Cosman's Dovetail DVD's - REVIEW - Pics
Garrett in Victoria
The name Rob Cosman is synonymous with hand-cut dovetails, and he continues to reinforce the association by touring the North American woodworking shows to demonstrate his techniques. He also produces and sells DVD;s that go into much more detail than possible at a show, and that lay out each and every step along the way to a perfect fit.
Cosman does not try to make his magic seem difficult. On the contrary. Just as in his demos, throughout the videos he stresses the point that successful dovetailing consists primarily of accurate marking, and the ability to saw to a straight line, and that anyone can do it.
Easy to say
A month ago, after seeing his latest demo at the local woodshow, I was inspired to come home and make my first ever attempt to cut some dovetails by hand: As is painfully evident, the result was not an aesthetic success.
I did follow at least some of his instructions, but clearly, the combination of no marking gauge and a bigger hammer wasn't the most efficacious. So, I went back and bought the DVD's.
Did they help? You be the judge. The joint accompanying the cover photos above is my second ever attempt, done this morning after watching them carefully several times, Here's a larger view. No test fit per Cosman, and I made no repairs. This is exactly how it came out except for a few strokes with a hand plane. (Another pass or two would have eliminated the ink line on the top of the left-side tail.)
I made a DT gauge per Cosman's and did the marking out exactly as he instructs. (Very ingenious procedure.) I used a $25 Lee Valley small rip Dozuki saw (Part no. 60T06.10)
that has zero set, follows the line better than I can, and cuts on the pull--which I prefer--to make the principal cuts. I also used a cheap coping saw to remove most of the waste since I don't (yet) have Cosman's recommended fret saw. (FWIW, I found waste removal is the operation with greatest potential for disaster.) As the large image above clearly attests, my second attempt still wouldn't pass muster on a piece of furniture, but I'm nonetheless encouraged to continue trying.
With so many router-based jigs available why cut dovetails by hand? People who have mastered hand-cut dovetails often argue that they can cut them faster than it would take them to set up a router jig. Whether true or not, router bits cannot be made small enough at the base to emulate traditional dovetails, and in any event, no one would argue that machined dovetails can equal the visual impact and beauty of the traditionally made joint. Aesthetics, and the sheer pleasure of craftsmanship. That's why dovetails are still cut by hand.
At show demonstrations, Cosman interacts constantly with the audience. Since that's not possible on a DVD, Hand-Cut Dovetails opens in Rob's shop with his trusty sidekick Bruce Dennis introducing Cosman, who remains to ask questions and make comments. The interplay ensures that the audio is not just a monologue.
Since accurate sawing is the primary key to success, Cosman first discusses the essential qualities of dovetail saws and promotes one from Lie Nielsen saw, because, he says, it's properly, purpose-made, and ready to go out of the box. In this DVD he uses what looks like a Veritas circular marking gauge, and in the next one, enthusiastically recommends a much more sophisticated model made by Glen-Drake Tools. He notes that most manufacturers produce dovetail saws with a cross-cut tooth configuration when what's really required is rip teeth. He also presents arguments in favour of minimal "set" i.e. the smallest possible kerf, and demonstrates with two saws why he espouses that view. (The demo certainly shows the difference in performance between rip and cross-cut saws.)
He then moves onto stock preparation for the sides and front, and offers several very useful tips to ensure precision. Similarly, he shows how to use a marking gauge to set the depth of cut perfectly. (He also discusses the advantages of the newer circular knife models over traditional pin marking gauges.)
In the great and raging debate about pins or tails first, Cosman comes down emphatically in favour of tails. He argues that this approach requires that the craftsman master only the ability to make a perpendicular saw cut.
He stresses the need to clamp the workpieces plumb, a basic first step to long term success. Two dividers are used in a very simple method to establish the number and size of pins. A shop-made jig sets the angles of the tails, while Rob explains that softwoods require more rake (wedging angle) than hardwoods. Cleverly, the indentations left by the dividers become the registration marks for his pen when he draws the lines for his stock removal.
Given its overwhelming importance, Cosman then spends a significant amount of time explaining and demonstrating his sawing technique. Actually making the cuts is very efficient and takes almost no time at all.
One of his well-known tricks is to remove most of the waste with a fret saw--not, he emphasizes, a coping saw. As well as eliminating a lot of chisel work, it allows for narrower tails than would be possible with a chisel. (Just how narrow is demonstrated in the second DVD.) He offers a tip on how to adjust the fretsaw's blade for work pieces that are longer than the saw's throat capacity.
He then moves on to cleaning up the joint with a chisel, and draws a sketch to argue against the oft-proffered advice to undercut the interior of the joint. He sneaks up on his lines with a sharp tool and gentle taps with his mallet. Another tip is given on how to avoid accidentally scarring the outside of the joint.
With the tails cleaned up he provides another tip to make the transfer of marks for the pins easier and more certain. Then, whereas he uses a pen to mark the tails out, he uses a knife to transfer the outlines for the pins. Once again, a tip: don't use a sharp knife such as an Exacto. He describes how he alters a knife to deliver accurate marks that are readily visible. He makes his marks in a particular order, again contributing to accuracy. With that done, his next step is absolutely counter-intuitive, but he explains the rationale very well. (I'll leave this one for purchasers of the DVD.)
After extending his lines with his jig and a pen, he once again sets up for vertical saw cuts, and basically repeats the waste removal process.
With the pieces cleaned up, he announces, we're ready to glue the joint together, and starts discussing the use of a small palette knife as an applicator for common white or yellow (aliphatic) glue. However, as yet hes made no trial fit, nor even eye-balled the 2 pieces close together. Nevertheless, he then grabs a small block of wood and a steel hammer--he explains why steel is more appropriate than a rubber mallet--and sets them ready to hand. As he begins to put glue on the palette knife, Bruce finally asks if he's going to test fit. His answer is No, because it will never fit as well the second time as the first time. He then shows Bruce that all the scribe lines are still visible on both pieces, so the joint must fit. Trust me.
Of course, the joint does go together and the fit is perfect.
While waiting for it to dry, Cosman describes half-blind dovetails, and acknowledges that cutting the sockets is a lot of work. Thus, when he recently had to complete a project with 62 drawers, he describes an approach he developed that considerably reduces the work involved.
With the glue now sufficiently set, he demonstrates how to plane the joint to a smooth finish. Although as noted above his fit is perfect even under a magnifying glass, he concludes this video with several very useful tips on how mere mortals can fix small errors and make them virtually invisible.
Advanced Hand-Cut Dovetails opens with Cosman describing what;s to come: first, the traditional approach to making half-blind dovetails, then the mitred-edge dovetail, and last the hounds-tooth dovetail (little dovetails cut into larger dovetails).
He starts the half-blind dovetail demo by carefully preparing the stock - both pieces have to be flat, parallel, and square - and then uses the wheel marking gauge to scribe them in the manner peculiar to half-blinds. Next, a quick review of the use of dividers for marking out the pins. The marking and cutting out of the tails is exactly the same as for through dovetails. At this point, the dialog takes us through a very precise and careful examination of the factors that are crucial for a tight fitting joint. In the case of the half-blind, for example, the shoulders of the tail board have to be cut "right on".
Transferring the markings to the pin board and cutting the pins --or, if you will, the sockets for the tails-- is not the same as for through dovetails. The thin set-back that will cover the ends of the tails is in the way. However, the procedure is explained clearly as he proceeds to cut the pins with a little bit of sawing and a lot of very careful chiseling. This section is replete with helpful hints on technique, including his shop-ground dovetail chisel.
Once again, no dry fit. Just a little glue from his palette knife buttered onto the long grain sides, and assembly with a small steel hammer and block. Perfect, of course.
The mitred-edge dovetail instruction begins with a description of its application (carcase construction), and the rationale for taking the extra trouble to make it the much more attractive appearance of a mitred joint versus a butt joint. With the front and side prepared as before, it's back to the marking gauge plus a protractor. A slight variation in approach takes the peculiarities of this joint into account.
Because he wants to have pins that narrow to nothing other than the width of the saw kerf, the use of the dividers is also slightly different. Once the tails are marked out, and the mitre waste area clearly indicated, the sawing of the tails begins. Again, the procedure differs somewhat from the norm, but it's shown and explained clearly and comprehensively. The tricky bit is to clear out the mitre waste very precisely to ensure that when assembled it's closed. With that done, the tail outlines are transferred to the pin board as for a through dovetail, but because the pins are so narrow, a very fine knife is required as is extra care in ensuring that the knife stays tight to the sides of the tails.
With the tails and pins cut out, the second half of the mitre remains to be marked and cut with the saw, followed by a little bit of paring with a really sharp chisel. Very, very carefully.
Once again, he goes directly to glue-up, and once again the result is a set of perfect dovetails PLUS a perfect mitre.
With that joint set aside to dry, he shows Bruce an example of the Hounds Tooth dovetail, basically a series of alternating large and small pins.(A triple Hounds Tooh can be seen on the left side of the cover in the opening photo above.) To Bruces comment that "This one looks really complicated to me," Rob replies, "Actually, Bruce, this is the least difficult of the ones we've done today." But, Bruce is right. It does look complicated
With the stock prepared, the marking of the tails and pins begins. Contrary to the half-blind dovetail, this one is marked from the face side. Again, the dividers are used to lay out not one but two sets of dovetails, and Rob remarked that a third set could be inserted to really show off. Scribe lines mark the different depths.
Cutting the tails out is, by now, straightforward except, of course, that there are two stop lines involved, one for the large and one for the small tails. The transfer of the tail markings to the pin board is much more complicated, and Rob stresses the importance of carefully marking the waste areas. The layout, though actually simple, can be very confusing visually. The pins are first cut out as if they were all the same size, and then the small ones are cut back from the wide end to the scribed line at the short end.
With that done, its the palette knife, glue, and then, the moment of truth.
Did it come out well?
Need you ask?
In summary, both DVD's are packed full of content, yet the material is presented logically and comprehensibly. The quality of both audio and video are professional. They are a matched set, and clearly show why Rob Cosman is known as Mr. Hand-Cut Dovetail.
Per ardua astra,
Garrett
Cosman's Dovetail DVD's - REVIEW - Pics
Posts
Re: Cosman's Dovetail DVD's - REVIEW - Pics
Edited #2Years Ago
Jim Shaver - Oakville, Ontario
Hi,
Years ago when Rob was first starting to do woodshows and be the LN rep in Canada I met him at a local woodshow. I was amazed at many things, one was his gift to talk and cut DT's with efoortless ease. We got to talking and before I knew it we had a few common connections.
Awhile later I remember he asked me if I knew of a place locally in the Toronto area that had a class room with Benches. A long story short, I was in one of his very first dove tail classes, it was at Sheridan College in Oakville (he still comes there at least once a year). I remember it well because it was during Thanksgiving and we had him over to the huse for dinner that night as well, that has to be 5-6 years ago now.
Rob's method for hand cut dove tails is the exact way I hand cut mine. I have a good number of his video's and DVD's, what you see is what you get...the real deal!
Take care,
Jim
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#3Practice, Practice and Practice
Dan Clermont in Burnaby
>Then go back and watch the video again.
I cut up a bunch of scraps and started to do 20 minute dovetails on the nights I didn't have a chance to spend much time on a project.
Everytime you make a dovetail you learn something new and when you re watch Rob's video you pick up a tip or confirm what you found on your previous test runs.
Here is a pic of my practice dovetails from a couple of weeks ago. Now I have dovetailed most of my projects but always pared to the line. These donvetails I attempted to split the line. The line was a fine line and as time went on I got better at splitting it
By the way, the far one on the right is Rob Cosmans from a local woodshow a couple of years back. Much tighter then mine
Cheers
Dan Clermont
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#4Re: Practice, Practice and Practice
Dan Clermont in Burnaby
>
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#5Follow through
Wiley Horne--Glendora, CA
>Garrett,
Not bad at all, but follow through on this one. Glue it up, and plane the sides down to the pin ends and see what you've got.
As best I can tell from the photo, I'm not seeing any systematic errors. The drawer 'side' and 'back' are proud of the pin ends, but some people plan the work that way. I look at the pin entries (small ends), and they look pretty parallel--can't tell whether the tails are sawn parallel, cause they're a little dinged up due to weak wood. Don't see much if any air between sawn faces, or at either baseline.
Soft wood like that is murder to work with. For example, maintaining a crisp baseline. That busted out place at the baseline is typical for wood that chips out. I would suggest next time, use poplar or soft maple or whatever scraps you've got--but some kind of reasonable hardwood .
But this joint you've just done can tell you a lot if you will finish it up. Look for things like whether the pin entries are sawn parallel, whether the tail end grain is sawn parallel, whether the baselines are overcut or mangled, whether there is air at the baseline or between sawn faces--all this tells a story. Maybe I'm missing something in your photo, but I think this is a very good first crack.
Please finish the joint and consider posting the final product, along with your assessment of it.
Wiley
Re: Cosman's Dovetail DVD's - REVIEW - Pics
Edited #6
Re: Years Ago
Jim DeLaney, Austintown, Ohio
>Yeah, Jim, but show us all your first real dovetail joint again...
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#7The "Martian" Dovetail?
Garrett in Victoria
>I remember that one.
It's what frightened me all these years from trying them myself (:-.
Cheers, Garrett
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#8Re: Cosman�s Dovetail DVD�s - REVIEW - Pics
Derek Cohen (in Perth, Australia)
>Garrett
That was an exceptionally good review of the two DVDs. I have watched them several times, often just as a refresher.
It is easy to lose focus on the important parts that make up a successful dovetailed joint, when even just a couple of weeks go by between dovetailing sessions. I try and remind myself that (in my view) the important parts are:
1. cut square.
2. cut to the line.
3. keep the baseline straight, and
4. MAKE SURE THAT ALL THE WOOD IS SQUARE TO BEGIN WITH!
Your second attempt looks far, far better than mine did.
Regards from Perth
Derek
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#9The "Martian" Dovetail !!
Jim Shaver - Oakville, Ontario
>LOL Garrett,
It scared me Too!!!
Then I took my time and actually did it right, using a class experience with Rob, it's not difficult, but the more you make, the better they get!!
take care,
Jim
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#10"perfection" the enemy of good enough
bill tindall
>Warning, philosophical discussion ahead
There is no doubt that dovetails are the best way to hold some kinds of wood parts together. For example, I observed at Winterthur that the cases held together by dovetailed rails were tight, while those with M&T often had gaps at the joint. It also seems that dovetails have become a way to flaunt one's woodworking skills. Yet, less that perfect dovetials will hold a drawer together just fine as witnessed by many antiques I have examined. Further, most of us don't have the inate ability to cut perfect dovetails with out lots of practice, which a amatuer woodworker never gets, nor should get if the goal is to build things.
Is it possible that these discussions of quests for perfect (flauntable) dovetails disuades some from using this valuable joint in their furniture?
When I teach a class in dovetails, I show students a drawer from a fine 150+ year old antique piece. It is clear that the person who made the drawer was trying to make a living making quality furniture and wasn't concerned that some amature 150 years later was going to judge his person by the perfection of his dovetails. In one session students have been able to produce dovetails as good as what held this drawer together for 150+ years. Yet, I fear that many of these students will not risk using this joint for fear that their work will be judged by the lack of perfection of their dovetials.
To this end, I think this fixation of dovetail perfection is misplaced. The discussion and pictures should be of a piece of furniture, or even a drawer, not the perfection of the dovetail that will be hidden from casual view.
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#11Re: "perfection" the enemy of good enough
William Duffield, on the Cohansey
>I sometimes wonder if demonstrating and teaching "perfect" dovetails are no more than a means to an end, that end being selling higher quality tools. I too use high quality tools for cutting dovetails, but I like to tell myself that I chose them to allow me to make strong dovetails more quickly and more comfortably. If more consistency is also a result, then that is good too, because it makes them go together more quickly, because there is less paring and other repairs required to get them to fit.
Of course, both Bill and I are referring to traditional styles of furniture here, with traditional joinery. Perhaps a COR style display case requires more precision because the dovetails on these are part of the aesthetics of the design, and are meant to be seen. Traditional styles, especially case goods, were usually meant to be seen from the front and sides only, the people to whom the customer was showing off were not expected to open the drawers or appreciate the joinery, and the joinery was hidden. The need to survive the trip from the cabinet shop to the customer's home in a horsedrawn wagon, over cobblestone streets, dirt roads, and bridges paved with logs, was sufficient to demonstrate the soundness of the joinery to the other cabinetmakers and joiners.
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#12Re: "perfection" the enemy of good enough
John Pappas
>Thanks, Bill. I just finished three drawers. The dovetails are very, very good, but not perfect. You said, very well, what I often think, but could not have expressed as well. John
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#13Re: "perfection" the enemy of good enough
Arw01
>Watching Rob in person, he is very fast and still VERY perfect. He has made his living as a professional furniture maker until just the last years when he was given the opportunity by Tom Lie-Nielsen to distribute in Canada because they had horrible shipping problems.
Currently Rob has 6 kids, only 1 of which would have been a baby when he was making a living as a furniture maker!
As to shilling product. I came into the basic hand tool class with what I felt were SHARP tools, they were capable of making sub .002 shavings. However, after the first day of _FIXING_ my tools, they were WAY sharper. I feel that the subsequent half day of further sharpening and tool preperation, robbed me of further class advancement. I watched as box after box of LN tools came right out of the box, got honed and started working. There was one LN No 8 blade that had a manufacturing flaw.
I struggled with my LV dovetail saw. It cut straight, but ragged, suspect the blade was bending in the cut due to my technique. Rob loaned me his saw for the rest of the week, and the difference and instantly visible.
This class was so enjoyable for me, over 60 hours of class time in 5 days, that I am REALLY thinking of taking the same class over again! There were a number of joints we just could not get too.
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#14Re: "perfection" the enemy of good enough
Paul Kierstead
>Some very interesting thoughts, Mr. Tindall. If I may through in a couple of factors:
- People now make things with dovetails showing. I suspect that the old makers would have been horrified ("Are you too lazy/cheap to put moulding on that???") but of course times change. The whole idea of showing joinery is of course a post-modern idea, right up there with photographs showing their edges, etc.
- Machinery has made us view things very differently. We are trained to consider any thing which is not 'perfect' to be a flaw. Carving for example: If you show people really hand carved stuff, they will often focus more on the faceting (as a flaw) then the depth, etc. that make hand carved things beautiful. They are trained to expect something pressed out, or perhaps done by C&C; they don't really know how to appreciate things made differently. Of course the flip side of this are those of the 'elite' who seem to have forgotten how to appreciate practical sensible things and have gone off the edge.
I think all of this drives people to router jigs, which is OK too; it beats the crap dado joints I see on some expensive furniture in stores sometimes. But to get them to accept imperfect dovetails will be to get them accept that beauty is not tightness of fit or 0.001" precision, and that is difficult.
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#15
Re: "perfection" the enemy of good enough
Jack Guzman from Maine
>I had been a little concerned about ever being able to achieve the perfection I've been seeing displayed in the magazines today.But seeing crude handcut dovetails in otherwise well made furniture gave me the confidence to just be happy with as good as I could get them.I agree,too much stress on perfection is detrimental to the confidence of new woodworkers.
Watching Rob however,really helped me improve my methods. He really is a good teacher.---Jack
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#16Re: "perfection" the enemy of good enough
paul womack
>dovetails have become a way to flaunt one's woodworking skills.
Indeed. Of course, in the Victorian era it would have been out of the question to have visible DT's on a carcase.
The craftsman would have executed a hidden dovetail joint, which is much more difficult, and if performed perfectly, is visually indistinct from a simple mitre...
http://www.pbs.org/wws/howto/dovetailbox.html
BugBear
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#17Another point of view
Stephen in Ottawa
>While it is true that perfect dovetails may not really be needed in order to perform the function that the particular instance of the joint may be called upon to do, such as hold a draw together, however being able to execute such a joint does give an immense amount of personal satisfaction. Since most of us here pursue woodworking as a hobby, it's this sort of satisfaction that makes it all worthwhile ( well, for me at least !). Most of us don't need to be concerned about being super productive, as the 18th. century cabinetmaker would have had to. We do this out of choice, not necessity so I really don't think such discussions about perfection are misplaced.
- Stephen
Re: Cosman's Dovetail DVD's - REVIEW - Pics
#18Re: Another point of view
William Duffield, on the Cohansey
>I agree that perfection is to be pursued with all dilligence, especially when it comes to joinery, not to mention when it comes to wispy shavings and the planes that make them. When achieved, it is to be celebrated, as well. However, even if you are a serious amateur, sometimes you still need to just get the product out the door. SWMBO will love the pieces of furniture y'all have built, whether or not the dovetails are perfect, and regardless of how many pieces Quality Control has sent to the pot bellied stove, or the "project wood box".
I always get compliments on my dovetails from family, friends, and especially from others on WC, even though I don't think they are deserved. I don't post pictures of my projects to show off my dovetails, but to demonstrate one or more other concepts that I think WC might find useful or encouraging. However, I certainly enjoy reading about and seeing others' successes, and the joy they obviously get from their accomplishments.