Options for frameless cabinet foul ups?

[Kodi Crescent]

I'm trying to build cabinets for a home office.  These are frameless cabinets (so far), but I seem to have fouled up on getting my cases square.

I assembled these with dominos and glue, and I thought I clamped them square at glue up; apparently I fouled up somewhere, or my stock isn't completely flat (Baltic Birch).  I can get 2 or 3 of the 4 inside corners square, but I can't get them all square.  Checking my inside diagonals with a bar gauge, I come up about 3mm off on the diagonals.

Any advice or options for fixing these?

 

[lwoirhaye]

Take the back off, bring the case to square at the front with a bar clamp and re-install the back.  Tack or screw the back in a few places and take the clamp off to check the opening if you want. This should keep the front square.  The back may still be out of square a little but at least the door will look right.

Plywood is unreliable for frameless construction for the reason you encountered among others.

 

[Oldwood]

Are you measuring the back of the cabinet to check for square? The front of the cabinet can be fudged quite a lot during install unless these are free standing cabinets.

 

[Kodi Crescent]

I was only checking the front.  The back is out of square about the same amount.

My back is dado'd into a groove on the sides and top.  It isn't glued, so it should have some ability to float in the groove.  Should I take my router and rout down to the groove in the back so I can lift the back out?

With regards to the suggestion of the bar clamp - am I to clamp this across corners to rack the case?

I'm using the Woodpecker's clamping squares to clamp.  I get contact on both edges right at the corner, and then I have about a 0.02" gap at 6" from the corner on one side.  How square is square enough?

 

[nclemmons]

If three are square and one is out of square, it sounds like you have a dimension difference across top to bottom or side to side.  Or a really bowed side.  One other idea would be if you are installing a shelf or top-to-bottom divider that might get the bow out and help.

 

[android]

I'm using the Woodpecker's clamping squares to clamp.  I get contact on both edges right at the corner, and then I have about a 0.02" gap at 6" from the corner on one side.  How square is square enough?

Ideally, you want the front edges of frameless cabinets that touch to run parallel without gaps. If you're using full overlay, your reveal needs to be even. You've got to determine how each step affects the next step. Errors just accumulate and grow.

 

[Kodi Crescent]

I think I'm going to start over.  I need to change materials and take an extremely hard look at my construction method. 

 

[sancho57]

If your having issues geting your frameless cabinet square and your making new ones. Make sure the sides are cut to the exact same dimensions. Make sure your tops and bottoms are cut to the same dimensions. Im sure you know that. Before you put you back on is when IMO they will come out of square.  So IMO there are a couple of ways to solve this .

Put a nailing strip acroos the back of the cabinet the exact length as the top and bottom. You can hide them by routing a glove about 3/4 inches from the back of the cabinent and slide your back in and then add your nailing strip.

Another way if you want is to cut the back about 1/4 oversize than the cabinet attch it to 3 corners then take a square pull the 4th corner into square then attach the 4th corner, take a router with a flush trim bit and cut the back panel flush.

Im sure there are other ways but thats how I would do it.

Hope this helps