Replies

1. 
   JohnWW | Feb 12, 2008 02:29am | #1

   I share your skepticism. I have often wondered how someone could reliably get dozens of slots to be pretty close to perfectly located in a complex piece. One horizontal and one vertical line are easy, but after that you need to get everything else very precisely measured and then cut.

   I'm not a big fan of biscuit joiners, but if I had to to do a face frame to carcass attachment with biscuits, I'd probably do one horizontal and one vertical row of matching slots in both the frame and the carcass, along with all of the additional slots in the carcass.

   Then, with the carcass lying on it's back, I'd place unglued biscuits in all of the carcass slots and then lay the face frame on top using the matching slots in some of the frame members to get things aligned. After that, you could mark the locations of the remaining uncut slots in the frame from the edges of the biscuits in the carcass, basically using the same technique that's used for laying out dovetail pins from the already cut tails. Exactly how you would do the marking in the narrow gap between the two pieces, I haven't figured out.

   John White

1. 
   xmike | Feb 12, 2008 05:05am | #2

   Hi John,

   Me either, although between Knots and Breaktime, the question is generating some interesting responses.

   I've come up with two very different (and complicated) approaches which I've posted, hoping someone who does this regularly will laugh and present a simpler approach.  I've even presented the question as an idea for a tutorial article.

   Folks have given me some great ideas.  However, I'm about to decide that for a critical and complex piece like I'm making at present, it's just too darn complicated with biscuits, and I'll do this one another way.

   Thanks for the response!

   Mike D

2. 
   tom77 | Feb 12, 2008 06:09pm | #5

   John,
   I think you are on the right track. But, my process is slightly different. I chose the most important horizontal and vertical face frame members. I cut a full set of biscuits slots in these two directions. This orients the face frame to the carcass. I then put additional biscuit locations in other face frame members, staying away from corners so that the carcass and frame are flexible enough to allow assembly. The trick is to stay away from the corners on secondary biscuit locations. The amount of flex required for assembly is small enough to not be noticeable.I hope this helps.Best regards, Tom.

1. 
   JohnWW | Feb 12, 2008 06:38pm | #6

   A good solution, but...It would bother me to have to flex the cabinet sides to get the fit, I know it wouldn't be seen, and the bowing is probably minor in any case, but I would like to keep everything straight. I would also like to get biscuits into the corners to strengthen the frame and to make sure the frame is tight to the face of the box.John W.

1. 
   tom77 | Feb 12, 2008 08:59pm | #7

   John,
   Thanks for the quick response. This is an interesting problem with several aspects. The amount of flexing required is a function of layout and slot cutting errors. I think these should be no more than 1/32", plus or minus. (perhaps a little more on a large cabinet) In my view, that is tolerable. If I screw up and experience larger errors, then I don't use that biscuit location. (and mutter some choice words)Another issue is this: Do biscuits really add any strength or do they primarily serve to align pieces? The data that I have seen is that, at least in solid wood, they do not add any strength. The question now is that still true when using plywood? I think the primary source of strength is the glue joint, and therefore the tight adhesion of frame to case is a function of joint preparation, glue application, and clamping.In your position at FWW, you have access to a lot more information. So, I am very interested in your views on this interesting subject.Best regards, Tom.

2. 
   xmike | Feb 12, 2008 10:42pm | #8

   Interestingly, a picture is slowly evolving that suggests that my original goal to use the biscuits to force alignment of center panels is not a good strategy.  (Even though I have a new biscuit joiner, perhaps it is not the universal tool :)  )

   The concept that I'm starting to see is that a few biscuits around the perimeter to keep the face frame from sliding around on the greasy glue film, as the clamps are installed, is perhaps the optimum use of biscuits in this application. 

   Then, if I want to use the face frame as an alignment tool for the center panels, force them into alignment (somehow) and pin them in place with a 23 gauge pin nailer to hold them in place until a clamp is applied. 

   Doubt has also been expressed as to wether or not a 1 3/4" wide face frame member will do anything to straighten a wayward plywood panel.  I personally find that it helps, since I discard panels that have a bow sufficiently large that I can see it lying there on the saw table.

   Interesting subject.  Thanks for the input!

   Mike D

2. 
   mdcc | Feb 12, 2008 05:34am | #3

   Hey Mike, I am far from being an expert but I have watched some on tv. I have wondered the same thing, always figured that people just screwed up a couple of the biscuit locations but didn't sweat it because the face frame would cover the empty slots. I have been watching Norm Abrams latest kitchen cabinet series and he using using an approach where you cut a continuous slot in the carcass and individual biscuit slots on the face frame. might be worth a look.

   Mark

1. 
   xmike | Feb 12, 2008 06:05am | #4

   Hi Mark,

   I'm watching the same series.  I like Norm - and I like the kitchen he's building.

   Norm's long slot covers the easy part along the length of the case parts, but does not address how to line up the face frame slots side to side.

   I'm sure it's easy, just hasn't been described clearly enough for my struggling brain.

   Mike D