain was lost when he added the separator. His overall assessment, and he notes it's in line with others who did the same upgrade, is that the collector's performance gains and losses factored together are about a wash. The baffle protects your impeller, keeps your filter clean, and means you're emptying a trash can instead of wrestling a bag. What it does not do, on this machine, is add airflow. Cost: materials only.

Upgrade Two: The Wynn Cartridge, the Real filters Upgrade

The Wynn Environmental 35C222NANO cartridge kit currently lists at $279.00 on Wynn's own site. That gets you a MERV 15 pleated cartridge with 222 square feet of nanofiber media, 17.5 inches in diameter and 23 inches tall, plus instructions, two clear collection bags, and a bracket kit. Wynn has built these 35-Series filters for over 18 years specifically as replacements for balloon bags on hobby and small-shop collectors, and they say the first thing you'll notice on startup is a big increase in airflow. One practical note: Wynn was running 5 to 7 business days behind on shipping 35 Series filters when I checked, so order before, not during, a big project.

One caution on labels: Wynn itself publishes a page titled "Misleading HEPA Claims," and I'd take the hint. MERV 15 is a genuinely good filtration rating for a shop cartridge, but it is not HEPA. Don't let anyone, including me, tell you otherwise.

Upgrade Three: The Rikon Impeller

The popular swap is Rikon's replacement impeller for its own 60-200 2 HP collector, part P60-200-22, listed at $119.99 on Rikon's parts page. It's a sturdy metal design with seven rear-facing blades, 11-3/4 inches in diameter, on a 20mm shaft. Forum reports back this up as an easy job: over on Wood Talk Online, a user described removing twelve screws for the impeller cover and a reverse-threaded nut, and that's essentially the whole operation. Pricing has been in the same range for years, too: Sawmill Creek users reported paying $99 plus $8 shipping back in 2017.

Worth knowing for context: the Rikon 60-200 collector this impeller comes from is rated at 1,189 CFM, which is actually lower than the HF unit's 1550 CFM rating.

Upgrade Four: The Remote

This one is pure quality of life. A LumberJocks builder mounted a long-range remote switch between the cart's 4x4 posts and called it "just plain convenient," and I believe it. When you're walking back and forth to a switch across the shop a dozen times a session, a remote earns its keep. The catch: I couldn't verify a specific model or price for a remote rated for a 2 HP motor. One LumberJocks thread notes that most remotes are rated for 1-1/2 HP motors, so read the amp rating carefully before you buy. Budget something modest, but verify the rating yourself.

The Math, Done Honestly

Adding up verified prices: $199.99 for the collector at the 2021 Inside Track price, $279.00 for the Wynn kit, $119.99 for the Rikon impeller, plus baffle materials and an unpriced remote. That's roughly $600 before the remote and plywood. If you've seen a "$250 mod stack" figure floating around, it doesn't survive contact with current manufacturer pricing; the filter alone is more than that now.

Against that, there's Grizzly's G0440HEP 2 HP Dual-Filtration HEPA Cyclone. Dealer US Tool Depot lists it at $3,475.00 MSRP with $299.00 shipping. A search result suggested grizzly.com has discounted it to around $2,778, but I couldn't confirm that on Grizzly's own page, so verify before you plan around it. The specs, as quoted from Grizzly's sheet: 1,354 CFM at 2.5 inches of static pressure, a 14-1/2-inch steel radial-fin impeller, 96 square feet of filter area at MERV-17, a primary filter at 99.9% of 0.2 to 2 microns, and a secondary HEPA stage at 99.97% of 0.3 microns. It's also 476 pounds shipping and 93-1/2 inches tall, which matters if your shop is a garage bay, not a barn. Grizzly claims the dual-filtration design can extend HEPA filter life up to 900%, potentially ten years. That's a manufacturer claim, not an independent test. Grizzly also sells a Quiet Series line, including the G0991 horizontal cyclone, billed as ultra-quiet, though those product pages blocked fetching, so I couldn't verify their specs or pricing.

So Which Path?

Here's my honest take. The modified HF stack gets you a machine that separates chips well, protects its impeller, and breathes through 222 square feet of MERV 15 media. What it does not get you is verified HEPA-grade filtration, a manufacturer-published CFM-at-static-pressure figure, or an independent lab test of anything. Neither path has independent measurements; the Grizzly's numbers, including that HEPA stage, are factory claims too. On paper, at least, the G0440HEP's secondary HEPA stage is a finer filtration spec than MERV 15.

My advice: start with the Wynn cartridge. It's the single biggest air-quality improvement per dollar. Add the baffle for the trash-can convenience and impeller protection, knowing the airflow trade-off. Then decide whether the dust in your shop justifies $3,475. For most of us, it doesn't yet.