What am I doing wrong?

[adrspach]

Hi. I process of my learning this new hobby I am trying to get to hand cut dove tailing. Following the general advice how to practice straight cutting I have prepared a board of the thickness i will be using in my next project. Marked lines on both sides and started cutting. as my present table which I use as a bench is too low I sit on a stool. I did not change my position during this experiment. i was using my right hand.
First I took Victor Brand jeweller's saw and here was the problem. I did 12 cuts in total. All my cuts were slowly curving towards the right about 2mm on 20mm length of cut. I have tried grip with index finger positioned on the top of the handle as well as full grip with the same effect. Only marginal difference was when i tried to cut with added presure but it stil was not much straighter.
Second small japanese saw from Chronos with one side rip and the other cross. Cuts were straight with both sides even thoug not all of them completely on the line.
Third Wenzloff dovetail saw. Harder to start saw tried to jump out of the cut. Simmilar to the japanese saw but a bit coarse cuts.
Fourth and last a second hand vintage heavy brass back dovetail saw (off bay) with teeth not very sharp and refiled unevenly by previous owner. BEST of the lot even though not as fast as other western saws. Straigth on line ( I know by now I have already done 3 dozens of cuts) and quite smooth with not too much of tearout.

Can you tell me what i am doing wwrong that I can not get comparable results from the Victor saw?
Thank you

 

[AndyT]

You need to tell us some more details - particularly the thickness and type of wood, and the actual teeth per inch count of the saws - but my guess is that the "jeweller's saw" will be intended for fine cuts in metal and will be far too fine for use in the wood you have. If there is not enough space in the gullet of each tooth to carry the sawdust, a saw will not cut true.
It's a trade-off - if the wood is thick (so the length of each stroke is quite long) the teeth will fill up with sawdust which cannot be ejected until the saw exits the back of the wood. To counteract this, you need bigger (coarser) teeth.

 

[adrspach]

8 mm hardwood unknown. My wife's grandad got it in seventies from some crates in London docks.
Victor 25 tpi
Japanese rip 14 tpi and cross 28 tpi
Wenzloff 15 tpi
Old dovetail E. Brown Liverpool 17 tpi
When I was cutting I was trying not to add any presure apart from already mentioned Victor and with Japanese saw as it would not cut nearly at all.
The wood was held vertical in woodvorking vice.

 

[sdjp]

Is this the jeweller's saw?

If so. then the key aspect is likely the handle shape - that's a style often called 'Gent's saw'.

It's most likely to be one of three things: Either the saw is filling with sawdust, your grip is such the you're pushing the saw off line, or the saw has been unevenly set. What's the handle like on that Japanese saw? Is it the classic long rod, or something else?

With an off centre grip, swapping to the left hand is likely to reverse the curve. With uneven set, swapping to the left hand should leave the curve unaffected. Sawdust … will pick up on one of those.
Note that this is dependent on a straight cutting saw still cutting straight (i.e. ruling out a significant technique difference). That's dependant on you feeling that your being consistent with your left hand - no reason why you couldn't be, but that might be too much practice needed for this to be a useful test.

To test if it's sawdust jamming, try to cut a board half the thickness, and one twice the thickened (clamping 2 boards together aught to work). I'm not sure that's the case - 8mm thick over a 150mm saw aught to be fine, I would have thought - and you can normally feel the saw stopping cutting when it gets filled.

My gut feeling is that you're likely to have the centre of grip on the gents saw just to the inside of the ideal point - one option might be to try to hold the jewellers saw with your hand deliberately twisted 'too far' to the right, and see how that cuts. If you find it curves to the left, then you can adjust it till it cuts straight.

 

[adrspach]

The Victor saw looks like you describe Gents saw handle.
The japanes saw is like long stick.
I will have a go tomorrow with the left handed cutting and report back.

 

[pedder]

Sounds like the set is uneven on the Victor saw. You can dress the side to wich it pulls (hope my german english is understandable) with a fine file or stone. Lay it flat with the pulling side upside, thand one light file or stone stroke from the jandle to the tip.

Quick search for aninstruction writte by a native speaker:

http://villagecarpenter.blogspot.de/200 ... r-saw.html

Cheers Pedder

 

[Jacob]

Too many saws. At least you should be able to tell which one is sharp!
I'd stick with just one saw probably the Wenzloff assuming it is sharp. Just keep at it until you can do it.
Do a lot of practice sawing to start with - draw lines a few mm apart around a bit of scrap say 2x1"and cut it into lots of domino shapes.
Practice practice!

 

[pedder]

Too many saws.

You can't have too many saws, can you??

:shock: :shock: :shock: :shock: :lol: :lol:

 

[MIGNAL]

Before you go stoning the side of that Victor saw try it in say 4 mm material, even Pine will do. See if it wanders then. I wouldn't do anything to any of the saws until you've got the technique sorted out.

 

[pedder]

Unless you really force the saw to one direction, it should saw straight. It is important not to push the saw in the cut. Just let the saw do the work. Light grip and closed eyes help.

But 2mm on 20mm means the saw set is wrong. On a well set saw you can't force the saw to make a curve like that.

Try tu lessen the set on the right side. If I was wrong send it to me, I will reset the saw and send it back to you.

All that can happen is, that there is no set anymor after dressing.

Cheers
Pedder

 

[matthewwh]

Sitting down is part of the problem, if you were in a wheelchair then fair enough, but you'll get much better results by positioning yourself correctly relative to the work and vice versa. Can you get some wooden blocks to put under the bench legs to raise the height to about 30 inches?

Agree with Pedder on the gents saw, although as you've got a Wenzloff I would be inclined to use that instead, after the first couple of hundred cuts it will bed in and become incredibly smooth and accurate. In any event, you're certainly not short of hardware, so here's a few technique pointers:

*Saws are designed to work vertically, so orientate your work in the vice so that the cuts are plumb.
*Always exit through the endgrain, so for a western saw start with one smooth, full, very light, forward stroke on the corner nearest to you.
*For the first few cuts you are driving and controlling the saw, hold it as normal but pinch with finger and thumb - as you would when holding a pencil.
*Don't allow the weight of the saw to rest on the work until the cut is well established, let it down gradually - like an aeroplane landing.
*Once the cut is established, the kerf will guide the saw and you need to minimise your influence over it. Switch the pressure from finger and thumb to squeezing with your little finger.
*It's better to stop a mm short of the bottom and clean up with a chisel than to risk over cutting and leave a gap.

Hope this helps,

 

[Jacob]

I didn't notice the sitting down. Matthew is right.
It was my first mistake when I started my first course years ago. He said to have a go at a mortice while I get your kit together. So I sat at a bench and started poking away at a mortice. I didn't notice they'd all gone quiet - the gaffer came back and gave me a very strict talking to about sitting down; basically never whilst you are working - odd exceptions if say you are doing a lot of marking up or just having a cup of tea!
I've been standing up ever since - well it feels like it anyway.

 

[Jacob]

...
*It's better to stop a mm short of the bottom and clean up with a chisel than to risk over cutting and leave a gap...

Nope.
DTs are always over cut (by as little as you can get away with). It makes it easy to clean out the corners (there aren't any, you've cut through them) so it's a lot faster and neater.

 

[Paul Chapman]

...
*It's better to stop a mm short of the bottom and clean up with a chisel than to risk over cutting and leave a gap...

Nope.
DTs are always over cut (by as little as you can get away with). It makes it easy to clean out the corners (there aren't any, you've cut through them) so it's a lot faster and neater.

You speak for yourself, Jacob. Many manage perfectly well without over-cutting.

Cheers :wink:

Paul

 

[Jacob]

...
*It's better to stop a mm short of the bottom and clean up with a chisel than to risk over cutting and leave a gap...

Nope.
DTs are always over cut (by as little as you can get away with). It makes it easy to clean out the corners (there aren't any, you've cut through them) so it's a lot faster and neater.

You speak for yourself, Jacob. Many manage perfectly well without over-cutting.

Cheers :wink:

Paul

They'd manage even better if they just followed some of the old shortcuts. All the old furniture I've ever looked at has over-cut DTs, sometimes dramatically so.

 

[Paul Chapman]

They'd manage even better if they just followed some of the old shortcuts. All the old furniture I've ever looked at has over-cut DTs, sometimes dramatically so.

Well, keep looking, Jacob. There are plenty of examples of old stuff out there where they are not over-cut.

Cheers :wink:

Paul

 

[matthewwh]

I've seen some bog awful dovetails in antique pine pieces too, I suppose it depends what sort of work you are trying to emulate.

Fair enough if you're banging together a planter for the garden out of pallet wood, but I wouldn't want to see it on a jewellery box.

 

[Jacob]

They'd manage even better if they just followed some of the old shortcuts. All the old furniture I've ever looked at has over-cut DTs, sometimes dramatically so.

Well, keep looking, Jacob. There are plenty of examples of old stuff out there where they are not over-cut.

Cheers :wink:

Paul

If it's done very carefully you wouldn't know.
The point is - the DT saw is the best tool for removing the corner. Non of that fiddling about with special chisels etc. Imagine doing dozens of them - the time saving would be enormous. And neater too - it's the fiddling about in the corners where things can go wrong.
Better class of work it'd be virtually invisible and require slightly more care, but still be a lot quicker and neater than fiddling about after the saw cut with chisels.
Basically it's how it's done, but "properly". You saw dead to the line plus an invisible gnats. Or more if you are in a hurry.
Stopping short of the line and then having to chisel is really clumsy and amateurish. It's no great problem - even the beginner should aim to cut to the line IMHO. Start as you mean to go on.

NB you still have to chisel out the waste of course but it's very easy if you have already sawn to the corners (and a gnats beyond)

 

[matthewwh]

Personally I always chisel the baselines anyway, so nipping out a mm of fluff in the corner is neither here nor there.

It just goes to show that there are many ways of working, collecting alternative methods can be as addictive as 'having a broad selection of tools to choose from'.

edit: just read the last line of your post JB, I think we are well into the minutiae of the job now.

 

[adrspach]

Reaso why I sit down is that at present i am still messing about indoor and my table would have to be lifted by at least 6 inches. tried to put some timber under but it started to be too wonky.
My shed bench is awaiting swap of whole frame that it will be right height for standing.
The wood had lines about 2mm apart andthey were positioned verticaly.

To report for my left handed attempt it was even worse and to the same side. Therefore you are guys probably right that side are set differently from each other. Even though I am not sure if there is set on one side at all as the saw strats binding already when it is in about 8mm (bees wax on the blade).
I will stone the Victor tommorrov an we will see.
As of knowing which saw is sharp. I am just a beginner but I think that I can recognise difference between completely blunt and sharp saw. For example the one which I bought today is about half inch too long for the wooden frame but new blades are already waiting I just need to cut them and drill them for right length.
Yes I do have few saws. I do this for fun as hobby therefore I want to enjoy it and if it is not too expensive why not? I am learning therefore I experiment what would be the best for my learning. that is why I tried all those saws. My surprise was that there was reasonable consistency with all saws but Victor.
So far I am concentrating on straigth cutting once that it reasonable I am going to learn to cut to right depth for clean corners.