I joined four 1x6x32" boards. The boards were flat and all lay flat together before joining. After joining, the middle was bowed. I drilled all of the holes on the left side of the boards. Should I have alternated sides? Or is there another reason for this?
Thanks for any help!
mo khan posted--->>>...location of pocket holes doesn't matter/span>
Perhaps mo khan meant to write ''orientation''---
which I would interpret that to mean alternating the screws ''direction''.
So that every other screw with it's point facing one another.
Location does matter---
the screws need to be placed at a suitable spacing, from each end and between the fasteners---
so as to provide adequate clamping pressure along the joined seams.
Review Kreg's manual and their instructions/recommendations---they also have some videos.
If I recall correctly, (I don't have the manual in front of me), Kreg suggests a spacing of 2'' from the ends and 6'' between screws.
On some projects, I've installed screws closer to the ends and a spacing of 4'' between screws. Perhaps it was a little overkill, but the results were acceptable, for the project at hand.
Hope you were able to resolve the issues you experienced.
Hi Dolores, I just ran across your post about your problem with the bowed lumber after you had build your project piece. I have ran across this many times in the past and believe it is a caused from a term that is known as "case Hardening" of the wood. This is caused when wood is dried too rapidly on the outer surface. When this is done moisture is trapped inside the cells of the wood below the outer surface, leaving the outer surface dry and the inter surface still holding a high moisture content. This causes the inter surface of the lumber to be in tension against the outer surface. When this lumber is worked and although it is finished in a flat even surface the moisture now begins to again excape the inter cells of the lumber and thus releases the tensions of the lumber which results in adverse movements of the lumber.
Look at it this way, is is like the hard dried surface of the outer layer acts like a moisture barrier that prevents the moisture from excaping the inter cells of the lumber. It remains there until it finds a method to excape to the surface.
There is nothing you can do different than what you have done. Once lumber is in this condition there is no method to determine if it is going to twist, cup or bow until you begin working it. I have made it a practice to cut my lumber down to near its final sizes and often lay it a side for as much as a day or two to see it it moves and changes directions before I finish cut it and use it in my project.
There is has been many times that I have cut even the finest wood available and have it twist and move and twist right off the saw blade with one side headed over to the next county or lifting up off the saw table.
Thanks, Jay. I believe you are right as sometimes it bows and sometimes it doesn't, no matter what I do.
Jay I have read and reread most of your replies and you are about the only person that can describe situations that occur in woodworking and I think everyone of us should take in consideration and practice what you explain to all of us.If we all followed what you say Im sure we would all be better woodworkers. All I can say is thanks for all of your contributions to this site