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How can I fix/tune this dovetail joint?

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Forum topic by Ryan Sandler posted 08-09-2019 12:31 AM 445 views 0 times favorited 13 replies Add to Favorites Watch
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Ryan Sandler

29 posts in 933 days


08-09-2019 12:31 AM

Topic tags/keywords: question maple chisel joining dovetail

I’m working on a pair of dovetailed drawers, with the fronts attached using half-blind dovetails. I’m a novice when it comes to hand-cut dovetails, and in particular I’ve never done half-blinds on a real project. My fumbling notwithstanding, I’m really close to having a nice fit on the first front corner I’ve tried. However, it’s not quite aligned right, and I can’t work out in my head where to trim to fix it.

Rather than trial-and-error it and ruin the parts that are fitting well, I thought I’d poll the forum and see if anyone can help me work out where I ought to trim to get these two boards mated correctly.

Here’s the joint. Not sure if it’s clear with the picture resolution, but the fit is pretty tight, but the boards are out of perpendicular along their widths, such that there’s a gap between the pin board and the shoulder of the tail board on the right side of the picture, but not the left. The face of the tails is flush with the endgrain of the pin board. Where is the likely culprit for the mis-fit?


13 replies so far

View AlaskaGuy's profile

AlaskaGuy

5338 posts in 2788 days


#1 posted 08-09-2019 12:35 AM

https://youtu.be/nEUn28pYVB0

-- Alaskan's for Global warming!

View Aj2's profile

Aj2

2423 posts in 2277 days


#2 posted 08-09-2019 01:01 AM

Before you start adding wedges . Check that the sockets don’t have more wood to remove.
It happens to me a lot. It’s not all that easy to cut the sockets down straight they usually slope inward .This will push the tail board out.
Good Luck

-- Aj

View therealSteveN's profile

therealSteveN

3606 posts in 1053 days


#3 posted 08-09-2019 01:21 AM

While cutting them always keep in mind the “compressibility of the wood involved” Softwoods always leave some line +, softer hardwoods just leave the line, and really hard stuff follow the line. Then when you fit them, you will end with tighter joints than if you just willy nilly cut the line.

Aj makes a good point, the “hanging Chad” will keep you from seating, and because they aren’t closed, they look gappy.

The video guy makes a point that your PVA glue, and wood dust may not age well. Don’t use PVA glue, unless you are using the special snot for outdoor use. Instead use the much more natural Hide Glue, and dust and it will mellow like the wood does. Especially on darker woods.

-- Think safe, be safe

View Rich's profile

Rich

4807 posts in 1068 days


#4 posted 08-09-2019 01:39 AM

Learn proper fill techniques. Until then, the Timbermate color labeled Maple/Beach/Pine will blend almost invisibly with the color of your drawer side. Just push it in with a putty knife, let it dry a couple of hours and then sand.

Edit: Obviously, continue to practice your dovetails so you don’t need to repair them. You really came close, and I have no doubt you’ll nail them after more tries. Still, knowing how to repair flaws—in your work or in the wood—is a very valuable skill to master. Stuff happens after all.

-- There's no such thing as a careless electrician

View Ryan Sandler's profile

Ryan Sandler

29 posts in 933 days


#5 posted 08-09-2019 01:58 AM

Lots of good advice here on filling gaps, but that wasn’t quite what I was asking for. The joint doesn’t quite fit together yet, and a little wood definitely needs to be shaved somewhere. Something is preventing shoulder of the right side of the tail board (but not the left side) from being flush with the pin board. I’m 90% sure the shoulders are cut straight, so there must be something bumping. Was hoping someone might have a good idea of where the problem is so I don’t cut something that doesn’t need cutting (creating a gap that I now have some great suggestions of how to fill :) ).

I’ll take another look for “hanging chads”, though I thought I got them all. The top edge of the sockets,, in the picture, as AJ mentioned, may be the culprit. I checked for straightness on the sides of the pins (and trimmed a bunch, because I didn’t cut very straight), but not there.

View MPython's profile

MPython

162 posts in 291 days


#6 posted 08-09-2019 03:17 AM

My guess is that there is more wood to be removed from your sockets. That happened to me recently. I kept paring the tails to get them to fit, but the tails weren’t the problem. The ends of the sockets weren’t quite square and wouldn’t allow the tails to seat properly. I finally diagnosed the problem with a set of feeder gauges. The errant sockets wouldn’t allow the thinnest feeler gauge to slip all the way to the bottom of the socket. a few pairing cuts solved the problem and the tails seated easily. Unfortunately, I had already paired too much off the tails in my misdirected effort to get them to seat. Now I’ve got some gappy dovetails. I should have tried the feeler gauge first, before I started carving up my tails. Lesson learned.

View Markmh1's profile

Markmh1

109 posts in 922 days


#7 posted 08-09-2019 01:45 PM

I believe you have a squareness issue.

I had untold grief with a Porter Cable jig. The jig was manufactured out of square and following directions
wouldn’t get me a good joint. Look at the problem with an eye toward square, parallel, and perpendicular
one piece to another. Check especially the supposed 90 degree angle of the top and side platen.

I found conventional cutting one way, then “sparking out” with climb cut back over would get a cleaner cut.
No little wood boogers left on the sides or corners.

Your work must also be prepared correctly. “Close enough” won’t get it correct.

Chucking large, properly prepared, pieces will help make alignment issues more evident. What you can’t see
in 4” becomes obvious in 8”.

It appears you are cutting one pass, so there should be no cutter issue.

Your combination square will be your new best friend.

Mark

View Derek Cohen's profile

Derek Cohen

465 posts in 4447 days


#8 posted 08-09-2019 03:00 PM



Before you start adding wedges . Check that the sockets don’t have more wood to remove.
It happens to me a lot. It’s not all that easy to cut the sockets down straight they usually slope inward .This will push the tail board out.
Good Luck

- Aj2

Correct.

If you look at the gaps, they indicate that there is an obstruction at the far end of the socket wall. A slight undercut will ensure this is removed.

Regards from Perth

Derek

-- Buildiing furniture, and reviewing and building tools at http://www.inthewoodshop.com

View Rich's profile

Rich

4807 posts in 1068 days


#9 posted 08-09-2019 03:26 PM


I had untold grief with a Porter Cable jig.

[...]

I found conventional cutting one way, then “sparking out” with climb cut back over would get a cleaner cut.
No little wood boogers left on the sides or corners.

- Markmh1

Sparking out? What the heck does that mean? Wood boogers? Good grief.

Besides, the OP is talking about hand cut dovetails, not a jig.

-- There's no such thing as a careless electrician

View controlfreak's profile

controlfreak

136 posts in 80 days


#10 posted 08-09-2019 03:56 PM

Sparking out? I haven’t ever seen wood sparks so I am guessing the jig and bit had an awkward meeting.

Hand cut dovetails are my next project/lesson after I finish my Moxon vise. I was looking at jigs but they seem so expensive and difficult to dial in. Hand cut to me looks beautiful and when I see them I am like “I want to master that” The biggest anxiety for me is getting the cut the line, leave the line thing resolved. Hopefully if I can get my jointer knives set right (all the dial gauge and holders in hand) and my new DW735 is good out of the box I will be ready for glue up this weekend.

View Aj2's profile

Aj2

2423 posts in 2277 days


#11 posted 08-09-2019 04:45 PM

I’ve also not heard of sparking out when dovetailing. So I googled it.

Looks awesome.:)

-- Aj

View pottz's profile

pottz

5956 posts in 1463 days


#12 posted 08-09-2019 05:37 PM



I’ve also not heard of sparking out when dovetailing. So I googled it.

Looks awesome.:)

- Aj2


i d say your gonna need a new jig and bit aj-lol.

-- sawdust the bigger the pile the bigger my smile-larry,so cal.

View therealSteveN's profile

therealSteveN

3606 posts in 1053 days


#13 posted 08-09-2019 09:42 PM

Probably a set of clean undies too.

-- Think safe, be safe

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