We discuss annealing of sterling silver often and many of us use simple sight indicators that the metal has reached annealing temperature. I have for years darkened my shop and just watched until the right red is reached, let the piece cool a bit and then quench it in water then pickle. When the question comes up, many of us offer the advice that a sharpie mark will disappear when annealing temperature has been reached. I am reading Charles Lewton-Brain’s book on Foldforming where he describes a number of annealing temperature indicators. Among them is the suggestion that a welders stick might be used. I did a search and found Tempilstiks that indicate many different specific temperatures. I have never heard them discussed in the context of jewelry making and wonder if anyone among us use them. Any thoughts are appreciated…Rob
Maybe Charles is referring to the flux on the welding stick. Paste fluxes which turn glassy around 1100F are good indicators in that scenario.
On page 30 he mentions Tempilstiks along with several other indicators to include, as you suggest, when borax flux turns glassy. When I see that change in the flux, I know it is time to get ready to add solder. I am just curious if anyone uses Tempilstiks or a similar product. They appear to be very temperature specific and this might be helpful for operations that need a very specific temperature indication. For instance, I could see using them when annealing or heat hardening in a kiln much the same way as a potter uses temperature cones…Rob
In James Binnion and Chris Ploofs class on making mokume billets, we used tempil sticks to indicate the proper temperature for annealing various metal combinations. Each combination of metals had certain limits on temperature for annealing.
Judy…Thanks, seems like a fairly simple way to confirm a specific temperature…Rob
I purchased 2 tempilstiks and found them useless for my needs.
First off I’ll give you background- I work primarily in copper & have been trying a copper matching solder which is very high temp.
I was having a little frustration working it out at first & my husband, who is a welder
(among other things) suggested it.
Well on copper I couldn’t get it to mark the surface enough to see.
Maybe I was doing something wrong & please advise if you figure it out, as I have 2 pricey sticks here unused.
They are described as being like a crayon. That being the case, they may need a rougher surface than a piece of copper sheet to write on. Most steel is a bit rougher than copper sheet. I am finding them in the $15 -$20 range from the manufacturer. I may buy one just to try it out. Thanks…Rob
That’s exactly what I found out - more of a brittle crayon .
I figure that they are usually sold for use on steel & would be coarser.
Looking at the Tempilstik instructions I see that there are specific directions for using it above 700 degrees F:
“At temperatures above 700° F (371° C) or under prolonged heating, the
Tempilstik° mark may evaporate or be absorbed. Under these conditions, stroke
the workpiece with the selected Tempilstik° from time to time during the heating
operation. When the rated temperature has been reached, it will leave a liquid
smear. This method should also be used if a smooth surface is involved, where
the hard Tempilstik° chalk will not leave a mark. (If it is necessary to mark a
smooth surface before heating, use Tempilaq°.)”
This is from an Amazon review: “I’ve found that if you rub the new stick against some sand paper or something abrasive when you first get it, it sort of takes the top layer off and you get a more waxy, usable stick.”
The lacquer looks interesting, it’s paint-on liquid that is also a temperature indicator: “Temperature Indicating Thinner, Liquid, Quick, Easy and Cost-Effective Method to Verify The Achievement of A Specific Temperature On A Wide Range of Surfaces, When Applied to Surface, Tempilaq Dries and Forms A Dull and Opaque Film, The Film Liquefies When Heat is Applied to The Surface When The Rated Temperature is Reached, As The Surface Cools, The Mark Re-Solidifies to Leave A Distinctly Different Mark, Confirming The Target Temperature Has Been Achieved.”
Thank you Marian !
When I purchased it from McMaster Carr, it came with no instructions & I never thought to look for any - I mean how hard could it be to understand.
Obviously there is more to it then I first thought. And now I have some work & experimenting to do.
I can’t thank you enough.
I researched for Europe and came accross Markal Thermomelt stick, which comes in wider variety of (higher) temperatures and is a little cheaper.