# Dovetails



## Anguspapa (May 4, 2013)

Right now I'm learning how to do dovetails and I'm doing something wrong.  i'm making a box for keepsake purposes and I'm doing through dovetails. The straight cut is not flush with the dovetail cut. You'll see in the picture I'm attaching. What a my doing wrong!? I own a porter cable dovetail jig. I have done everything the instructions say. I appreciate your help as always. Thank you.





















Eric


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## BZawat (Sep 21, 2012)

I'm not familiar with that specific jig, but if I had to guess I'd say that your bit height is off slightly when routing the pin board. From the pic you posted, it looks like the joint would flush out if your pin sockets were cut a little deeper.


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## Anguspapa (May 4, 2013)

BZawat said:


> I'm not familiar with that specific jig, but if I had to guess I'd say that your bit height is off slightly when routing the pin board. From the pic you posted, it looks like the joint would flush out if your pin sockets were cut a little deeper.


There is an adjuster on the side of the jig that you base the death of the router on. You use that to adjust the dovetail cut and the straight cut. If I am understanding you right I should be doing my straight cut a little bit deeper? Thanks once again 

Eric


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## Oneal-Woodworking (Apr 14, 2013)

Anguspapa said:


> . What a my doing wrong!? I own a porter cable dovetail jig. I have done everything the instructions say. I appreciate your help as always. Thank you.


 
The jig you have is great but you did not follow 'all' the instructions. I have and use that same tool and all of the instructions for 'tuning' the perfect joints are there (usually found on stickers stuck ON the machine itself for quick reference). 

The router bit depth adjustment pods only get you in the 'ballpark'. You will have to follow the instructions to 'tune' the joint to perfection depending on your particular bit being used and the thickness of your material at the time. 


As a general rule I ALWAYS mill a bit of extra material when doing dovetailed boxes so I can test and tune the joints before running an entire batch of boxes. Same thing applies if I am only doing one single box. EXTRA gets milled to 'tune' on before moving to real parts.

I like to see at least two joints come out perfect in scrap of the same exact thickness material come out before moving on to any 'real' box parts using that same tool. 

If you mill the parts for one of your boxes about 3 or 4 inches too long this will usually give you 3 or 4 'tries' to tune the joint to perfection without wasting much wood. (as you 'tune' the joint you need to cut off the parts that got done incorrectly but once you have set everything perfectly for your particular bit and thickness you can THEN trim those pieces to the exact size they need to be before doing the final cuts and turning them into your box - only a very few inches need to be wasted or cut off and tossed in the trash that way...)


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## epicfail48 (Mar 27, 2014)

Straight but isnt set to take a low enough cut on the pin board. Simple fix, just drop the straight bit another hair. Remember, always cut a joint in a scrap piece before moving onto the project lumber


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## GeorgeC (Jul 30, 2008)

OnealWoodworking said:


> The jig you have is great but you did not follow 'all' the instructions. I have and use that same tool and all of the instructions for 'tuning' the perfect joints are there (usually found on stickers stuck ON the machine itself for quick reference).
> 
> The router bit depth adjustment pods only get you in the 'ballpark'. You will have to follow the instructions to 'tune' the joint to perfection depending on your particular bit being used and the thickness of your material at the time.
> 
> ...


Very good writeup. I have the same jig and this is well written.

George


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## mengtian (Nov 8, 2012)

Quite honestly...If I need to do one or two boxes I do the dovetails by hand. A lot of practice two years ago has paid off in the long run:yes: 

As far as your currrent problem...I agree with the others here. You need to get some scrap milled to the same thickness and use them to fine tune.

I am in the same boat (or will be this week when I iattempt half blind rabetted doevetails with the same jig. I have milled plenty of extra wood for practice!


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## Anguspapa (May 4, 2013)

The box I have pictured above is just a guinea pig for a nicer one that is going to be made out of hardwood. I took a belt sander and 36 grit paper, took it straight down. When I use that the hardwood witch will probably be walnut and maple. I'll make sure I do a test like everyone has suggested. As always I think everyone for their input and their knowledge. 
Eric


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## Al B Thayer (Dec 10, 2011)

Extending the bit up or down determines how tight or loose the two pieces are.

How far the router moves in to the wood also determines how far the side piece slides into the fronts and backs.

Where the two pieces register against the stops determines the spacing of the dovetails and how they lay out.

Al


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## Oneal-Woodworking (Apr 14, 2013)

Anguspapa said:


> The box I have pictured above is just a guinea pig for a nicer one that is going to be made out of hardwood. I took a belt sander and 36 grit paper, took it straight down. When I use that the hardwood witch will probably be walnut and maple. I'll make sure I do a test like everyone has suggested. As always I think everyone for their input and their knowledge.
> Eric


So long as you are using a thickness planer or drum sander to get you in the ballpark of the thickness you want - You should NOT have to be sanding a whole lot with the belt sander before cutting your parts on the dovetail jig. 

If you 'require' a 36 grit paper on your belt sander to get things 'right' before milling on your dovetail jig - There is a very good chance that you are introducing a lot of possible 'error' to the mix. When I say 'error' - I am talking about the thickness of the material and it being all the SAME thickness (or as close as possible).

The tool you have can produce some VERY nice dovetails and it is VERY 'tuneable' to allow for the different thicknesses of materials and bits used but... Your material really 'needs' to be a consistent thickness before you can really depend on any of those 'adjustments' that you make to the jig. 

The more hand sanding like that that you do before the box is routed and assembled - The more likely you are to end up with boards that are sanded unevenly and end up thicker on one side than the other. 

Your boards all need to be as close to a 'uniform' thickness as possible or else you will chase your tail all day long trying to get the joints tuned correctly. (joint may fit 'correctly' on one side of the joint but not on the other)

I never mess with the 'outside' of any box parts before milling on the DT machine if I can help it (providing they got run through a decent thickness planer or drum sander first). The insides YES - But the outside NO. The outside of the box can be sanded AFTER it is built and you introduce less variation in the thickness of the wood this way.


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## epicfail48 (Mar 27, 2014)

OnealWoodworking said:


> So long as you are using a thickness planer or drum sander to get you in the ballpark of the thickness you want - You should NOT have to be sanding a whole lot with the belt sander before cutting your parts on the dovetail jig.
> 
> If you 'require' a 36 grit paper on your belt sander to get things 'right' before milling on your dovetail jig - There is a very good chance that you are introducing a lot of possible 'error' to the mix. When I say 'error' - I am talking about the thickness of the material and it being all the SAME thickness (or as close as possible).
> 
> ...


I think he was saying that after he assembled the box with the ill-fitting dovetails he pictured, he sanded down the pin board to sit flush with the tails. Great advise regardless


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## Anguspapa (May 4, 2013)

epicfail48 said:


> I think he was saying that after he assembled the box with the ill-fitting dovetails he pictured, he sanded down the pin board to sit flush with the tails. Great advise regardless


That is what I did with the belt sander and 36 grit. I glued the joints, assembled the box, squared it, and then hit the pins with the belt sander. Do you guys feel this is correct and good?
Eric


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## epicfail48 (Mar 27, 2014)

Anguspapa said:


> That is what I did with the belt sander and 36 grit. I glued the joints, assembled the box, squared it, and then hit the pins with the belt sander. Do you guys feel this is correct and good?
> Eric


Not quite correct, but a good way to make lemons from lemonade


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## Al B Thayer (Dec 10, 2011)

Anguspapa said:


> That is what I did with the belt sander and 36 grit. I glued the joints, assembled the box, squared it, and then hit the pins with the belt sander. Do you guys feel this is correct and good?
> Eric


I think you can get them to fit perfectly and never use the belt sander. Your first picture doesn't come through on iPad so I'm not seeing the part you belt sanded. My drawers are all finish sanded before I dove tail. So after assembly I just have a little 220 work and I'm ready to finish.

If you work the fixture into shape your going to love it.

Al


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## Oneal-Woodworking (Apr 14, 2013)

epicfail48 said:


> Not quite correct, but a good way to make lemons from lemonade


Might not be 'correct' but I *always* set up so that I got a slight bit extra sticking out so that I can sand down after the box it built to get everything 'perfectly' flush. :smile:

On a half blind dovetail type drawer box - I will add a 1/16th to the 'desired' length of my front and back pieces (the length of these is generally cut to the EXACT width that you want your box to be if looking at the dovetail joint from the side) and set my bit / template to have those parts stick out a slight fuzz on either side of the assembled joint. 

This only leaves an ever so slight bit of material in the front and back of the box to sand down to after the box is assembled to be 'perfectly' flush with the much larger area of the drawer box side. 

In this example - If your drawer box SIDE sticks out past the front and back pieces when you assemble the parts - You got a LOT of sanding to do to make things look perfect and your sides end up not being as thick as you planned for them to be. 

'Wood WILL be Wood' and it does not matter WHAT sort of drawer box dovetail tools you have available to use - You will simply NOT be able to set up and then bang out 50 dovetail joints in a row that are all 'perfect' in fit and flushness for the entire length of the joint. Once you figure this out - You have to ask yourself, "Which part would I 'prefer' to stick out given that things will never be 'perfect' when working with wood and which parts should I try to 'make' stick out a bit to save me sanding time later... :yes: 

Leaving that slight fuzz to stick out on the front and back when looking at the *side* of the 1/2 blind DT box means that I got a slight bit of room for 'error' if something during the process if slightly 'off'. You can always sand more to get the 'exact' size you want - But it is hard to add more wood when stuff is short... :yes:



Walnut and Maple boxes look freakin SWEET when put together...









I prefer mine to be perfectly flush on the sides and I tune my tools to be able to get there as quickly as possible. I have NO desire to be sanding all day because I had the wrong part left 'sticking out' on the box. :smile:






























Everything in these pictures above was done using the same exact tool that YOU have now Anguspapa... :yes:

It was also done fairly quickly... :thumbsup:

You currently HAVE a very nice tool for doing boxes with. :yes:


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## sawduststeve (Jan 11, 2009)

I have the same jig and one thing that i have found is that placing some 1 1/2" painters tape across the front board that you are cutting tails does a real nice job of preventing splintering of the wood. I built kitchen cabinets for our church and dovetailed all the drawers, I used 1/2" baltic birch plywood that has 7 plies. This makes real nice drawers and more than suitable for most cabinet jobs. So no prior sanding or planing is necessary. Good Luck!


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## ryan50hrl (Jun 30, 2012)

So...I have a porter cable jig and it works flawlessly.


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## epicfail48 (Mar 27, 2014)

OnealWoodworking said:


> Might not be 'correct' but I *always* set up so that I got a slight bit extra sticking out so that I can sand down after the box it built to get everything 'perfectly' flush. :smile:
> 
> On a half blind dovetail type drawer box - I will add a 1/16th to the 'desired' length of my front and back pieces (the length of these is generally cut to the EXACT width that you want your box to be if looking at the dovetail joint from the side) and set my bit / template to have those parts stick out a slight fuzz on either side of the assembled joint.
> 
> ...


Actually leaving the pins and tails slightly proud IS the correct way, according to everything ive read. Easier shooting for 1/64 or so proud and sanding than getting it perfectly flush. I was referring to the OPs case, where the faces were proud and he sanded the faces flush. Not the general 'proper' way, but the OP took a bad situation and did a good job correcting it


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## Al B Thayer (Dec 10, 2011)

Epic
You can leave them proud if you like. I don't belt sand so I dial them in. Which fixture do you use?

Al


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## epicfail48 (Mar 27, 2014)

Al B Thayer said:


> Epic
> You can leave them proud if you like. I don't belt sand so I dial them in. Which fixture do you use?
> 
> Al


Box joint jig attached to my miter gauge


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## Al B Thayer (Dec 10, 2011)

epicfail48 said:


> Box joint jig attached to my miter gauge


That was one of the first fixtures I made. 

Al


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## madmantrapper (Feb 6, 2013)

Oneal, you are not saying you adjust the bit depth after doing the pins and before doing the tails. The trick is to never adjust bit depth between the two. If material thickness is all the same and the machine is setup for the thickness correctly, you should never have to adjust the bit depth.


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## madmantrapper (Feb 6, 2013)

sawduststeve said:


> I have the same jig and one thing that i have found is that placing some 1 1/2" painters tape across the front board that you are cutting tails does a real nice job of preventing splintering of the wood. I built kitchen cabinets for our church and dovetailed all the drawers, I used 1/2" baltic birch plywood that has 7 plies. This makes real nice drawers and more than suitable for most cabinet jobs. So no prior sanding or planing is necessary. Good Luck!


Plywood for drawers other then the bottom, never heard of that before.


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## epicfail48 (Mar 27, 2014)

madmantrapper said:


> Plywood for drawers other then the bottom, never heard of that before.


Baltic birch is a bit of a special beast. Its solid birch throughout, so it may as well be solid hardwood. Holds joinery just as well, as compared to standard plywood where the layers de-laminate


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## ryan50hrl (Jun 30, 2012)

madmantrapper said:


> Plywood for drawers other then the bottom, never heard of that before.



I've seen it a lot....


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## BZawat (Sep 21, 2012)

madmantrapper said:


> Oneal, you are not saying you adjust the bit depth after doing the pins and before doing the tails. The trick is to never adjust bit depth between the two. If material thickness is all the same and the machine is setup for the thickness correctly, you should never have to adjust the bit depth.



In a thru dovetail joint like the OP posted, the tails are routed with a dovetail bit. The pins are routed with a straight bit. In this case the proper way to fix the joint's fit would have been to increase the straight bit's cutting depth on the pin board. This would have allowed the tails to sit deeper in their sockets and flush up the joint. 

Half blind DT's are routed with only 1 bit, and there the bit depth should not change between pins & tails.


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