Tool Talk: Pneumatic vs. Electric

[Bird]

If it works I might start leaving my compressor on for ready air.

I know it might not be the recommended way, but I keep my compressor tank pressurized, hose connected, and blow gun on the end of the hose. Of course, it's only 12' from the back door to the shop door, across a covered breezeway, so when I shave with the electric razor, I step out there and blow the whiskers out of the razor. It I go out in the yard, I usually blow off the bottom of my shoes before coming back in the house. But insteas of one of the automatic drains, I replaced the petcock in the bottom center of the upright tank with an elbow, a short piece of pipe coming out to the edge of the tank, and a ball valve. So anytime I run the motor on the compressor, I then quickly open and close that ball valve to blow out any moisture.

 

[jimmer2880]

I have a Dewalt 18V impact wrench. While it's OK I have had two uses that it cost me. The first one it would not loosen the lugs nuts on my Tundra. It seemed to be working OK, but when I charged the battery it worked. The other times was using it to tighten the top nuts on my Dodge Caravan front shocks. I thought I got it tight, but it was still making a clunking noise. I took those shocks on and off three times and finally took it to the dealer. They said the nuts were loose. No problems after that. It does not behave like a pneumatic tool, so you have to be mindful.

If you are using Air or Electric, it's not very smart to not use a torque wrench when tightening nuts/bolts. If you read the manual, I'll bet you a dollar it agrees with me.

While I use my air impact and air ratchet to get the initial tightening, I always leave the last turn or 2 for the torque wrench.

It's a safety thing. You have to step up to some very expensive air tools to get one that accurately torques to the set amt.

 

[ultrarunner]

The machine shop had a project for NASA that stipulated only pneumatic or hydraulic power tools... no electrical equipment of any kind allowed...

 

[BobRip]

If you are using Air or Electric, it's not very smart to not use a torque wrench when tightening nuts/bolts. If you read the manual, I'll bet you a dollar it agrees with me.

While I use my air impact and air ratchet to get the initial tightening, I always leave the last turn or 2 for the torque wrench.

It's a safety thing. You have to step up to some very expensive air tools to get one that accurately torques to the set amt.

I agree, but the shock bolt is hard to put a torque wrench on. You have to hold the shaft with one wrench and torqued to nut.

 

[Cami]

@Iplayfarmer: 7 CFM for a 7" pneumatic angle grinder seems really low. Be cautious, I've seen air consumption charts that only assume a certain ammount of utilization; much less than continuous duty.

 

[JoelD]

Agreed on the 7 inch grinder, I couldn't imagine my 10cfm keeping up with that. A 2-1/2 cutting wheel runs my compressor down in short order. Those fast spinning tools need industrial strength compressors. I'll take my electric cutting wheel any day.

Joel

 

[dirt clod]

The machine shop had a project for NASA that stipulated only pneumatic or hydraulic power tools... no electrical equipment of any kind allowed...

interesting did they give any reason why? I Wouldn't think a small electrical motor would induce anything into metal

 

[Iplayfarmer]

@Iplayfarmer: 7 CFM for a 7" pneumatic angle grinder seems really low. Be cautious, I've seen air consumption charts that only assume a certain ammount of utilization; much less than continuous duty.

Could be.

I have heard, though, that the difference between a good high end air tool and a lower end air tool is air consumption. I know JET is a good name in woodworking tools. I would assume it would be a good name in air tools too.

What kind of CFM do you think a grinder like this ought to use?

 

[Bird]

I have heard, though, that the difference between a good high end air tool and a lower end air tool is air consumption. I know JET is a good name in woodworking tools. I would assume it would be a good name in air tools too.

What kind of CFM do you think a grinder like this ought to use?

When I was repairing air tools, Snap-On, Matco, MAC, Chicago Pneumatic, and Ingersoll-Rand were all good tools. But my best customer was a big company that had a lot of Sioux tools. In my opinion, Sioux makes by far the best, most powerul air tools. But if you look at the specs for the Sioux Pneumatic Grinders you'll see they're rated at 25 scfm (little die grinder) to 35 scfm (7" or 8" angle grinder). And yes, I think that's continuous running. I ran them enough to test them with a compressor that only put out about 11 scfm and using 1/4" and 3/8" air hoses; not what I'd have used if I were actually working them long and hard as their owners did.

Of course, a 7" Chicago Pneumatic grinder may use as much as 24 scfm.

As for Jet air tools, I was fortunate enough to only get two in my shop; an air hammer and a nibbler, neither repairable because no parts were available. They may be pretty good new, but I'd consider them like Harbor Freight tools; maybe good for the price, but disposable instead of repairable.

 

[ultrarunner]

interesting did they give any reason why? I Wouldn't think a small electrical motor would induce anything into metal

Don't really know all the details other than it was a safety precaution...

We had a contract to build rocket fuel mixing equipment for the Space Shuttle... the machines we built and serviced were also 100% hydraulic with Pyrogard fluid and Pneumatic controls...

At least I didn't have to worry about getting an electric shock because there was nothing electrical anywhere...

 

[PILOON]

We had a contract to completely re-wire a Fairchilf F227 that had caught fire (well kinda a flash fire, quickly put out).
They were refurbishing the interior, lots of adhesieves and plastics etc and using step ladders for ease of work.
Step ladder shorted out an extension cord and BOOM !
Quickly extinguished but chemicals corroded all electrical connections and DOT mandated replacement of all wiring and connectors avionics etc. due to corrosion.

For me, beautiful 3 month contract, we negotiated it on a cost plus basis and made out real well.

Aerospace always uses air tools, safer and much better control for precise work, besides rivits need air tools and air tools are more durable.

 

[BXpanded]

When I realized my small die grinder required a 5 hp compressor to run almost continuously, I replaced it with a Milwaukee electric die grinder. I use electrics for almost anything that spins now. Grinders, sanders, buffers, drills are all electric. Much cheaper on the utility bill and less maintenance. Air tools require oiling, clean filters and long stiff hoses. Electrics run pretty much maintenance free. Air is used for painting and occasionally for an impact wrench. Use cordless stuff for nut running, quick drilling, hole reaming and lighter impact wrench needs.

 

[Iplayfarmer]

As for Jet air tools, I was fortunate enough to only get two in my shop; an air hammer and a nibbler, neither repairable because no parts were available. They may be pretty good new, but I'd consider them like Harbor Freight tools; maybe good for the price, but disposable instead of repairable.

That's Good info. Thanks for sharing.

 

[Matt_Jr]

I havn't read through the entire thread so forgive me if I repeat some stuff. Both have their advantages and disadvantages and I'll list them to the best of my ability.

Pnuematic tool advantages:
1. More power
2. Higher rpm's
3. Stays cool (no electric motor to overheat)
4. Don't have to wory about using in a flamable enviroment(no motor that has arcing)
5. Air tools have a longer life expectancy
6. usually more durable
7. Can be used while standing in water without worry
8. pnuematic tools are lighter
9. Can be rebuilt when worn out or broke and kits are readily available from tool suppliers or on line(snap-on, matco, cornwell, mac, ingersol-rand)
10. Smaller, and can fit where the others can't

Pnuematic tool Disadvantages
1. Initial investment very high compared to electric
2. Requires compressor
3. Have to wait for the compressor to build up pressure before use
4. Requires lubrication for long life
5. Dry clean air is a must for long tool life
6. Requires grease and oil for long tool life.
7. Compressors are noisy
8. Compressors can be very expensive
9. If work is done far from compressor, power decreases with more hose needed
10. Tools are useless without an air compressor (Can't use at the neighbor's house without a compressor)
11. Leaky air hoses or fittings can be a annoying

Electric advantages
1. No need to wait for compressor to build up air pressure
2. Can be used anywhere there's an outlet
3. Initial cost usually less than pnuematic
4. Low maintenance
5. No need for fittings, hoses, filters, oil, grease, etc..
6. Can be run off a generator, a strong enough inverter(with a car battery)

Electric disadvantages
1. Heavier than pnuematic
2. Can't use around flamable vapors
3. Not as strong as pnuematic
4. Not safe to stand in water while in use
5. Extension cords must be capable of handling current.
6. Electric motors can be destroyed by debris if not sealed

Battery powered advantages
1. Modern battery powered tools have come a long way and are much stronger than even a few years ago
2. Can be used any where
3. Can be rechared by your cars battery with an inverter
4. No cords or hoses to drag around
5. Batteries are rechargeable and offer more life than even a few years ago.
6. Little to no maintenance needed.
7. Batteries charge pretty quick these days

Battery powered Disadvantages
1. Battery must be charged to use and often have a short shelf life
2. Power surges can cause batteries to be damaged while charging
3. Batteries go bad if not used regularly
4. Extra or replacement batteries can be expensive on some tools
5. Shouldn't be used around flamable vapors
6. Good battery powered tools can be very expensive
7. Not as durable as air(because of weight)


Those are the few I can think of now. I personally prefer air almost all the time. They have way more power and if you get the stuff off the tool truck, you can't go wrong. The composite stuff IR makes if very strong and light and getting much quiter. Even the tool truck guys are putting their name on the IR stuff and selling it. Stay away from the cheap stuff, especially the kits that have everything for under 150 bucks(pnuematic stuff). May not work out of the box. Ask me how I know.

 

[Bird]

Wow, Matt! That must have taken a little time, thought, and lots of typing, but I think you did a good job of summing it all up.

 

[Matt_Jr]

Thanks Bird. I need the typing practice.

 

[some zilch]

I dont own an electric or cordless impact but used a 18v cordless snap-on impact that made a 3/4" air impact look like a toy. that thing was NICE!

you have to be joking, right?

my 1/2" IR gun will make any battery powered impact look like a child's toy, and i have a dewalt battery impact to compare it to. the dewalt is handy in the right situation, but not anywhere near what a typical 1/2" air impact will do. my I/R 1/2" air gun is a top-of-the-line model, and is rated around 700ft/lbs. i'd like to see any battery powered impact come close.

I also have a 3/4" air impact of unknown brand, probably a Napa. It hits like there is no tomarrow, and would be silly to think a battery powered gun could out work it.

i work in heavy equipment repair, so i have guns to 1". i dont even take the dewalt to work, as it has no place in such a demanding environment. its great aat home, in my shop, but i would be kdding myself if i thought it could keep up with (or outpace) my 1/2" or 3/4" guns.