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Forum topic by Hillsboro posted 07-15-2010 03:16 AM 1257 views 0 times favorited 10 replies Add to Favorites Watch
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Hillsboro

44 posts in 2360 days


07-15-2010 03:16 AM

I have just cut half blind dovetails for to make two drawers. Unfortunately when I put the fronts and sides together the drawer bottom edges do not lie flat, but rock on the diagonal. I have never had this problem before.

Any thoughts on how to correct this would be appreciated (please see photo below). I hope I do not have to rebuild them.

This is not an issue where simply a bit of planing will fix the problem. The diagonal corner lies flat on the work bench and the other two corners do as well thus making a bit of a see-saw effect. The drawer appears twisted almost as though the tails and pins were cut improperly. But how can that be given they were cut on a jig? Clearly I am very very confused. Also, if i remove one side everything squares up. ?

Thanks,

Phil Stevens


10 replies so far

View NewPickeringWdWrkr's profile

NewPickeringWdWrkr

338 posts in 2476 days


#1 posted 07-15-2010 04:37 AM

I had that happen on my first drawer (I haven’t built another since.

What I did to straighten it out was to hand plane the low spot – in your case, towards the rear right corner – on the bottom edge only. But I didn’t have that much skew. It would take a lot of material removal to get that one flat.

Sorry I’m not sure what else to suggest here, but will put a watch on to see what else may get suggested

-- Mike - Antero's Urban Wood Designs http://anterosurbanwooddesigns.com

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jusfine

2405 posts in 2389 days


#2 posted 07-15-2010 04:53 AM

Seems to me the only way that could happen was if your material was not cut at exactly 90 degrees.

I have built many drawers with my PC Omnijig, and never had that problem.

Are they both the same? Is the drawer box square, corner to corner?

I guess I would clamp one corner down on a flat surface, then try to draw the other corner down with a clamp, tapping the joints to see if it will flex a bit and lie straighter, but that is quite a bit to correct.

-- Randy "You are judged as much by the questions you ask as the answers you give..."

View TomHintz's profile

TomHintz

207 posts in 2861 days


#3 posted 07-15-2010 08:59 AM

It does look like you could pane your way out of this. (Don’t tell anyone I advocated using hand tools….)
I have seen this problem a bunch over the years, including in my shop when I first got my Leigh jig. Jusfine hit right on the head, in every case we looked at either the wood itself was not cut exactly 90-degrees or the wood used to setup the jig originally was not a perfect 90-degrees. Check both and I think you will find your problem as the joint itself looks fine.
Good luck!

-- Tom Hintz, www.newwoodworker.com

View TopamaxSurvivor's profile

TopamaxSurvivor

17669 posts in 3139 days


#4 posted 07-15-2010 09:29 AM

Seems like you could pare the dovetails a bit on 2 opposite corners to loosen it a bit, make it lay flat, mix up a little wood filler paste with some white glue and sawdust.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View mstenner's profile

mstenner

57 posts in 2617 days


#5 posted 07-15-2010 12:40 PM

Do the boards have a bit of twist? That would do it too. The trouble with that scenario is that discovering it after you cut the dovetails, removing the twist won’t help.

-- -Michael

View tbone's profile

tbone

273 posts in 3147 days


#6 posted 07-15-2010 05:03 PM

I, too, was thinking you might have a twist in at least one board. Disassemble the drawer and check to see if all four boards lay perfectly flat and are perfectly square.

It looks like you MAY be able to reverse those side panels as a test. Put the left one on the right side—and vice versa—and see if the problem reverses itself. Good luck.

-- Kinky Friedman: "The first thing I'll do if I'm elected is demand a recount."

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mstenner

57 posts in 2617 days


#7 posted 07-15-2010 05:08 PM

tbone, I agree. Unfortunately, when I discovered this problem I had cut the sides from the same board and so the twist was the same, and in the same direction. The best test is (as you say) just checking the boards on a flat surface.

-- -Michael

View PurpLev's profile

PurpLev

8523 posts in 3111 days


#8 posted 07-15-2010 05:20 PM

if the ends are not cut 90 it’ll cause this – but in this case, it actually looks like the boards (front) has a slight twist which will also cause this to happen. regardless, the dovetails joint has nothing to do with the seesaw effect, but it’s the boards that cause that.

As already suggested – you could hand plane the high spots to flatten the bottom/top – but you’ll still have twisted boards in the drawer. as long as it’s not visually displeasing you should be good to go but it’s hard to assess. unsquare milling makes everything so much harder later on.

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View Hillsboro's profile

Hillsboro

44 posts in 2360 days


#9 posted 07-16-2010 03:26 AM

Gentlemen:

Thank you all for your thoughts and suggestions. Topamaxsurvivor gave me the solution. Here is what I found:

1. The drawer fronts are cherry and have very, very slight cup in them. Clearly an error on my part when I purchased the wood (not planed flat). This cause the pins and tails to not line up top to bottom.

2. I implemented Topamaxsurvivor’s suggestion and very carefully trimmed a bit off of the edge of the pins at one joint. While this left the joint loose and showing gaps, when dry fitted the drawer now lays flat. I will fill the gaps with some thin scrap, and glue.

Once the drawer bottoms are added, and the drawers finished I rather doubt anyone except me will see the repair.

Thanks again to all.

Phil Stevens

View TopamaxSurvivor's profile

TopamaxSurvivor

17669 posts in 3139 days


#10 posted 07-16-2010 04:59 AM

Glad I was able to help out :-)) I have never done that and am not much of a woodworker by LJ standards, but I’m learning!

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

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