Wide Drawer Bottom Support

[Ron Duca]

I have a set of design plans for a four-drawer dresser that I'm going to modify to make into a five-drawer CD/DVD Storage cabinet. The drawers will be 3/4" plywood, 40"W x 18" x 6"D and I will use rabbet and dado joints. I am also going to use ball bearing full extension slides. I originally planned to use 1/4" hardboard or plywood bottoms with a 1/2" strip of 3/4" plywood turned sideways and glued across the width of the bottoms for support. Would that support prevent the drawer bottoms from sagging or should I use something thicker for the bottoms like 3/8" or even 1/2" plywood (without a support strip)?

[Chris Friesen]

ply would make a sturdier bottom than hardboard. You may also consider using a hardwood support in the middle rather than just plywood. (In plywood half the material is going the "wrong way" for what you want.) Given that CDs are not particularly light, you might consider using 1/2" for the bottoms.

Also, most full extension slides are not designed for drawers that are wider than they are deep (aka "lateral" drawers). You may want to bump up the load rating, or get slides designed for lateral use.

[Jesse Cloud]

Hey Ron,
Please don't take offense, but not knowing how much experience you have in this sort of thing, I thought it wise to caution you about a 40 inch wide drawer. Its not easy to get something that big to come out square and ball bearing drawer slides don't have much tolerance (probably about +- 1/32).

If you haven't built something like this before, you might think about making more, but smaller drawers, maybe 20 inch wide... That would avoid the sag problem and lower the risk.

Hope this helps!

[Ron Duca]

Thanks for the advice. This is my first "dresser" and one of the reasons I posted my question was to see what kind of responses I might get to building 40" wide drawers. Most everything I've read suggests limiting the drawer widths to 24". The plan I'm using shows them at 38" wide and recommends using 18" Blum type slides. I was considering the ball-bearing slides because they are heavier duty. The ones locally available are rated up to 100 lbs., but they also say "up to 24" drawer widths".

So, now I guess I'll plan to modify my cabinet to contain two columns of narrower drawers. I'll lose some storage space, but the drawers should be more stable and slide properly.

And now I have another thought. With 40" drawers, would the Blum type slides be strong enough, and would they keep the drawers straight moving in and out?

[frank shic]

ron, as long as you don't exceed the maximal load on the drawer slides and install them correctly, you shouldn't have a problem except for some slight side-to-side movement. i was thinking about your wide drawer problem and another possible solution would be to nail or screw a piece of cambered hardwood underneath the drawer bottom with the bow facing upwards.

[Greg Cole]

Hi Ron,
I have made a couple pretty wide drawers (32" IIRC) for tool storage stuff for the shop at the day job. I wound up using 1/2" ply for the bottom & 3/4 ply for the drawer box itself. I used a "frame and panel" style of construction for the drawer bottom. I used 4" wide 3/4" hard maple for center rail in the middle of the drawer bottom. The rail sticks up just a tad under 1/4" on the topside of the drawer bottom. I also morticed the center rail in place to make it as stout as possible.
We literally toss angle grinders, sawzalls & misc powered hand tools in'em every day...

Worth the price paid...

Greg

[frank shic]

greg has pointed out another great solution: solid wood drawer bottoms! if you don't want to spend the extra time building frame and panel, you could just bevel the edges so that the wood will fit in the dado.

[Cliff Rohrabacher]

I have used 1/2" for some over size shop drawers that I load with heavy stuff. I fully captured the ply rather than slide it in after the drawers were glued up.

[Ron Duca]

Cliff,

I have a beginner's question. What do you mean by, "I fully captured the ply rather than slide it in after the drawers were glued up."? Does that mean you didn't cut a groove for the drawer bottom?

[frank shic]

ron, it probably means that he did not chop off the bottom of the back of the drawer to allow sliding the bottom in through the back and instead had it captured on all four sides with a dado through each.

[Ron Duca]

I've done a lot of research and had decided to go with the Blum Tandem with Blumotion slides. I thoroughly studied the literature and installation instructions and was convinced that I could installed these slides, even though I have never installed them before.

Today however, I went to my local supply store and was ready to order five pair of the slides until the saleswoman asked me if I had ever installed these slide before. I said no, and she then said, "You do know that you've selected the hardest slides to install, don't you?". We further discussed this issue and I left the store, ready to go back to the drawing board.

I'm may be a novice woodworker, but those slides just don't look that hard to install to me. Am I being unrealistic or is the installation really that difficult?

[Jesse Cloud]

[quote=Ron Duca;685981
.....
I'm may be a novice woodworker, but those slides just don't look that hard to install to me. Am I being unrealistic or is the installation really that difficult?[/quote]

Hey Ron,
I suspect the issue with the slides is that there is very little tolerance for the two pieces (one on the case, one on the drawer) that fit together. If your plywood bows a little or the case is a little wider at the back than at the front, the slides will bind or jump loose. If you like the design, my advice (free and thats about what its worth;)) is to be very anal about getting things square, doing it over if there's more than 1/32 difference and be prepared to put some shims under the slides if things aren't totally square.

Another good approach is to use a 'story stick'. Take a piece of scrap the height of your project and mark the vertical distances for all the slides, dadoes, etc on the stick. Then use the stick to mark the sides of the case. Its a good way to minimize measuring and marking error.

Let us know how the project goes!

[Joe Jensen]

I have a set of design plans for a four-drawer dresser that I'm going to modify to make into a five-drawer CD/DVD Storage cabinet. The drawers will be 3/4" plywood, 40"W x 18" x 6"D and I will use rabbet and dado joints. I am also going to use ball bearing full extension slides. I originally planned to use 1/4" hardboard or plywood bottoms with a 1/2" strip of 3/4" plywood turned sideways and glued across the width of the bottoms for support. Would that support prevent the drawer bottoms from sagging or should I use something thicker for the bottoms like 3/8" or even 1/2" plywood (without a support strip)?

Ron, I've built some wide drawers for the shop and with regular Accuride 100lb slides, the drawer has a hard time going in and out evenly. All the slide manufacturers recommend a different style of slide for wide drawers due to this problem. The drawers sway side to side too much. I have the 100lb full extension top of the line Accurides on 20" wide drawers and they are barely stable enough. I have the Accuride slides for wide drawers on 30" wide drawers, and they are good. But, they are very large and ugly.

If it's possible, I'd say redesign, or don't do full extension slides...joe

[Craig D Peltier]

Hi, just over the past few days I built drawers (3) 55 inches wide. I used half inch birch ply sides and bottom. I used 22inch slides for a built in. KV slides rated for 100lbs. The drawers work fine.Just for good measure I put one support across the depth underneath of 1/2 inch ply in the middle. Heres on e pic of draw.The dog weighs 27lbs.He's the guinea pig.:)

74527

[frank shic]

ron, go for it with the blumotion slides! don't let a saleswoman or salesman who's probably never installed them themsevles dissuade you. at the very least, it'll give us all another thread to discuss: blumotion slide installation. although i haven't used them yet, i would definitely incorporate them into my next project if it involved dovetail drawers since they're so much cleaner looking than epoxy slides or ball-bearing slides.

[Ron Duca]

Partially based on Craig's success with his 55" wide drawers using KV 8400 slides, I'm back to planning to try the same KV slides, with a twist. I'm going to add a little something and I could use some help locating a particular item. The item is a little roller, nylon I think. I saw some kitchen cabinets at Lowe's the other day. One was a vertical pullout that had a slide on the bottom, and installed on the cabinet frame near the top was a little roller on each side that stuck out just enough to keep the top part of the pullout from wobbling as it slides in and out. I would like to find some of those and install one on each side of the drawers near the back. If they are the right size, they would help minimize the side to side play in the drawers and take some of the stress off the slides. I might need to install a second pair near the front of the drawer also, only inside the cabinet walls.

Does anybody know what kind of rollers I'm referring to, or where I might find some?

[Cary Swoveland]

Ron,

If the top drawer is opened fully, with full extension slides, is the cabinet going to be at all tippy? Do you need to tether it to a wall?

Cary

[Ron Duca]

The entire unit will be about 76 inches tall with the lower 48 inches being the five horizontal drawers that I'm trying to decide on a type of slides to use. The upper part of the cabinet will be five vertical drawers, or pullouts, which I have not yet designed. I've pretty much given up on finding an existing woodworking plan for such drawers and will design my own.

To answer your question though, yes, the unit will most definitely be tethered near the top. There will be no chance of it tipping over.

[laura vianello]

I have built 6 drawers 37" wide x 18" with Blum Tandem soft close and they are very good. The tolerances are much easier than ball bearing. I am currently building 37"x27" in the same way: 1/2 ply with dados. I only wish the quality of this ply would be better but the hardware is my favorite. I am not an expert by any mean.

[Bill Adamsen]

Solid wood is significantly stronger than plywood, especially in terms of stiffness. A shelf or drawer bottom made from solid wood will sag less than one made from plywood of the same dimensions. A centerboard or rudder made from solid wood will flex much less than one fabricated from plywood. I make drawer bottoms from solid wood and the approach is exceptionally easy when using full bb side slides as I think you mentioned you were planning to do. As in traditional drawer construction, the bottom should expand beyond the back of the drawer, an accommodation you don't need to make with plywood. Still, 40 inches is a wide drawer.

[Martin Wasner]

Ten.
Year.
Old.
Post.

[Larry Edgerton]

Ron, I've built some wide drawers for the shop and with regular Accuride 100lb slides, the drawer has a hard time going in and out evenly. All the slide manufacturers recommend a different style of slide for wide drawers due to this problem. The drawers sway side to side too much. I have the 100lb full extension top of the line Accurides on 20" wide drawers and they are barely stable enough. I have the Accuride slides for wide drawers on 30" wide drawers, and they are good. But, they are very large and ugly.

If it's possible, I'd say redesign, or don't do full extension slides...joe

Joe I routinely use drawers that are wider than is considered acceptable, 36"ish. I have some in my own kitchen, my wife loves them. Here is waht has worked for me.

I use prefinished 1/2" maple bottoms in a 22" deep drawer, captured and have not had a failure with no support. I use no particleboard for anything, its junk.

I tried Blums, but I had issues with drawers with big heavy pans so I switched to KV or Accuride 100# slides, full extension. What I do do that is different is I install a third 100# slide flat under the drawer to keep the drawer coming out square to the opening. This eliminated the problems that come up when someone pushes the drawers closed from one side. Took a bit of head scratching, but it works well.

If a customer insists on Blums so they can not see the slides I just don't make any wide drawers, their choice.

[Martin Wasner]

If a customer insists on Blums so they can not see the slides I just don't make any wide drawers, their choice.

I guess I'll reply in earnest to the decade old thread.

I routinely do 40" wide drawers with Blum undermounts.

A 563H is inadequate, step up to the 569.
Add the Blum Tandem Stabilizer. They work nicely. Blum claims a max drawer width of 52" with it, I've never done one that big though.

I don't bother adding any bracing on the underside in a normal scenario. It's still only 21" deep or less, and when the drawers start getting that big, any weight you can save is a win.

[Alan Lightstone]

Wonder if they lasted.

10yo. LOL. Nice of everyone (except the OP who's long gone - he only posted that month to this original post) to respond, though.

[Sam Blasco]

I don't think wider drawers are all that much more difficult to square up if you are reasonably seasoned. And to save weight on the bottoms, 1/4" plywood (good cabinet grade ply) works well if you add a couple of 1/2" ply stiffeners evenly spaced glued to the bottom and tacked to the front and back. Perfectly concealed, too, if you plan on 1/2" space before the bottom of the groove.

[Richard McComas]

I have 15 drawers in my kitchen for 36 wide to 48 wide. I use rack & pinion slide hardware. They work perfectly. The do add a considerable expense.

As I understand it Blum has some device that work similar for their under-mounts.

This is a short video of the slides.



http://i119.photobucket.com/albums/o159/rmccomas0043/Videos/th_rack.mp4 (http://i119.photobucket.com/albums/o159/rmccomas0043/Videos/rack.mp4)

Doesn't look like Photo Bucket going to cooperate on the video so here's a better image,

http://i119.photobucket.com/albums/o159/rmccomas0043/Rack_zpsljjpkaic.jpg

You can see the slides are tied together with a round bar and a couple of gears.

Blum has something called Lateral Stabilizers

https://www.wurthlac.com/storefront/content/attachments/LateralStabilizer563_569_ProductPage.pdf