From: djb@invalid.com   
      
   On 22/02/2026 17:30, Jim Wilkins wrote:   
   > "David Billington"  wrote in message   
   > news:10nf3et$24dkv$1@dont-email.me...   
   >   
   > I've got a small Gallenkamp Hotspot kiln bought for enamelling but good   
   > for heat treat as it'll go to about 1050C, and a 18" top loader ceramic   
   > kiln which gets used for larger pieces such as normalising CRS when   
   > required. Both are controlled with PID controllers with thermocouples   
   > which are added on and the kilns plug into them and the power controller   
   > set to 100%. One is just ramp/soak the other can take more complex   
   > heat/soak/cool if required.   
   >   
   > ------------------------------------------   
   >   
   > That's a better approach with more control.   
   >   
   > My enameling kiln draws 2 KW and in an hour would double my average   
   > daily electricity use. I try to avoid consuming that much unless   
   > there's no alternative (lathe, mill) and use my stock of free firewood   
   > instead, trying to develop skill in the old methods on uncritical   
   > hobby jobs.   
   >   
   > I bought this model of tube furnace minus the controller for about 1%   
   > of this price. It draws around 500W warming up and heats the small   
   > volume quickly, then its thick insulation holds at low duty cycle.   
   > https://cbisurplus.com/product/lindberg-54233-59545-type-54233   
   1500aoc-heavy-duty-tube-furnace-w-59545-control-console/   
   >   
   >   
   > The 50mm tube is meant to be Pyrex, I have car exhaust pipe and   
   > stainless flange-end sanitary (brewing) tubing for it, if necessary   
   > the tube could be evacuated or filled with inert gas. The size was   
   > good for tempering a long narrow froe blade of 5160 at 175C, twice for   
   > an hour each. I intended it for custom long drills and reamers.   
   >   
   > Its thermocouples are Type P (Platinel), a near but not exact match to   
   > type K. My on/off controller doesn't have a P setting so I read   
   > temperature with a Type K alarm indicator that does. This gear is all   
   > from auctions or flea markets and often needed some repair or fiddling   
   > to work right. Reseating the socketed ICs fixed the 'broken' 5 channel   
   > Type K readout that monitors my wood stove from the kitchen.   
   >   
   >   
   It occurred to me when I was posting that last reply that you have to   
   deal with your electrical energy budget issues and that might make you   
   favour a different solution if available, not something I have to think   
   about so much with a 240V 32A supply in the workshop, more in the house.   
      
   Looks to be a nice furnace but what you have must be a lower temperature   
   model. 1500C would likely be a Mullite liner and SiC elements. AIUI SiC   
   are fairly easy to control with a phase angle controller and take care   
   of the change in resistance while heating and element ageing.  MoSi2    
   elements get more involved due to their characteristics  but not   
   required for 1500C usage.   
      
   I'd not heard of type P before as never run across one. Here in the   
   UK/Europe R and S are common for higher temperature applications, it   
   seems often US made stuff uses larger gauge K type to provide longer   
   life at elevated temperatures. For the Gallenkamp I use a K, the other   
   furnace I have an N type as more durable at the higher temperatures I   
   may have been using as that one goes to 1300C or would do if I replaced   
   the elements as they're old but it does what I require currently and   
   will make 1100C if needed.   
      
   Reseating socketed chips is one I use as well. I've saved a woman I know   
   quite a bit of money as when one of her temperature controllers gave a   
   thermocouple failure alarm I asked if she had pulled the guts and   
   reseated them, she wasn't aware you could do so RTFM. Others offered to   
   sell her a replacement. The Cal Controls ones I and she use and maybe   
   other makes allow the guts to be pulled from the panel mounting which   
   wipes the contacts and they had just become oxidised as only solder   
   coated so that was all that was required to get it working again, it's   
   now part of her yearly service routine. I've seen banks of them on   
   plastic extruder lines so the ability to hot swap the controller guts is   
   useful, saves having to pull the panel apart. IIRC those were on RS485   
   so the settings could be re-established remotely.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)