Making a rasp for saw handle shaping

[rob streeper]

I've been struggling with ways to prevent split-outs at sharp corners of saw handles. I have a set of really fine Liogier rasps and IF my technique is perfect I get few if any split-outs. I was reading on Noel's site that he can make a double handled rasp with the cutting direction oriented perpendicular to the long axis of the rasp. However, I'm not ready to place another order yet so I thought I'd try my hand at making my own special rasp.
I had some W-1 drill rod and O-1 flat stock laying around the shop. S-7 would be better for the punches. I read that files are typically made from W-1, W-2 or 1095 so I should be okay with O-1.

First the punches. I have no idea how to shape the points so I'll just wing it.

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I decided to make three, 1/8", 3/16" and 1/4" in diameter.

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The rasp blank was cut out using an angle grinder.

Next to harden the punches. I used an acetylene torch and heated to red-orange at the cutting point end and then quenched in a cold saturated solution of CaCL2/NaCl.

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Here's how they turned out.

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I then cleaned up the tips on my small belt grinder.

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I clamped the blank in the vise and got to punching.

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Overall the feel of the result is okay for a first try. Now to drag out the oven and heat treat it and a number of floats I have made up.

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Prepare my quench bath, here I am using used vacuum pump oil. I use this firstly because it is a highly refined mineral oil without any additives such as detergents that are found in motor oils and second I get it for free as a byproduct of my paying work. After filtration and drying it is fine for this purpose. The particular oil here is Inland 19.

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Now to warm up the oven, this one reads in oF.

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Hits the soak temperature in about 15 minutes. This oven usually holds +/- 5 oF

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In we go.

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Wait 20 minutes.

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Quickly remove one-by-one and drop in the oil.

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Fish them back out after they stop sizzling.

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Wire brush lightly to remove the scale and carbon.

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The Rc of these is running right at 63-64 or so. I'll draw the temper of the tangs of the rasp by heating with oxy-acetylene and the floats go back into the oven at about 545 oF for normalization to Rc 57-58.

Now to draw the hardness of the tangs. The Peter Wright anvil acts as a convenient heat sink to keep the toothed section cool-ish.

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Now, does it work? The saw handle is my polycarbonate infused mesquite - very tough and tends to clog cutting tools.

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And it works! no split-outs into the kerf where the saw blade fits.

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Well, that was fun. Is it a Liogier? Not on your life, Noel is a magician. Maybe that's why he's considered a French national treasure or whatever.

Before somebody jumps down my neck about how irresponsible I am to present such hazardous info on the Internet where some innocent little Lamby-kins might get them self dead I will now provide mandatory safety note:

Don't under any circumstances try to do what I have just done. The work involved high temperatures, high amperage appliances, flammable and explosive gases and liquids, sharp things, power tools, eye hazards and so on. If you try to do this you will almost certainly die either in a bright flash of light with accompanying explosion and fire or perhaps some protracted agonizing horror of lingering death.

Consider yourself warned. :)

P.S. Here's the annealing curve and equation for O-1.

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[RayG]

Nice work Rob,

You are inspiring me to have a go at making some rasps..

I have made floats, but I always have trouble with warping when quenching, because of the large differences in surface area on each side.

For tempering I use a toaster oven with a retrofitted PID controller.


Ray

[rob streeper]

Thanks Ray,

Overall it was pretty easy. Mistakes make themselves known immediately. It'll take a lot of practice to get up to something comparable to the professionals though.

[rob streeper]

Here it is provisionally fitted up with a couple of file handles.

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Testing...

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Does exactly what I want it to. It's got a little too much flex so I'm going to grind the tangs down a bit to bring the handles closer to the center.

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Much betterer.

[planemaker]

Rob. Can I suggest you get yourself a Japanese Feather File for shaping the flat profiles around the handle. The tooth configuration is ideally suited. The added bonus; it will also leave you with a surface that requires only a very light sanding during final prep.


Stewie;

http://www.leevalley.com/en/wood/page.aspx?p=32951&cat=1,320,43072,43089&ap=1

[rob streeper]

Thanks Stewie,

I was thinking about making a posting on files for shaping handles - I've got some favorites. Want to collaborate? I'll post mine when the weather lets up in a day or so.

Cheers,
Rob

[Heavansabove]

Rob, that rasp looks very useful, I imagine Liogier will make this style. Perhaps even more useful in a curved version.

Cheers
Peter

[rob streeper]

Rob, that rasp looks very useful, I imagine Liogier will make this style. Perhaps even more useful in a curved version.

Cheers
Peter

Amazing, great minds think alike. I just happen to have some 1/2" O-1 drill rod too...

[rob streeper]

By the way, if anybody wants it I've got an Excel spreadsheet set up to calculate the drawing temperatures of various tool steels. Send me a PM and I'll forward it to you.

[planemaker]

Rob, that rasp looks very useful, I imagine Liogier will make this style. Perhaps even more useful in a curved version.

Cheers
Peter

Hi Peter. Logier do make a 2 tanged version that designed to be used in a similar fashion to a drawknife or spokeshave. Available in stitches #8; #11, & #14. My personal preference would be #14 with a sapphire finish.

http://www.hand-stitched-rasp-riffler.com/saphir/rasps/laterale.html

At present I am waiting on the arrival of a Logiers Luthier Rasp. Not for saw handle work, but for bedding irons on traditional hand planes. I want to compare its performance to that of my Bed Float.

http://www.hand-stitched-rasp-riffler.com/saphir/rasps/luthier.html

http://www.henryeckert.com/index.php?route=product/category&path=39_140_142

Stewie;

[Heavansabove]

Hi Peter. Logier do make a 2 tanged version that designed to be used in a similar fashion to a drawknife or spokeshave. Available in stitches #8; #11, & #14. My personal preference would be #14 with a sapphire finish.

http://www.hand-stitched-rasp-riffler.com/saphir/rasps/laterale.html

At present I am waiting on the arrival of a Logiers Luthier Rasp. Not for saw handle work, but for bedding irons on traditional hand planes. I want to compare its performance to that of my Bed Float.

http://www.hand-stitched-rasp-riffler.com/saphir/rasps/luthier.html

http://www.henryeckert.com/index.php?route=product/category&path=39_140_142

Stewie;

Thanks Stewie, I thought I had seen such a rasp, but could not find on the Liogier site, as SWMBO might say a "boy look". I think this style useful for saw handles.

Cheers
Peter

[rob streeper]

As promised I'm back at it, the weather has eased up after producing a good 9" of rain as measured by my trashcanometer.


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I've done some redesign of my tooth punch.

Here is the front.


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The side.


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And the bottom.


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The design is rationalized by the following illustrations.

First the punch is driven down into the body of the rasp.


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As the tip of the punch penetrates the surface the back of the punch vectors it to the left.

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Which thus raises the newly formed tooth.


Now for the setup. I had a bit of a revelation yesterday and realized that, since I don't have one of those extraordinary vises used in the Liogier videos, I could use a lead brick to protect my newly punched round rasp teeth.

Abdul gives everything a check.


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The hammers are both by Glen Stollmeyer, D-2 steel with wisteria handles. Great stuff.


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Abdul checks my progress.

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And we're done.


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Lessons learned:

1) Sharpen the punch regularly - I made 5 trips to the grinder finishing this rasp.

2) A smaller hammer, swung with more force, makes for more regular punching than does a heavier hammer swung with less force.

3) Rounds are harder to do.

4) Keep the punch tip just short of perpendicular to the work surface on the round.

5) I still have a lot to learn.

Next up is to grind some tangs on each end, harden and fit handles.

[code4pay]

Awesome job making a rasp it is on my to do list.

In my copy of the modern blacksmith to make rasps he suggests " the cutting point is created by grindings small slanted facet on the end of a one-point stone-carving tool. Hold the toll at a slant to the prepared surface of the rasp blank and strike it with a one-pound hammer. A single tooth is thus bent outwards from the surface" .

Sent from my GT-I9100 using Tapatalk

[rob streeper]

Here it is with tangs formed and handles fitted. Now for hardening.

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[issatree]

Hi Rob Streeper,
That was a good look & read on the work you did.

I was interested as to the Liquid CaCL2/NaCl as for quenching the hot stuff.
Could you put into English for those who don't know what the Letters mean, Please.
I do a bit of quenching now & then, & I just thought your Liquid maybe a better solution, than what I use, being a heap of Electic Soda in some Tank Water.

[rob streeper]

Isatree,

I'll explain as far as I know.

NaCl is table salt, sodium chloride. Use the rock salt form as there are additives in regular table salt such as iodide, silicates and carbonates. Kosher salt will also do.

CaCl2 is calcium chloride. You can find it in the form of so-called 'non salt' ice melter, check the label make sure that the non-salt ice melter is not urea or something other than calcium chloride. I get mine from my wife's stash of food grade calcium chloride that she uses for making cheese.

To make the solution you simply use some deionized / distilled / reverse osmosis or similar water (tap will work in a pinch) and put in a couple of handfuls of each salt until it stops dissolving, then add a little more. This solution stores indefinitely and can be used cold or heated depending on the kind of quench you want to do. Hotter makes for less distortion.

Next in the line up the temperature range of quenchants are oils, also used hot or cold. There are special quenching oils but good quality mineral oil works fine for hobby stuff. Be careful with heating it because of burns and fire. Like fried chicken, not fried face.

Next are molten salts. I've been experimenting with these. Various mixtures of sodium nitrite, sodium nitrate and postassium nitrate. Dangerous for those not accustomed to working with hot liquid oxidizers.

Molten metals, such as lead and tin can also be used - careful, very toxic..

Gasses and air can also be used for the appropriate alloys.

Basically everything has it's application. Check with the steel manufacturer for the recommended quenchant and conditions.

Cheers,
Rob

[Robson Valley]

May I suggest an easy method to control the "packing" of waste in the stitching?

First charge the clean file with chalk or some other powder, even baker's flour will work. Anything to fill the bottoms of the teeth. The brushing clean-out ought to be 10X easier.

I use old-fashioned school stick chalk when working aluminium. All my files cut clean and smooth and none ever get Al shavings packed in them. Same deal rasping any plastics.
Woods and soapstone (steatite) don't seem to pack my rifflers at all.

[rob streeper]

Cool Robson Valley, thanks for the tip.

[ian]

Abdul gives everything a check.


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Abdul checks my progress.

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good to see that the boss is on the job

[RayG]

Isatree,

I'll explain as far as I know.

NaCl is table salt, sodium chloride. Use the rock salt form as there are additives in regular table salt such as iodide, silicates and carbonates. Kosher salt will also do.

CaCl2 is calcium chloride. You can find it in the form of so-called 'non salt' ice melter, check the label make sure that the non-salt ice melter is not urea or something other than calcium chloride. I get mine from my wife's stash of food grade calcium chloride that she uses for making cheese.

To make the solution you simply use some deionized / distilled / reverse osmosis or similar water (tap will work in a pinch) and put in a couple of handfuls of each salt until it stops dissolving, then add a little more. This solution stores indefinitely and can be used cold or heated depending on the kind of quench you want to do. Hotter makes for less distortion.

Next in the line up the temperature range of quenchants are oils, also used hot or cold. There are special quenching oils but good quality mineral oil works fine for hobby stuff. Be careful with heating it because of burns and fire. Like fried chicken, not fried face.

Next are molten salts. I've been experimenting with these. Various mixtures of sodium nitrite, sodium nitrate and postassium nitrate. Dangerous for those not accustomed to working with hot liquid oxidizers.

Molten metals, such as lead and tin can also be used - careful, very toxic..

Gasses and air can also be used for the appropriate alloys.

Basically everything has it's application. Check with the steel manufacturer for the recommended quenchant and conditions.

Cheers,
Rob


Hi Rob,

I managed to get a small quantity of Aqua Quench 365, it's a polymer based quenchant that you mix with water and you vary the concentration to change the properties, you can mix it up to have the same quenchant properties as oil.

The advantages are it's cleaner and safer ( no fire risk and no smoke ).

http://www.houghtonintl.com/en-us/products/heattreatment/Pages/Aqua-Quench-C.aspx

Ray

[planemaker]

Hi Rob and Ray. This product may also be of some interest to you both.

Stewie;

http://www.precisionbrand.com/FaqDetails.aspx?FaqCategoryid=10

[rob streeper]

Hi Rob and Ray. This product may also be of some interest to you both.

Stewie;

http://www.precisionbrand.com/FaqDetails.aspx?FaqCategoryid=10


Hi Stewie,

I didn't use foil for the floats and rasps because both the Airou and Liogier videos show that the rasps are sand or bead blasted after hardening which is done bare metal to flame. The appear to have a fair amount of scale too. Their furnaces may be set up to be at least somewhat reducing. Perhaps the roughness of the resulting surface after decarburization helps the function of the finished tool.

Rob

[planemaker]

Hi Rob. Here's a post on the U.K. hand tool forum that has some relevance to your current work. The guys name is Jim Hendricks.

Stewie;

http://www.ukworkshop.co.uk/forums/plane-makers-something-to-float-yer-boat-t84424.html

[rob streeper]

Here's the annealing temp calculator. No way to send it via private message on this site.

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[RayG]

Hi Rob,

If you are interested in heat treatment, I can recommend the "Heat Treaters Guide Practices and Procedures for Irons and Steels ASM International" It's a bit pricey, but well worth it if you are going to get into heat treating steels.

http://www.asminternational.org/learning/more/-/journal_content/56/10192/06400G/PUBLICATION/

Ray