In pictures and articles, woodworkers are shown lifting completed face frames over 60″ long cases (with two dividers and a drawer line), with a caption that blandly reads “Biscuits assure perfect alignment of face frame and case – careful measurement is essential”. No where is there mention of just how that last is accomplished.
I can think of several ways to screw that up. Because, while there’s “lots” of room for slop lengthwise along the long axis of the biscuits, there’s precious little side-to-side, sooooo . . .
How does the owner of a new PC biscuit joiner, a complex case, and a face frame align case, biscuits, and frame so that they do, in fact, align, perfectly?
Once again, inquiring minds want to know.
Mike D
Replies
Mike,
Make the face frame first...
Make the face frame first? Hummmmmmmm . . . I've got to think that through.
Mike D
I think I've had the same question as you. It's easy if the case and frame are flush in places so you can use the same joiner fence settup, but where measuring and compensating are involved it's tedious and the errors compound easily, especially where case walls bow in or out slightly. I've done it, but am not sure it's worth it in retrospect. My solution is to use fewer biscuits in general and keep them around the corners. For me the biscuits are not for strength, but for alighnment only. I'll pocket screw the from the case to the frame (an operation which doesn't have the same 'mating' problem) so this adds mechanical strength and also eliminates the need for long clamps. As for the other contributor's suggestion of making the frames first, its a great idea since these must usually be more accurate than the cases, but I don't see what it has to do with your question since sooner or later you've got to glue the two things together. I've got a newer biscuit joiner and sometimw wonder whether I'll ever use the bags of plates that I bought with it. It's like a brad nailer: just an extra hand during assembly.
Brian
My question is just why biscuits are required for a good joint between face frame and carcase.
His flannelness cuts a slot in the carcase. I didn't see why or how this was done, but my impression is it reduces the glue surface by about 20%, negating the benefit of the biscuit's strength.
Back when I was studying mathematics there used to be an expression in the textbooks, "Proof is left as an exercise to the reader.*" In translation, "The author cannot be bothered to explain this."
* Who fondly remembers two one hour lectures on one said "exercise."
My favorite in engineering school was " it will be obvious to the discerning student, that . . ."
I was clearly not often "discerning".
Mike D
One of my engineering profs started the first lecture of the course by saying "As is obvious to the most casual observer. . .". I didn't understand anything for the next 6 weeks!
I do indeed recall those... I can't say that my memory of them is 'fond' however. I especially like some of the engineering classes wherein the final exam consisted of three problems, took three hours to complete, and was worth 50% of the class grade. God bless "partial credit"Cheers,Michael
Yeah, building the face frame first is key - you know the size of the face frame before you build the case.
Another key is to build the frame larger than what you need. Not by much - maybe a 1/4". This way, you can use a plane or router with a flush-cutting bit to true up the frame and make it perfect.
Tom's Workbench
http://tomsworkbench.com
That is a great idea. Can’t believe I hadn’t thunk that one.
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Using a flush trim on the bottom would solve that nagging little up or down that appears on my cabinet work.
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One thing that has worked well for me was to biscuit the bottom edge of the cabinet and face fame frame first. You want the bottom of the face frame and inside bottom of the carcass to be flush. Then after that you can just scribe lines onto the back of the face frame. Then just use a straight piece clamped on this line as a fence for the biscuit cutter. Not exactly perfect but biscuits are sloppy at best.
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Mike_D,
I share your pain. Ironically, I just finished putting a face frame on a large garage cabinet with two dividers and a drawer line. Like you, I struggled and tried to "discern" with little success. I found that it was easier to line up the edge boards but not the dividers, because the dividers line up on center, not on edge. As a compromise, I did not add biscuits to the dividers, and used a groove along the outside edges, as does his flannelness. Used finish nails to secure the whole thing.
Mike,
Obviously there's more than one way to skin this cat, but I can tell you how we do it in my shop. (We make face-frame kitchen cabinets professionally).
The assembled cabinet, up to 8' long and often rather complex, is laid on low horses on its back. (The back is not attached yet). Then using biscuits for alignment we cut and dry-fit the entire face frame, piece by piece. Two biscuits will hold any face frame member temporarily in place. Once it's all ready, we remove the parts and glue up everything at once. You need lots and lots of clamps.
There are 2 main advantages to this system: it's always a perfect fit because you dry-fit one piece at a time. It's the fastest overall system, taking into account that the clamps usually can come off an hour later.
regards,
David Ring
http://www.touchwood.co.il/?id=1&lang=e
This seems to me like the most mistake proof way as well.
Thanks.
Mike D
Here's a little suggestion. Build the cabinet, or cabinets, and after you have installed it, or them, then build the face frame. Start with the base horizontal, and work your way up. Finish with the top horizontal. Cut and fit as you go. Make sure everything is square and plumb. It works. You have to get creative with clamping, to seat the face frame by adding temporary blocks to clamt to. Try it .
Jack.
But isn't the whole point of building the face frame first is to avoid having to piece it together?--------------------------------------------------------
Cheap Tools at MyToolbox.netSee some of my work at AWorkOfWood.com
That has been my conclusion also.
Mike D
This undertaking is exactly why I go to Church. This way, I know who to thank when it works out! Norm was just doing this on Saturday. He left about a 1/16" to rout off when finished.
In college Physics class I remember Dr. Erickson whipping out solutions on the board so fast the chalk smoked. When finished he would print Q.E.D.! Quite Easily Done. We would sit in silence and awe. That's when I started going to Church. I got a B.S. in that subject.
Edited 2/17/2008 9:56 am ET by Close Enough
Ah, memories best left forgotten.
I had a nice young East Indian gentleman (Dr. Something - can't remember now) in Atomic and Nuclear Physics, who liked to do the wondrous writing-with-chalk-with-both-hands-at-the-same-time trick.
Most of us had a terrible time understanding much of what he said - not because of his accent - he spoke beautiful British English - we just didn't know what the heck he was talking about, usually some 200 words into one of his 2000 word, 6 chalk-board proofs into why a given atomic particle, observed on film, actually existed in nature and/or behaved the way it did.
The greatest compliment he ever paid me was "Good GOD, Mr D, how can someone as smart as you be so incredibly stupid at the same time?"
I finally passed his course after taking it twice, thanking my lucky stars the whole way that I was an EE and not a Physics major.
Mike D
P.S. He left me convinced that Quantum Dynamics is a religion, not a science, as it also passeth all understanding. :)
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