I had one of my glass-fritted Buchner funnels somehow separate into two pieces. It was clogged with a few hundred grams of paracetamol, which had been vac filtered as a slurry, put it in a bucket of water to soften up the chunk of paracetamol, When I came back a few days later,the damn thing had separated into two pieces, the column and the part with the frit and vac takeoff, just cleanly fell off, as if someone had made them as two separate pieces and stuck them together with kid's PVA glue!
Think I'm going to go at it, carefully with the brazing torch and fuse it back together again.
And more than a little nervous, I've found someone who's other half is a glassblower, and I'm seeing what I can do about getting a few expensive broken pieces of glass repaired cheaply, possibly even free.. Problem is one of the items is horribly gunked up, it's probably something akin to BBQ charcoal bricks by now, as it's been repeatedly assaulted with boiling chromic acid, but there is a remaining black layer on the inside of the 5ml pear-shaped microflask, (its a 5ml pear shaped flask with integrated vigreaux column and sidearm with a condenser) that just won't come off.
I think I'm going to have to resort to the last line of defense against the very worst stains. Piranha acid. It's a mixture of concentrated sulfuric acid and hydrogen peroxide, usually 3:1 sulfuric to peroxide, 30% peroxide. Dangerous stuff, very dangerous if there are traces of solvents or organics around, it can explode, showering brutally powerful oxidizing agent everywhere. Although there won't be anything organic in the microflask I need repairing, due to it having been subjected to saturation-bombing with chromic acid, which will rip the SHIT out of most anything. Piranha is more powerful still, piranha acid can even oxidize inorganic,, graphitic carbon to CO2, there is very little it won't destroy. WILL get the job done, but not nice stuff to make or use, and definitely never something I'd store. Make what I need on the spot, use it, and destroy the residues of peroxide.