HF staple gun

[vavet]

I have a HF pneumatic stapler. It's about 5 years old. I bought for a project, shot maybe 100 staples through it. I used it for one other project about a year ago, probably another 100 staples.
I've been using it this year for insulation fabric. I've probably put 10k staples through it in the last month and it's having issues.

As any self-respecting GJer, I took it apart to try to diagnose it. Yes, I could buy a new one for $20, but that's not what this is about. At this point, I want to understand how it works.
I'm attaching pics.
When the nosepiece is depressed, it presses up on a piece under the trigger. This makes the trigger live. The trigger presses up on a valve, which releases air from the hollow body into a small orifice that provides air to the back side of the piston. This shoots the piston and anvil downward.
What draws the piston back? This where I'm falling on my face and is the problem with the stapler. The piston doesn't come back up so the anvil can't drive a new staple down.
I've watched some YouTube videos of the HF unit and other pneumatic staplers, but no one explains the theory behind operation.

Any insight?

 

[vavet]

More pics

 

[rlitman]

...Yes, I could buy a new one for $20...

It's time to get a new one. With the volume of nails you've put through it, my guess is that either the driver is bent, the bumper is shot, and/or the check valve seals are gone. Either way, you're due for a complete rebuild, which will cost more in parts than a complete replacement. And at this point, even if you manage to get the current problem fixed, you'll be taking it apart soon enough again to regret that decision.

 

[dogdog]

The theory is very similar to the quick exhaust valves I think...

I have the same, maybe similiar ( they have a few versions I think) that does similiar things... it was weak and can't staple anything and staples would get crooked and bend because the piston were slow...

The fix for me was drilling or enlarge the hole on the top portion of the gun... to 1/4 size... I clean off the shavings and old grease.. then lube it back with air compressor oil... seems ok now... Not sure you particular situation... mine was weak straight off the box...

 

[vavet]

The theory is very similar to the quick exhaust valves I think...

I have the same, maybe similiar ( they have a few versions I think) that does similiar things... it was weak and can't staple anything and staples would get crooked and bend because the piston were slow...

The fix for me was drilling or enlarge the hole on the top portion of the gun... to 1/4 size... I clean off the shavings and old grease.. then lube it back with air compressor oil... seems ok now... Not sure you particular situation... mine was weak straight off the box...

I'm stapling into pine studs - not too weak. In fact, I had the opposite issue. It was too strong. I had to file down the anvil and use a longer staple than necessary to prevent overdriving.

 

[rlitman]

I'm stapling into pine studs - not too weak. In fact, I had the opposite issue. It was too strong. I had to file down the anvil and use a longer staple than necessary to prevent overdriving.

It's depth adjustable. Look for the barrel nut on the safety bar next to the trigger, and spin it up or down to set the depth.

 

[Skunkape]

I'm a beekeeper, and used that stapler for assembling a lot of boxes and frames... Mine got to where it was leaking air. It was good while it lasted, but decided I'd spring for the Hitachi since it would see a ton of use every year.. Can't complain, I got every cent of my 20 bucks out of it.

 

[vavet]

Does it make sense that an air stapler would not work as well shooting staples up compared to sideways or down?
I borrowed a Bostich stapler from my work last night and tried to continue my project. It's far from perfect, but better than my HF unit. This is a unit that has never given us any issues at work, but we haven't used it much, either.

 

[rlitman]

No, it should work the same in all orientations. The force of gravity on the piston is insignificant compared to the force from the air.

 

[1990 Grand Wag]

Buy a new one for 15 bucks, call it a day!

 

[vavet]

OK, y'all convinced me. I just bought a new stapler, but I bought the 20 gauge, wide crown stapler this time. It was a few dollars more, but the staples cost less. It's better for what I'm doing anyway. When all you have is a hammer, everything looks like a nail, right? Besides, I still want to understand the intricacies of what makes these things work.

 

[cheechi]

That 20ga wide crown stapler is a T50 stapler. Make sure you buy name brand, I use Arrow & Stanley. Generally HF's nails & staples are much poorer quality and their guns are decent. That said, their T50's aren't as bad as some of their other ones.

 

[rlitman]

Buy a new one for 15 bucks, call it a day!

Now FIVE bucks until 12/24. If you haven't got one already, this is the time to.

 

[dogdog]

fine print says you have to purchase >$50 worth of goods before that coupon is effective.

 

[DFB]

$5 for the 18ga nailer stapler with $49 purchase right now I think


To answer your question I had Porter Cable stapler that would do the exact same thing fire one shot and not retract. I eventually discovered a blockage of a waxy substance like hardened grease blocking the exhaust port. It took a long time to diagnose. Soak the ports with WD use ALOT of compress air. My bet is something WILL dislodge.

Good Luck