Lessons Learned Hand Cutting Dovetails

[Frederick Skelly]

I'm writing this to give the next guy ideas that may help. Those of you who are already expert will not get anything out of this. (Though you might be able to straighten me out if I've taken a wrong turn in technique!) Please understand this is just my experience and that yours may vary.

Background. A few weeks ago, I decided I wanted to learn to cut Dovetails better, with the ultimate goal of a near perfect fit right off of the saw. I got on this kick because I bought a lovely LN tapered DT saw a couple months back. After using it a while, I wrote a "chop the waste vs saw the waste (https://sawmillcreek.org/showthread.php?262982-Why-saw-the-waste-in-dovetails-vs-chiselling-it&highlight=Chop+waste)" thread. Coming out of that, I decided to bite the bullet and buy the Knew Concepts Fret Saw. That saw really was a game changer for me. I recommend it if you can spare the money to get one. After reading a dovetail thread here that recommended it, I bought a copy of The Complete Dovetail by Ian Kirby (https://www.amazon.com/Complete-Dovetail-Handmade-Furnitures-Signature/dp/0941936678/ref=sr_1_1?ie=UTF8&qid=1523222142&sr=8-1&keywords=the+complete+dovetail). I also read a Chris Schwartz blog one of you posted about cutting "a dovetail a day (https://www.popularwoodworking.com/woodworking-blogs/editors-blog/a-dovetail-a-day)". I combined the two approaches, using Kirby's method to repeatedly cut practice dovetails as suggested by Schwartz.

Getting to the point: Here's what I've learned so far, after 31 pairs of dovetails in 2 weekends:
* Practice really does make perfect. The last 9 I've cut - including a box I just finished - were spot on. The previous 22 were spotty - some good, some downright cruddy. I couldn't get consistent.

* Lesson #1: If your tails are not square and flat, your joint will have gaps. If the tail is even a 32nd inch out, you will have a gap. It MUST be square right off the saw or you have to pare it flat/square with a chisel.

* Lesson #2: After practicing, I discovered that the way I was starting my saw cuts was impacting my ability to cut the tails square. I've read again and again to start a western saw on the push stroke, not the pull stroke. But when I followed Kirby's advice and started the kerf on the pull stroke, I could perfectly cut to the perpendicular layout line; i.e., my line of cut got perfectly square. I realize this is bad technique, but it just worked better for me. All I'm saying is "try it" if you too have a problem cutting to the perpendicular line. YMMV. (Edit: What I'm trying to say is that I have better control following the perpendicular layout line if I start on the pull stroke.)

* Lesson #3: When marking the pins, put a non slip mat under the tail board. That really helped.

* Lesson #4: When marking the pins, use a knife, but DO NOT score a deep groove. The saw falls into that groove and your pin comes out too narrow. (This experience is probably unique to me only. But it bit me several times until I figured it out.) Instead, I mark the pins lightly and run a sharp pencil down the groove. I cut the pin so that half the pencil line shows on the finished pin.

* Lesson #5: Tap the joint together with a cross peen hammer, instead of a mallet. I thought Kirby was nuts. But as I was dry fitting the joints, I could easily feel and hear when a pin was too fat and needed paring. This really reduced my splitting the wood.

* Lesson #6: If you get the tails square and the joints properly cut/fitted, the 4 sides of your box just pull together and it comes out beautifully square - without diagonal clamping. This was truly pleasing to watch and experience.

I'll be making a ton more dovetail boxes to really lock in the skills/techniques. Might add new lessons here if I get more. But I hope some of this helps someone else some day.

Fred

[Jim Koepke]

Fred,

Thanks for posting this. It has great tips on cutting dovetails.

jtk

[Kevin Smira]

Good post Fred...

On #1...for me, if the cut is out more than 1/8” over 6”, there’s a gap. I check this by leaving my saw in the kerf and putting my 6” combination square on the back sided the tail board. If the the gap between the saw plate and my combination square is more that 1/8”, I know I’ll have to pare.

[Edwin Santos]

Thanks for posting Fred. I appreciate your helpful dissection of the nuances and love your enthusiasm. Please post some of your work!
It's never a bad day sitting at the bench cutting dovetails.
Edwin

[ken hatch]

Fred,

All good points. The light hand in marking is very effective and I usually add the "140 trick" to aid in marking the pins. And last but most important is saw to fit from the saw. BTW, I almost never "dry" fit, a good visual inspection will usually tell if the joint will fit and at most I'll place the tail and pin board lightly together to check before glue up.

ken

[Shane MacMillan]

* Lesson #4: When marking the pins, use a knife, but DO NOT score a deep groove. The saw falls into that groove and your pin comes out too narrow. (This experience is probably unique to me only. But it bit me several times until I figured it out.) Instead, I mark the pins lightly and run a sharp pencil down the groove. I cut the pin so that half the pencil line shows on the finished pin.

This one use to mess me up a lot. I would want a nice easy to see follow edge so would score 3 or 4 times making a nice knife wall. Never worked though as you always mark with wrong side of the bevel and saw would always fall into it.

[Kevin Smira]

* Lesson #4: When marking the pins, use a knife, but DO NOT score a deep groove. The saw falls into that groove and your pin comes out too narrow. (This experience is probably unique to me only. But it bit me several times until I figured it out.) Instead, I mark the pins lightly and run a sharp pencil down the groove. I cut the pin so that half the pencil line shows on the finished pin.

This one use to mess me up a lot. I would want a nice easy to see follow edge so would score 3 or 4 times making a nice knife wall. Never worked though as you always mark with wrong side of the bevel and saw would always fall into it.

I use the "rob cosman" method of marking the pins from the tail board. If not familiar with that method, it involves not wasting the tail board initially. Using the kerf cuts in the tail board, I have a marking knife that is the same thickness of my saw plate with set (marking knife doesn't have set). Using the marking knife in the kerf cut of the tail board gives my saw a "starting" kerf on my pin board. That's the only way I cut dovetails because that's the only way I know (that's the way I was taught). I also use the "140" trick as well.

[Shane MacMillan]

I use the "rob cosman" method of marking the pins from the tail board. If not familiar with that method, it involves not wasting the tail board initially. Using the kerf cuts in the tail board, I have a marking knife that is the same thickness of my saw plate with set (marking knife doesn't have set). Using the marking knife in the kerf cut of the tail board gives my saw a "starting" kerf on my pin board. That's the only way I cut dovetails because that's the only way I know (that's the way I was taught). I also use the "140" trick as well.

I have watched his videos and tried it a few times but I didn't have anything that would fit in the kerf besides the saw it self. It worked well but I need to work on it more. I have some old hack saw blades around but none fit in the kerf. I'm thinking of trying to hammer the set out of the blades and try again. If I can get that to work I'll look into making a kerf saw out of the blade. I though about getting his marking knife but can't bring myself to spend the money on it yet. Funny how I'll spend that on a normal marking knife though. lol

[Kevin Smira]

I have watched his videos and tried it a few times but I didn't have anything that would fit in the kerf besides the saw it self. It worked well but I need to work on it more. I have some old hack saw blades around but none fit in the kerf. I'm thinking of trying to hammer the set out of the blades and try again. If I can get that to work I'll look into making a kerf saw out of the blade. I though about getting his marking knife but can't bring myself to spend the money on it yet. Funny how I'll spend that on a normal marking knife though. lol

While I'm sure his marking knife will work with other saws, the knife is designed around his saw. Meaning it's the same thickness of the plate plus the set (knife doesn't have set). At the very least, you could use your own saw holding it in your hands close to the toe of the saw. One thing to note however is that you offset your tail board the thickness of the saw plate and set. So, I set my saw on my plane and use my marking gauge to set the thickness of the saw plate (plus set). Then, I offset my tail board to the left using the now set up marking gauge. If I'm offsetting to the left (meaning pushing the board to the left), I use the marking knife on the right side of the pin and them reverse (offset right, cut left). This way of marking doesn't care about "splitting the line", "leaving just a bit of line left and paring to" or any of the other methods. This produces the exact width of the tail on the pin board. Now all you have to do is saw the kerf. The only place I chisel on a DT joint is to clean up the waste area left from my Knew Concepts fret saw.

Kevin

[steven c newman]

Doesn't Roy Underhill just use the saw to do the marking?

[Kevin Smira]

Doesn't Roy Underhill just use the saw to do the marking?

I believe he does...and I think I've seen Frank K do it too...but now all I see Frank K do is just cut without marking anything...he's also a "pins first" guy. The "using the saw" method is what I described above.

[Pat Barry]

Using the reflected image in a somewhat polishef saw plate provides a great way to visualize square. There are numerous videos of this out there to watch and learn from.

[Phil Mueller]

Sawing square and leaving the knife mark are critical and been my demise more times than I care to mention. I started using a magnetic guide (OH NO!), and found the joint suddenly fitting off the saw...so I know that’s been my issue. The plan was to use the guide for training...not sure I’ll ditch it for some time though.

[Shane MacMillan]

Sawing square and leaving the knife mark are critical and been my demise more times than I care to mention. I started using a magnetic guide (OH NO!), and found the joint suddenly fitting off the saw...so I know that’s been my issue. The plan was to use the guide for training...not sure I’ll ditch it for some time though.


Which guide are you using?

[Phil Mueller]

I got the clear urethane guides from Katz-Moses Woodworking.

[Matt Lau]

I was just about to ask about the guide!

After I build a workbench, I'm thinking of slowly building a worthy tool storage for my tools.
It'd be really nice if I could dovetail the carcass.

[Derek Cohen]

Matt, you do not need to use a guide to saw dovetails. Take the time to saw two lines simultaneously. In the following picture I am demonstrating the use of blue tape, but note that the saw is moving along both the horizontal and the vertical line ...

http://www.inthewoodshop.com/Furniture/ThroughDovetails3_html_m254d06bf.jpg

The blue tape makes transfering lines so much more accurate, and this is a big part of well-fitting dovetails. In reality, dovetailing is nothing more than accurate sawing.

Here is one of my articles in this regard: http://www.inthewoodshop.com/Furniture/ThroughDovetails3.html

The other ingredient to sawing straight is a light grip. Let the saw do the work. Don't force it.

Regards from Perth

Derek

[Chet R Parks]

Derek, Just a curiosity question. Is there a reason why you don't wrap the tape around the corner and continue cutting the tape with a square instead of marking the vertical line with a pencil or knife?
Chet

[James Waldron]

+1 for Derek's blue tape. It's so good that after three or four projects, you don't actually need the tape any longer; you develop an eye for the two lines and automatically follow them. (If I get rusty, I go back to the tape for a couple of joints to "tune up" my eye.)

+1 as well for the light touch. The saw has a straight blade and wants to cut straight. You can "push" it off line. Let the tool do the work and take it easy. (That does assume you've got a properly sharpened and properly set tooth line.)

[John Redford]

I got the clear urethane guides from Katz-Moses Woodworking.

I use this guide as well - it has brought remarkable improvement.

[Jim Koepke]

A lot of good tips on technique in this thread.

My build thread on a box made out of firewood contains almost every tip of mine learned over the years. My original plan was to add a link to this at the end of that thread. Then it occurred to me it condensing out the dovetail insights and add them to this thread might be better. People looking for information on hand cut dovetails might be more likely to find this thread.

Before getting one of them magical round tuits my appointment for more dental surgery arrived and now there is too much distraction going on in my jaws to do much of anything.

So a link to a post with all of the lessons of my learnings on hand cut dovetails is here:

https://sawmillcreek.org/showthread.php?259750-A-Box-From-Firewood&highlight=

One of my most helpful tools is a small try square for checking the squareness of tails. Lee Valley sells one that ended up in my cart and now in my shop:

http://www.leevalley.com/us/wood/page.aspx?p=72730&cat=1,42936,42941&ap=1

jtk

[Frederick Skelly]

Well, I'm up to 48 pairs of dovetails now. I started actually making boxes (instead of L-shaped corners) a while back, when I finally started getting "consistently good enough" results right off the saw. (So my shop is getting very well organized by the influx of small boxes!) I've learned two new things and want to include them here.

Lesson #2A. This is a revision to original lesson-learned #2, because by testing and trying and analyzing, I found something that worked better for me: Don't start the saw on the back stroke as I previously suggested. Instead, start it on the push stroke, but do so by sawing "uphill". My results are far more controllable and predictable. Thanks to Ken Hatch for posting the item from Joel at Tools for Working Wood. As usual, I found Joel's advice to be good. Here's the article on Sawing Uphill (http://www.toolsforworkingwood.com/store/blog/161). I'd like to respectfully note that Derek Cohen shows a similar approach on his website too. (And it's kind of implied in post #17 here.)

Lesson #7. When you saw out the waste, take your fretsaw to within 1/16" (if not less) from the baseline. Then just pare to the baseline. It's a thin, easy shaving that way and much quicker than other ways I have tried.

I'm having fun and learning stuff. Hope to continue getting steadily better.

Fred

[Jim Koepke]

I'm having fun and learning stuff. Hope to continue getting steadily better.

Don't worry, if you continue making them, they will continue to get better.

jtk

[Frederick Skelly]

Don't worry, if you continue making them, they will continue to get better.

jtk

Thanks Jim!

FYI, I've been on the fence about buying one of those small try squares from LV for some time now. Wanted a Vesper but didn't really want to drop the coin - so the LV was tempting, but I was concerned it might be too small. Based on your recommendation above, I ordered one last week!

Take care.
Fred

[Jim Koepke]

Thanks Jim!

FYI, I've been on the fence about buying one of those small try squares from LV for some time now. Wanted a Vesper but didn't really want to drop the coin - so the LV was tempting, but I was concerned it might be too small. Based on your recommendation above, I ordered one last week!

Take care.
Fred

The LV square is a nice one. It is a bit on the small side but that doesn't make it less useful. One of my thoughts has to build a wooden housing around it, but as it is used more and more those thoughts might fade.

jtk

[Chris Parks]

https://www.youtube.com/watch?v=vKuy3NdLhlE&index=21&list=PLEb0Ut6A7deZhW9Sbf0EGMmTaxGrJpTyJ&t=0s

I think there are a lot of old school lessons to be found here but it won't appeal to the crowd that measures until it bleeds.

[andy bessette]

https://www.youtube.com/watch?v=vKuy3NdLhlE&index=21&list=PLEb0Ut6A7deZhW9Sbf0EGMmTaxGrJpTyJ&t=0s ...

I want to be just like this guy when I grow up.