Filing A Curve

Hi,

I was watching the video posted by Jason of the guy making a ring from a couple of brass nuts. I noticed he was filing the ring by starting with his left hand high, and following the curve with his left hand dropping as he pushed forward. This seems to be the usual procedure for most if not all of the people I see filing curves which is not surprising as it is the natural way of doing it.

When I was taught workshop practice at the Tech however, the tutor went to a lot of trouble to stop the class doing it that way. He taught us to start a cut with the left hand low, and to raise it as the file was pushed forward. There was a lot of muttering about it initially, but once the technique was mastered, it seemed to give better results, although this may have been because we were getting a lot of practice in filing.

Is the way I was taught the "correct" way or doesn't it matter which way it is done. The guy making the ring certainly ended up with a nice curve.

Regards,

Alan

I was taught to file curves the second way you describe, with the file following an arc in the opposite direction to the arc you're filing on the workpiece. I guess you're trying to use more of the length of the file, rather than clogging up one short section with the waste.

When drawfiling on the other hand the arc of the file follows the arc on the workpiece, but then the file's perpendicular to the work so rolling it the other way ends up digging in the file edges and less material is being removed anyway.

Rob

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Second method was standard when I was an apprentice too. Has always worked for me. Jewelry making as shown in the video is a different game from toolmaking though. Probably not so critical to get the curves within a thou all over, just so long as it looks good. Which is not to say it's not fine work -- look at what watch and clockmakers do freehand on their little lathes -- just a different way of working.

I was taught the second method during my apprenticeship; I also taught apprentices the same method when I was training NVQ/BTEC apprentices in the practical aspects of Mech.Eng. IIRC the other way tended to leave a minute flat on the surface you're filing which you ended up having to draw file to finish off.

George.

Thinking intuitively, how about this:-

If you follow the first method your left hand is mainly being used to apply pressure to the cut with the right hand following through.

In the second method the right hand on the file handle is applying the pressure to the cut with the left guiding. The right hand is doing most of the work and as it is generally stronger than the left and closer to the body will tire less and be able to take 'deeper' cuts. Which, if you are doing this all day allows for a higher output of parts. It feels like you have greater control over the file too.

regards Martin

Since he is sitting down does that make nearest hand down a bit of a problem hitting either your clothes or the tray/swarf bib for jewellers? Right hand up when standing is also more difficult to do smoothly as you get older and the shoulder muscles start to weaken.

I perhaps should have added that I think that as the accepted/taught practice almost certainly originated in industry many moons ago it would likely have been for standing operations using large files and that max rate of metal removal. It may therefor be less relevant to operations that are very different to that use.

Often the things that get taught with regards to hand tools have their origins back in the mists of time and don't always apply. For example I remember being taught to always lay a wood plane down on it's side. I discovered many years later that particular practice originated with wooden planes where the iron was held with a wooden wedge. Putting the plane down on a bench on it's sole would sometimes alter the set of the blade which was undesireable. The problem does not occur with iron bodied planes but the practice is still taught, or at least it was 50 odd yeards ago when I was a school. People remember what to do long after the reason for doing it has been forgotten.

regards Martin

I was taught the "Left Hand down" method, so that the file effectively reversed around the radius from bottom to top, to blend into the upper flat surface.

My woodwork master taught us to lay a plane on its side, whether metal or wooden, so that the blade was not damaged, as it could be if placed with the blade downwards.

Howard

Exactly right. otherwise you have to sharpen it more often.

I file curves with the left up, right down as well. Don't remember where I learn't it but possibly one of the few useful things from DCT as metalwork was becoming around 1975.

Neil

I’ve heard this many times. If a steel blade is so easily damaged by placing it on a wooden bench you have to wonder how it cuts wood in the first place.

a plane is to cut it must be razor blade sharp. Putting it face down means that it will be in contact with a bench which may have hardened glue etc. bonded to it so any pick up which moves the body will blunt it against this rubbish. So it makes sense to put it on its side. What...  you say. My bench has no such rubbish! It’s perfectly smooth! Ok I say don’t damage the bench then  with a sharp plane blade....but  if it’s like my bench it’s piled with tools so putting it on it’s side means that it cannot be put onto another tool which could and I say could damage the fine edge and produce ridges in any planed work. Why take the risk? The old practise of putting any plane on its side was and still is good practise

A sharp plane will really  sing to you when used. When used on a hard tough wood it won’t take long to need honing why take the risk?

Edited By Zan on 29/01/2019 00:12:16

Edited By Zan on 29/01/2019 00:14:28

... If a steel blade is so easily damaged by placing it on a wooden bench you have to wonder how it cuts wood in the first place.

If you ever spend as much time as I have pulling nails and other metal objects out of school woodwork benches, you'll understand.

George

Don’t woodwork bench’s have a well for the very purpose of putting a plane down without the blade touching anything?

Mike

I think my point was that life and technonolgy moves on but habits/methods persist. Sometimes there are new reasons to continue to do things on the same way sometimes there aren't. A freind of mine has a story regarding an ex tracer who worked for them. This was the early days of digitising drawings. The girl was supposed to move the digitising arm over an existing drawing in order to store the image on their early computer. They used a pen plotter to print the results which consisted of a roll feed which could move an A1 sheet backwards and forwards whilst the pens were driven along the top axis. When they came to print this girls work they found the printer was spending most of it's time moving from one corner of the drawing, drawing a few lines and then moving to a completely different part of the sheet. When they asked her why she had done things in such a fragmented way she said that as a tracer you did a bit and then went somewhere else on the drawing whilst the ink dried. She found it very hard to shake the habit.

So you may feel that the way you place your plane on your bench has a valid reason behind it, but it's not the same reason that it once was because it's not the same tool.

regards Martin

The well is so you can get the tools below the bench top and move larger pieces of wood over both sides of the bench without fouling them. Interesting post following by Martin about not keeping up with the times since the well should nowadays be made deep enough to accommodate the much bulkier power tools but nobody thinks of that when making that style of bench.

Newly wed couple cook their first Sunday roast. The wife takes the meat, cuts the ends off, puts them on top of the roast and puts the meat in the oven. Not liking to start an argument so early in the marriage the husband says nothing. Several weeks go by with the same thing happening each time. Finally the young man can stand it no longer and says 'tell me why you do that thing with the roast'? His wife says "what thing". "That thing where you cut the ends off the meat and place them on top of the joint" . "Thats how you do it" says the wife. "My mum always did it like that" "oh says the husband". A couple of weeks later they are having a meal with her parents. "Mum" says the wife "why do we do that thing with the roast dinner, you know with cutting the ends off and all"? Mum says she's always done it like that because thats what her mum did. They are due to see the grandmother in a week or so and because they are all now so intrigued, resolve to ask the old lady and solve the riddle. The visit comes around and the old lady is finally asked the question why she always cut the ends off the meat and put them on the top of the joint before putting it in the oven.

"Oh thats easy" the old lady replies "you see when we got married, we only had a little oven and that was the only way you could get it in"

As I said the method remains long after the reason has been forgotten.

regards Martin

and before you all go PC on me I do the cooking at home.

Posted by Georgineer on 29/01/2019 09:07:56:

Posted by Vic on 28/01/2019 22:58:00:

... If a steel blade is so easily damaged by placing it on a wooden bench you have to wonder how it cuts wood in the first place.

If you ever spend as much time as I have pulling nails and other metal objects out of school woodwork benches, you'll understand.

George

A friend of mine is a D&T Technician at a school with 1100 boys. They do have three or four planes “on display” in one of the classrooms but they virtually never get used, that’s what the planer thicknesser in the back room is for. The boys do get through a lot of sandpaper though. As for nails in benches I’ve never seen any when I’ve been in there, but then it is a private school and the benches have MDF protectors on them most of the time.

The other school of thought says that if you lay a plane on it's side there is more risk of it coming into contact with other tools on the bench and being damaged by them than if it stands upright.