Woodworking Talk banner
21 - 33 of 33 Posts

·
The Nut in the Cellar
Joined
·
1,295 Posts
If this were my project, I'd probably use #20 biscuits spaced 4" apart. Been doing biscuit joins for decades and never had one come apart. As an alternative, the blind spline join B Coll described would work. I've done those using plywood as the spline also.
 
  • Like
Reactions: B Coll

·
Registered
Joined
·
9 Posts
Discussion Starter · #22 ·
Those little rods aren't going to support those heavy books. Looks like rods drilled into studs to me..a 2x12 isn't a 1x6...
I intend to drill all the rods into studs and then sink them into the shelf about 3/4 of the shelf’s depth. Those steel rods are 1/2 inch in diameter.
Do you think it won’t be enough?
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #23 ·
I agree with something more than those rods for books. Most floating shelves are for nick knacks, pictures and such.

I think you are looking for trouble unless you go with 3/4” thick rods.
Yes maybe it’ll be wiser to use 3/4” rods instead of 1/2” to be safe.
 

·
where's my table saw?
Joined
·
30,364 Posts
I intend to drill all the rods into studs and then sink them into the shelf about 3/4 of the shelf’s depth. Those steel rods are 1/2 inch in diameter.
Do you think it won’t be enough?
Yes, 1/2" diameter rods will not bend. This is why all the details must be given to avoid the "what if' types of questions. How much weigh? How many books? Did you weight them? How far apart are the rods, 16 on center like normal studs? We are just normal humans who try to use common sense and reason to figure out these issues. There may be some "geniuses" among us, but they choose not to brag about it, and are waiting to be discovered!

I have bent a lot of metal including rods, even rerods which are the toughest steel I've ever encountered. I had to heat it red hot to bend it.
Make a test using the 1/2" rod, drill your 1/2" hole 3" into the edge and slip a pipe over the rod trying to bend it across the board.
I'll wager the wood will split before the rod bends.
 

·
Registered
Joined
·
780 Posts
This is just a bad idea. Choose a different design or build a bookshelf.
 

·
The Nut in the Cellar
Joined
·
1,295 Posts
I agree with something more than those rods for books. Most floating shelves are for nick knacks, pictures and such.

I think you are looking for trouble unless you go with 3/4” thick rods.
Been thinking some about this project and I'm thinking like DrRobert. This design may not be sufficient for the intended use. If I were doing a floating shelf to hold heavy loads, I would do a torsion box design and attach it with a ledger board on the wall. I did a fireplace mantle that floats. The design is a bit thicker than what you have in mind, but it could be done thinner. The torsion box is strong enough to hold a lot of weight. Maybe something to ponder.
Wood Brickwork Rectangle Brick Wall
 
  • Like
Reactions: Smidarnar

·
Registered
Joined
·
593 Posts
Confusing thread. It seems like there are two pertinent points, how to join the two shelf pieces and strength of the supporting rods. The simple answer to the shelf joinery problem is to not join them. Just cut the ends square, sand them smooth, butt them together (or leave a bit of a gap so it looks intentional) and let the steel rod supports hold them in place. 2x12 planks are not going to flex under a load of books. If you really want them joined, then just cut a groove in the end of each piece, insert a spline, and glue them. With the proposed mounting system, there will be little stress on the joint.
For the steel rod supports, I don't know the answer, but you can find it by either finding someone to do some calculations or do a test; bore a hole in the edge of a 2x4 stud, tap a rod in, and start loading it incrementally and take notes. When it bends, make note of the weight and then remove the weight and see if the rod returns to straight. When it bends and does not return your done. Hopefully it will support the weight of the books that each rod will need to support. If your support rods will be located in each stud at 16" on center, then that is the number of books it will need to support; what ever fits within 16". That's not much.
 

·
where's my table saw?
Joined
·
30,364 Posts
There's floating shelves all over the contemporary world.
In this case, the wood is 45 mm thick or 1.77" and 300 mm or 11.87" wide.
So far we have had dowels, rod, biscuits, Dominos, and butt glue suggested.
A good 3" half lap joint will have plenty of long grain surface for glue strength to bond with as well as 7/8" of end to end grain all 11.7"wide.
I'll wager it will hold all the books you can stack within a 16" span, having 1/2 the load on 8" of span, and the other 1/2 on the remaining 8". As the load gets closer to the support rod it will have a shorter lever arm (distance to the support) so the downforce will be less. This is a calculus problem and it is over my paygrade.
 
  • Like
Reactions: Smidarnar

·
Registered
Joined
·
3,591 Posts
i will throw finger joint into the suggestion pool. if you lay the boards where you can go along and find similar grain and color where they will mate up, the joint will almost disappear. and it should be adequately strong for that application.
realize that no matter the joint, you will need min 2 people to handle the install, maybe 3. i would tilt the rods up slightly (5 degrees), to compensate for future sag...
Wood Rectangle Font Hardwood Handwriting
 

·
Registered
Joined
·
17 Posts
Just finished reading this thread and thought I'd post my initial thoughts. First off, for joining the two boards, if the look of one continuous shelf board is what you like, I would go with the scarf joint for best appearance and should be plenty strong.
The one thing to me that hasn't been mentioned is the use of 2" X 12" boards for the shelf. I'm guessing you want that thick look, but if I were making a shelf of that length and width I would be going with 1" thick stock. If your shelf supports are 16" on center, 1" thick should be plenty thick for support with out any sag. The weight of a 2" X 12" X 13 ft long should be about 86lb. A 1" thick shelf would be half as much. Less weight on your supports.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #32 ·
Ok thank you all for posting your advise and thoughts! I’m new here (probably the only Icelander as well) and this seems to be the platform I’ve been needing for a while now.

I suddenly took a different turn and decided to go with a 45 mm thick wawa/obeche plank.
It’s super light so good for the support rods. I’ve done a few stain tests and with Rustin’s dark teak I get close to the walnut look.

Rectangle Wood Material property Vehicle door Tints and shades


I still haven’t decided which way to go regarding the joint but I’ll put pictures on this thread when it’s done.
 
21 - 33 of 33 Posts
Top