Carpentry and Woodworking - Question on Brad Nailer PSI

Hello & happy new year!

For Christmas, I received a Craftsman 1hp air compressor and a Bostich 5/8"-2" finishing nailer. The nailer miss-fires about every fourth or fifth nail (maybe 20-25% of the time). The manual for the nailer says it's either a worn part or the PSI is too low. It says to use either 150 PSI or 150% of the max PSI rated in the compressor. The compressor's max PSI is 125, so 150% would be 187.5 PSI. Currently, the compressor is set to 90 PSI. My question is, can I safely turn the compressor up to 150 PSI?

I'm confused as to why the manual would specifically say to go over the max PSI of the air compressor. Should I consider taking it back and exchanging the compressor for one that can safely do 150 PSI?

Thanks,
Jeremy

I usually set my pressure between 90psi and 125psi depending on the type of wood I'm working with. While I don't use nail guns all the time, I believe higher pressures are seldom needed.

I have a 25 yr old craftsman 1 hp, 12 gal compressor so I don't know how similiar it would be to yours but unless I'm mistaken it has a 120psi pop off valves - that prevents pressure build up beyond that psi.

Does the compressor work well for other uses? Do you know someone with a larger compressor? Are you oiling the nail gun before use? I would suspect the nail gun before the compressor but a larger compressor is always nice :D

Like I said, I only recently got the setup and so this is the first time I've really tried it out. I believe there is a release valve at 125 PSI on the compressor.

The Bostich BT200 claims to be oil free, so I haven't oiled it.

I don't see how you can get a compressor to operate above its capacity. What pressure triggers your compressor to run again?

I guess maybe I'm reading the Bostich book wrong? Here's the exact wording"

"Air hoses should have a minimum of 150 PSI working pressure rating or 150% of the maximum pressure that could be produced by the air system."

Jeremy - That statement is to make sure that you don't use under rated hoses. It's saying that the hose should be able to withstand more pressure than the compressor can provide.

I have a Bostich finish nailer. I never have to use more than 80 PSI on my compressor for nailing 2" finish nails into softwood. I usually crank it up a bit for hardwood but I can't remember ever using more than 100#.

Try experimenting a bit with some scrap woods. Try different pressures and note the nail penetration. It isn't an exact thing, but you should be able to set the nails pretty consistently. I try to get the nail penetration around 0ne nail head diameter.

The problem isn't that I can't get nails to set properly, they do that great. The major problem I'm having is that the gun miss fires about 20% of the time. This leaves nasty holes in my finished wood.

I thought the problem might be air pressure, but apparently not. Any other ideas what it could be?

It might be a bad/cheap set of nails. Barring that I'd take the gun back.

I have 1-1/4" Pasload brand nails. They were out of the 1-1/4" Bostich. I'll try another brand of nail first, as that's the cheaper of the two solutions!

Never even thought about the nails!

My compressor kicks on at about 80 psi, so that's what my regulator is set at. The misfires are likely due to incompatable nails, too high of pressure or lack of oil in the tool. Or as mentioned, could be a bad nailer- if so, exchange it before its too late!

Paslode nails are usually good quality. Are you sure the gun doesn't require a few drops of oil with each use?

jeremy1701,

I can't say at all that my experience last weekend is relevant, but here goes.

Among other nailers, I have a Porter Cable stapler. It's fairly new and I haven't used it very much, but it sure comes in handy from time to time. Last weekend, I was stapling a 1/4" luaun plywood back to a cabinet I was building and the stapler was acting just as you described. By the way, the staples I was using were sold with the Porter Cable name on the box and I was oiling the stapler as directed (the Porter Cable does require oil).

It would drive some staples perfectly, then it would leave an indentation, but no staple. I would guess the success rate wasn't much better than 50%....very frustrating. Ok, my son says, "Dad, your compressor is set much lower than usual." I said, "Doesn't matter. If it drives one staple with enough force, it should do it consistently."

Long story short, I had reduced the pressure recently to use my HVLP conversion sprayer, and it was set somewhere between 75 and 80 P.S.I....I usually have it set at between 100 and 110. To experiment, I set the pressure to 60 and it wouldn't work at all. I moved it up to 100, and it works perfectly every time. Go figure. I am not going to even try to explain this, but it is 100% repeatable.

Good luck,

Randy is right on target with his comment about problems if the pressure is too low. If your gun has a nose piece that comes off the front, open it up and see if the driver (the piece that drives the nail) is left protruding out after a good shot. That shows there is not enough pressure to drive the piston back up all the way.

My guns work fine on 80 lbs, but as mentioned, you may need to set your regulator higher. Also possible your gauges are a bit off and could read low.

XSleeper,

Thanks for the explanation. I don't like mysteries! Now I'm quite happy with the results of my experiment.

Cheers,

I returned the Bostich for a Dewalt. Doing a little googling turned up quite a few others with the same problem. Apparently, the Bostich uses a plastic shear pin that is no good.

I'll let you know how the Dewalt works on my next project.

Thanks all!
Jeremy