All my prep is finally done, and in my final tool test before starting to lay down my floor, I'm finding the MIIIFS stapler regularly splits the tongues on my planks. The wood is 3/4" solid Brazilian Cherry by BR111, in 3" planks.

Here is a photo of a test piece...



Is this an acceptable amount? It doesn't appear to interfere with the fit of the next piece, but I'm concerned about the quality of the fastening. I bought the MIIIFS so switching to a cleat nailer would be painful, but if you guys tell me my floor will fail from the staples then I will do what I have to.

Thanks,
Garrett in San Diego

That's a troublesome side effect of the Brazillian Cherry. I just finished one last week (we used a Porta-Nailer) and nearly every board looked like the one in your photo. I've never had to go back on any and haven't heard of too many guys that have had troubles due to it, but apparently it's pretty common with that species and not your nailer. Press on and keep an eye out that the fit stays tight. Sometimes if there are resulting splinters, they can trap themselves in unwanted places keeping the boards from coming together properly.
Hope that helps
William

Looks to me that the staple is going in a little low. Try putting a couple of strips of Duct tape up on the plate of the stapler to "lift" the front edge a tad. Playing with this can help, but you will still have those boards that split no matter what you do. If you shim with duct tape, and install over 15lb felt, you've probably done as much as you can. Worse come to worse, if they still split after all this, and you've laid a section wide enough to walk on, does it make noise? If not, you should be O.K. Good Luck.

Yeah, it's common with b. cherry; some other woods as well. I agree with SK about shimming up the nailer abit. The staples do seem to sit a little low. Try not to nail too close together; no more than 8" oc. If you're getting breaking at the ends, nail further back from ends; 3" or so. Many of the b. cherry floors I've done seem to do this but I have had no problems with noisy floors. Try adjusting pressure so staple just seats in that tongue pocket and no further. Too high of pressure will contribute to tongue split.