Router Forums banner
1 - 11 of 11 Posts

·
Registered
Joined
·
193 Posts
Discussion Starter · #1 ·
I am making a coffee table and would like some help on how to make the joints. One of my concerns is that the table is quite large and therefore heavy.

All the pieces shown in the sketch are 3/4" walnut.

My initial thought is that I would use half-lap joints. Is this an okay way to go?

To make the actual connections, I was considering using pocket screws to attach the sides to the top surface and then run screws through the bottom surface to attach it to the sides. I also considered biscuits but I'm not quite sure how to do it if I use half lap joints. The easiest way would be to just use butt joints with glue but I question the structural soundness of this.

I really need some ideas on how to proceed with this as I am at a loss. The sketch below shows only the table top. I will be attaching a rectangular base to the bottom and legs will be attached to the base. I think I can handle that part of it. It's just the table top that I'm having trouble with.

The dimensions of the large surfaces are 36" x 50". The dimensions of the sides are 5.5" x 36". I will also be putting a back on this. The front will remain open and a drawer will be installed in it.
 

Attachments

·
Administrator
David - Machinist in wood
Joined
·
4,196 Posts
Which way is the grain going to run for the short pieces that connect the top piece to the bottom piece in your sketch? You'll need to allow for movement of the top/bottom because they will expand/contract in 36" direction. For the top I would use biscuits and glue with good jointed edges for tight glue up. Do you have a way to sand something 36" wide?

I regularly make Walnut panels 28" x 17", not quite as large as yours, but that's how I do them and they come out just fine. Here's a posting about those - 5 Walnut plaques

David
 

·
Registered
Joined
·
21,703 Posts
The most obvious one would be rabbets at the ends of the table's top and bottom layers. You could also cut a groove in the top and bottom layers, then in the side pieces and use a spline. I would also add a center piece and divide the drawer into two. A huge drawer gets sticky pretty easily.

You could do it with an interlocking miter bit, but the setup will not be easy. I guess you could use half blind dovetails to maximize strength.

But my approach would be a splined joint. The grain of the spline should go crosswise to the grain of the pieces, so you'll have to use many short pieces instead of one long piece to get that grain direction right. Expansion could be a problem in some climates, in which case, you glue up the middle and let the rest slip. Of course, you could always glue up the end pieces so the grain runs vertically, which would elininate most of the expansion/contraction issue.

You'll want to be very careful to check for square when doing glue up, maybe use a high end clamp like the Bessy that will hold it square. The spline should be a very snug fit, and at least a quarter inch wide. You can do all this on the table saw, or with a table mounted router with a fence.

Another positive about splines is that you can round over or shape the edge. If you can use a stopped groove, the spline will be buried, out of sight. Again, I'd definetly do two drawers with a divider in the middle.

I would not use biscuits, they are loosy goosy and expand to fit. I don't think much of biscuits for this kind of job. In fact, anyone want to buy my Porter Cable biscuit joiner?
 

·
Registered
Joined
·
193 Posts
Discussion Starter · #4 ·
Which way is the grain going to run for the short pieces that connect the top piece to the bottom piece in your sketch?
Thanks for your comments David. The grain on the side pieces run in the same direction as the surfaces. I'm assuming there shouldn't be any expansion/contraction concerns by doing it this way.
 

·
Registered
Joined
·
193 Posts
Discussion Starter · #5 ·
The most obvious one would be rabbets at the ends of the table's top and bottom layers. You could also cut a groove in the top and bottom layers, then in the side pieces and use a spline. I would also add a center piece and divide the drawer into two. A huge drawer gets sticky pretty easily.

You could do it with an interlocking miter bit, but the setup will not be easy. I guess you could use half blind dovetails to maximize strength.

But my approach would be a splined joint. The grain of the spline should go crosswise to the grain of the pieces, so you'll have to use many short pieces instead of one long piece to get that grain direction right. Expansion could be a problem in some climates, in which case, you glue up the middle and let the rest slip. Of course, you could always glue up the end pieces so the grain runs vertically, which would elininate most of the expansion/contraction issue.

You'll want to be very careful to check for square when doing glue up, maybe use a high end clamp like the Bessy that will hold it square. The spline should be a very snug fit, and at least a quarter inch wide. You can do all this on the table saw, or with a table mounted router with a fence.

Another positive about splines is that you can round over or shape the edge. If you can use a stopped groove, the spline will be buried, out of sight. Again, I'd definetly do two drawers with a divider in the middle.

I would not use biscuits, they are loosy goosy and expand to fit. I don't think much of biscuits for this kind of job. In fact, anyone want to buy my Porter Cable biscuit joiner?
Thanks for your reply Tom. I'm not familiar with using splines so I'm hesitant about going that direction. I like your idea about the center support and using two drawers. I will go that direction. As for using a table saw or router table, these pieces are much too heavy for me to feel safe using them. Whatever I do at this point needs to be done with handheld power tools.
 

·
Registered
Joined
·
31,264 Posts
rebated rabbets...
splines as loose tenons...
blind or exposed... butt joint or mitered...
skip the pocket screws and use pins...
 

Attachments

·
Registered
Joined
·
1,892 Posts
I would go the pocket hole route. Attach the top to the sides and the bottom with screws through it just like you thought off doing. The only downside is that the holes will show if you are looking into the box. If you have a drawer then obviously you wouldn't see them.
 

·
Registered
Joined
·
6 Posts
Chuck, The tried and true most straight forward method is using dowel joints and the easiest, most accurate tool to use is the "Dowel Wizard" Wood Doweling Tool - Dowel Wizard lets you easily drill wood dowel holes. The attached photos are one of my coffee tables I built using this method.
 

Attachments

·
Registered
Joined
·
193 Posts
Discussion Starter · #11 ·
I've built a few coffee tables in my years of woodworking and may be able to help you. My email is [email protected], just drop me a line with your contact information and I believe I can help you.

Best regards,

Woodchips39
Thank you for the offer Gordon. Much appreciated, however at this point I've already proceeded with the pocket screw method. I put in pocket screws every 4 inches and it turns out that the structure is very sound which was my main concern.

The coffee table that you posted in your second post looks very nice. I often use dowels as well and use a Task ProCenter dowel jig which works very well. I just wasn't able to figure out how to use it on the butt joints on my table.

https://www.amazon.com/Task-Pro-Center/pages/3044419011
 
1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top