Restoring Bailey No.5 Jack Plane


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Powder coat requires heat though, which could potentially warp the nice flat sole

 

Not even near close enough of a temperature to warp anything. 400F is nothing for steel. 

 

 

Please correct me if I'm wrong but, powder coating requires an electrical charge, not heat.

 

Edit:  Heat to cure..  Shouldn't be hot enough to warp the sole tho.

 

Powder coat is applied with static electricity, then baked.  But yes, not even close enough to warp a part. 

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400 f may not warp the sole, but could change the hardness to some degree. Buddy at work makes knives, uses his kitchen oven at about 400 to temper the blades after quenching. I know from experience that cast iron becomes much tougher to cut or drill after heat exposure, but I have no idea about how hot or how long it takes to do it.

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400 f may not warp the sole, but could change the hardness to some degree. Buddy at work makes knives, uses his kitchen oven at about 400 to temper the blades after quenching. I know from experience that cast iron becomes much tougher to cut or drill after heat exposure, but I have no idea about how hot or how long it takes to do it.

 

No.  Almost all steels become ductile at 600+F, and the annealing temperature for most steels is 12-1600F (stainless is much higher). 400F is bath water for steel. Physical properties of steel wont be changed at 400F, and the only thing that will change is oxidation resistance after a powder coating. A kitchen oven will do nothing to a steel blade, regardless of what your friend does or not. Heat treatment is in the 4 digit range, hot working is 750+. No kitchen oven goes above 500f to my knowledge. 

 

edit: not trying to diss your friend, Im an engineer, and my specialty is steel fabrication and design for power plants. I spend a good chunk of my time determing the type of rust and amount required for mild steel pipes and temperature associations for steam piping. A hand plane in a powder coating rig is just fine, I promise. 

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I have no doubt you are correct about steel. However, the plane body should be made of cas iron. I am NOT a metallurgist, but I know from personal experience that cast iron becomes much "tougher", difficult to cut or drill, after exposure to relatively low levels of heat. The circumstances I refer to also involve repeated heating and cooling, which plays a large part, I'm sure.

Regarding my friend, the knifemaker, he tells me that oven baking is a common practice for reducing the brittleness of knife blades after the actual " heat treatment", and that a kitchen oven @ 400-450 is fine for certain common steels, but harder steels require higher temperatures. And self-cleaning ovens do indeed exceed 500 degrees in the cleaning cycle. Some claim to reach near 1000* F.

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I hear that you can use a dremel tool to grind off the lock on a oven and put it into self clean then bake thin crust pizzas in 90 secs. I wouldn't know anything about doing this but it does make a crisp crust that has bit of char like a wood burning oven. You just have to look away when you open the door. 

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Cast iron is still pretty resilient. http://www.ductile.org/didata/Section7/7intro.htm as you can see, 400F isn't anywhere close to any of the treatment temperatures required for annealing or heat treatment, even with iron.  Not trying to start a debate or argument, its just how it is. Powder coating a hand plane would be perfectly safe, there are no exceptions to this unless it was severely flawed before any process started anyway. Melting point of cast iron is 2100F, its critical temperature is 1500F, 400F does absolutely nothing to cast iron. Most electric stoves hit 425F, never seen a cast iron skillet warp on a stove top... 

 

the process your friend is speaking of, he MUST be talking in celcius. That process is called annealing. After the knife material is forged, shaped, hammered into place, it becomes very brittle and strong. They are then annealed and allowed to cool down slowly then quenched at a certain temperature. Im not a knife maker, but I am 1000000% postiive even 500F is far too low for that to do anything.

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The low temperature tempering process happens after initial heat treating. Here is a quote from Sandvik Materials Technology ( http://www.smt.sandvik.com/en/products/strip-steel/strip-products/knife-steel/hardening-guide/purpose-of-hardening-and-tempering/ ) regarding knife steels:

"To reduce the brittleness, the material is tempered, usually by heating it to 175–350°C (347–662°F) for 2 hours, which results in a hardness of 53–63 HRC and a good balance between sharpness retention, grindability and toughness."

Now, don't get me wrong, I am not arguing that such temperatures will harm the OP's plane, only that such material does not have to be heated anywhere near critical temperature to cause some change in physical properties. I believe most powder coating processes heat to somewhere around 400* F for a matter of minutes, not hours.

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The low temperature tempering process happens after initial heat treating. Here is a quote from Sandvik Materials Technology ( http://www.smt.sandvik.com/en/products/strip-steel/strip-products/knife-steel/hardening-guide/purpose-of-hardening-and-tempering/ ) regarding knife steels:

"To reduce the brittleness, the material is tempered, usually by heating it to 175–350°C (347–662°F) for 2 hours, which results in a hardness of 53–63 HRC and a good balance between sharpness retention, grindability and toughness."

Now, don't get me wrong, I am not arguing that such temperatures will harm the OP's plane, only that such material does not have to be heated anywhere near critical temperature to cause some change in physical properties. I believe most powder coating processes heat to somewhere around 400* F for a matter of minutes, not hours.

 

Thats not true tempering though. That temperature allows some internal stresses to be released (which is probably the goal on a hand forged knife blade I'd imagine), but doesn't provide a true heat treatment effect.  I'll explain more in a private message if you so desire.

 

To bring this back into relevancy for the thread, a cast iron hand plane would be heat treated already correct?  

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OK I called about getting a single plane powder coated black with a gloss overcoat. Two different shops same prices $195 tptal. $70 for the paint and $125 for the setup. I can get my own powder coat gun and use a retired oven that likes to over heat and do it myself for less and I have more than a dozen planes to do. I guess it will be paint or I set up Chef's Powder Coat and Donuts... 

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This is a dull discussion. If you present yourself as an expert then know the answers. Carbon steel is annealed at kitchen oven temps, that much I know. I didn't know about cast iron but it's easy to look up. Cast iron anneals at temperatures way beyond kitchen ovens.

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*sigh.  I agree with you. 

 

http://www.riheattreating.com/heat-treating-specialties.html

 

page 25

 

http://ethesis.nitrkl.ac.in/1138/1/Heat_Treatment_of_Low_Carbon_Steel.pdf

 

http://www.keytometals.com/articles/art15.htm

 

 

 

That or your kitchen oven doubles as a forge. I dunno... 

 

Anyone is completely free to offer me a credible source that shows the effects of cast iron and carbon steel @ 400F, I'd love to see it. That or I have about 8 years of schooling I need to go redo! 

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OK I called about getting a single plane powder coated black with a gloss overcoat. Two different shops same prices $195 tptal. $70 for the paint and $125 for the setup. I can get my own powder coat gun and use a retired oven that likes to over heat and do it myself for less and I have more than a dozen planes to do. I guess it will be paint or I set up Chef's Powder Coat and Donuts... 

 

 Give these guys an email, I've used them for guitar parts and they were pretty cost effective. (50$ for 2 guitar bridges and 2 sets of tuners, granted no finishing work was required on their part...) 

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This is a dull discussion. If you present yourself as an expert then know the answers. Carbon steel is annealed [edit: tempered] at kitchen oven temps, that much I know. I didn't know about cast iron but it's easy to look up. Cast iron anneals at temperatures way beyond kitchen ovens.

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I don't find it dull at all. maybe a little overkill to the OP.  however it does bring back memories from when I was a submariner.  great deal of metallurgy that I have long since forgotten. kind of, (only kind of) fun to review.

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