Plane Maker’s Bed Float Reproduction

 

Part war of attrition…part friendship…and mostly encouragement was all I needed to get my backside out into the shop again and make a prototype tool…as “suggested” by a very good friend of mine…Toby Nava.

So having absolutely no idea where to start…a few more head scratchings and observations of other fine tools led me to make one…and by chance one for me too! (how clever was that!!)

Steel….O1…of course…3mm ground gauge plate…

Toby requested 6 1/2″ of tooth area and a total length of 8″ so that’s the dimensions. In retrospect…and if I ever make another..I should have cut it a few inches longer, leaving enough steel to use as hold-down space…but it worked out ok…

The handle was to be a tanged version as opposed to scales…so that was marked up too using a chisel as a template.

Now…this is where the pondering starts…I suppose it would have been nice to cut the teeth all by hand or employ piskies to do it for me…but I have long since lost interest in the magic of repetitive tasks like this with hand tools…and there is no way I have the skills to get the teeth all at the right pitch and even…so I thought I would use the milling machine.

Over the last few weeks I had been contemplating how to do this…I notice that Noel Liogier uses their mill and a tiny bullnose cutter…at an angle to create waves of teeth with round bottoms…very clever. But I had a 60 deg dovetail cutter…(don’t ask me why)…and I figured that should do the trick.
At first I thought I would mount the steel upright on a right-angle plate but then I had a brainwave…the mill tilts doesn’t it!?

I’d completely forgotten!!!

The “side” was set just forward of upright…so about 87 degrees…other commercial makers are around 80 degrees but I think that’s too forward myself..so I pulled it back a tad.

It was a slow start…but as I became more confident I could speed up so it went quite quickly after that.

The stock is 60 mm wide…3mm thick so this will make two floats…

I am in the process of making a precision “RAS” (radial arm saw)…using a Proxxon drill and some neat cutters…

…which would have made the cutting job a breeze…but since it isn’t ready yet…I had to resort to the old hacksaw….

…a long job…this stuff is pretty thick…good job I didn’t choose 5mm!

Then to cut the tang…

I use a lot of box…and burr oak…mahogany…so I needed to get some offcuts to test…and chose a piece of boxwood…seemed tough enough…

Just did two opposing faces…to get an idea of the flatness…the smoothness and the crispness of interface…

…yup…I’m happy with that…and thanks to Philly of PHILLY PLANES for telling me to test it BEFORE I hardened it…(just in case!). Cheers Phil!!

So…now to stamp it with the KT mark…using old hammer stamps…(yes bootfair!)….

Done…..

OH…sorry…the letters are a bit off square…you get this when you are working a manual process as I was trying to line up the “T” with the grain of the steel…..all the best makers do this ya know…!!!

So…to the handles…choices choices!

Now it just needs hardening ….

I have a huge pot of vegetable oil…deep enough to put the steel in at a slight angle and at one go in a sliding motion. I’m hoping that will suffice..

Decarburisation is a different issue entirely…the kiln is a lot different than a coke forge or worse still oxy/acetylene in that it is a very small enclosed space…I intended to do what I do with the irons I made…put a bunch of charcoal in the kiln near the ceramic shelf to eat up all the residual oxygen during hardening….it’s only in there for 15 minutes….but advice from another craftsman made me think again. Apparently this eats at the element..and we don’t want that!
This is the kiln…

There seems to be three schools of thought about these niche tools…

1) The old stories of creating them from dead files…tempering the file in the fire and cutting the teeth and either using as is,  or hardening fully and repeat when blunt.

2) Concerning new ones…harden to maximum and temper back very little…and repeating when blunt…akin to 1)

3) Again..from new tool stock…harden to maximum and temper back to around RC50ish and then sharpen as necessary until no more…like saws…then retooth.

I have to choose an option for this iteration of this build…so I have chosen option 3)

The reason for this is that option 1) is out (for now)….leaving option 2 or 3 and I have chosen 3) for no other reason than others have had some success with this…I can always re-harden and go to option 2) if this fails.

There has some discussion on the decarburization (ruining of tool steel by rapid leeching of carbon) of the sharp edges rendering them soft forever.

To prevent this…and since I have used charcoal in the furnace before…and since sage advice indicates that this could ruin the element…I have gone for the prophylactic approach of preventing any oxygen present in the furnace from getting to the steel.

But first I came up with this idea…

By wiring them together face to face…and since the teeth mesh together if I fire both at once…I am further minimizing the exposure of the teeth directly to the oxygen…..and I hope prevents warping of either since they will be trying to fight each other! (that’s the theory anyway!)

It certainly shows how accurate that DRO (digital readout) on the mill is!!

A “slip” or rather “mud pie” of clay and Borax was then applied…in two coats and allowed to dry each time so that I could see the silver glint and patch up where necessary…this was left to harden slowly.

Some time ago I bought a PID (proportional-integral-derivative) controller and SSR (solid state relay) from China for peanuts…so I thought I would test it out with a new thin K-Type thermocouple and control the kiln automatically…instead of switching it off and on manually for 15 minutes which is a real pain…

For those who are not familiar with industrial control devices…a PID will proportionally adjust the power getting to the heating element to keep it close to the desired temperature without much hysteresis or time lag. This stops it from constantly being under and over temperature caused by the slow reaction of the element.

As this electronics (box on the left showing it’s SEVEN degrees out there BBBRRRR!)….is only capable of directly controlling up to 3A…an SSR or solid state relay is needed (white box on right with light on).

This just allows more power as the PID controls this and the SSR then controls the power going to the kiln.

Chinese electronics has now allowed mere amateurs to have devices which were before only available on expensive kit.

So the “mud” was applied..boy is this mucky!!

Ok!!! I’m never gonna make a potter so Clarice Cliff can rest easy in her grave….but it was all worth it in the end…read on!

This concoction which can only be described as “MUD” is seen drying here after a couple of slight “errors” on my part….not the least of which is that I am now the proud owner of most of the country’s fire clay supply!!

This stuff is so cheap that when I ordered some on eBay…I didn’t look at the quantity and it was only when the truck pulled up at my house with a hoist did I realise that £20 get you an AWFUL LOT of the stuff.  So anyone who wants a bag…feel free to just pay me the postage!!

Quite the opposite occurred with the Borax…where I seem to have bought the purest scientific version of DAZ I could find!

But…never mind…the worst thing was convincing my wife that all this was in the aid of science and I needed to use the kitchen as I was just making a very special cake!!

So…to the PID or “accurate temperature control thingy” to make it more understandable….

Well give the Chinese their due..they make some cunning electrickery for very few dollars…it was amazingly easy to tune…not too much fiddling with the “d” variable thankfully…and it taught itself what 800 degrees celsius was and stayed there.

It stayed there within ONE DEGREE either side…so you can’t wish for better than that.

And the solid state relay (SSR) didn’t even blink. Well…actually it DID blink…quite a bit…as it switched on and off frantically trying to keep up with the commands it was being sent but it performed effortlessly! So much so that I am building this into a box with a socket to keep my heater accurate for when I’m not using the kiln. I am actually considering using the kiln AS the heater…such was the toastiness of the workshop during and for many hours, AFTER this hardening malarky!

Armed with this total confidence temperature-wise….I popped the “cake” into the oven…(gas mark 10 for 15 minutes!)….


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..where upon…in very short shrift…the fire clay lived up to it’s name and looked like Hades itself!

After 15 minutes of cooking…I opened the door to the kiln…suitably attired in my “DIY PPE” (personal protection equipment for those who like to live dangerously!) which protected any part of my body I should have preferred not to be singed…..and with my wife standing by with a fire extinguisher…dunked it in the vegetable oil.

I have to say…since the last time I did this my recollection of the reaction of plunging a lump of steel at nigh on 1000 degrees into cold liquid was not quite as vivid as this attempt!!

I guess the fire clay made it more….um…explosive!!

This “after” shot makes it look as if I’m calm…this is because it was a little after the “missing” picture. Missing because my wife was frantically trying to remember how to get the seal off the fire extinguisher!!!

Ok…it wasn’t quite “dangerous” but it was…um…surprising. The fire clay doesn’t like being subjected to that much shock so it left the steel it was adhering to…with a bit of…shall we say…kinetic energy!

Which was handy because it saved me from chipping it all off afterwards…the only bits left were the ones the reinforcement of the wires….

But was all this preparation a success though!? Darn right it was!

As can be seen…no warpage (?)….no separation of the wires…and no decarburization!! Success indeed!

Armed with this renewed confidence I then made my mistake. Instead of calmly cleaning off the oil and tempering it….I put it back in the kiln…at the prescribed higher tempering temperature and shut the door.

Ordinarily for plane irons I would shove it in the domestic oven after the family roast…which is off and cooling. This…is BELOW the flashpoint of vegetable oil.
UNFORTUNATELY…..500C ISN’T!

By this time…my wife had retired scratching her head…to the house…and taking the fire extinguisher with her!!

I will say that blowing on flaming steel frantically does eventually work however!

Sadly…burnt vegetable oil on metal…as every housewife knows..stains rather badly…

…..which is rather a shame…but they are prototypes and these things happen!

So to the long awaited testing.

I grabbed the nearest spare handle I could find which I just knew I had a use for when I made it all those years ago from some scrap lilac from MAC Timbers.

…bit of beech…clamped to my “new” French bench….and off we go…

SUCCESS!!!

Then on to a “bit of boxwood”….(close your eyes if you don’t like to see rare breeds being sacrificed in the name of science!!!)….

Success again. (you may get the impression here that I am just a tad pleased after all this “theory”!!)

The great thing is you can hog the stock off really fast but if you lay off the pressure to a gently stroking action…the surface (left in the above picture) becomes really smooth.

So…I guess I ought to sharpen it!!

Using Switzerland’s “nearly finest (without going overdrawn)” steel….a BAHCO “SWISS MADE” (as opposed to no name “SWISS CHEESE”) three-square needle file…


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..I set about the job in the same way as you would tickle a saw…for effectively that is what a float is…a rather large kerfed “saw”.

Technical note here…I don’t actually file like this…but I had to hold the camera with the other hand!

After a surprisingly short time (one episode of “Murder She Wrote”)….it was done….

So…now to test the real thing….did it work?

…hell yes….and this is across the grain English boxwood!

In the interest of my health and safety, and having proven the operation of the Heath Robinson PID setup…I decided it was time to put it all away safely…

That’s better!!!

Certainly, I am now encouraged to use this little kiln more often now that I know I can regulate the temperature automatically without having to manually switch it on and off..which exhibited a fairly large hysteresis of at least +/- 10 degrees instead of +/- 1 degree celsius which the PID is capable of.

I also received a Holtzapffel pattern Walnut handle from Matthew at Workshop Heaven….

…which I think is one of the most attractive of all handle shapes ever and works well with the float shape…

And I seem to have bought a few of these…I suppose I had better make some more float shapes now…seems rude not to!

 

I sent one of the floats to my friend Toby (Toby Tools) to test as he is in the process of making some planes and he sent me his review which I reproduce below (pictures courtesy of Toby Nava –  Copyright 2014)

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Ok, sorry took so long to get back with my review…. I had a bit to do to get this ready (make handle and sharpen) and I also had to have a good play with the float before I could comment.

Firstly… Thanks Jim for being so kind as to give me this tool, I’ve been going on about floats for far too long …

First impression of the tool was that of a kid a Christmas when he gets an Xbox or Playstation for the first time….sad I know!

Not having a spare handle about,  I made one and I selected Holm Oak and used copper pipe as the ferrule.

Once it had a handle…. couldn’t resist and have it a go…  It worked out of the box…. that can’t be said about a lot of tools these days so it passed the second test.
Moving onto the sharpening, usually a daunting task but the three-square needle file just sits in the teeth gully and a consistent cutting edge is easily achieved.  The tempering and hardening are just right, not too hard so it takes ages to sharpen and not too soft that it can’t hold an edge. The perfect balance or what I would consider perfect in regards to the tool and it’s intended use.


Once the sharpening was done I used it for its intended purpose…making a plane in this case, the wedge.  I will in due time be using it to level the beds and such.

As you can see, it leaves a smooth and flawless finish, abrasives will not need to be used.

The wood is beech…. so average on the hardness and it worked as you would expect from a hand made tool for someone who care about what he’s doing.

This is about as far as I’ve got with it but as I progress in my plane making you will be seeing more and more if it.

I can’t believe I have done woodwork without these types of tool until now.

Toby Nava (Toby Tools)

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I’m rather glad that Toby “coerced” me into making one of these things and I’ve ordered one of Matthew’s finest Holtzapffel style handles just to celebrate!

To say that it’s been a “learning experience” is probably an understatement. I had to scrape to the bottom of the grey cells to remember metalwork, metallurgy, chemistry, electronics, woodworking and bravery….not to mention testing of sanity but it was fun.

Would I do it again…

NO! But feel free to copy or avoid any of this experience at your leisure!

DISCLAIMER: THERE ARE POTENTIALLY DANGEROUS TECHNIQUES INVOLVED IN THIS PROJECT WHICH COULD RESULT IN INJURY. DO NOT TRY ANYTHING I HAVE DESCRIBED UNLESS YOU ARE TOTALLY CONFIDENT YOU CAN DO SO SAFELY OR ARE CLINICALLY INSANE. REMEMBER…THERE IS NO MORE IMPORTANT SAFETY ITEMS THAN WEARING SAFETY GLASSES! CONSIDER YOURSELF WELL AND TRULY WARNED!!

 

3 Responses to Plane Maker’s Bed Float Reproduction

  1. A cracking result Jim, fully befitting my reserve stock of extra pretty handles!

    Floats (and files in general) are somewhat under appreciated as woodworking tools but as you have shown the results can be very impressive indeed.

    The PID looks like a very useful bit of kit, temperature control to +/- 1 degree is industrial territory so to achieve it in the home workshop is very impressive.

    I look forward to seeing the next plane – perhaps when things are a little bit warmer though eh?

    Many thanks for the detailed write-up of the process.

    All the best,

    Matthew

  2. Andrea says:

    Great job Jim, but where is mine? ;-)

  3. Pingback: Welcome to the journal of KT Tools….. | KT Productions Blog

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