Building my first bed. (A bedbolt holds the rails running the lenght of the bed to the head & foot boards). Here’s the problem, or maybe it’s not a problem. Hopefully, someone can tell me. Here is a diagram. http://s3.amazonaws.com/finewoodworking.s3.tauntoncloud.com/app/uploads/2019/04/27230924/bed3.gif
The bottom rails in the foot and head boards are mortised into the posts. As I have it layed out now, the bed bolt intersects this joint. The counter bore for the bed bolt (oun the outside of the post) will go completely thru the face of the post and (barely into) the tennon. This means that as I tighten the down the bolt, pressure will be exerted on the tennon. Seems to me that if there is any play in the mortise and tennon joint, then the pressure of the bed bolt could really weaken the glue bond. Is this a problem?? ( Even if I go with a shallower counterbore, there woiuldn’t be much material left in the post between the bottom of the counterbore and the mortise.)
I could move the bed bolt up the post so it is above the mortise. (The side rails are thicker than the head/foot board rails.) However, in this case the bolt would not be centered top to bottom in the bed rail. It would be about 1/3 from the top. Seems like this un even pressure could be a problem. True?
The mortise and tennons are cut, but the holes and counterbores for the bed bolts are not.
I have done quite a bit of reading for this project, but this is one of those issues I did not anticipate or read about. Maybe it is no big deal. I would really appreciate any help/insights. Thanks.
Edited 5/27/2002 11:27:01 AM ET by tomg
Replies
The question you pose is not usually a problem, because the design you are using is not one that is ideal for bed bolt usage. Usually, shallow mortise and tennons are used for both the side and end rails, so no bolt goes thru the side of a mortise. since you've already cut the joints, I suggest you go ahead a place the bolt in the upper third of the joint. In a normal design, at least one of the bolts is not centered in the side or end rail anyway, as it would interfere with the opposing bolt.
Regards,
Carl
I would proceed as you have it sketched, but would make the counterbore on the post as shallow as possible. If you don't crank down too hard on the bed bolts, the bolt will act as a pin in the footboard rail joint. I think it would reinforce that joint rather than weakening it.
Bob Lang
http://www.craftsmanplans.com
Tomg,
I agree with Bob. The way you have it sketched the rail is not hanging from the bolt; it looks like about the only function the bolt serves is to hold the tenon in the mortise. In other words, the load will be carried by the M/T joint, not by the bolt. If that's the case (if I'm not missing something) the bolts need not be torqued down very tight--just tight enough to keep the joint together.
Alan
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