I am installing 3/4" prefinished ash plank using a manual nailer. I love the nailer (Porta-Nails 402P) , but have noticed that, on occassion, the nailer is wreaking very small cracks along the edge of the boards.

These cracks are not easily seen except from a low angle view into reflected light, but they are there and they are aggravating.

They only happen, like I said, occassionally. I'm trying to watch carefully and to determine whether it is the type of board, the way I hammer, the way I hold the tool,...but nothing is seeming to correlate.

I am sealing the cracks with Cabot satin polyurethane, which hides the cracks quite well, but what a pain!

Has anyone else had experience with this problem? Any ideas? Thanks!

it the way you hold the tool. when you are about to hit it the gun and your hand move a little
Jeff

Thanks for the possibility, Jeff!

I have been watching carefully how I nail, and must admit that I sometimes hold the nailer sloppily. However, it seems that some boards show signs of cracks at every point where I nail, but all surrounding boards do not!

I am now suspecting that perhaps certain boards are softer than others, or are milled differently.

You are right in that the cracks are too small to be made by the entire nailer--one side of the nailer is making contact with the edge of the wood. I think it's a matter of moving the nailer with my left hand as I nail...

The impact of the nailer is being applied to the edge of the board. Most nailers now have an adapter to transfer the impact to the tongue to prevent this damage. Wasnt necessary back in the unfinished days