face frame joinery Question?

[Bob DiGiacomo]

A cabinet maker that I used to work with showed me a new way to join face frames together quickly, and I am wondering how strong the joint really is.

Step 1 glue up the face frame using boards that are 3/4 thick by 2" wide just use butt joints and let the frame dry over night.

Step 2 on the back side of the frame across the butt joint use a biscuit jointer (without any alignment guards attached) and make two biscuit slots that you fill in with biscuits and glue. Finally sand flat and attach to the cabinet. Since the biscuits are on the back side of the frame no one will ever see them.

Has anyone ever heard of this method or used it on any projects?

[Chris McDowell]

Not only have I never heard of that, but in my opinion it is one of the worst ideas I have ever heard of. Why would anyone just use butt joints and glue up frames over night only to cut joinery the next day? Just use glue and pocket holes with screws and your done.

[Alan Turner]

Face cut biscuits is an old way of strengthing an end grain joint, or repairing a split. Make a jig for your bandsaw and you can halve them quickly. This is not a method we use, but it does work and is quick.

[Jim Becker]

What you describe is a modified spline joint of sorts. There are some new polymer biscuits out now that are designed for this kind of joint...they have little fingers that actually draw the joint together tightly. It's kind of the same idea that is sometimes used in framing where some corrugated fasteners are driven across a miter joint on the back side to tie things together.

That all said, the initial butt joints are going to be pretty weak and it's not all that much more work to use the biscuits in the standard way if you want to use them. Personally, I moved on to pocket screws...faster and very strong. Frankly, I even use them for cabinet doors now. The "evidence" on the back side really doesn't bother me.

[Nancy Laird]

Bob, use the butt joints, but use face-frame biscuits in the joints. Work well. We have well-used doors and frames in our kitchen and pantry that are made in this fashion, still in good shape after 6-plus years. You won't have an ugly backside to the frame with screw holes or half-biscuits showing.

Nancy (123 days)

[Jim Becker]

Now Nancy, wouldn't you have to stick your head into some very small places to see anything on the back of a face frame?? :D :D :D

[glenn bradley]

I've not heard of it but that doesn't mean much. I just use FF size biscuits or pocket holes.

[Bob DiGiacomo]

Thanks everyone,
Just wanted to know your opinions.:D

[Art Mulder]

Has anyone ever heard of this method or used it on any projects?

Never heard of it for a face frame, and I agree... why not just use pocket holes and be done?

However, I have heard of doing this on the back of picture frame joints, and I have actually done it myself on a pair of picture frames (http://www.imaging.robarts.ca/%7Eamulder/wood/p.frame/).
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Actually, I wonder... is the glue joint on a miter stronger than a end-to-side-grain butt joint that was described? I would think so, but I'm not sure.

[Nancy Laird]

Now Nancy, wouldn't you have to stick your head into some very small places to see anything on the back of a face frame?? :D :D :D

You're right, Jim. I was thinking doors made rail-and-stile. It's just me, but I don't like pocket holes. :(

Nancy (123 days)

[John Stevens]

Actually, I wonder... is the glue joint on a miter stronger than a end-to-side-grain butt joint that was described? I would think so, but I'm not sure.

That end-to-side grain joint with a biscuit is surprisingly strong. Try this: take a piece of scrap wood and make a biscuit slot perpendicular to the grain, in the middle of the piece. Now take another piece of scrap wood and cut a slot parallell to the grain. Glue the two pieces together with a biscuit with white or yellow glue and let the glue cure for 24 hours. You should have something that looks like a "T"

Now install the thing in a vise or jig it so you can hang weights on it in order to try to pull the vertical leg of the T away from the top-horizontal leg. Surprising, eh?

My pet theory for this is: as the biscuit expands in the slot, it drives the glue into the pores of the wood, so that makes a strong glue joint even when it's end-to-side grain.

Whatever the reason, after you try this, you'll have much more confidence the strength of an end-to-side biscuit joint.

Regards,

John

[Art Mulder]

That end-to-side grain joint with a biscuit is surprisingly strong.

I meant without the biscuit, John. :p

[James Phillips]

Actually, I wonder... is the glue joint on a miter stronger than a end-to-side-grain butt joint that was described? I would think so, but I'm not sure.

I actually think it would be weaker. It is essentially an end grain to end grain glue joint. I guess since it is mitered it lives between end grain and long grain, but it is still going to soak up alot of the glue in the joint.