"contact trip" on framing nailers

[Günter VögelBerg]

I have a Bostitch f21pl nailer that has served me well for at least ten years. However, it has always bothered me that it would not "contact trip" and I had to depress the trigger each time. Well, I found a part from Bostitch (CNTK5) to allow it to do just that. I installed it tonight and it works, but the problem I am having is that unless I am very cautious to only have a very brief depression of both the safety and the trigger it fires two nails, resulting in one not going in all the way or jamming the gun. I can't find anything in the manual that addresses this. I tried adjusting the depth and the air pressure and it did not make a difference. Thoughts?

[Jason Roehl]

It's technique. It's hard to describe, but you have to almost bounce it off the surface and let it recoil. If you try to hold it to the surface, the recoil will push it off just enough to reset the firing mechanism, then your force holding it to the surface causes it to fire again.

[Rege Sullivan]

I have a PC framing nailer that works exactly as you describe. It takes some getting use to but you can fasten a 4x8 sheet in well under a minute. I am not sure I would want that type of action in a nailer where placement was critical.

[Günter VögelBerg]

So I am gathering that it is either/or and it is not conducive to having both modes?

[Mike Kees]

Gunter you can either push the tip in and try to fire only one fastener or just "bump fire" the way most all pros do. It is very possible to place fasteners with precision and speed. As a carpenter I have been doing this for 30 years. I pretty well never fire by pushing the tip in first. When I need to place something,I will use a hand nail then go with the nailer.

[Bill Dufour]

My PC framing nailer got a free upgrade to a selective trigger. This allows single fire or rotate a cam and it is bump fire. PC would mail you a replacement trigger for free to help avoid lawsuits? I thin kthat is the way the new trigger worked until it got stolen from my backyard.
Bill D

[Jim Becker]

My Senco LOVES to double fire...often at the most inopportune time/position. Go figure... :o

[Tom M King]

It was never a problem back when the guns were heavy, like the Senco SN4. As framing nailers got lighter, you have to have quicker reflexes as the gun bounces off the wood after the first fire. If you don't stop your pushing down immediately after the first fire, the push will send it back down after the bounce, but before you can take your finger off the trigger. Often, that second one fires while you're backing off the pressure, and that keeps it from being driven all the way in.

I still use my SN4 for a lot of things. I bought it new in 1975. I have a couple of newer, lighter framing guns, but I pick the best one for what I'm doing, and the old, heavy one gets the call if the job calls for many repetitions of bump firing.

[Tom M King]

We built these trusses in place in an 1850 house by pulling up the 2x12x16's through a small access ceiling door. There were some number of thousands of 3-1/2" framing nails to shoot. The trusses solved several structural problems with that house, including severely sagging rafters.

My SN4 had a split firing seal, and my old rebuild kit also had the big white firing seal split. We put enough screws in everthing to pull all the parts together using clamps, but then needed to fire the thousands of nails. The lightweight guns weren't going to get it done. Even with an operator (me) with good technique, I just got too tired to keep the fast pace up.

I shut that job down until the new firing seal for the SN4 came. With that gun back in service, it was a breeze, not including holding the heavy gun up.
http://historic-house-restoration.com/images/CIMG2142_1280x960_.jpg

[Günter VögelBerg]

Thanks, guys. Sounds like maybe I need some practice. I replaced the trigger with the old one for now. I see there are some newer guns that have switches to let you select the firing mode. That's tempting, but this Bostitch has seen me through two major remodels and has taken tons of abuse and is still working great so I don't know if I could part with it.

[Marc Jeske]

It's technique. It's hard to describe, but you have to almost bounce it off the surface and let it recoil. If you try to hold it to the surface, the recoil will push it off just enough to reset the firing mechanism, then your force holding it to the surface causes it to fire again.

This is also my experience... it all has to do w technique "english".. needs to be learned w some experience.

I think using a gun in this setting is like using a circ saw w no guard.. Gotta be REALLY conscious of what that thing can contact... A bad move of your foot or hand when this is laying on a floor or scaffold, going down a ladder and not noticing co workers head below.. will end up w a memorable day.

Marc

[Marc Jeske]

And, one thing worse than planting a nail in someones head, would be TWO nails !!

:eek:

Marc

[Aaron Rosenthal]

One of the reasons I NEVER let my "guys" use my Paslode stick framing gun was because my old model is a bump fire and all my finishing nailers are trigger activated. Newer nailers are the norm for newer carps., and they had trouble with mine spitting out nails like a machine gun LOL!

[Bill Carey]

Back in the mist of time when I worked for an outfit referred to as wReck and Destroy, the super came to me and told me to put his buddy on trim since he's tired of the Chicago winters. This guy was a stud on roofs - setting trusses and nailing off the sheeting like a madman, all bump and run nailing. So I bring him into a house ready for trim, set him up, and show him the trim gun: how you need to press it and pull the trigger, not bump and go like he's used to. Even made him explain it back to me. Then he takes the gun from me, and before I can say WTH, he presses it against his palm, pulls the trigger and shoots a 2" trim nail thru his hand. Needless to say he was back on roofs as soon as he was back to work, and he's probably still setting trusses in heaven or somewhere else.

[Günter VögelBerg]

Back in the mist of time when I worked for an outfit referred to as wReck and Destroy, the super came to me and told me to put his buddy on trim since he's tired of the Chicago winters. This guy was a stud on roofs - setting trusses and nailing off the sheeting like a madman, all bump and run nailing. So I bring him into a house ready for trim, set him up, and show him the trim gun: how you need to press it and pull the trigger, not bump and go like he's used to. Even made him explain it back to me. Then he takes the gun from me, and before I can say WTH, he presses it against his palm, pulls the trigger and shoots a 2" trim nail thru his hand. Needless to say he was back on roofs as soon as he was back to work, and he's probably still setting trusses in heaven or somewhere else.

Seems to me that this was not the result of a misunderstanding of the firing mechanism, but rather a misunderstanding of the rule of cause and effect.

[Todd Mason-Darnell]

Not be, but to be the safety police, unless you are a full time framer, I would really recommend not using bump fire for the framing gun. I know it is "faster" and is really cool, but I have seen a ton of people nail their hands to walls, put nails in their thighs and injury other people when the gun went off when they did not expect it.

You should treat it with the same level of respect as you would treat a firearm.

[John Stankus]

Not be, but to be the safety police, unless you are a full time framer, I would really recommend not using bump fire for the framing gun. I know it is "faster" and is really cool, but I have seen a ton of people nail their hands to walls, put nails in their thighs and injury other people when the gun went off when they did not expect it.

You should treat it with the same level of respect as you would treat a firearm.

I need to figure out how to convert my Dad's nail gun to fire only on trigger pull. Helped him with a couple sections of privacy fence and the bump fire scared the (expletive deleted) out of me. Had several occasions of two nails for one. I need to figure out what model he has ( I think is might be an older Senco) and see what needs to be done to covert it.

John

[Tom M King]

I don't think there is any way to make the old Senco's single action only.

[Jason Roehl]

I need to figure out how to convert my Dad's nail gun to fire only on trigger pull. Helped him with a couple sections of privacy fence and the bump fire scared the (expletive deleted) out of me. Had several occasions of two nails for one. I need to figure out what model he has ( I think is might be an older Senco) and see what needs to be done to covert it.

John

The "double-tap" is also a technique issue--you can't "squeeze" the trigger like you would with a firearm; you have to pull it and release it firmly and quickly.

[James Pallas]

I’ve had lots of experience with nail guns of all kinds. I’ve shot many millions of nails. I would guess that I’ve double shot a few, don’t know how many but less than 50 I would bet. I would not want to use a gun that doesn’t bump fire, frame or trim. I definitely would not recommend a bump fire gun for inexperienced or occasional users. It’s all technique, you have to be loose and flexible. The worst mistake is to push hard and tighten up for the shot. If you have ever seen an inexperienced person on a jack hammer that gets it in a white knuckled grip or better yet a ball tamper it is absolutely great comedy. Same technique different tools.
Jim

[Günter VögelBerg]

I’ve had lots of experience with nail guns of all kinds. I’ve shot many millions of nails. I would guess that I’ve double shot a few, don’t know how many but less than 50 I would bet. I would not want to use a gun that doesn’t bump fire, frame or trim. I definitely would not recommend a bump fire gun for inexperienced or occasional users. It’s all technique, you have to be loose and flexible. The worst mistake is to push hard and tighten up for the shot. If you have ever seen an inexperienced person on a jack hammer that gets it in a white knuckled grip or better yet a ball tamper it is absolutely great comedy. Same technique different tools.
Jim

Seems this is essentially my problem. Like...I can build stuff. I have some experience. I like to think I am more competent than the average home owner. But I am not wearing a nail apron 5 days a week.