Dovetail beautification

[Dan Sheehan]

Any suggetsions for improving the appearance of mediocre dovetails? I'm building a jewelry box in cherry and have just a couple of poor fits. But everything shows and it needs to look nice.

I used a small wedge to fill the worst gap and that worked really well. On the narrowest gaps I tried supposedly "stainable" Minwax wood filler and then tinted putty. Yeah, right. All that did was highlight the spaces and now it looks worse. I hadn't planned to stain it either.

I don't know if the box is salvageable. I know I can do better. I have more wood and will probably just try again. But I may have more problems too. What would you do in these cases?

Thanks in advance for your help.

[Derek Cohen]

You may be able to try this is the conditions are right: http://www.inthewoodshop.com/Furniture/PeeningDovetailsinWood.html

Regards from Perth

Derek

[Jim Koepke]

Sometimes the best way to hide a mistake is to show it off.

In this case, cut along the lines of the dovetails and insert contrasting shims to highlight the area.

Try to find or make veneer to match the width of the saw blade.

jtk

[Tom Vanzant]

Thanks Derek... you just saved me a drawer.

[Simon Frez-Albrecht]

If all hope is lost, in order to save scrapping the wood, you can just cut off the dovetails and start again. Unless the box has to be a really specific dimension, this way it will only shrink an inch or so in each dimension.

Sorry I don't have any better advice!

[Tony Shea]

Your best fix for small gaps in dovetails is filling them with a sawdust/glue combination. Sand out some of the cherry your box is made of and gather up the dust. Go out and buy yourself a bottle of Liquid Hide Glue (this is important) and mix some of the dust with a small amount of glue. You have to use the hide glue as most other glues will not take a stain or finish very well. Hide glue on the other hand is very friendly with finishes. Play around with the ratio;s of dust to glue, it's really not that important. Keep filling these gaps until it is level with the surface, it may take a couple attempts to get it level. There will be a tiny tell tale sign that you've filled the gap but is really unnoticeable to the untrained eye or whoever is receiving the box. Im surprised no one has suggested you try this method as it works very well.

[Greg Wease]

Thin shims and Derek's peening technique would be my first choice. Sawdust and glue is next down the list of fixes. Commercial putty is a no-go for many reasons. Even if you match the putty color perfectly today, the cherry will darken considerably over time and the putty will not. Your dovetails will improve with patience and practice.

[Joe A Faulkner]

Well smash my thumb. That is the neatest little trick. I'm definitely filing this one away.

[Salem Ganzhorn]

I do something similar but find bandsaw dust good for mixing with glue.
Salem

[Carl Beckett]

Some time back I had some dovetails that I didnt like the way they fit, and I set a wet rag across them. They soaked up the water and swelled shut - and stayed shut once dry.

Has anyone tried something like this? (its been years ago when I did this, and my memory isnt so great these days (young children is my excuse.... and age)).

I believe the wood was Alder - fairly soft.

Hmm.... maybe a little test project for the afternoon (swelling with water might not be all that much different than peening/mashing with a hammer - allows the cells to burst and take up more physical space)

[Jessica Pierce-LaRose]

I've had luck in other joints using the method Jim describes, (kerfing the joint and inserting veneer) either using a similar coloured veneer that hid well, or a black veneer that made a neat accent joint. Tage Frid describes this in one of his books. I've had good luck using little hobby razor saws, or gauged saws sold for roughing in nut slots when making guitars. As I believe Tage describes, I take the veneer and press it in a vice or a clamp to compress it a bit, and when put in the slot with glue, it lightly expands and helps fill the cut. Depending on the size of the gap, this latter part can work without kerfing first.

I've had some success with the peening method, but for the life of me, I can't get it to work with some harder woods.

Have you flushed the joint? I've had some tails that looked like they were going to be awful, but after I planed the slightly protruding parts down, everything looked great. I'm still not sure what's happening there, but I've had that a few times now.

[David Keller NC]

Dan - Since your box is already glued together, I'm assuming taking it back apart and fixing the dovetails is a non-starter because it would be easier to just start over with another set of pieces. However, if you really want to salvage this effort, some advice based on making the same exact mistake (trying to use wood putty to fill a gap).

As everyone notes, wood putty is pretty much useless unless you're filling a gap in a baseboard that will be painted over. Even the sawdust & hide glue trick won't work very well over the long haul when used on cherry because the sawdust presents different grain orientations (side, end, face) that will make the repair obvious to the careful observer.

I have 3 suggestions:

1) Remove the wood putty and take the box apart. If you've used PVA glue, then you can loosen the joints and remove the wood putty at the same time by using a vinegar soaked cloth. Saturate an absorbant cloth with pure household vinegar and place it over the joint, then cover that with saran wrap (use blue painter's tape to hold it down). The vinegar will break down the bonds of the PVA glue and most wood puttys. It will take several hours, during which time you will need to keep the joint wet (the reason for the saran wrap). You can minimize the fussing by placing the whole assembly in a water-tight plastic box which will keep the humidity high. Patience is required here - it's a lot harder to remove PVA than to reverse a hide-glued joint.

2) Paint the box. While painting cherry is perhaps not ideal, painted boxes can look very nice, particularly when decorated with stencils or hand-painted designs. One antique painted box with somewhat primitive compass designs sold for over $100.000 recently.

3) Veneer the box. This is the route I've taken with several mess-ups that were beyond salvaging. It makes for an attractive result, and many, many antique boxes, particularly tea caddies, were veneered.

I would not recommend attempting kerf the wood putty out of the joint. While that will work if your original saw cuts were exactly square, if there is any deviation it will be very difficult to get all of the wood putty out of the joint. It's also difficult to keep the saw on the wood putty without wandering, because the putty is quite a bit harder than the surrounding wood.

[Jim Koepke]

Have you flushed the joint? I've had some tails that looked like they were going to be awful, but after I planed the slightly protruding parts down, everything looked great. I'm still not sure what's happening there, but I've had that a few times now.

I have noticed an effect like this at times. It looks like the wood is "blowing out" from the planing, but since there is a "backer board" (in the adjacent pin or tail) the blow out is limited and looks like it is filling the void.

When this is used on a really bad miss-fitting dovetail, it will be clear what is happening.

jtk

[Andrew Pitonyak]

I have been thinking about this and I am improving, but I have a long way to go. I have assembled a few tips that I plan on testing, perhaps they will help you.


Learn to cut to the line.This is requirement number one. Do you leave the pencil line? Remove the pencil line? Do you cut on the waste side of the line? Mark both sides of the board and check to see how well you did.
Learn to cut square. You can make the cut, place the saw back into the cut and check to see if the cut is square (for cuts that should be square) and vertical (for cuts that should be vertical). This provides feedback on how well you cut.
While removing waste, do not cut past the line on the bottom.

And now for the big problem. Do you trim the tails or the pins? I am told that it is easier to trim pins (something about following the grain when you trim with the chisel). OK, so I will assume pins. If I do at least an OK job in cutting, this is where I usually really mess up. I trim off too much and things look horrible. I got a Tip from Chris Schwarz at WIA. Do not trim the entire pin, instead, trim only the inner portion of the tail staying away from the edges. Need to try that one.

[Chris Griggs]

Some time back I had some dovetails that I didnt like the way they fit, and I set a wet rag across them. They soaked up the water and swelled shut - and stayed shut once dry.

Has anyone tried something like this? (its been years ago when I did this, and my memory isnt so great these days (young children is my excuse.... and age)).

I believe the wood was Alder - fairly soft.

Hmm.... maybe a little test project for the afternoon (swelling with water might not be all that much different than peening/mashing with a hammer - allows the cells to burst and take up more physical space)

I do this all the time. Actually, I combine peening with swelling. It's worked for me in cherry, walnut, soft maple, poplar, and pine. I'll peen a little to make the gap smaller, and than get a wet rag, heat it up in the micro wave, and swell the wood as if I am swelling out a dent. I first did this unintentionally, when I was simply trying to swell out some dents from some overzealous peening. There are practical limits to how big of a gap you can fill with this, and obviously you want to keep the moisture localized, but for most small gaps it works quite well.

[Tom Vanzant]

1+ on Chris' tip. It's the same thing as undercutting a tenon shoulder, the visible juncture is all that actually touches....just don't relieve the corner of the tail that shows.