I am scouting for a way to augment a homemade strip heater for bending plastic. To bend thicker slabs of polycarbonate requires application of heat to both sides of the plastic. I think the best candidate for the upper heat source would be a stainless steel heater strip, available relatively cheaply. The photos I've seen of these devices show the heater strip, made of steel, with two contacts coming out of the top at one end. The contacts are also made of steel, or metal at least, with no evidence of ceramic or composition insulators, just steel on steel. How do these contacts create a useable circuit without shorting out on the case?

 

Hello,

Is the heater like the ones on this page:
https://www.omega.nl/pptst/HCS_HEATER.html

Bertus

 

Yes. That's the one. The description indicates that the inner element is ceramic, and-okay, it must work as advertised, but I don't see anything insulating the contacts. What invisible force is keeping the contacts insulated from each other and the stainless steel case? As I understand it, stainless may not be magnetic, but it is a conductor.

 

Hello,

Did you have a close look at the page?



Bertus

 

our shop at work made a heater, It was basically a flat heating "rope" in a depression with some sort of cloth insulation covring the board. The "rope" would be used to say wrap a pipe.

We used a Va

Our benter was about 3' x 8" maybe 3/4" thick. Covered with cloth insulation and the heating rope laid within the depression.

We used a Variac to control temperature. it wasn't used very often and I think it was built to make a glove box.

 

Well, so much for my visual inspection. I have one of those things tucked away somewhere. I've never used it, but-clearly-neither have I ever taken a close look at the contacts. Thank you for pointing that out.

 

our shop at work made a heater, It was basically a flat heating "rope" in a depression with some sort of cloth insulation covring the board. The "rope" would be used to say wrap a pipe.

Our benter was about 3' x 8" maybe 3/4" thick. Covered with cloth insulation and the heating rope laid within the depression.

Thanks for the suggestion. I may resort to doing something like that. First have to find a stainless heater I stashed somewhere, and try it.

 

They are insulated. I have worked with quite a few in assorted sizes. Here in the US most are manufactured by Watlow or Chromalox and branded with the name of your choice. Your image is what we called a "strip heater" The terminals are usually mica insulated and the inside is normally mineral insulated. Anyway rest assured they are insulated.

Ron

 

Spmething like: https://www.omega.com/en-us/industr...ape-and-rope-heaters/sth-sst-swh/p/STH051-020