June 26, 20232 yr Hi, Thought I would show my HT Oven made from a Toaster Oven... Opened the casing up and direct wired the Elements and added some K-Wool around the casing on 3 sides. Put in the Thermocouple and a firebrick to even the heat and she works pretty nice. Keeps a pretty even heat with no more than a 10 degree swing from what I can see. I also use this PID for my Cast Bullet Furnace and my Gun Kote Oven!
July 11, 20232 yr Looks a treat. Might be worth building my own. Have a old knife I made out of A2, that I guess I ought to heat treat after 20 years...
July 11, 20232 yr I did this a few years back with a secondhand toaster oven, and it was a total failure. I think the water from the rigidizer may have shorted out the electric elements.
August 6, 20232 yr Author Hi, Well, thanks for the warning, even though, I do not use rigidizer. The added K-Wool and the PID does make a better product and easy to use.
August 7, 20232 yr Hmm. A heat treating oven would not be reaching very high temperatures for kaowool. If the blanket is not exposed it would be far different than direct flame impingement in a gas forge. If I understood correctly, he took the cover off, wrapped the inner compartment with wool (on 3 sides) then reinstalled the outer cover. To err on the side of safety we would certainly recommend a rigidizer/sealant, but this seems like a low risk situation to me. There would be more potential for airborne fibers during the installation than during use it would seem. Still, better safe than sorry.
August 7, 20232 yr Ceramic blanket refractories don't need to reach vitrifying temperatures to be breathing hazards. Any reckless use should be discouraged when possible. Frosty The Lucky.
August 7, 20232 yr Agreed. I'm just trying to figure out if it actually is reckless. Generally speaking, if the blanket is contained between 2 metal sheets and not directly exposed to the working area would you consider that appropriately sealed off? I would cautiously answer that it is. I'm not trying to pick a fight with anyone or even really pick a side. I do think we should err on the side of caution, but I also think we should be realistic or at least avoid being alarmist if it is not truly appropriate.
August 7, 20232 yr True it would be okay I suppose. I've only ever seen the inside of a couple toaster ovens and there's hardly any gap between the inner liner and shell. I don't know what compressing ceramic fiber enough to fit would do to it's insulating properties. Probably see better insulation by wrapping the outside in R20 fiberglass insulation just not close enough to burn the works. I temper things small enough in a yard sale toaster oven and moderate the temps with a couple brick tiles on the rack and cover it with a steel box I salvaged somewhere. Of course if a person used a non-bio-persistent refractory wool it wouldn't matter so much. These refractory fibers can be dissolved in the body and safely expelled through normal means. Frosty The Lucky.
August 7, 20232 yr My tempering oven isn't pretty, but I took the guts out of an old toaster oven and I also use a PID controller. The only reason I took it apart is the interior dimensions were too small for some of my larger blades. However, since I know I'll never have the oven over 600 degrees F, I chose to use rockwool insulation that is rated for up to 1200 F, and it's sandwiched between two layers of sheet metal. Originally I thought I'd use the heat treat oven I built a few years ago to attain quench temperatures and then temper afterwards, but it takes quite a few hours to cool back down to tempering temperatures after being up around 1500 F. I can't run them both on the same circuit at the same time without tripping a breaker though.
August 10, 20232 yr Author On 8/7/2023 at 11:05 AM, Steve Sells said: his lungs, he will find out, at least he has 2 of them Hi, Let's see, I'm going to lose my lungs from a piece of K-Wool sandwiched and sealed between two pieces of sheet metal??? Got anymore of those Crystal Balls??? Thanks, for the "Concern"!
August 10, 20232 yr You are not the only person reading this thread. Other people need to be aware of the dangers of unsealed koawool. When did you ever say sealed? I said it needs to be sealed, if it is there is no worry. But dont worry about me wont bother you again
August 10, 20232 yr Have you read this yet? If not you really need to and anyone else reading this thread. https://www.iforgeiron.com/topic/53239-ceramic-wool-insulation-safety-alert/ I can't control the wind, all I can do is adjust my sails.
August 11, 20232 yr He's probably read it Randy and is using the information and our well known reaction to unsafe behavior to troll us. It's a pattern he's starting to show. Frosty The Lucky.
August 11, 20232 yr You could go cheaper and use rockwool instead as well, the toaster oven and use will not make it hot enough to break down the rockwool.
August 11, 20232 yr Author 10 hours ago, Frosty said: He's probably read it Randy and is using the information and our well known reaction to unsafe behavior to troll us. It's a pattern he's starting to show. Frosty The Lucky. Hi, Do the Mods allow you to call people Trolls on this Forum? I have never called for any unsafe practices on this Forum that I know of? Mod note, upon review there is no one being called a troll, a comment was only made about trolling actions
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