mdf or plywood drawer carcass

[footprintsinconc]

well, i am finally getting to start finishing my work bench. i have asked this question before, but i thought i'd get a fresh opinion on what i should use for the drawer carcass.

i have 5/8" mdf and 1/2" + 3/8" normal plywood. the drawers will be 13" wide x 24" long. they will ride on drawer slides. two of the drawers will be 3" tall and the other two will be 7" tall.

what is your suggestion/recommendation on the wood to be used and the jointery i should use.

thanks in advace.

[jackellis]

I'll tell you this having just made a drawer out of 1/2" plywood from a cabinet shop. Dovetail joints won't cut that cleanly unless you use high quality plywood. "Normal" plywood probably won't cut it.

One of the first projects I built with my BT was a small, simple cabinet with several drawers to hold all the tools I was accumulating. I used a modified lock joint cut with the table saw and those joints are still among the best I've ever made. Cut rabbets on the sides of the front and rear pieces and dadoes in the sides. You'll get all of the strength of a dovetail but it's likely to be a bit cleaner and simpler.

I personally dislike MDF because it makes way too much really fine dust and because it needs to be sealed pretty well to resist moisture. I've used MDF a few times but I prefer plywood and solid wood.

[cabinetman]

You didn't say how fancy you want to get. But, what will work just fine and being very simple to do is use the plywood, rabbet the sides, and make a groove at least 1/4" higher than the bottom edge on the sides and the back of the front. Cut the back to be the height from the top of the groove to the top of the drawer sides. This will facilitate assembly of the drawer without the bottom, which is good for easy finishing. Then, square the drawer, slide the bottom in from the back all the way to the front, and tack the bottom into the underside of the back of the drawer. This will make for a drawer with a removable bottom.

[footprintsinconc]

thanks, jackellis & cabinetman.

i like the suggestion of squaring the box and then sliding the drawer bottom in from the back.

thanks once again!

[JimD]

There is another reason that locating the bottom 1/4 inch or so up the sides is a good idea, especially with 1/4 plywood bottoms. It will sag a little but it has to sag 1/4 inch before it can contact the frame or drawer below.

I use 1/2 baltic birch plywood for drawers these days and I dovetail it together. I leave my HF jig set up for this plywood most of the time so it takes less time to cut dovetails than to make a different joint. I use dovetails on all four corners but if you were making a lot of drawers, it would probably be worthwhile to use a dado for the back. I locate the bottom up far enough to get it in the middle of a dovetail. I do not usually make the bottom removeable but it is a pretty good idea. I haven't broken any but it could happen.

Jim

[Crockett]

Just wondering if anyone else uses pocket holes to create their drawer boxes? It is fast, seems to be very strong and when you attach the drawer faces the holes can't be seen in the front and the the holes on the back can't be seen unless the drawer is taken out. I just metnion it because it seems a lot faster than dovetails, especially if they are hard to cut well in plywood. I wish I had the skill/patience for dovetails (even with a jig!).
Al

[gwyneth]

You didn't say how fancy you want to get. But, what will work just fine and being very simple to do is use the plywood, rabbet the sides, and make a groove at least 1/4" higher than the bottom edge on the sides and the back of the front. Cut the back to be the height from the top of the groove to the top of the drawer sides. This will facilitate assembly of the drawer without the bottom, which is good for easy finishing. Then, square the drawer, slide the bottom in from the back all the way to the front, and tack the bottom into the underside of the back of the drawer. This will make for a drawer with a removable bottom.

This sounds like a great method...by rabbet the sides do you mean cut the rabbets in the front piece to accomodate the sides? Or cut them in the sides to accomodate the front?

Also, what do you suggest for drawer bottoms? And if you finish it, before or after slipping it in?

This suggestion was incredibly timely, btw.

[cabinetman]

This sounds like a great method...by rabbet the sides do you mean cut the rabbets in the front piece to accomodate the sides? Or cut them in the sides to accomodate the front?

Also, what do you suggest for drawer bottoms? And if you finish it, before or after slipping it in?

This suggestion was incredibly timely, btw.

You rabbet the sides to accomodate the front and back. Leave the bottom out until you're done finishing. It's easier to spray or brush if the bottom is out. Then slide bottom in, square the drawer, and fasten to the underside of the back.

[footprintsinconc]

pocket holes, that sounds interesting. since i am doing only four drawers, i'm thinking that i will do two of them with dados and two with pocket holes and test it out.

cabinetman, you say that the carcass should be finished before you slide the bottom in and then square the drawer. arent you suppose to join the carcass so that it is square in the first place? i cant see the carcass squaring itself after the bottom is slid in. the joint isnt going to flex because you have glued and fastened it, isnt that correct?

thanks

[cabinetman]

pocket holes, that sounds interesting. since i am doing only four drawers, i'm thinking that i will do two of them with dados and two with pocket holes and test it out.

cabinetman, you say that the carcass should be finished before you slide the bottom in and then square the drawer. arent you suppose to join the carcass so that it is square in the first place? i cant see the carcass squaring itself after the bottom is slid in. the joint isnt going to flex because you have glued and fastened it, isnt that correct?
thanks

What we are talking about is the drawer. I don't refer to a drawer as a carcass. Cabinet cases to me are considered carcasses. A drawer assembles square as you stated will have some movement, even a little, that can be eliminated by having a good fitting bottom that squares the drawer. It's usually only tacked at the back edge. There has been times that once the drawer was together, I flipped it upside down, checked it for square, then run a small bead of yellow glue around the bottom where meets the sides. This was done on really large drawers where the sides were long enough to have some longitudinal flex.

[JimD]

I have a friend who makes custom cabinets for a living and uses pocket screws. He has a dovetail jig but has not learned to use it. I should spend a few hours with him sometime so he could achieve success with the dovetail. He is happy with the pocket screws. If you want to use solid wood for the drawer sides then pocket screws work pretty well. I have not had success with pocket screws into 1/2 inch plywood (I tried them once and the plywood wanted to split). Around here 3/4 pine is the "normal" drawer material and pocket screws work fine in 3/4 softwood.

Jim

[footprintsinconc]

build and finished!

well things didnt go as planned! i dont know about you guys, but i usually doing other than what i plan, it bothers me alot afterwards

i ended up cutting the pieces for pocket screws only and forgot to make the back pieces longer for dados and had drilled all the pockets aswell before i realized what i had done, so i just put everything togather and have also applied the finish. all they need are drawers slides and they are ready to be installed.

cabinetman, you are right: after joining the sides of the drawer, i needed to square a couple of the drawers, and all it took was to hold the front, then move the back one way or the other, really flexible - not ridgid as i though it would be.

i would love to try out dovetailing, but i'd have to get the jig first, but i have other tools that i want to buy first.

well i made them out 5/8"mdf and 1/4" mdf for the bottom so it is removable. i may add some support in the middle at the bottom on the two deeper drawers if needed with time. lets see how they last, time will tell.

here are some pictures.

edit: oh, writing the post, i just rambled on and forgot to thank everyone for their suggestions. so thank you!

[drumpriest]

They look good and functional to me! I do dovetails often, but depending upon the use of the drawers...they don't always need them. I think it's mostly that dovetail mystique out there. A friend of mine is doing cabinets as a hobby, and he rarely does dovetails, usually pocket screws, and after years of use in a kitchen (with slides) he's not seen any issues.

[footprintsinconc]

thanks keith!

these drawrs are for my workbench, so they will hold tools and stuff related to ww. i dont know exactly what is going to go in them yet. i had a difficult time trying to figure out the what the drawer sizes should be since i didnt know what i was going to put in there. i still have to organize, but with time, i will find out how they handle the use or abuse in the shop .

[BigguyZ]

I was looking at using 1/2" BB plywood for some drawers for a built-in. Some of the drawers may be quite wide (46" or so). But anyways, I'm wondering if MDF finished with shellac wouldn't be just as practical as using BB- even if it's not as visually appealing...