Thread: Making Rasps - Anyone have pictures of the gravers?

https://www.youtube.com/watch?v=_Mtf...=Howit%27smade

A start - these are aurious.

Not exactly about graver shapes, but the frequency with which he claims to need to sharpen his chisels stuck with me.

https://www.youtube.com/watch?v=X8rPM9QadBc&feature=youtu.be

Rafael

Hi David. The "Ken Hawkins" series of videos may have what you need. He was a Sheffield based collector of tools and knowledge, and I remember footage of him punching teeth into a rasp.

he's definitely got one of punching files. I'll have to go see if rasps were included in that.

i'm afraid of watching the video or I may want to try files, too.

Maybe it was files. Sorry. I've gone down to many rabbit holes on YouTube.

Originally Posted by D.W.

How its made: 1434Handmade rasps - YouTube

A start - these are aurious.

David,

I am intrigued! The YouTube you refer to seems to suggest that there are left-handed & right-handed rasps. Does this refers to the angle at which the teeth are punched? As a leftie I had never heard that a rasp could be either left- or right-handed!

Cheers
Yvan

Can't find it on a very quick search, but Liogier have made a video of the process in which you get a pretty good view of the business end of the tool a couple of times. In the absence of a pic of the tool, here's a couple of shots of 9-grain teeth that might help you reverse-engineer the punch.

Looking from the front of the teeth: Teeth a.jpg

And from the back: Teeth b.jpg

I think you can see that the point of the tool is a shallow vee, cut back at a shallow angle (I've uploaded the pics at as high resolution as these cropped bits retained so you should be able to enlarge them to a good size).

According to Liogier it takes a year to train a new person to the level of speed & accuracy required, but we're talking about a very high level of skill, the teeth on the Liogiers I have are amazingly consistent. The finer grains in particular must take a while to master!
3 grades.jpg

But I think you're right that a rasp doesn't need to be perfect, particularly the coarser grades. A coarse rasp with uneven teeth should still cut aggressively and the quality of the surface doesn't usually matter because you'll be following up with something more refined. Hand-cut rasps are poisonously expensive, but they really are noticeably superior to anything else. When I first got a Nicholson #49 back in the late 70s it was a revelation & I thought it was as good as a rasp could be, but the Liogiers I splashed out on some years later were a step up again.

So go to it with my blessing - I'll be in the line-up with orders when you start production....

Cheers,

Originally Posted by yvan

David,

I am intrigued! The YouTube you refer to seems to suggest that there are left-handed & right-handed rasps. Does this refers to the angle at which the teeth are punched? As a leftie I had never heard that a rasp could be either left- or right-handed!

Cheers
Yvan

Yep, yvan, you are spot-on - the LH rasp teeth spiral the opposite way. Liogier mention it several times in their blurbs & iirc, you have to state on the order form which "hand" you want. It makes sense in theory, but how much better that would be for you only you would be able to determine. A lot of lefties like my dad just adapted to tools designed for right-handers, one way or another. My dad was amazingly ambi-dextrous, so if the situation demanded it, he just became a right-hander. It was a wonderful talent, he could work comfortably in situations where my stolid, stubborn right-handedness is a nuisance!

Cheers,

Originally Posted by D.W.

I can do everything else (heat treatment, shaping a blank to be toothed, etc) without any issue , which is why i thought i'd give it a shot.

Hi David.
The molten Salt bath before the heat treatment mentioned in your link on the Aurious is something completely new to me . How will you be doing that ? I didn't know salt melted. If I had been asked I probably would have said it just burnt up. Molten salt - Wikipedia

There are other methods that do the same thing for heat treating. Ive seen heat treated items being wrapped in soft wire and coated with a Boric acid and metho mix. Would you use that method ? Or are there other methods to choose from?

Rob

Originally Posted by yvan

David,

I am intrigued! The YouTube you refer to seems to suggest that there are left-handed & right-handed rasps. Does this refers to the angle at which the teeth are punched? As a leftie I had never heard that a rasp could be either left- or right-handed!

Cheers
Yvan

From what i've already learned today, the rasp teeth are like little shovels and they are handed so that when you are working rasp across wood or at least askew to it, the shovels are oriented into the wood pushing and not slicing.

if you use a right handed rasp left handled, then you end up turning the teeth to the side and just as you would shovel a narrow swath if you turned the shovels width in the direction of the shoveling, so, too, do you have the same effect "off handing" a rasp with the opposite grasp.

I guess this never occurred to me before because most rasps are probably right handed.

Originally Posted by auscab

Hi David.
The molten Salt bath before the heat treatment mentioned in your link on the Aurious is something completely new to me . How will you be doing that ? I didn't know salt melted. If I had been asked I probably would have said it just burnt up. Molten salt - Wikipedia

There are other methods that do the same thing for heat treating. Ive seen heat treated items being wrapped in soft wire and coated with a Boric acid and metho mix. Would you use that method ? Or are there other methods to choose from?

Rob

Hi, rob - I did it with an induction forge instead. There probably is some case that you could burn and decarburize teeth if you had a too hot forge, though I think if you were careful, even that is avoidable with a lower temp forge and a longer soak.

at any rate, these are nice and thick, and the thicker stock is to a point, the easier it is for my induction forge to really sizzle it. It can keep a whole length of a file at critical temperature or a little above without issue, and while it might be counterintuitive, the teeth are less in cross section and actually take *less* effect from the magnetic current and will have to receive their heat from the body of the rasp.

Put differently - I got lucky! I do have the skill to heat something like a rasp without *over* heating it, though.

Not that I wouldn't love to have a molten salt bath - the trouble is with molten salt, to justify it, i'd need it to get up into stainless ranges, and the salts that do that give off toxic fumes, which wouldn't go over so well in my garage under the living space.

Originally Posted by auscab

Hi David.
The molten Salt bath before the heat treatment mentioned in your link on the Aurious is something completely new to me . How will you be doing that ? I didn't know salt melted. If I had been asked I probably would have said it just burnt up. Molten salt - Wikipedia

There are other methods that do the same thing for heat treating. Ive seen heat treated items being wrapped in soft wire and coated with a Boric acid and metho mix. Would you use that method ? Or are there other methods to choose from?

Rob

(i'm guessing the various coatings are just mechanisms to prevent decarbing the teeth. it would be pretty tragic if you had a wonderful rasp and you burned the carbon out of the teeth! they wouldn't last long.)

Originally Posted by IanW

Can't find it on a very quick search, but Liogier have made a video of the process in which you get a pretty good view of the business end of the tool a couple of times. In the absence of a pic of the tool, here's a couple of shots of 9-grain teeth that might help you reverse-engineer the punch.

Looking from the front of the teeth: Teeth a.jpg

And from the back: Teeth b.jpg

I think you can see that the point of the tool is a shallow vee, cut back at a shallow angle (I've uploaded the pics at as high resolution as these cropped bits retained so you should be able to enlarge them to a good size).

According to Liogier it takes a year to train a new person to the level of speed & accuracy required, but we're talking about a very high level of skill, the teeth on the Liogiers I have are amazingly consistent. The finer grains in particular must take a while to master!
3 grades.jpg

But I think you're right that a rasp doesn't need to be perfect, particularly the coarser grades. A coarse rasp with uneven teeth should still cut aggressively and the quality of the surface doesn't usually matter because you'll be following up with something more refined. Hand-cut rasps are poisonously expensive, but they really are noticeably superior to anything else. When I first got a Nicholson #49 back in the late 70s it was a revelation & I thought it was as good as a rasp could be, but the Liogiers I splashed out on some years later were a step up again.

So go to it with my blessing - I'll be in the line-up with orders when you start production....

Cheers,

Those are similar to my teeth, though mine aren't quite as sharp diving into the tool (the scooped V), but admittedly, I just belt ground a few gravers and they could be cleaned up if needed.

I think of the folks on here who do a lot of hand work, we could be solid at doing teeth in a rhythm and neatly within a week or two, but we are far different than an hourly applicant coming off of the street and if we're using hand tools a lot and in some rhythm, we have a huge neural head start.

Here's one of the Liogier videos.

The making of LIOGIER hand-stitched wood rasp - YouTube