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Making a drawer box

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Forum topic by jnswhit posted 10-25-2020 05:31 PM 611 views 0 times favorited 21 replies Add to Favorites Watch
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jnswhit

2 posts in 32 days


10-25-2020 05:31 PM

I am attempting to make a wide drawer box and cannot figure out what size wood to use. Baltic Birch plywood seems like the best choice but 3/4” or 1/2”. the drawer size is 33”x22”x10”. Normally I would just go with 3/4” but after calculating the weight it looks like the drawer will weigh 28LBS out of 1/2” and 42lbs out of 3/4”. This drawer is going to be used in the base cabinet of a kitchen filled with relatively heavy pots and pans. Anyone have any idea if the 1/2” willwork? Should I reinforce the box? The span seems like the weak point. Any ideas or experience with making such a drawer box would be appreciated.


21 replies so far

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Loren

10784 posts in 4560 days


#1 posted 10-25-2020 05:37 PM

1/2” will work. Do what you can to reinforce the bottom and glue it in. I use 3/8” (approx) reinforcement blocks toenailed in with brad nails. I sometimes haven’t glued bottoms in and normally it’s not a problem. Undermount slides add support too. The heavy pans can push the back to bulge out and if the bottom is not glued in a groove it can pop out in the middle.

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Rich

6142 posts in 1502 days


#2 posted 10-26-2020 04:29 AM

The weight of the ply won’t be a factor if adequate drawer slides are used. The 1/2” ply will work fine though, assuming you have sturdy joints. I’m not sure what part you are asking about reinforcing, but it’s not necessary—again, assuming the drawer box joints are strong.

Another place that can be overdone is the drawer bottom. I’ve seen drawers of a similar dimension to the one you’re planning that used 1/8” ply for the bottom, and they are holding up just fine, even loaded with heavy pots and pans. When the drawer bottom is captive on all four sides, it’s incredibly strong. It won’t sag like it would if it were a shelf, supported only on the ends. Nevertheless, I never have, nor ever would, built a drawer with that thickness on the bottom. What I’m leading up to is that it’s often assumed that you need a thick piece to support the contents of the drawer when it will be holding heavy objects. There’s no harm in using a 1/2” ply for the bottom, but 1/4” will be adequate for any load that 100lb drawer slides will support.

That’s part of the balance of design. Don’t build a drawer box to support more than your slides are rated for. Again, it’s no big deal, but why do it?

I use undermount slides exclusively for my cabinet construction. It’s a matter of aesthetics though, not strength. Undermount slides will do nothing to add support for the bottom of the drawer since it’s already being supported by being captive in the groove in the drawer sides.

Getting back to the joints, those are the most likely points of failure. If you try to construct them with pocket screws (which I see so many Instagram and Youtube hacks do), it’s going to fall apart eventually. Stick with half-blind dovetails or, at a minimum a drawer lock joint. That’s what will give it lasting strength.

I never glue in my drawer bottoms. It serves no purpose. The back will never bow enough to let the drawer bottom pop out. Think about it. To have that happen, the rear joints would have to fail, because bowing the back out will also pull in the sides, which is prevented by the drawer bottom. Sure, it’s plywood, and movement is not an issue, but why bother?

Think about the physics of the load. If the contents are not fluid, then the load will all be vertical. I don’t care how many pots and pans, or cans of vegetables you load in there, there will never be significant pressure on the walls of the drawer to cause failure. Yes, if you fill it with 100 lbs of lead shot, then the walls will all be strained, but again, if it’s properly constructed, it will withstand even that load.

To sum up, strong joints are the essential element to construct a drawer box that will not fail over time.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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AlaskaGuy

6204 posts in 3222 days


#3 posted 10-26-2020 05:40 AM

I have always been a fan of big drawers have built quite a few over the years. As stated above 1/2 BB ply will be fine.

The photos below are of 3’ and 4’ 10” deep drawer made through out with 1/2 BB Ply. To my eye 3/4 is too bulky looking even for big drawers. I use lock rabbet joint.

I apologize for photo quality the lighting is bad and so is the guy behind the camera.

For shallower drawers or drawer with light load 1/4 BB ply is good. It’s amazing how strong BB ply is. I in this photo this is a 44×20 draw box supporting 120 lbs with less that 3/16 deflection in the center of the drawer.

-- Alaskan's for Global warming!

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Fred Hargis

6557 posts in 3406 days


#4 posted 10-26-2020 01:17 PM

I disagree with Rich about gluing in the drawer bottoms. IMO it makes a much stronger drawer…and I find that to be true of frame and panel drawers if the panel is plywood.

-- Our village hasn't lost it's idiot, he was elected to congress.

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Rich

6142 posts in 1502 days


#5 posted 10-26-2020 02:36 PM


I disagree with Rich about gluing in the drawer bottoms. IMO it makes a much stronger drawer…and I find that to be true of frame and panel drawers if the panel is plywood.

- Fred Hargis

I don’t want to turn this into a debate about something as insignificant as gluing in drawer bottoms, but I stand by my post. As I stated earlier, do it if you want, but it isn’t necessary. I respect Fred, and he is entitled to his opinion, but my comments are based on experience, not opinion.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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sansoo22

1282 posts in 567 days


#6 posted 10-26-2020 02:56 PM

It may be due to my inexperience but I like the lock rabbet joint for drawers. It’s a joint I can setup fairly easily and bang out a handful of drawers in a short amount of time. For large drawers I always use 1/2” ply for the bottoms even though its overkill. Like Rich said the failure point is either joints or overloaded slides. The thicker drawer bottom just makes me feel better. If I was doing production work that opinion might change since time is money and switching setups takes time.

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Fred Hargis

6557 posts in 3406 days


#7 posted 10-26-2020 03:16 PM

I disagree with Rich about gluing in the drawer bottoms. IMO it makes a much stronger drawer…and I find that to be true of frame and panel drawers if the panel is plywood.

- Fred Hargis

I don t want to turn this into a debate about something as insignificant as gluing in drawer bottoms, but I stand by my post. As I stated earlier, do it if you want, but it isn t necessary. I respect Fred, and he is entitled to his opinion, but my comments are based on experience, not opinion.

- Rich

As are mine. My opinion is formed from my experience as I’m sure yours are as well.

-- Our village hasn't lost it's idiot, he was elected to congress.

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jnswhit

2 posts in 32 days


#8 posted 10-30-2020 06:56 PM

Thanks for the input, I was thinking 1/2 BB and now I need to figure out the joints. Thanks everyone

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Loren

10784 posts in 4560 days


#9 posted 10-30-2020 09:42 PM

What I said was true. I have experienced it personally in a kitchen I built. I won’t explain further other than to recommend gluing in the bottom if going with 1/2” stock to avoid the issue on such a wide drawer to be loaded so heavily with pots and pans.

edit: There’s always somebody here looking for a tape measuring contest I guess. I don’t play those games. I reckon tensions are up with politics and disease issues though so no biggie. I recognize the patterns in this kind of snippy behavior from previous experience on this site. I guess I just have to tolerate it and swallow my clarifications unless I want somebody putting down my skills and boasting about his or her education at me.

View Rich's profile (online now)

Rich

6142 posts in 1502 days


#10 posted 10-30-2020 10:13 PM


What I said was true. I have experienced it personally in a kitchen I built. I won t explain further other than to recommend gluing in the bottom if going with 1/2” stock to avoid the issue on such a wide drawer to be loaded so heavily with pots and pans.

- Loren

If a drawer failed due to the sides or back bowing out from the load, then as I explained in my post #2 above, it was a poorly constructed drawer. In that case, you probably should glue in the bottom just to play it safe.

To repeat: Do you have to glue in the bottom? No. Will it add strength to a properly constructed drawer? No. Is it OK to do it if it gives you a sense of security? Absolutely. No harm will come from doing it.

As someone with an engineering degree and decades of experience building drawers, I can speak with confidence. Some of the drawers I built for my shop are probably carrying loads that exceed even the rating of the drawer slides, and none have failed.

But, if it makes you feel good, then by all means glue away.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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CWWoodworking

1131 posts in 1091 days


#11 posted 10-30-2020 10:14 PM

I like 5/8”, pocket hole together. If your making heirloom stuff, use dovetails.

One thing that hasn’t been mentioned is drawer slides. If these are in a kitchen, Quality of slide is very important.

Don’t use box store slides.

Blum tandems is what I use for expensive stuff. Blum standard and durislide ball bearing for Something cheaper.

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AlaskaGuy

6204 posts in 3222 days


#12 posted 10-31-2020 12:54 AM

Made quite a few 1/2’’ BB ply drawere with this joint. They seem to hold up well.

-- Alaskan's for Global warming!

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therealSteveN

6628 posts in 1487 days


#13 posted 10-31-2020 05:14 AM

AK, unless it’s for what CW referred to as heirloom stuff I use a DT too, but 90+% of the cabinets I have made are done with the lock rabbet joint like you are showing. 1/2” plywood, with a 1/4” bottom, and glued in. That joint is easy to set up, and not overly fussy to get to the exact set up. Flip on a false front, unless they are just plain old shop cabinets, and they are ready to set in.

In the past I would have agreed with CW about Blum drawer slides, today, too many makers put out a very nice product without heavy cost. I pick slides based on intended use, and especially weight, so some 100 pound minimum slides here, and ball bearing, w self closing. It’s not right to make the cook chase drawers home down low.

-- Think safe, be safe

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paulLumberJock

28 posts in 111 days


#14 posted 10-31-2020 05:23 AM

I had some large kitchen drawers I made for my own kitchen.. The were about 48” wide and about 22” deep.
I felt better about using 3/4 sides and 1/2 bottoms. Was it necessary? Probably not, but it did not add much cost.
I used K-V drawer slides rated at 200 lbs for those drawers. I am glad I did. (The smaller drawers have K-V 100 lb slides, glad I upgraded the big heavy ones).

View Rich's profile (online now)

Rich

6142 posts in 1502 days


#15 posted 10-31-2020 05:54 AM

Dovetails all the way. Heirloom or not. I have a Leigh jig I bought maybe 20 years ago that I use for stuff like this, but for my plywood drawer boxes, I use a plain old Porter Cable 4210. The only factor in cutting the joints with it is the bit depth—regardless of the thickness of the sides. I have a dedicated router with the bit set up at the ready, so I can just cut away without even doing test boards. (Quick hint, if you cut the drawer sides a bit long, then even if you screw up the joint, you have spare material to fix it before cutting to final length).

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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