Capilliary temp gauge

[Brian]

I post this as it may help someone in the future...I recently purchased a 35-36 temp gauge that had been in storage for who knows how long hanging upside down. This had caused the red liquid to entirely fill the glass tube. In attempting to move the air bubble back up the capilliary tube into the glass tube, I tried putting it in the freezer, alternating with putting the bulb in boiling water, whilst keeping the tube uppermost. I managed to get two bubbles to rise up into the tube, but the red liquid was still just about all the way up the tube. In between times I had the gauge suspended from my shed roof, bulb downmost....
Lying in bed one morning at around 2.00 AM, it occurred to me that it is insufficient to merely place the bulb in boiling water, the capilliary tube must be heated too. I dreamed up getting a length of galv pipe or similar, long enough to take the entire length, capping it one end with a plate, so it would hold water and stand up, to immerse the full length into this device and fill it with boiling water. Use an oxy-acetylene torch to keep the water boiling. This doesn't just heat the bulb, but the entire length. Sure enough...5 bubble later, my temp gauge now reads correctly, when at room temp the red liquid is barely visible in very bottom of the tube where it joins onto the capilliary.