I bought this vacuum pump to stabilize wood turning blanks and degas wine. The pump arrived before my vacuum pot, so I decided to setup it up for degassing wine. My one and only criticism of the unit is the two fitting for attaching a vacuum line. They are a 1/4" Flare and 1/2" Acme. If you're a refrigeration guy, these are perfect, but if you're a woodworking wino, they can be problematic. I wanted to end up with a 3/8" nipple fitting for a hose. After a couple a trips to hardware stores and purchasing the wrong fittings, I became frustrated and removed the fitting from the pump, took it to the store, handing it to the clerk and told him what I wanted. After much digging around, the clerk came up with a variety of fittings that when combined would accomplish my goal.

One thing I noticed when I removed the fitting from the pump, was the thread sealant. Instead of typical semi soft pipe putty, the sealant was hard like glue. When I reinstalled the pump's fitting, I used Teflon tape. I assembled my degassing rig and fired it up. The vacuum gauge read a maximum vacuum of about 25 Hg. Fine for wine but not ideal for stabilizing wood.

The next day my vacuum pot arrived. It came with all the fittings and vacuum gauge installed. All that needed to be done was to attach the vacuum line directly to the 1/4" flare fitting on the pump. No adapter needed. I fired up the vacuum pot (after changing the pump oil) and watched as it maxed out at about 27 Hg of vacuum. Acceptable but not great. Out of curiosity, I put a few drops of oil around the pump's fitting were it screws into the pump body. Within a few minutes, the oil had disappeared. Before doing the next batch of wood, I removed the fitting, cleaned the threads with a pick and wire brush, and reinstalled the fitting using 5 minute epoxy as thread sealant. The next time I ran the pump, it pulled a 29+ Hg vacuum that eventually got past 29.5 Hg. At my elevation of 825' above sea level, that's about as good of a vacuum as you can get.

I am on my 5th batch of wood and have not changed the oil in the pump. It's still pulling a near perfect vacuum. Speaking of oil, when the pump is running, an oil mist is emitted from the exhaust port. I would avoid breathing it. Rather than wear a filter mask I simply put the pump outside. The good news is, when the pump reaches maximum vacuum (and there are no significant vacuum leaks) the mist diminishes almost completely. I still run the pump outside. In cold weather, I keep the vacuum pot inside and run the power cord and vacuum line under the garage door to the pump outside. The cold air helps keep the pump cool during operation. In 50+ degree temps, the pump gets pretty warm after running for a couple hours or more...not burning hot, but uncomfortably warm (which is normal).

Overall, I'm very pleased with this pump, especially at this price.

After about 10 hours of running, base pressure is 3-4 um on a Hastings DV-4 gauge (two different gauge tubes), which is well below the 22 um in the spec, but NOT the 2.2 um in the "Answered Questions" comments from the seller. I use Inland 19 oil for direct drive pumps as the included oil has no vapor pressure specs. My use is more scientific and required the swap of the supplied refrigeration fittings for KF16 flanges. This swap required me to attach a 3/8 pipe fitting to the rather thin wall of the suction flange with Torr Seal. Be aware that there is an input screen below the refrigeration fittings to protect the pump from mm sized particles and this screen must be kept clean (which is virtually impossible to inspect with the refrigeration fittings in place).

For normal operation (after the third oil change), the pump will easily evacuate one liter to under 10 um in less than 30 sec. However, once every 5 to 15 evacuations from atmosphere, the pressure reduction stalls at about 200 um in the first 10 seconds. Adding a leak to momentarily raise the pressure to over 1000 um allows the pump to reach the 10 um base pressure. Once the pump is switched off, the pressure rises to over 1000 um is less than 10 seconds. To hold vacuum without the pump running requires additional valves to isolate what was evacuated and to vent to pump.

The pump does seem to produce excessive exhaust oil under load, but I have solved this with a makeshift trap attached to the exhaust plastic fitting.

This pump pulls a better vacuum than I needed for evacuating my A/C's refrigerant lines. It also seems to be well made with quality parts because despite being left running for almost 3 hours, the motor casing and pump head barely got warm at all so I have no doubt that this pump's claim of being rated for Continuous Duty is true. Another pump I looked at actually claimed to have max runtime of 30 minutes which isn't long enough to use for anything you would actually use these kinds of pumps for. The only thing I think this pump is missing is a cap to cover the exhaust port when not in use to keep dust and debris from settling inside the pump. It's obviously an easy fix with a piece of tape or something but I've seen even the cheapest pumps come with a rubber cap for this purpose so it seemed kind of lazy to me. That's my only complaint and it has nothing to do with the quality or function of the pump, just the thoughtfulness of someone in marketing. I would absolutely recommend this pump to anyone.

I am using this to pull vacuum on vacuum bags for carbon fiber resin infusion. The manual notes that you're suppose to let the pump run through a break in period. I let the pump run for about 30 minutes before I shut it off and drained the oil out of it. I also bought vacuum pump oil with this pump because I did not know that it comes with a bottle of oil to fill the pump back up after the break-in period.

I had some trouble getting the oil to show in the sight glass but a little rocking back and forth fixed that. This pump spews oil fog constantly while running. The first time I really used this I had it running for 7 hours straight. It had no problem with this. Other than the fog of oil that filled my garage it pulled more than 30 In/Hg the entire time (my gauge only goes down to 30, but it was past the 30 mark onto the stopper).

This machine will not hold vacuum when you turn it off. You will need to clamp the lines or install a ball valve. I did not know this initially and I turned the pump off to inspect a bag. About 10 minutes go by and I notice oil in my resin catch can. The vacuum in the bag had sucked oil back up through the hose. Luckily I had a catch can in-line so no oil was sucked into my composite piece.

Overall for the price this vacuum is hard to beat. I have more than 12 hours of run time on this with two fairly long stints. The vacuum didn't get hot during either of them and ran like a champ the entire time. I need to figure out a way to either filter the oil out of the exhaust or re-condense it, but otherwise it's worked well so far.

I received the pump just in time to complete an urgent project. The directions include an "oil flush" procedure, so I filled the pump with oil, ran the pump for 1 minute, then drained the oil . The pump only came with one bottle of oil, and it took the entire bottle to fill up the pump, so now the pump is empty, and I have no oil to refill it for use. I bet the company who designed this pump package is still laughing about it. Well, now I have a properly flushed pump, that I can't use.
Also, I needed the pump to vacuum bag a carbon fiber part, but I couldn't find anything online, or in my local hardware store, that would adapt either the 1/4 male flare or 1/2 male acme fittings on the pump to a regular straight or pipe thread. I needed a 3/8 barbed fitting to come off the pump to hook up the vacuum tubing, and hours of searching for an adapter revealed nothing.
Edit 12/11/2018:
I was able to find vacuum pump oil at a local auto parts store, though there were no specifications on either the pump directions included in the box, or the oil bottle I bought. They were also different colors (the oil provided was light amber, the oil I found is clear). I ran the pump with the 2nd fill of oil, and it ran great. It does shoot a lot of oil fog out of the air exhaust while pulling down to final vacuum pressure, but I detected no oil fog exhaust while the pump ran once the system was at full vacuum pressure. The gauge I used at 170' AGL on a cool, clear night showed a full 30.00" of Hg (I know, max is 29.92 at standard ATP). Since the pump works, and pulls a full vacuum, I upped my rating to four stars. The problem of the manufacturer supplying only enough oil to flush the pump, and not enough to actually use the pump, took off the 5th star.