Biscuit Joinery

[Guest Screamer]

Is Biscuit joinery strong enough to support shelf?

I am planning do make a bookcase entertainment center. It must support a television (CRT), Hi-Fi etc.

I am planning to use 3 biscuit joints per side.

[GNiessen]

The biscuits do add their shear strength to what would be an end grain glue-up. They also would hold the joint together acting as a tenon.

But a stronger choice would be to inset the ends of the shelf in a dado. Without knowing how large a TV it is hard to say what you should do for that shelf. But CRT's are heavy and consider the weight is focused in the middle of the self. That shelf should have support of a facing trim and be inset in a back dado also.

[Sac]

The biscuits do add their shear strength to what would be an end grain glue-up. They also would hold the joint together acting as a tenon.

But a stronger choice would be to inset the ends of the shelf in a dado. Without knowing how large a TV it is hard to say what you should do for that shelf. But CRT's are heavy and consider the weight is focused in the middle of the self. That shelf should have support of a facing trim and be inset in a back dado also.

I would hajve to agree here. If you are going to put on a CRT then a dado would probably be better. Those things weigh a ton. And when you build it, make sure that you build it big enough for a new flatscreen, for when that CRT dies.

[Frank Speyerer]

Here's a similar post that may offer you additional input.

In the case of a shelf that will be required to support your heavy electronics a dado would probably be better.

[Guest Screamer]

Thanks for the replies. Then it must be a dado. How deep must it be? And I thought of it Chuck aka Sac. I want to buy a LCD TV in the near future. So biscuit joinery is only for alignment and light joinery like moldings etc.

I thought so.

What make me post to this forum is the following statement by Chris Baylor.

"For certain types of woodworking joints such as edge-to-edge joints, miter joints, T-joints and corner joints, there is hardly a better choice than biscuit joinery. Biscuit joints are strong and accurate, particularly when cutting slots with a woodworking tool called a biscuit joiner (or plate joiner)."

http://woodworking.about.com/od/joinery/p/BiscuitJoinery.htm

The original plan for this project come from the following link:

http://americanwoodworker.com/blogs/projects/archive/2009/10/07/bookcase-entertainment-center.aspx

Regards

Johan

[PaulMarcel]

The dado doesn't have to be that deep. 1/8"-3/16" will do it. I assume you're using plywood. With hardwood, you could do 1/8 or much larger as long as what isn't cut is still pretty stout. With ply, the deeper you go, the weaker it gets, and quickly so keep it shallow.

So, I don't have a biscuit joiner (I use fork split myself... ) but if ever you wanted to use the biscuit joiner for a project like that and need something stronger than a biscuit, you still can. Use the joiner to make the matching cuts in both surfaces then cut a piece of hardwood into strips the thickness of the biscuit slot (5/16"). Depending on the biscuit number you cut for, you get different depths (I have no idea what those are exactly; large one looks like 1/2"). Yeah, the joiner cuts round slots, but I think you could still cut those hardwood pieces easily and quickly on a bandsaw; use a real biscuit to know the shape. Batch them for the next time, too. Doesn't take as long as you think; I make home-cut Dominos (my joiner of choice) often for special needs.

You need sheer strength so make sure the grain runs across the joint, not parallel to it.

[Bombarde16]

Is Biscuit joinery strong enough to support shelf?

I am planning do make a bookcase entertainment center. It must support a television (CRT), Hi-Fi etc.

(Seconding everyone else's vote for something stronger.)

One other thing that jumps out in this project are the doors. You're certainly not going to use biscuits to do a set of glass panel doors; so you may as well jump into "real" joinery with both feet.

[Bombarde16]

Is Biscuit joinery strong enough to support shelf?

I am planning do make a bookcase entertainment center. It must support a television (CRT), Hi-Fi etc.

(Seconding everyone else's vote for something stronger.)

One other thing that jumps out in this project are the doors. You're certainly not going to use biscuits to do a set of glass panel doors; so you may as well jump into "real" joinery with both feet.

[dryhter]

Hey Johan,

That is the problem about the www alot of information out there, he is talking about non- weight bearing applications for the most part. About.com is not the best place to get your woodworking information, good thing you made it here. After looking at the plans for the entertainment center you could probably use biscuits for the shelf that the TV sits on as long as you beef up the undercarriage of the cabinet under it to carry all the weight, not transferring weight to the sides of the shelf.