Harbor freight vacuum pump

[Howley]

I just picked up the 3cfm automotive vacuum pump for my vacuum hold down pucks.

Questions:
The hookup is for the r12 and r134 adapter, I assume I take this off and adapt a 1/4" threaded hose adapter?

When I cover over the vacuum end, a mist or fog comes out of the pump, is this normal or do I have a bad pump?

Thanks, John :confused:

[donclifton]

The harbor Frieght pumps do put out a lot of oil compare to a good A/C vacuum pump. I added a plastic tube to mine and put it in a coffee can.
Don

[Howley]

So this is normal? I had no idea these pumps did this.
You know I was expecting greater suction also, I guess the proof will be when I actually hook it up to a puck.

Thanks for the info!, John

[genek]

That mist or fog could be water vapor from the oil. The oil will absorb moisture and when you pull into a deep vacuum it boils off the water.
cheap vacuum pumps will spit oil.

[donclifton]

It's oil, I ran A/C service for 40 years and the good pumps don't put out that much but cost a heck of a lot more than the harbor freight pump. My harbor freight pump can get down to 10 micron's.
Don

[Burkhardt]

For about the same money as the Harborfreight A/C pump you can buy a refurbished oilless GAST pump (http://www.ebay.com/itm/Vacuum-Veneer-Thomas-Pump-2660-Vacuum-Compressor-3-4CFM-24-VAC-Aerator-/280921060745?pt=LH_DefaultDomain_0&hash=item4168333589), usually around $110-$120. They are made for continuous use.

[Howley]

Thank you everyone for the feedback, it really helps!!

Today I took off the r12/r134 adapter and noticed there is a check valve on the bottom of it. I assume this is to hold the vacuum when the pump is turned off. Any issue with not having a check valve in line?

Thanks again for your feedback!!

[genek]

That check valve keeps the system from sucking the oil out of the vacuum pump. You could have gotten an adapter to fit the valve and converted it to your hose at any hvac supply house.

[Howley]

I will look for one tomorrow! Maybe an air filter would be a good idea also?

Thanks, John

[bcondon]

I simply used a barb 1/4" to a 1/4" female fitting and used
teflon tape onto one of the fittings and t sealed just fine.


I vented my mine to the outside using a shelf with a removable box over the machine and a microwave fan mounted on the box to blow the mist through a dryer vent.

The room got badly oil vapored and I doubt that is good to breath!
(If the wood dust doesn't kill you, the oil vapor will!)

Bob Condon

[coryatjohn]

plus... that oil vapor mixed with wood dust in the air, add a spark from static discharge and you could be having a bad day!

[srwtlc]

And if you try to finish a product that got misted with a lacquer or conversion varnish, you'll be seeing fisheyes. That's another bad day!

[Brady Watson]

For about the same money as the Harborfreight A/C pump you can buy a refurbished oilless GAST pump (http://www.ebay.com/itm/Vacuum-Veneer-Thomas-Pump-2660-Vacuum-Compressor-3-4CFM-24-VAC-Aerator-/280921060745?pt=LH_DefaultDomain_0&hash=item4168333589), usually around $110-$120. They are made for continuous use.

Word. Add an automotive type fuel filter to the inlet or get the glass bowl filters they make for them & you're all set. HF paint pot works great as a 'catch can' for vacuum bagging with resins (FRP layups) etc.

I added an 11 gal surge steel tank, vacuum 'mac valve' that turns the pump on & off automatically at set levels and a few other goodies for a nice universal hi-vac powerplant. It runs as well as it did the first day.

-B

[bcondon]

I am looking for the order of the pieces...


Pump -> Filter -> 11 Gal Tank -> ?? Valve?? 1/4" Line -> pucks/table
|
|- Mac Valve



-or-


Pump -> 11 Gal Tank -> Filter -> ?? Valve?? 1/4" Line -> pucks/table
|
|- Mac Valve




Thanks

Bob Condon

[Chuck Keysor]

I think I am in Bob's camp, of needing more, basic information. Or probably I am worse off than Bob.

I don't have a background in any of this vacuum business. Maybe 7 years ago, I spent $175 for an old Welch "Duo-Vac" vacuum pump and motor assembled onto a single chassis. It may weigh 80 pounds or more. I bought it from a man that used it for making neon lights. I thought I may make neon lights some day, but more likely, use it for vacuum bag clamping. Then after I bought my Shopbot, I though I could use it for vacuum fixturing. But when I read these posts, I just know so little about it, I get nowhere. I had looked around in the library for info relating to these applications and came up with nothing. And the little looking I did recently on the Internet turned up too much information that I couldn't filter correctly.

It would be nice to find an article about the ABCs of vacuum pumps: How to maintain them, how to connect to them, how to set them up for various applications, and then how to do advanced things, such as Brady described with his MAC valve, how to filter them, what does a surge tank do, how to size it, where do you buy fittings, gasket materials, what types of hose do you need, etc, all written up like a nice Fine Wood Working article with lots of good pictures. Can anyone suggest such a source of information? Or is there anyone who knows all these things that would want to be my next door neighbor????? (hmmm, I tried the smiley/wink face here....... and it went up to the title line.....)

Thanks, Chuck

[bcondon]

Hmmmm. the spaces are removed when you save the post so the Mac Valve should be attached to the tank.

I am assuming that the glass bulb filter would be the same unit that you used on the output side of an air compressor for spray painting ... Many remove water also.

The rest I understand but was looking where Brady put the filter.

I was also glad to hear that the ugly oil mist was normal. A friend built a
50 foot boat and used a $60 Gast surplus pump and added a motor... His comment was that the pump expected life was 5000 hours and he used it 400
so he told his wife he needed to build 10 more boats... That is when the neighbors heard the crashing noises...:D

Thanks!! Bob Condon

[Brady Watson]

The rest I understand but was looking where Brady put the filter.



Bob - place the filter closest to your inlet hose from the Bot. You want to trap particles as far away from the pump itself so that they aren't getting carried into the tubing or orifice closest to the 'business' end.

I'm on the road for the next week and a half...so no pics of my 'nautilus' or access to part numbers until I get back.

Keep in mind some of this stuff isn't cheap...but it saves your pump. The switch I bought years ago is similar to: MSC Part #56499197 - McMaster also sells one similar. Either is around $80. The tank I picked up @ Depot - Husky brand. Ripped off their stuff, threaded in what I needed to hook to the pump. Pretty easy with brass fittings. If you have the option to up-size the diameter of the inlet hose, do it. In other words, go 3/8 or 1/2 instead of 1/4 if you can. It is easier to suck thru a graden hose than a drinking straw.

These little pump setups are ideal for vacuum bagging, and for non-porous part fixturing using pucks, a dedicated jig etc. They can't move a lot of air/CFM, so they need to be used differently than a universal type bleeder board or BradyVac system, with high CFM, low vac powerplants like a Fein, ShopVac or Lighthouse motor (or big professional pumps). This is one place where gasketing is almost always required, so check out AllStar Adhesives and get yourself some spoilboard cover and/or vacuum tape to ensure success.

-B

[bcondon]

The AllStar Adhesives gasket worked GREAT!

[rawhide]

check out this site.joe woodworker.com.they have refurbished vacuum pumps for 105$.