NavList:

I just bought an A-12 sextant with a dry bubble chamber, which I need to refill.

The manual calls for “chemically pure xylene”, I can find high purity xylene on Amazon, which seems to be good, but it’s expensive.

I know Hardware store Xylene contains impurities, what would be the harm of these impurities in a bubble chamber besides possibly leaving a residue?

And couldn’t you check for residue, by pouring the xyline into an open container and letting it to evaporate and then see if it left a film?

Thanks.