Kreg Jig use on 90-degree joint with solid cherry panel and plywood shelves

[bill steinike]

I have a concern on using pocket screws with a solid cherry panel joined to plywood shelves (90-degree joint).  I used pocket screws in place of a dado as its easier but am now concerned that the 2 different wood types will expand differently and crack the hardwood panel.  Do you suggest using a slot in one of the pocket screws and/or what is suggested for this application?

Thanks,
Bill

[Jay Boutwell]

Hi Bill any time that a solid piece of wood is jointed to something that is stable and does not respond to moisture content as rapid and in fact there is little change in plywood, you should never pin and or glue them together with out allowing them to be able to move independently of each other.  One way is like you mentioned slotting the screws and another way is the dado or a slot that holds the panel in place but with out trapping it so the panel can not move.

This is the reason for the floating door panel as it is allowed 1/4 inch gap between the rails and sitles  (1/8 inch on each side).  Most do not realize that a door with a solid wood panel is actually made up of 5 separate pieces.  There is the two rails and the two stiles and then the panel.   There is one exception and that is when a plywood panel is used in place of a solid wood panel.  The panel is held tight in the groves by using a rubber B_B that is known as a space ball and or a rubber of foam strip known as a panel aligner.  It keeps the panel in a centered location preventing the ever annoying panel rattle and unstained parts of the door panel from becoming exposed  when the climate move it.    As a rule of thumb there should never be any mechanical fastener or glue that will prevent the movement of a solid panel under climate changes.

[michael evans]

Good advice Jay .

[bill steinike]

thanks for the input, do you have any suggestions on the best way to slot the kreg jig pilot hole?  

Jay Boutwell said:

Hi Bill any time that a solid piece of wood is jointed to something that is stable and does not respond to moisture content as rapid and in fact there is little change in plywood, you should never pin and or glue them together with out allowing them to be able to move independently of each other.  One way is like you mentioned slotting the screws and another way is the dado or a slot that holds the panel in place but with out trapping it so the panel can not move.

This is the reason for the floating door panel as it is allowed 1/4 inch gap between the rails and sitles  (1/8 inch on each side).  Most do not realize that a door with a solid wood panel is actually made up of 5 separate pieces.  There is the two rails and the two stiles and then the panel.   There is one exception and that is when a plywood panel is used in place of a solid wood panel.  The panel is held tight in the groves by using a rubber B_B that is known as a space ball and or a rubber of foam strip known as a panel aligner.  It keeps the panel in a centered location preventing the ever annoying panel rattle and unstained parts of the door panel from becoming exposed  when the climate move it.    As a rule of thumb there should never be any mechanical fastener or glue that will prevent the movement of a solid panel under climate changes.

[Jay Boutwell]

Bill, most likely I would use a drill bit and bore the hole in the panel oversized larger than the screw shank.  Be sure to leave the screw loose enough that the panel will be able to move sideways uner the screw head. To be safe I would do this to all of the screws.

bill steinike said:

thanks for the input, do you have any suggestions on the best way to slot the kreg jig pilot hole?  

Jay Boutwell said:

Hi Bill any time that a solid piece of wood is jointed to something that is stable and does not respond to moisture content as rapid and in fact there is little change in plywood, you should never pin and or glue them together with out allowing them to be able to move independently of each other.  One way is like you mentioned slotting the screws and another way is the dado or a slot that holds the panel in place but with out trapping it so the panel can not move.

This is the reason for the floating door panel as it is allowed 1/4 inch gap between the rails and sitles  (1/8 inch on each side).  Most do not realize that a door with a solid wood panel is actually made up of 5 separate pieces.  There is the two rails and the two stiles and then the panel.   There is one exception and that is when a plywood panel is used in place of a solid wood panel.  The panel is held tight in the groves by using a rubber B_B that is known as a space ball and or a rubber of foam strip known as a panel aligner.  It keeps the panel in a centered location preventing the ever annoying panel rattle and unstained parts of the door panel from becoming exposed  when the climate move it.    As a rule of thumb there should never be any mechanical fastener or glue that will prevent the movement of a solid panel under climate changes.

[Ken Darga]

Elongated holes can be made by---

drilling two holes "X" distance apart---

remove the material between the two holes.

The "X" dimension is determined by the size of the hole plus the length of the desired slot.

Removal of the material between the two holes can be accomplished by routing.

A counterbored hole can be accomplished using a forstner bit to recess the screw head,

then followed by adding the hole to accommodate the screw shank.

[Ken Darga]

PS---the waste material between the two drilled holes, and also be removed by chiseling it out.

[bill steinike]

thanks for the suggestions, i will give that a try.