Tenon Strength / Rail strength- Max?

[purduephotog]

Good evening-

I'm drawing up plans for a wine rack that will involve either 4 or 6 'posts' and a series of wood slats to hold the bottles. Each slat (front and back) holds 10 bottles for a weight around 20 lbs, so not very much. Each post will be approximately 6 foot tall which translates into a 150 bottles, or about 200 lbs carrying (50lbs per post).

The 'double wide' version would hold 50 lbs per post on the outer posts, but the center two posts would be double-tenon and therefore hold 100 lbs.

My concern is, not having built anything like this (I'll be making a mockup with some with MDF when I get a free moment)- what do I need to worry about? If I'm cutting into 2" post square stock and putting a 1" high by 1/2" tenon into the post every 6 inches am I severely compromising the carrying capacity of the wood? Or is it going to be "OK" because the tenon (ideally) will fit perfectly and continue to transmit the load to the floor.

The second question i"ll have later is how to cut multiple in register partial chord circles over 44" of material, but that's another day's issue...

Thanks in advance-

Jason

[C&S]

No. The compressive strength of wood along the grain is very high. The likely mode of failure would the the assembly bowing out. The wood on the outside of the bow would be in tension and the wood on the inside would be in compression. The wood in the middle is not under stress.

have you ever drilled holes in floor joists to run plumbing or wiring? When you drill ahole in the middle it ahas nearly no effect on the strength of the joist. If you notch the top or the bottom, you have significantly compromised the joist. The mortises are in the middle so they have a minimal impact.

Or is it going to be

The other 1.5" of material is plenty to carry the load.

[Todd the wood junkie]

Without seeing exact plans for this, I would say the following regarding your main concern: I'd personally be less concerned about the vertical load on the post (assuming your tenons are snug and you are using a fairly strong wood like oak, ash, or the like), than the horizontal regidity your design may need to consider. With 200 lbs going up 6 feet, you will want to make sure the center of gravity is'nt too high, and that that it offers rigidity (maybe tie the posts together diagonally every 2 feet vertically)