Plane Makers...something to float yer boat??

[Sheffield Tony]

Now it's going to be exciting if the heat treating will induce a lot of warp.

That's a thought. A deep pot of quenching oil might be an advantage so that it can go in upright, which might reduce any urge to take on a curve ?

Another pitfall could be loss of carbon from the cutting edges ?

 

[jimi43]

Now it's going to be exciting if the heat treating will induce a lot of warp.

That's a thought. A deep pot of quenching oil might be an advantage so that it can go in upright, which might reduce any urge to take on a curve ?

Another pitfall could be loss of carbon from the cutting edges ?

Hi Tony

Yes...all being considered. I am in conversation with Philly and Aaron in other threads and on Messenger to try to prevent any distortion or decarburisation....

I have a huge pot of 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.

This is the kiln...

I have two..so this will be a test.

Any other ideas are of course....most welcome indeed!

Jimi

 

[rxh]

Fascinating stuff - well done Jimi.

If it does take a bend during quenching all is probably not lost. You could temper it and then straighten using the "three bolts" method.

 

[Corneel]

According to George Willson on sawmillcreek it is possible to straighten it for a very short period right after quenching. But you'll have to find the relevant thread overthere for the details.

 

[jimi43]

Fascinating stuff - well done Jimi.

If it does take a bend during quenching all is probably not lost. You could temper it and then straighten using the "three bolts" method.

Tell me more mate...I think I know what you are talking about but more detail would be most appreciated.

Thanks Corneel...I'll go and investigate.

Jimi

 

[tobytools]

jim,
the rate you have been achieving of late is outstanding, we all need a little push now at then. if i wasn't prodded and poked by some id still be miserable working a job i didn't love and not pursuing a career in what i love

can't wait to see it in the steel.
im watching carefully as to how this is done. i have a project in the pipe line. just waiting for my steel to arrive (i didn't have the size needed and what i do have is for plane irons.)

keep your escalation of tooling up jimi, we all love it

thanks mate.
TT

 

[rxh]

Jimi, this is what I meant. I have used this way successfully to straighten various things or bend them. A bit of copper or aluminum packing would protect the teeth. It helps to have an assistant when setting it up.

 

[jimi43]

Jimi, this is what I meant. I have used this way successfully to straighten various things or bend them. A bit of copper or aluminum packing would protect the teeth. It helps to have an assistant when setting it up.

Gotcha! Now I know that every day in every way I find out something new!

Brilliant..simply brilliant! =D>

(all the old boys go DOH! Doesn't he know that one! :mrgreen: )

Jimi

 

[Sheffield Tony]

Hi Tony

Yes...all being considered. I am in conversation with Philly and Aaron in other threads and on Messenger to try to prevent any distortion or decarburisation....

Ok, I see you have it in hand. I'd lost track of that thread when it seemed to have slid into linisher envy !

Your heat treatment set up is a bit more sophisticated than my blowtorch (or 2), housebrick and baked bean can full of cooking oil(*). I'll leave you to get on with it !

(*) This was a refinement. When making my travisher iron, I learned that it is unwise to hold your quenching oil in a plastic container. Can't beileve I did that

 

[Corneel]

It was a bit of searching, but in here George Wilson explains how he straightens floats after tempering, while thet are still hot:

http://www.sawmillcreek.org/archive/index.php/t-162029.html?s=416384fb2151fbf7781179cf112bed39

 

[AndyT]

I should have added a bit more from my reading of Holtzapffel - after the description of hardening and tempering there is a mention that floats used by comb makers were sharpened by turning an edge with a burnisher, like sharpening a cabinet scraper.

I wonder if this is worth a try, for planemaker's floats? Here's the whole page for anyone who has not already downloaded the entire work:

 

[jimi43]

It was a bit of searching, but in here George Wilson explains how he straightens floats after tempering, while thet are still hot:

http://www.sawmillcreek.org/archive/index.php/t-162029.html?s=416384fb2151fbf7781179cf112bed39

Most helpful Corneel...I am embarking on the hardening this weekend now that I have some slip clay and Borax...

I will report back on the results...fingers crossed!

Andy...thanks for the additional information...Mr H certainly was a lad!

Cheers

Jimi

 

[jimi43]

This mysterious tool has created quite a bit of research..thanks guys for the various input.

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 tools 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 Aaron rightly states 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 shows how accurate that DRO 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 is now hardening.

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 that's where we're up to at the moment....other things are going on in the workshop...so I hope to get this test batch of floats hardened and tempered this week....

Cheers

Jimi

 

[swagman]

http://www.thermometricscorp.com/thermocouple.html

 

[jimi43]

http://www.thermometricscorp.com/thermocouple.html

Yes Stewie...I'm using the thin fibre K type thermocouple...it's apparently less vulnerable to sulphur attack...we shall see! :mrgreen:

Jimi

 

[swagman]

http://www.thermometricscorp.com/thermocouple.html

Yes Stewie...I'm using the thin fibre K type thermocouple...it's apparently less vulnerable to sulphur attack...we shall see! :mrgreen:

Jimi

If the K type bombs out Jimi, you might be okay with the N type.

Stewie;

 

[Racers]

I had one of those SSR's as a remote switching for a power amp, it worked well but didn't half come on with a bang.

Whats the rating of the kiln? you might need to screw the SSR to a heat sink.

Pete

 

[jimi43]

I had one of those SSR's as a remote switching for a power amp, it worked well but didn't half come on with a bang.

Whats the rating of the kiln? you might need to screw the SSR to a heat sink.

Pete

It's 1kW and is actually drawing 4.5A...so it's only running at 20% max.

I am waiting for an enclosure...and I will include a small heatsink...just in case.

Cheers mate

Jimi

 

[AndyT]

Well, one truth emerges loud and clear from this thread - it really is worth having a shed like Jim's which contains one of everything anyone might ever need! ;-)

 

[jimi43]

Well, one truth emerges loud and clear from this thread - it really is worth having a shed like Jim's which contains one of everything anyone might ever need! ;-)

Steptoe's yard Andy....but as far as I know....I don't have a horse...

Yet..... :mrgreen:

Jimi