How wide can a drawer be

[mr_skittle]

I'm sure this discussion has happened here before but it's time for another round.  

I'm working on some built-in cabinets and the constraints presented are leading me to a 4ft+ wide drawer that is about 24in deep. Here are a couple of things I'm already considering:
1. side mount slides probably won't work because of their tendency to rack side to side
2. the bottom will need more than the standard 1/4 ply
3. two, well places pulls will be necessary
4. While splitting the drawer into two would be a reasonable idea, the design constraints would make it look awkward 

My questions are:
1. How do under mount slides handle racking?
2. What am I not considering that I should be? 
3. While I'm pretty set on the design, are there any suggestions that might help


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[Willyou]

I can tell you what I did that worked good. Not sure if it is the best way.
I built a chest of drawers a few years ago with similar dimensions. I did not use metal slides and could not manage to keep the drawers from racking and binding. So, I made a center guide rail under the drawers as precisely as I could. It works quite well allowing me to push/pull the drawers by one handle without binding.

I have built other drawers that are not quite that wide using full extension metal slides. These had a tendency to swing side to side a bit when open, but they didn't bind. Maybe yours would do the same. I suspect that 3/4 extension slides would be more stable. I would not expect them to bind.

I have no experience with the under mounts. Because they lie flat, I wonder if they have the load carrying capacity for a large drawer without paying for a real beefy model. Others here will know.

[ez-duzit]

Wide drawers are common in engineering blueprint file cabinets. No problem with regular side mount slides.

[Cooler]

I made a cabinet with doors and pull outs.  The drawers are about 40" wide and about 18" deep.  This was wider than the hardware specified, but I've had no problems with it (though it is lightly used).  I think the shallow depth contributed to the satisfactory result.  I used full extension hardware.  I don't recall the brand; I have the cabinet for 20 years now.

[mr_skittle]

Perhaps I'm wrong about the side mount slides. I suspect it will be a little-used drawer full of blankets and decorations. I have thought about some sort of guide mounted to the underside of the drawer but haven't given it a ton of thought yet.

[Cooler]

Perhaps I'm wrong about the side mount slides. I suspect it will be a little-used drawer full of blankets and decorations. I have thought about some sort of guide mounted to the underside of the drawer but haven't given it a ton of thought yet.

That is how I am using the drawers.  When I get home I will take some measurements and report.  I don't remember what I used for the bottom but probably whatever I had on hand that was more than 1/4".  I might have used 3/4" ply for all I can remember.  I'll look at that too.

[jteneyck]

I built a dresser a few years ago with 37" wide drawers.  I used Blum Tandem/BluMotion 21" undermount slides and they work fine even though the width exceeds Blum's recommendations.   I didn't use them, but Blum makes a cross connector to hold the slides in perfect alignment which improves racking resistance.  At 48" I think I would use them.  

I built the drawers from 1/2" thick maple for the boxes and 1/2" plywood for the bottoms. 

John

[mr_skittle]

John, Now that you mention it I do remember using those cross connectors on some undermount slides when I was still working at a cabinet shop. Little bit of a PITA to install but they do work well. I'll have to look around for that product. I'm guessing they come at a premium.

The drawer will be somewhere between 1/2" and 5/8" depending on where the boards come in after gluing and flattening them. I had some nice 6/4 birch that I resawed and glued up but I still need to clean them up with the wide belt sander. Last them they came in around 9/16, which should be plenty thick.

[Stwood_]

Use 1/2 or 3/4 for the bottom.
Maybe consider using 4 (four) undermount slides under there. Surely 4 undermount wouldn't rack.

[Steve N]

Use 1/2 or 3/4 for the bottom.
Maybe consider using 4 (four) undermount slides under there. Surely 4 undermount wouldn't rack.

With no mention at all about what kinda weight is to be in the drawer I wonder if anything suggested will work? 4' is 4', that could house hundreds of pounds potentially.

I've not used the ties John spoke of but they may help with alignment as much as twisting/strength/solidity. The biggest concern I have about multiple slides is alignment. Seems if they aren't spot on you could get jammed simply because they wanted to go slightly different directions. The same could be a problem with just 2 slides, but much easier fixed.
Maybe some very heavy weight slides, and the ties John mentioned may be a better thought?

Has anyone done more than 2 slides before? I have not, maybe it's not difficult. (shrugs)