I got my Wilesco D21 about 10 years ago. The first time or two that I ran it I used tap water. I started to get a little bit of fogging on the top of the sight glass. I assumed that it was a little bit of mineral deposits and thought it would dissolve using distilled water. It never improved but didn’t really get much worse. I was out of the steam hobby for a few years and it sat on the shelf. I got it out and started playing again a couple of months ago. I always would blowdown the boiler after a session and leave the gauge and whistle off. I had a long weekend a week ago and decided to just leave the water in it, since I was going to do a lot of playing. The haze got much worse, and is actually worse than you can see in the picture.It covers the whole glass, but is much worse at the top.I decided it was time to take the glass out and clean it. I washed it with soap and it did nothing. Next I used denatured alcohol and it did nothing. Time to break out the acetone and still nothing. I soaked it in my citric acid pickling jar for 12 hours and still nothing. Tried WD-40 and fine steel wool and still nothing. I decided it was time to put in my spare. What would cause this? The only thing that I can think of is some leftover flux from when they soldered the boiler. Anyone else ever have this and any ideas what caused it?
Well John, if it is actually just mineral deposit from using tap water, then vinegar is likely the best shot you have at cleaning it. I'd try that first, or rather next and see what happens.
I always use decalcifier spray - that should work
Arnold
If my citric acid and steel wool didn’t do it then it’s not mineral deposits. I thought the glass might have been etched but it still feels smooth. I think that whatever it was might have actually chemically changed the glass. I put the new one in so I’m not really worried about it. I’m just very curious as to what could have happened. I figured that I’m probably not the first one to see this, and wondering if someone could satisfy my curiosity.
SiO2 is pretty impervious to just about anything but hydrofluoric acid, which would etch it to where you'd feel the difference. If there was ever any HF in your boiler, it is unlikely that you'd still have a boiler.
SiO2 is pretty impervious to just about anything but hydrofluoric acid, which would etch it to where you'd feel the difference. If there was ever any HF in your boiler, it is unlikely that you'd still have a boiler.
Just distilled water and quite a few gallons at that! That’s why I don’t know how if it was anything in it from manufacturing, that any could be left after all of the use it’s had. This may end up being an unsolved mystery.
It's not mineral deposits. Steam etches glass. I work on steam heating systems and this is why we change boiler sight glasses. I suppose if you like you can try polishing it with toothpaste and possibly clarifying it.
Thanks for the answer! I just replaced it with a spare that I already had. I was perplexed as to what caused it.