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Hand cut bridle joints

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Anyone got any tips on getting the "mortise" part of the bridle joint cleaned up (hands tools only)?

1626101857373.png


My cuts with the saw are getting pretty good now, and I am cutting to within 0.5mm from my knife line and cleaning up with a chisel. I find it diffcult get the inside of the "mortice" flat though, and invariably end up taking too much off.

I thought of making a jig that is exactly the same height as sides of the mortice so I can rest my chisel on that. But that probably isn't practical as I would need a new jig for each size I do. I also tried putting the piece in my vice so I can rest the chisel on the jaw of the outside vice. But my vice isn't very true and tends to skew slightly when tightened up. So that didn't really work either.

The tenon side is much easier as I can quickly remove the 0.5mm down to the knife line with my router plane.
 

Jacob

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Anyone got any tips on getting the "mortise" part of the bridle joint cleaned up (hands tools only)?

View attachment 113914

My cuts with the saw are getting pretty good now, and I am cutting to within 0.5mm from my knife line and cleaning up with a chisel. I find it diffcult get the inside of the "mortice" flat though, and invariably end up taking too much off.

I thought of making a jig that is exactly the same height as sides of the mortice so I can rest my chisel on that. But that probably isn't practical as I would need a new jig for each size I do. I also tried putting the piece in my vice so I can rest the chisel on the jaw of the outside vice. But my vice isn't very true and tends to skew slightly when tightened up. So that didn't really work either.

The tenon side is much easier as I can quickly remove the 0.5mm down to the knife line with my router plane.
Taking too much off the inside of a bridle joint is OK within reason - as long as it is from the middle areas of the face and you haven't gone over your gauge lines. So basically - the gauge lines are sacrosanct - work to the lines but not beyond them.Easier with a long thin paring chisel - the length helps guide your angle and helps you see whats going on.
 

thetyreman

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I'd recommend sawing straight to the line instead of going 0.5mm off, with enough practise you'll get it bang on, then make the tenon slightly fatter and take tiny amounts off it until it fits just right. A pairing chisel as jacob says is very useful, I use one a lot, especially for the tenon, it's easier to control than a normal chisel.
 

Jacob

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I'd recommend sawing straight to the line instead of going 0.5mm off, with enough practise you'll get it bang on, then make the tenon slightly fatter and take tiny amounts off it until it fits just right. A pairing chisel as jacob says is very useful, I use one a lot, especially for the tenon, it's easier to control than a normal chisel.
and it's easier with a rip filed saw - it does make a difference. Still possible with a crosscut of course, I wouldn't dash out and buy another immediately!
 

Argus

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Floats.

As above, when you get to the point where your 'mortise' flats are shaped to your satisfaction, and you need to flatten the faces, I recommend an old fashioned joiners' float.

They can be rare and hard to find, though a French firm, Liogier, now makes one that is very good.

Here's a video about it:


I won't say that they are easy to get (bit expensive) but it is a quality tool and will last a lifetime. They can also a bit of a fiddle to sharpen, but like a good saw, you get it right once, then maintain it occasionally with a file.... just like a saw.

What is it?

Imagine a Rip Saw profile. You sharpen each tooth with a file so that each peak is level. Now, instead of a thin saw plate being a couple of mm wide at the tip, you stretch the whole thing sideways to make a 'float' which is now about 1 inch in width, 1/4 inch or so thick, with the same rip-saw profile, sharpened like a saw. It will now cut cross grain in a straight line inside your bridle. At first it looks a bit like a rasp, but is more precise and will give a dead flat surface inside your joint if it is sharpened correctly.
It is repeatable if you are making a lot, if you use guide blocks of the exact same thickness as each side of your bridle, and slide them flat on a smooth board. You will get each bridle with smooth, flat parallel cheeks, time after time.

Good luck.
 
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Trainee neophyte

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@Argus

I'm not too bad a making tenons, but my mortices are shocking. I have never come across this tool before, and new knowledge is always good. Thank you.
 

Adam W.

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Yeah, floats are the way to go. Classic Hand Tools sell them, but they're pricey.
 

C64

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Workshop heaven has the Liogier floats on their website which are a little cheaper than the LN floats sold by classic hand tools. Quite like to get one or two but like the poster above said, I should really saw to the line and hit it first time. At the moment, I just use ordinary files to clean up the faces of tenon and mortise walls as I’m knocking off any high spots.
 

Argus

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Needless to say, I use floats a lot. An extremely versatile old-school tool - unobtainable for a long time.

The Liogier floats are very rugged, tempered just right to be hard enough to sharpen and machined flat - a float's blade must be flat........ which is more than I can say for the Lie-Nielsen ones. I bought a couple about 10 years ago, and they both went back because the blade was curved.

Noel Liogier makes some excellent rasps, too. All hand-made.

All floats need sharpening - they won't cut from new, but when you've done that you have one of the most versatile and under-rated tools to be had. If you can sharpen a rip saw, then a float is no different.

In any case, a float is a finishing tool, just for the last swipes when you have done all the paring to the line. It can get into a cutting position in some odd spaces other tools can't reach and can leave a dead flat surface with some care.

Sadly, the hand made ones are expensive........ but they are hand-made.

.
 
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Ttrees

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I cheat and transfer graphite using a plate.
If you have some chunky piece of cast iron or aluminium, you could try and see what you think of it,
If you don't like that idea, then at the very least the tool will give an
idea of some high spots, like in this photo.
There is still a big shadow gap, so that tells one there is still a lump somewhere.
SAM_3900.JPG

And another picture of the transfer whilst cleaning out an old mortise, must make a wee plate from some cast iron, as you have to apply graphite frequently onto aluminium.

I've tried to find a recent photo, as I try and do this job pairing away from me now, getting nice shavings whilst tenting is easier that way I find, as I tend to overuse the graphite making patterns, when getting close if orientated the way below.
This can lead to surfaces resembling Japanese scraping techniques AKA a lot of wasted time.
SAM_2841.JPG
 
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Needless to say, I use floats a lot. An extremely versatile old-school tool - unobtainable for a long time.

The Liogier floats are very rugged, tempered just right to be hard enough to sharpen and machined flat - a float's blade must be flat........ which is more than I can say for the Lie-Nielsen ones. I bought a couple about 10 years ago, and they both went back because the blade was curved.

Noel Liogier makes some excellent rasps, too. All hand-made.

All floats need sharpening - they won't cut from new, but when you've done that you have one of the most versatile and under-rated tools to be had. If you can sharpen a rip saw, then a float is no different.

In any case, a float is a finishing tool, just for the last swipes when you have done all the paring to the line. It can get into a cutting position in some odd spaces other tools can't reach and can leave a dead flat surface with some care.

Sadly, the hand made ones are expensive........ but they are hand-made.

.
When you said expensive hand made, I was bracing myself for bad axe saw prices.

€50 does not seem expensive.

So is it basically a rough file? Isn't it going to tear out along the edges? Something you avoid by paring into the middle?
 

Ttrees

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Agreed with Jacob, the edges are sacrosanct.
I would be hesitant to use a tool that might hit my lines.

If you're having to do some heavy paring, especially on something deep, then make sure that you get as close to the line as you can, as this will allow for as much "tenting" as possible, (leaving material left in the middle)

If you don't and stay away from the line, then your chisel is likely going to end up perpendicular, and the waste stands a much better chance of pushing the bevel beyond the line (if you've still a ways to go yet)

Tenting can be cleaned up with a quick succession of thin shavings, which won't have the strength to force the bevel beyond what you're working to.

Ps The plate taught me a lesson that I hadn't been getting the chisel
as close to the bassline everywhere,
Yes I'd get it dead on at the surface, but 1mm beneath there would be hairline lumps, which obviously emphasized in the photo with the glove.
This in turn didn't allow me to tent as much as I liked leading to some unintentional diving of the cut.

That shadow line is what will tell you if there's a lump just below, you can use your widest chisel to do the same job (providing its flat)


Tom
 
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MorrisWoodman12

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A hand router. Ideal for such a job.
(ebay).
A hand router is brilliant for the tenon but the mortice?
And fleabay??? I bought a serviceable #71 several years ago for about £40 (in OK but not good condition) but have you seen the prices these days? Ow! You'll be lucky to get any change from £100 and more likely be paying £120 for a good one with all it's bits.
Martin
 

pe2dave

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A hand router is brilliant for the tenon but the mortice?
And fleabay??? I bought a serviceable #71 several years ago for about £40 (in OK but not good condition) but have you seen the prices these days? Ow! You'll be lucky to get any change from £100 and more likely be paying £120 for a good one with all it's bits.
Martin
The question related to the tenon.
I've bought 3 off ebay. If you like new, I'm sure you can find one? New cutters are available.
 

Argus

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When you said expensive hand made, I was bracing myself for bad axe saw prices.

€50 does not seem expensive.

So is it basically a rough file? Isn't it going to tear out along the edges? Something you avoid by paring into the middle?

The price is subjective....... you'd pay that for a football match ticket these days. One of those floats will last a lifetime.

No, It's not a rough file. If you want a rough file, they are much, much cheaper; also, it isn't a shaping or cutting tool - rasps will do a better job.

So, what is a float?

It is a finishing cut....gentle forward motion each time. The last few strokes are done with a float and it is capable of good precision. Cut with the grain it will leave a perfectly smooth surface. Cut across the grain and it will leave a flat surface, but with an element of tear - just like a sharp router. So, you don't do that. The sideways approach is best, done from an angle, just like slicing with a chisel blade.
Never force it - it will dig in. The secret is in the name - when it is sharp and you are gentle with it the tool will float across a surface, producing very fine shavings, almost like a good scraper.

The technique is to either use it to shape end grain - plane makers used floats to get the throat faces and iron beds exact - or to take an oblique cut on cross-grain, very lightly, as you would with a paring cut. Cut directly across the grain will result in the dreaded, predictable tear-out. It needs to be an oblique angle against supported grain all the time.

Looking at it, the edge-profile is the same as a rip saw. I've just measured my Liogier float and it comes in at 9 teeth per inch.
So, in a well set and sharpened float, what you have is a flat set of rip-type teeth, about an inch wide that are all exactly aligned in height so that each one strikes the work at the same level and the same angle. Each tooth is about 1/8 inch apart and should be razor-sharp from a file-swipe, presented at about 60 degrees forward angle.
If you had a plane iron mounted and cutting at this angle, it would be the equivalent of 'half-pitch', which is perfect for wavy grained timber.
A float has the equivalent of several dozen half-pitch blades, cutting in sequence, one after the other.
As each tooth transits the work, its cut overlaps its neighbour. It follows that if your stroke is exact or regulated by a block you'll end up with a perfectly flat surface.

I hope that I've explained what is an unusual tool these days......

Going back to the OP's question about the final leveling the faces of his bridle joint, if it's done with a float, it should, in my opinion, be the very final tool, used after all the fine paring down to the line leaves a slightly proud level that you have mentioned. At this point, hang up the chisel and reach for the float..
If the bridle part is clamped to a very flat board and two blocks about a couple of inches square that are exactly as thick as the bridle's sides are set loose and free to move against each edge, the float can be rested face down on these and the last few strokes taken with sucessive, small nibbles advancing to the middle until there is nothing removed.Turn it round and repeat. At this point you should have a level bridle cheek and if the cutting is gradual and gentle as I described, very flat.

Now, turn it over and repeat on the other side, small, light, oblique skims until it is all flat and nothing is removed.
A combination of a sharp float, and gentle, oblique motion will give a very good and exact finish that can be repeated if you have a batch to do.
Once all this is done, you can cut and fashion your tenon part to fit tightly into the middle gap which should be parallel and flat-sided.

I hope that I've explained how a float is intended to work.... more importantly what it's not supposed to do!

Good luck
 
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