Hand cut dovetails in sapele

[B3nder]

Howdy,

I want to improve my dovetails. So am trying to refine
mtb dovetails. I had a load of sapele which I was using
to practice on, however all isn't rosy.

Marking out I get and cutting tails goes well.
Using a pair of dividers and sliding bevel.

I cut on the waste side of the lines and complete using a
Fret saw and chisel.

I then transfer to the other piece using a knife. I then cut again
on the waste side. Using Fret saw anxiety chisel again.

When I try to make the joint they are mega tight and end up
splitting the tails or pins.

I've chamfered the joints facilitate making the joints. I thought
the more I did the better images would become.

Angel this for fettl8 get to get a good fit or adjustments in my
Process.

I guess if anything gets its better to adjust the pins to for.

Cheers.

 

[rafezetter]

I'm sure others will be along with a more detailed analysis but what I've learned from previous advice on this topic is it's unlikely you'll be able to get a perfect match of pins to tails (and no voids) without a great deal of practise, so you'll have to pare away one or t'other until they fit, just as mortice and tenons.

Apparently a good practise method is to do 1 set per day for a week or two with scrap - preferably hardwood to eliminate the problems adherent with softwood dovetails - and you'll get a better understanding of how YOUR particular tools are performing; and to use the SAME ones each time.

There can be issues as small as the flats on the backs of your chisels are not utterly flat, or that you have too large a backbevel so the sharp edge of the chisel is just a hair above the flat of the back, do that both sides and voila; too tight a fit even though it LOOKS spot on.

Or using a marking knife with a central bevel rather than one where the cutting surface has a FLAT back when transferring, so you end up with the same situation as the chisel but in reverse, an invisible difference, but enough to make the joint loose.

Of all the joints I've read about in the years on this forum, dovetails seem to be the ones that take the most practise to get to fit "off the saw" because of the variables of so many mating faces.

 

[mikefab]

If they are always too tight across all the tails and pins, and you are cutting to your knife lines that you have transferred, then perhaps you need to change the alignment just slightly when you transfer from the tails to the pin board.

I did a box making course a few years ago in Devon. The method taught on that was as follows:
- lay a bench plane flat on its side on the bench just in from the vice.
- fix the pin board in the vice so the top is flush with the side of the plane.
-move the plane in a bit and balance the tail board between the top of the pin board and the plane
- place a piece of white paper on the bench between the plane and the vice (I.e. in the gap underneath the tail board)

- shine an anglepoise lamp onto the piece of paper.

-Adjust the position of the tail board until a tiny line of light is *just* visible at the base of the tails.

-transfer the marks using a knife.

I suppose that little bit of light shining through means that the board are just slightly offset, and this is the allowance you need to make it fit.

You also need yo be meticulous in checking that everything is cut square and to the lines prior to assembly. Sapele will not be tolerant of being bashed together if the fit isn't right, as you have discovered. Pine is much more forgiving in the this regard!

Hope this is of some help.

Mike

 

[deema]

I would like to suggest that there are three possible causes.
1. The rails are not cut at 90 degrees and th sides slope. When you transfer to the pins the slope causes the pins to be tight. Try testing the sides with a small square, or alternatively gang up two boards and cut two sets of tails at once. This helps to get everything square as the wider width exaggerates any deviations.

2. Your cutting away from the knife line on the pins. Try chiselling out a small knife wall to start the Saw exactly where it should be.

3. The pins are not cut square. Although you can't gang up the boards, you can use a piece of waste to clamped to the back of the board to help elongated the cut and emphasis any out of true.

An old test is to scribe loads of vertical lines on a Board and star put cutting each one until you can do after a a few hours practice not only will you be able to do it with your eyes shut, but also without any marks to guide you.

Stick with it.

 

[Derek Cohen (Perth Oz)]

Dovetails that fit off the saw require that you ..

1. saw the tails square ( as in my case, since I go tails first). Whether you mark them first or just saw without lines is not important. Your saw cuts must be square.

This does take practice, but the squareness can be achieved by deeply knifing the lines across the top of the tail board, and using these to guide the saw. These are the most important saw cuts of all - they must be square, and the future fit depends on them. Forget about sawing "in the waste" at this stage. That is irrelevant. Saw on the lines.

2. Transfer the tail board to the pin board accurately. Any deviation here and the joint will not fit.

You need a vise set up that holds everything steady. This is where the Moxon dovetail vise has the advantage.

Always transfer with a knife, never a pencil. The pencil is not clear enough.

If your eyesight is like mine ... old eyes ... and lines blur without reading glasses, then ensure you have good lighting. I go a step further, and several years ago developed a method where transfer is done using blue tape. Not only does this make it easy to see the lines, but it feels like you are cutting against a fence. I get at least 95% success rate with dovetails straight off the saw. Links below to articles on blue tape use.

3. Saw the pin board to the very edge if the line (on the waste side, of course). Do not leave any waste for paring away with a chisel. This requires a go-for--it attitude. Go for it!

4. Chisel the baseline before removing the waste. A chisel line will prevent it being pushed back. You can chop away the waste or remove it with a fretsaw first. It still requires that the baseline is saved.

5. Chamfer inside and underneath the tails before pushing them together. If you have done the above to the line, you will have a tight fit. Hide glue will lubricate the parts and they will go together seamlessly.

Articles on blue tape:

http://www.inthewoodshop.com/Furniture/ ... eTape.html

http://www.inthewoodshop.com/Furniture/ ... ails3.html

Regards from Perth

Derek

 

[Ttrees]

Hello
Have you seen the way Cosman lays out his work recently ?
He uses a marking guage and takes a measurement of the saw plate and off sets the work before marking
the tails out.
Look in this video at 13.30
https://www.youtube.com/watch?v=87vbqCQUigE
I think there might be a clearer example on his channel but I can't remember where it is explained.
Good luck
Tom

 

[G S Haydon]

Morning

You're halfway there, mainly due to the fact your practicing. To me it sounds like you're leaving too much of the line in. Try and split the line if you can. It's hard to describe, but by repetition, you should work out how much of the line (gauge, pencil or knife lines) you need to leave in. This will transfer to all other types of joint making, and once understood, will move you along very well.

Derek mentions using a knife, that is appropriate and a good tip. However a sharp pencil is also effective. It's horses for courses really, on occasion a knife can work well, other times a pencil is more effective.

 

[B3nder]

Thanks for the info. I'll keep trying.

 

[Jacob]

You need a knife for the shoulder line but for everything else I find a scribe point much easier to manage. Actually it's an old dart (without flights). Or a sharp pencil.
Cutting tails (i.e. pin holes) is the easiest step as even if it's wrong you are going to transfer marks to the pins so it'll fit anyway. Just a DT saw cut - with a bit of practice you can do it freehand without marks - no need to "cut on the waste side of the lines and complete using a Fret saw and chisel" just saw as near as you can get and leave it at that.
Always slightly over cut with the saw i.e. up to the shoulder line and just a gnat's over. Then you don't need to fiddle about cleaning out corners between pins or tail.

 

[custard]

Good for you, you're knuckling down and giving it a go, where as most aspiring woodworkers run scared from hand dovetailing. So, item one is respect for your grit and determination!

=D>

Here's my 2p's worth on dovetailing.

1. A dovetail is unlike virtually any other woodworking joint in that it doesn't have to be a superb fit in order to be strong and serviceable. So relax! Your drawers and cabinets won't collapse if there are a few gaps here and there in your dovetails. In that respect dovetails are way easier to cut than for example mortice and tenon or housing joints. Someone once photographed all the dovetails on masses of antiques. Measured against modern standards most of them looked dog rough, but it hadn't prevented those pieces of furniture from lasting hundreds of years.

2. I've met and worked alongside hundreds of furniture makers, including some of the best known and most highly respected names in the business. I've never met two who cut dovetails in exactly the same manner. However, they all manage to produce superb dovetails despite going about in slightly different ways. So don't think there's some magic technique out there that will automatically lead to Guild Mark quality dovetails, at the end of the day there's no substitute for practise and finding a way to make your particular method work for you.

3. Derek Cohen gave you some useful tips. In particular points one and two on his list are vital. If the first tail board cuts aren't at precisely 90 degrees then no matter what you subsequently do you're stuffed. There are ways to deal with that, you can use a magnetic jig (like David Barron's jig or the Veritas version), you can gang up several tail boards and cut them all at once (which means the workpiece is effectively wider which in turn makes it easier to cut at 90 degrees), you can use a small square to run the saw against for the first stroke (which will give you a reference groove to set you up accurately), or you can just keep practising (which in the long term is generally the best approach!).

4. Derek's second point is equally valid. It's the transfer that's at the heart of top quality dovetailing, but the mechanics of the transfer (where you transfer the tail layout to the pins or vice versa) rarely gets the attention it deserves. Furthermore, your problems with over thick tails suggest it's the transfer that you need to focus on. The blue tape method is cheap and effective, but for professional makers it's too slow which is why it rarely gets mentioned by the more famous makers. The off-set method is equally effective, but it's complex and may require additional and specialist tools. It may help to think about it this way, if you knife the transfer then unless some tiny trace of the knife line remains on the pin you're doomed to have a gappy dovetail, but if the entire knife line is still visible on the finished pin then the fit will be too tight. That doesn't give you a lot of tolerance. The professional maker with time pressures has to get it right every time straight from the saw, but the hobbyist can cut on the waste side and pare to the line at his or her leisure. There's a little trick that many makers use which is to tap the tailboard towards you during the transfer, so it's overhanging by 0.5-1mm on a through dovetail, or across the line by 0.5-1mm on a half lap dovetail. You can then fully remove the knife line and still have a snug fit.

5. Personally I prefer a pencil as it's all too easy for the saw to drop into the knife line resulting in a gappy job. But the fact is that a pencil simply won't fit into the very narrow "London pattern" dovetails, so if you want to consolidate on one single method then a knife is your only option.

Good luck!

 

[Trafalgar]

Saw the tails square as has been mentioned using deeply knifed lines (end and long grain lines) as your guide. Put the saw in the deeply knifed lines and saw.

When marking the pins, nudge the tail board ever so slightly past the end of the pin board - around a 32nd (this is a visual, it is not measured) is a good place to start when practicing. Knife deeply on both the end and long grain of the pin board. Saw on the knifed lines of the pin board (don't worry about sawing in the waste). They'll either be a perfect fit, or slightly loose which in that case you nudge the tail board a little farther the next time. Work it out on scrap first. The harder the species the less you have to nudge the tail board past the end of the pin board but in using this method you always have to nudge it past by some amount. The deeply knifed lines on the pin board provide a trough for the saw to run in and make it easier to start the cut as well. In using this method you are using deeply knifed lines on both boards in order to help guide the saw and help with diagnosing unacceptable efforts.

Though slightly non-traditional (?) it's worth a try if nothing else is working for you. If this doesn't result in a pretty close fit the first time you try it, you should be able to tell where your sawing went awry by examining the knifed lines vs. the saw cuts. If the cuts were bang on in the knifed lines then all you need to do the next time is adjust the projection of the tail board past the end of the pin board -- less if joint was too tight, more if joint was too loose.

Relax your hands and wrists a little. Don't put a death grip on the saw.

I'd lose the fret saw; they almost inevitably bruise the arris of at least a few pins or tails. There are ways to avoid this, but it adds time and tedium to the process. Cutting joints isn't where you make up time on a project, but it shouldn't take a day and half to dovetail a drawer either.

All my lousy two cents' worth.

 

[custard]

When marking the pins, nudge the tail board ever so slightly past the end of the pin board - around a 32nd (this is a visual, it is not measured) is a good place to start when practicing. Knife deeply on both the end and long grain of the pin board. Saw on the knifed lines of the pin board (don't worry about sawing in the waste). They'll either be a perfect fit, or slightly loose which in that case you nudge the tail board a little farther the next time. Work it out on scrap first. The harder the species the less you have to nudge the tail board past the end of the pin board but in using this method you always have to nudge it past by some amount. The deeply knifed lines on the pin board provide a trough for the saw to run in and make it easier to start the cut as well. In using this method you are using deeply knifed lines on both boards in order to help guide the saw and help with diagnosing unacceptable efforts.

Though slightly non-traditional (?) it's worth a try if nothing else is working for you. If this doesn't result in a pretty close fit the first time you try it, you should be able to tell where your sawing went awry by examining the knifed lines vs. the saw cuts. If the cuts were bang on in the knifed lines then all you need to do the next time is adjust the projection of the tail board past the end of the pin board -- less if joint was too tight, more if joint was too loose.

That's pretty much the same method I referred to in my post, your 1/32" is my 0.5-1.0mm!

This is getting into PHD level dovetailing rather than the simple method the OP is looking for, but there's a really elegant technique to achieve this, in the UK it's sometimes called "the merest glimmer of light method".

Basically you place a bright light beneath the joint during the transfer and tap the tail board forward until the light is just about, but not quite, extinguished. What's lovely about this technique is that it automatically adjusts the overhang to take account of the relative densities of the timbers used in the drawer front and drawer sides. So Sycamore drawer sides will give a tighter fit, which is okay as it's easily compressed, where as Oak or Ebony drawer sides will be a fraction looser, which is appropriate to prevent these harder timbers splitting.

If I can remember I'll photograph the process next time I use it and post the results. I don't use this technique every time, but when I have a job that I absolutely, categorically have to get right, then it's how I go about the job.

For example, this drawer front is one of three from a laminated and curved section that already represents about 50 or 60 hours of work just for the drawer fronts. Furthermore I wanted needle point or London pattern dovetails despite this being a curved drawer. Screwing this up would really have spoilt my day, which is when the "merest glimmer of light" method comes in useful,

 

[monkeybiter]

Here's a piccy I took today of some vintage drawers from some old Italian furniture. They are, by definition, professionally made.
Can you do better?

 

[B3nder]

Blimey loads of great advice thanks to one and all.

I will try the 0.5mm overhang and stick with the knife for marking.
Although a dart is a great alternative.

Something I didn't think to do was, to check for square on the cuts as suggested above.
It getting better, just not close enough. I'm going to keep trying with the saw fit rather than
Adjusting with a chisel. Worst case I'll have lots of fire wood!

I will tr6 to sort some pics over the next day or so.

 

[Trafalgar]

When marking the pins, nudge the tail board ever so slightly past the end of the pin board - around a 32nd (this is a visual, it is not measured) is a good place to start when practicing. Knife deeply on both the end and long grain of the pin board. Saw on the knifed lines of the pin board (don't worry about sawing in the waste). They'll either be a perfect fit, or slightly loose which in that case you nudge the tail board a little farther the next time. Work it out on scrap first. The harder the species the less you have to nudge the tail board past the end of the pin board but in using this method you always have to nudge it past by some amount. The deeply knifed lines on the pin board provide a trough for the saw to run in and make it easier to start the cut as well. In using this method you are using deeply knifed lines on both boards in order to help guide the saw and help with diagnosing unacceptable efforts.

Though slightly non-traditional (?) it's worth a try if nothing else is working for you. If this doesn't result in a pretty close fit the first time you try it, you should be able to tell where your sawing went awry by examining the knifed lines vs. the saw cuts. If the cuts were bang on in the knifed lines then all you need to do the next time is adjust the projection of the tail board past the end of the pin board -- less if joint was too tight, more if joint was too loose.

That's pretty much the same method I referred to in my post, your 1/32" is my 0.5-1.0mm!

This is getting into PHD level dovetailing rather than the simple method the OP is looking for, but there's a really elegant technique to achieve this, in the UK it's sometimes called "the merest glimmer of light method".

Basically you place a bright light beneath the joint during the transfer and tap the tail board forward until the light is just about, but not quite, extinguished. What's lovely about this technique is that it automatically adjusts the overhang to take account of the relative densities of the timbers used in the drawer front and drawer sides. So Sycamore drawer sides will give a tighter fit, which is okay as it's easily compressed, where as Oak or Ebony drawer sides will be a fraction looser, which is appropriate to prevent these harder timbers splitting.

If I can remember I'll photograph the process next time I use it and post the results. I don't use this technique every time, but when I have a job that I absolutely, categorically have to get right, then it's how I go about the job.

For example, this drawer front is one of three from a laminated and curved section that already represents about 50 or 60 hours of work just for the drawer fronts. Furthermore I wanted needle point or London pattern dovetails despite this being a curved drawer. Screwing this up would really have spoilt my day, which is when the "merest glimmer of light" method comes in useful,

I ran across this method mentioned in a book by George Buchanan, I think, several years ago. Works for me. Faster in most instances too, though clearly with the breathtaking work in your photos one would take more time to get things just right.

 

[Eric The Viking]

Here's a piccy I took today of some vintage drawers from some old Italian furniture. They are, by definition, professionally made.

That is the most encouraging post I've seen for years! I might even do better than that, one day

 

[Jacob]

Back in the day when hand cut dovetails were the normal way to make stuff they weren't half as bothered as we are nowadays. It's only latterly that DTs have become this venerated technique with endless discussions of how to do them, and the DTs becoming the most salient feature of a design.
If you look at even good quality old furniture you could be surprised; a lot done freehand and slightly irregular, very variable angles (non of this 1/6, 1/8, nonsense!) nearly all obviously over-cut and so on. NB the so called "London" pattern is the most common on light domestic furniture drawers - not because it's stylish but because it's the easiest to do. I doubt it was called the "London" pattern back then.
Different world.

PS and I doubt they used coping saws to remove the waste - a very fiddly and slow technique. I'm sure they would have just whacked it out with chisels - with a few quick vertical saw cuts to help.

 

[woodbrains]

Hello,

Have you tried cutting the pins first when doing half blinds? For some reason this seems a less common method but makes sense to me. It is MUCH easier to mark the tails through the wide tail sockets, in fact I use a pencil so my poor old eyes can see the marks. It is also easier to cut the tail sockets, true up any inaccuracies and generally clean out the corners when you aren't concerned with needing them to fit the tails yet. When the pins are looking perfect, it is easier to cut the tails to fit, there is less work to do and the cuts are simpler, so less chance on going wrong.

Mike.

 

[Andy Kev.]

Back in the day when hand cut dovetails were the normal way to make stuff they weren't half as bothered as we are nowadays. It's only latterly that DTs have become this venerated technique with endless discussions of how to do them, and the DTs becoming the most salient feature of a design.
If you look at even good quality old furniture you could be surprised; a lot done freehand and slightly irregular, very variable angles (non of this 1/6, 1/8, nonsense!) nearly all obviously over-cut and so on. NB the so called "London" pattern is the most common on light domestic furniture drawers - not because it's stylish but because it's the easiest to do. I doubt it was called the "London" pattern back then.
Different world.

PS and I doubt they used coping saws to remove the waste - a very fiddly and slow technique. I'm sure they would have just whacked it out with chisels - with a few quick vertical saw cuts to help.

I would imagine that the chosen angle of the dovetail is a matter for nobody but the maker or perhaps in the case of a pro, the client so IMO you're right to describe the prescriptive approach to angles as nonsense. It seems to me that the rest of it is about the pursuit of consistently producing clean, crisp joints of which one can be proud and that is something which can seem extremely daunting to the beginner while being second nature to the seasoned practitioner - hence the perennial questions/debates.

 

[custard]

Hello,

Have you tried cutting the pins first when doing half blinds? For some reason this seems a less common method but makes sense to me.

Interesting, I use the pins first method for cutting secret mitred dovetails because that's the only way to do it. And I've met several accomplished craftsmen who always cut pins first. I agree that once you've built the simple fixtures and jigs necessary for a pins first approach the transfer does become easier. I suspect the reason is that a tails first transfer demands that you preserve the majority of the knife line for a snug fit, where as with a pin first transfer the knife line has to be completely removed which makes life easier. Even though personally I'm more comfortable with a tails first approach due to force of habit, like you I recognise the advantages of pins first and I'm puzzled why it isn't more commonly used.