Idle Curiousity about brad air nailers

[LCHIEN]

I was skulking around the other night and wondered how much air reservoir was in an air hose and air nailer, absent the air compressor air tank. And how many brads it might fire.

My calculation of the interior volume of an air hose (assuming minimal expansion and 231 cu inches = 1 US Gallon):
100 ft 3/8" typical rubber or PVC hose: 0.58 Gallons (G)
50 ft 3/8" Air hose 0.29 G
100 ft 1/4" Air hose such my Polyurethane ones: 0.258 G
50 ft. 1/4" Air hose 0.129 G
And estimating the interior size of the air reservoir in the handle of my brad nailer, 0.026 G (not very much).

I put a ball valve between the air compressor and the hose to the air gun. I used a 1/4" PU hose and 18 ga brad nailer
I let the air compressor come up to full pressure output of 100PSI regulated and cut off the valve.
Basically it fired two 2" brads fully. The third one buckled and did not go in all the way.
I opened the valve and allowed the hose to charge back up and cut off the valve again.
Second try, same result.

Extrapolating, twice the air stored in a 3/8" rubber hose might fire 4 brads.

I guess I can measure and figure how much the hose expands and stores more volume... but I doubt it is more than 10% or so.

[dbhost]

I never thought about that. Hmmmm.

[twistsol]

When you do the math and the experiment, at some point the curiosity is no longer idle.

[LCHIEN]

To answer my last question I measured the OD of several hoses including two PU 1/4" ID hoses, two rubber hoses 3/4" ID and one nylon coiled hose before and after application and then again after removing pressure to see if there was any expansion to speak of.

I really could not find a significant change when under pressure, the change was usually less than the variation in OD from one location to another on the same hose.
Certainly much less than 5% OD change. A 5% OD change would indicate a 10% change in volume since the volume is proportional to the square of the diameter.