Thursday, January 17

Completing Construction

Today I completed the initial sanding, reassembled the cradles, using glue this time, plugged the screw holes, attached the rocker bases and the roof panels. This completes construction of the cradles.

One of the issues I have with this plan is the way they say to attach the base to the body; the plan says to simply apply glue to the lower edges of the sides, foot board and headboard and center it on the base plate. The weight of the cradle body will act as a clamp until the glue dries. Maybe that would work, I don’t know as I’ve never tried it.

My biggest objection to this method is in the area of wood movement. Wood expands and contracts with the atmospheric humidity levels. Finishing wood helps some, but no finish can entirely seal out moisture in the air. The body parts all have their grain running horizontally. Wood expands across the grain, not lengthwise. So as these panels move, they will move up and down together. In humid weather the cradle will get just a bit taller, dry weather it will be just a bit shorter, but the movement will be equal all around the body so nothing should be prone to popping loose or cracking.

But the base plate is perpendicular (or nearly so) to the body panels and when it moves it will do so across the width of the cradle – and the body panels can not move with it. If the base is glued to the body either the glue joints will fail and the cradle will come apart or crack.

The base plate is not huge, not like a dining table top where movement can be considerable, so maybe if an elastomeric glue were used it would work out OK. If I were building this for myself, I might be tempted to try it and see. But I’m not, so I don’t want to take any chances of these cradles disappointing anyone.

To address this issue, I do not glue the bases to the bodies, but install 3 screws in each end of the cradle. The center holes are regular counter sunk screw holes. But the outer two holes are enlarged into ovals before countersinking them. These ovals will allow a smidge of extra space to allow the wood to move unimpeded and the screws to bend just a bit as the wood expands and contracts.

Over the years these screws may stretch a bit but because they are not plugged, a light twist with a screw driver will snug them up again and keep the base plates in firm contact with the cradle sides.

The roof panels were supposed to be installed in the same manner; just glue them on, but I’m not comfortable with that, so I’ll use some small finish nails to reinforce these joints without marring the appearance of the roof panels. But I’ll do that after the glue sets up hard.

See you tomorrow,


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