dovetail drawer assembly issue

Re: dovetail drawer assembly issue

wilbur

>I haven't tried this, but how about band clamps along with some right angle guides to help maintain the squareness of your drawer? That would seem to deliver even pressure across the length and width of your drawer.

Couple things

Ellis Walentine

>Dovetailed drawers present a unique clamping situation because either the pins or the tails stick out a little bit, so it is usually just about impossible to simply use glue blocks or clamps (even K-body-type clamps). I have used several methods that you might like to try for yourself. One way is to use corner blocks (glue pads/blocks) cut from Homasote, which caves in under pressure and molds itself to the ins and outs of the pins and tails. Of course you have to sand/scrape/plane the corners afterwards to remove the dried glue and Homasote. Paste wax on the blocks helps a lot.

Another method is to make up glue blocks that have dados across them so that the high pins or tails won't interfere with the clamping pressure. This works well, too.

A variation on the first suggestion is to make up rounded corner blocks out of 8/4 maple or other close-grained wood, the height of the drawer, with the grain going across the block, not along it. Rip a v-groove in one face and line the V with strips of waxed homasote or leather or cork. Stand one block at each corner of the drawer and tighten the whole thing with a single 2" band clamp. The rounded exteriors of the blocks (preferably also waxed) allow the band to slip around as it tightens, instead of catching and pulling the block around the corner with the clamp.

Ellis

Re: dovetail drawer assembly issue

Denis Ch�nard, Orl�ans, Ont.

>If your joints are tight, then you can get away without clamps, once driven together they should not move until the glue cures.

For added insurance, you could do like Chris Becksvoort and use pine cauls. By applying clamping pressure the pine will give and shape itself to the layout of your dovetails. The cauls will glue themselves to the drawer, but not very strongly, you can rap the cauls loose with a hammer once the drawer is glued.

DC

band clamps

bill tindal, E.TN

>my experience with band clamps is that they are a good way to hold something together but an ineffective way to pull something together. I am quite sure they would not supply enough force to seat dove-tails into the pins. It takes a good snug with the bar clamp to seat the tails onto the pins.

Re: dovetail drawer assembly issue

Wiley Horne

>Clamping is yet another reason why Ian Kirby's advice to make the sides ever so slightly proud is a good idea (the other one is that you're sure to preserve your reference, which is the width pin to pin).

Any more, I have found that if I use hide glue, I don't need to do the side to side clamping--just hammer it together and the tack is fast enough I can just clamp front to back briefly, and then no clamps other than to make sure it's setting up square. Plus the hide glue tends to pull everything together, especially since the wetting tends to swell all the mating surfaces just a bit.

Wiley

Re: dovetail drawer assembly issue

David Charlesworth

>Bill,

This issue demonstrates why drawer and box dovetails need to be tight enough to not need clamping at all.

Fast grab water based glues like Titebond are helpful here as the water swells things up and tightens the joint relative to its dry state.

I also advocate the ends of the pins being just under the surface of the drawer sides (like Kirby) as this makes knocking the joints together with a big hammer, on the bench, much, much easier.

Clamping in two directions at once is very difficult. It can sometimes be achieved (on a shallow job) by one set of sash clamps underneath and one set hanging down from above. The whole job being raised sufficiently off the bench on a pair of wooden bearers, and with the use of custom made hardwood pressure blocks.

David

agree, with minor difference

Andrew F in Australia

>Hi Bill,

I do the same thing as David, but I use lightweight (Record) bar clamps or the Irwin Kwik Grip (lightweight) clamps if I'd need to do this, as the weight doesn't distort things.

In any case, after about half an hour under the clamps, remove the drawer and put it in the opening to finish drying, with the front proud of the top drawer rail and drawer blade by a uniform amount, leaving a gap parallel to the top rail -> allows the drawer to fit the opening properly and adjust to a slightly out of square drawer opening easier, as well as a small amount of wind in the drawer runners/kickers.

Cheers,

Andrew

Re: dovetail drawer assembly issue

Miles

>David Charlesworth... suggesting a 'big hammer'- whatever next? Is this not the man who routinely splits the hairs on a flea when marking out, & if a cigarette paper can slip into a joint finds it 'a little sloppy' :-)

I'll have to try this bit of advice just like all the others... unless David has a special line in precision hammers that we don't!

Didn't read too well, try again

Andrew F in Australia

>What I'm trying to say is that when you put the drawer into the opening to cure, leave the drawer front proud of the carcase (especially as you don't need glue squeezeout to glue your drawer front to the drawer divider/leg.)

Leave it proud by the same amount both sides so that the gap between the upper rail and the inside upper edge of the drawer front is a uniform gap.

Ensures that the drawer front is now fitted parallel to the opening.

Cheers,

Andrew

(who's being constantly interrupted by kids and telephones at the moment. Apologies.)

dovetail drawer assembly issue summary

bill tindal, E.TN

>1. Several responses dealt with the issue of pins sticking proud of the tails or visa versa. This aspect of clamping is not the problem for me. I have fitted the fronts to the opening and the tails are slightly proud which solves lots of problems but precludes drying the drawer in the opening (for which I have come up with what I think is a clever fix and I will post later).

2. The nature of yellow glue is such that it develops high tack and impact strength quickly upon assembly. Hence, pounding a joint home(that last 1/64"), or any other joint adjustment with yellow glue is best achieved by steady force to shear the glue rather than pulsed forces like from blows of a hammer.

3. I like to assemble a drawer on a planer surface. I see the utility of putting the clamps under and over drawer as this would leave room on the sides for the cross clamps. But I will need to come up with spacers that would ensure the drawer remained in a plane. Fortunately these drawers are wanting to assemble flat, no doubt as a result of an improved marking technique for the pins that I will post later.

4. What seems to be working satisfactorily was suggested by some..... Apply glue, hammer together, snug tails onto pins with clamp pressure to ensure they are seated, remove these clamps because as several suggested these joints are now secure, and finally apply clamp pressure with cauls across the length of the drawer (if needed) for final drying. I hadn't appreciated that I could remove the drawer width clamps once I ensured the drawer sides were pulled up tight on the pins.

5. Thanks to all for the suggestions.

Re: dovetail drawer assembly issue

David Charlesworth

>Miles, Bill,

The big hammer is a great tool for knocking together joints!

(Every dog has its day). You can hear when the shoulder lines close due to the change of tone, and you won't get that infuriating binding or hanging up, just before shoulder line closure.

I bought one of the last Suminagashi hammers from that charming Japanese craftsman who requested that if you used his exrtra fine hammer you should ensure that you "did a good job"! I had been lusting after one of these for over 20 years......

Of course one uses a suitable piece of flat scrap so that the work is not marked and the force is distributed.

If you need a clamp to close the shoulder lines removal as soon as possible will prevent the thin components from being locked into a bow or an S shaped curve. This should be possible while the glue is still 'plastic' but holding well.

I don't quite understand Andrews cunning method, as to me this implies that the drawer is already slightly undersized, and there is not much allowance for clean up and final fitting.

I remember a previous thread. Good sideways fitting only has a few thou" clearance, in the UK tradition.

Drawers can be a fascinating aspect of craftsmanship.

best wishes,

David

Re: dovetail drawer assembly issue summary

David Charlesworth

>Bill,

The pair of bearers I use to lift the drawer are parallel and checked with winding sticks to ensure a true surface for the work to sit on.

David

Re: dovetail drawer assembly issue

Pam Niedermayer - Austin, TX

>What are the shape and weight of your Suminagashi hammer?

As I understood it, Andrew assembles the drawer and immediately inserts it into its cabinet slot. Kind of a cool idea, as long as you can avoid gluing it to the cabinet interior. The proud bit is to make sure this trick doesn't deform the drawer asymmetrically.

Pam

Concur

Bill Houghton, Sebastopol, CA

>Just today, I moved the old, rectangular dining room table (replaced by my grandmother's round one) into another room, which involved tipping it on its side, causing the failed dowel joint in one leg to open up. I've got a big canvas band clamp (like the link below, but with canvas rather than nylon), and it was unable to close up the joint. A truck mechanic's plastic mallet, probably rather heavier than David Charlesworth's big hammer, closed it up Right Now, so the band clamp could keep it together, and I could safely set it up on its feet again.

Here's "the link below" *LINK*

Bill Houghton, Sebastopol, CA

>Ooops.


Wetzler clamps band clamp

Re: dovetail drawer assembly issue

Andrew F in Australia

>Hi David,

I've only got a couple of minutes, so please excuse the rushed reply

Drawer fronts are planed to be a tight fit in the opening originally. To get the drawer front into the opening, a very slight splay is planed onto the inner edge of the drawer front, except at the underside of the drawer front, where the splay is put onto the show corner of the drawer during final fitting.

Drawer backs are planed to be a match to the angles on the drawer front, but a smidgeon skinnier in length, maybe 1/2mm, so that the drawer will not bind on removal.

Dovetails are cut to fit exactly to depth, so that drawer closes easily.

When done, dry-fit and install drawer guides (talking solid timber construction here.)

Take drawer apart, glue, clean up all surplus glue, light clamp for half an hour, until glue skins over.

Insert drawer into opening as described previously, leave front proud with about a consistent 1/8" gap between the inner, upper corner of the drawer front and the upper drawer rail (ie: so front dovetails don't glue themselves in the carcase.) This is where you change the shape of the drawer slightly to match the configuration of the runners, kickers, guides, blades, etc...

Let the glue dry properly.

Then fit the drawer properly - the cigarette paper's width of a gap on the top and sides, and a slight splay planed onto the corner between the underside edge of the drawer front and the show face to give the appearance of a cigarette paper's gap on the underside of the drawer face as well.

Trust that this makes sense. By fitting the drawer to the opening while the glue's still plastic, it takes a bit of time off the fitting stage. The drawer bottom will hold it in place when you put this in at the later date.

ps: This info also relates to traditional drawers where the underside edge of the drawer back is located 19mm higher than the underside of the drawer side, with the slip being used to hold the drawer bottom in place.

Trust that this makes a bit more sense but I must apologise as it's rip-tear-bust here, and definitely not quiet enough to allow a meaningful proofread to occur.

Cheers,

Andrew