Problem with nail gun & compressor

[lcm1947]

Long story short my wife purchased a DeWalt brad gun and SA or maybe it's a CSA, 1 gal, 1 HP compressor about a year ago for me on my birthday. Not knowing anything about either I was extremely pleased with the tools. Well, I just started to realize very very recently that they don't match very well. Example: The nailer or Brader is rated at 3.4 cfm @ 120 psi. The compressor is only 1.4 cfm and 125 psi. This seems way underpowered for the gun doesn't it? Why in the world would an actual tool shop/retailer sell this combo to her if like I am thinking they don't match up at all. Now I have actually used the combo twice but only shot maybe 10 brads per use but I do remember the compressor having to come on once so I had to wait on it to fill the tank again. Am I thinking right that I should take the compressor back and raise holy cane with them for selling this combo to an ignorant female or is it a correct combo? Any comments and advice or opinions welcome. Do you think it'll hurt either the compressor or gun by the way?

[Jim-Iowa]

Well that sounds like a lot of CFM and pressure for a brad nailer?
I have a Harbor freight brad nailer and have driven it for 10 yrs with a 3/4 hp Ingersoll Rand Diaphram portable with no tank at all.
I doubt the CFM is any higher than your compressor?
I got curious and went out to the garage and checked the rating on this compressor. It is better than I thought 3.1 Cfm @40 lbs & 2.1 @90 lbs. Not bad for a compressor about the size of a 12" toolbox.
I have run the pressure between 40 and 90 lbs and have never had a problem with it at all.

I see a lot of packages out there with the small compressors and they seem to do the job.
I wish mine had a tank and pressure switch, but other than having to turn it off and on all the time it works great. I have put trim in 5 houses and loaned it out and it has done several others.

[monte]

Have you tried it Lee? It should work fine.

[JimD]

I think it will work OK. I like it when the compressor doesn't come on, because it is noisy, but it is not a big deal. It also does not necessarily mean you can't drive a few more nails. The worst that will happen is they won't go in all the way. If you want more air storage, you should be able to rig up a separate tank using one of the ones sold to be portable. If you put a tee on the outlet from the compressor and ran one side to a separate tank you could have 5 gallons of storage. You could still remove the portable tank if you needed to.

The reason I think it will work OK is I typically do not drive nails continuously. It's line things up, drive 1-4, line up again, drive another 1-4, etc.. If you were going to drive a dozen or more nails continuously then you might have an issue. I doubt you will do that, however. In the time between nails, the compressor will catch up. I should store air at 100-125psi and regulate it down to where you have it set so it can run off the tank for a few nails. The compressor does not have to have as high a cfm as the gun.

Jim

[stewchi]

Brad nails use very little air to shoot, you should be around 60-90 PSI depending on the hardness of the what your nailing. You probably can’t use an paint sprayer or pneumatic sander but nails will be fine. The air compressor fill up a diaphragm in the nail gun that releases when you pull the trigger. The air shooting out of the diaphragm is what propels the nail. These diaphragms are not very big and you can physically only shoot so many nails, so almost any compressor will have time to refill the diaphragm. You don’t have to wait for the compressor to turn off before you shoot your next nail, as long as the pressure is above what you need to drive the nail flush. Most nail guns have a max pressure of 90 PSI. The lower the PSI you use the more CFM you will get. So don’t worry about it keep shooting those nails.

[Tequila]

That nailer rating of 120psi is probably the max pressure that it can handle. Even shooting long brads into oak I don't need to set the pressure on my PC brad nailer over around 90. Keeping the gun pressure lower will let you get more shots out of the tank for each compressor on/off cycle.

[JimD]

The only nailer I have used that needed more than 90 psi is my HF stapler (is that a nailer?). It will not drive a 1 1/2 inch staple into even softwood unless you go above 90 psi. I don't know if it will ever drive a 1 1/2 inch staple into hardwood. I don't like changing my regulator when switching guns so I have just relegated it to driving shorter staples (which it does fine). I do not know if all the HF nailers are this way or not. My PC and Bostich nailers work great at 90 psi or somewhat less depending on what length fasterner they are driving. All will push the maximum length fastener they can handle into hardwood at 90 psi. The HF will not come close.

Jim

[lcm1947]

Ok thanks guys. It is working so I guess it'll do. Rereading the instructions on the nailer it does say that I can go down to 70 psi so I'll try that and see how it performs. I'm just learning about compressors and it's a bit confusing with all the cfm's and psi's. I was just under the impression that you had to have a compressor that could deliver at least the cfm's that a tool called for but it seems that's not the case or my compressor couldn't power the nailer and it clearly does since I used it.

[LCHIEN]

My input would be that the air consumption of a nailer depends entirely on how often you are shooting it.
3.4 cfm for a brad nailer is huge, I would expect continuous machine gun shooting to hit that comsumption. Also 120 PSI for a nailer is high; on cheaper nailers the depth it sets the head is almost always set by the pressure, most will use 70-90 psi. Probablky the 120psi is the burst rating?

With a smallish 1 gallon tank, it may cycle continuously. That alone is not bad but just noisy. Most compressors have a "Hysteresis" which an example is the motor stops when the pressure is at 135 and cuts on at 125. THis assumes you have an output regulator settable at maybe 0-120 psi. Different values for every compressor.

If your tank has an output pressure gage, then look at it, if it does not drop and you r gun is setting the neails as deep as you want, then you are probably OK. I think with that tank (smallish) it will still be OK for non agressive brad usage - e.g. a hobby not a production situation.

If you want more, look around there are pancake compressors with tanks of 6 gal and higher cfms than yours that will work all day and night for brad nailers and cost around $100.

[lcm1947]

As always thanks Loring. Maybe that rating of 3.4 cfm means that that's the maximum it's capable of - maybe?, but it does state 3.4cfm. It's a model D51238 18 gauge DeWalt if you'd care to double check it. Anyway, it also says not to exceed 70 - 120 psi so thinking the higher the better I kept it at 120 psi. I see now that lower is better so I'll try at 70 - 90 and check it out. I am looking around for another one anyway as this if fine for nailing it's sure not much good for blowing off tables, tools, etc. Not with that little tank although I have hooked one of those 5 gal HF portable tanks to it so actually have a 5 gal capacity now or would that be 5 gal. plus the 1 gal tank on the compressor itself making it a 6 gal capacity. The other thing that worries me, not about using a nailer but for blowing stuff off etc is it takes forever to fill that hooked up 5 gallon tank back up once it empties and I am concerned about it burning that little motor up and that's mainly why I'm thinking about a larger one so to save the motor on the 1 gal.

[LCHIEN]

quote:Originally posted by lcm1947

... I was just under the impression that you had to have a compressor that could deliver at least the cfm's that a tool called for but it seems that's not the case or my compressor couldn't power the nailer and it clearly does since I used it.

tHAT APPLIES FOR continuous duty tools versus one-shot kind of tools.

A grinder, or a sprayer uses air continuously or at least for several minutes at a time. If the air consumption is greater than the pump then the tank will go down, the motor will run contniuously but not be able to keep up and the air pressure will fall too low.

If you use a one shot item, nail gun or stapler, then the air used is the amount to drive the piston one trip. its a fixed amount of air so it really depends upon how often you shoot. Every few seconds does not use much air, the air is withdrawn from the tank, when the tank goes below a certain pressure then th motor runs for a while to charge the tank back full.

A few tools used in bursts: air nozzle to clear dust (depends on your trigger finger), nailers, staplers.

[lcm1947]

Thanks again Loring. That info helps. I'm starting to understand more about these strange machines. Appreciate your time and help everybody.

[LCHIEN]

The bigger (added tank volume) tank will allow you to have longer bursts from your air nozzle before it drops off. But the continuous air flow is limited by the motor compressor.
Or, more nails shot before the compressor kicks on.

But the downside is that it will take longer to fill up with air when you first turn it on.

[lcm1947]

And again I appreciate the help Loring.

[Stick]

quote:Originally posted by LCHIEN

The bigger (added tank volume) tank will allow you to have longer bursts from your air nozzle before it drops off. But the continuous air flow is limited by the motor compressor.
Or, more nails shot before the compressor kicks on.

But the downside is that it will take longer to fill up with air when you first turn it on.

The same holds true even on very large air systems. Where I work we have a bank of 15 receivers (tanks) that are each about 8 feet across and 15 feet high, all piped together and supplied by three 150 CFM compressors running at 350 psig, then regulated down to 270 for one purpose, then the whole setup is also regulated down to 100 for service air. We have a need for HUGE volumes of air in one shot, hence the 15 receivers. To refill them after that operation takes up to an hour with all 3 compressors running.

Same with smaller systems. I use large air tools like 1" drive impact, air grinders, etc on the farm, and even with my 10hp 30CFM compressor with its 250 gallon tank, it still can't keep up to continuous use. That's the whole purose to having a receiver tank, for air storage.