# Best way to assure bookcase is square when installing back



## personalt (Mar 10, 2008)

I have a 36" w x 92"h x 12"d bookcase that I am building out of 3/4" plywood. I routed the back of each side so the back could sit recessed. (back is 1/2" plywood). Top and bottom where secured with pocket screws and glue. 

Would these bessy angle clamps be good for assuring the whole bookcase is square before installing the back? 

I did one today but have two more to do tomorrow. For this one I cut the back 1/8" short and made sure the spacing was uniform all around before I nailed it on but was wondering if there was a better way to hold it square.


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## woodnthings (Jan 24, 2009)

*the back itself is your guide*

Assuming .... the back is square and fits well with an even gap all around, that's all you need to get the carcass square. No fancy clamps. :no:


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## Steve Neul (Sep 2, 2011)

Like woodenthings said the back will hold the cabinet square however when installing it the front of the cabinet can twist some making the front out of square. What you can do when you are installing it is to measure the cabinet corner to corner both ways and see if the front is square. You might have to shim it a little and screw it to the wall or ceiling to make the front square too.


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## Al B Thayer (Dec 10, 2011)

I agree the back will square it. But care should be taken when putting the carcass together. At glue up be sure when left to setup it's setting square and true. I just set one bar clamp on the longest diagonal and pull it into square. If it's too long for one clamp I just use two.

If you cut the back perfectly square you can't go wrong.

al


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## shoot summ (Feb 21, 2014)

I always measure the carcass corner to corner diagonally. The measurements should be the same, adjust until they are...


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## Belg (Oct 2, 2011)

shoot summ said:


> I always measure the carcass corner to corner diagonally. The measurements should be the same, adjust until they are...


I do the measurements but when working with larger pieces have trouble getting the corners to shift without damaging edges, any tips?


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## Ghidrah (Mar 2, 2010)

In the past pretty much every issue I had regarding carcass square was related to the individual parts not being the same, (L, W, H,) and or the cuts made within the panels. The better I got at ensuring dupe measure and cut the squarer the product.


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## MT Stringer (Jul 21, 2009)

Take a few minutes and make several of these. If your parts are cut correctly, these will help keep the carcase square. :thumbsup:

Make 'em whatever size you need.
Good luck.
Mike


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## Belg (Oct 2, 2011)

MT Stringer said:


> Take a few minutes and make several of these. If your parts are cut correctly, these will help keep the carcase square. :thumbsup:
> 
> Make 'em whatever size you need.
> Good luck.
> Mike


Mike I made those for myself. In the version I found they clipped the rear sharp corner as to not get it stuck in the glue on an inside glue up.


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## MT Stringer (Jul 21, 2009)

Belg said:


> Mike I made those for myself. In the version I found they clipped the rear sharp corner as to not get it stuck in the glue on an inside glue up.


I was thinking of doing that just last night. I have five kitchen cabinets to build soon so these will come in handy again.

The cabinet in my post is 45 inches tall and 37 inches wide x 18 inches deep.

It was easy to assemble. :thumbsup:


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## tradewater (Aug 2, 2015)

As others mentioned, perfectly square (and flat) components ( Festool tracksaw and MFT work best for me ), and then I like Woodpecker's precision clamping guides for the assembly...


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## was2ndlast (Apr 11, 2014)

tradewater said:


> As others mentioned, perfectly square (and flat) components ( Festool tracksaw and MFT work best for me ), and then I like Woodpecker's precision clamping guides for the assembly...


Yeah but you need the parallel accesory to be dead on both sides. I don't have it so I tend to use the table saw when cutting the components...unless it's a full sheet then use my ts55 and carefully line up.


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## sancho57 (Oct 23, 2011)

Another method for squaring that I used to use is as already mentioned be sure all the pieces are cut to the right dimensions.
Sides the exact same length and the top and bottom the exact same length. Then after assembly I cut a my back ( I use 6 mm ply)
about 1/4" wider and longer then the finish dimension. I'll nail, staple screw ( how ever you want to do it ) 3 corners of the the back of the finished cab. Take a square on the 4th corner and adj the box to square then add the 4th fastener. Then take your router and with a flush trim bit trim the outside of the back.

I still use that method for garage cabs and other things.


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## FrankC (Aug 24, 2012)

sancho said:


> Another method for squaring that I used to use is as already mentioned be sure all the pieces are cut to the right dimensions.
> Sides the exact same length and the top and bottom the exact same length. Then after assembly I cut a my back ( I use 6 mm ply)
> about 1/4" wider and longer then the finish dimension. I'll nail, staple screw ( how ever you want to do it ) 3 corners of the the back of the finished cab. Take a square on the 4th corner and adj the box to square then add the 4th fastener. Then take your router and with a flush trim bit trim the outside of the back.
> 
> I still use that method for garage cabs and other things.


Just curious, how do you get the carcass to move after fastening three sides?


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## SedaliaSteve (Dec 22, 2008)

Everybody here is right on about making sure that all parts are square and properly sized. It still is easy to mess up in the gluing stage. Whenever I'm making a cabinet or something that really needs to be square I use hide glue since it sets much slower than regular wood glue. That way I can make sure each joint is good with no bows or other issues. Then I still have time to take a square to everywhere and measure crossways to make sure they match. It's very easy to get a bit off here on a big piece. I have lots of pipe clamps and some 8 foot pipes and I use a clamp crossways to bring it back to square. If you don't have one long enough, use two together. With hide glue I leave it in the clamps 24 hours but the extra time it gives me is worth it.
Steve


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## sancho57 (Oct 23, 2011)

FrankC said:


> Just curious, how do you get the carcass to move after fastening three sides?


I use this method smaller type cabinets and book cases but once I got the back panel screw on in 3 corners I take a square and push the carcass over until its square then drive in the 4th screw, take a router with a flush trim bit and flush up the back panel.


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