Any question answered...

glue to hold together some plastic

I wouldn't hold out too much hope whatever kind of plastic, but if you actually know what it is your best results will come from using the appropriate activator on the bond surfaces before applying the adhesive, e.g. https://www.loctiteproducts.com/en/products/fix/super-glue/loctite_plasticsbondingsystem.html is a two part product for bonding polythene and polypropylene which are common plastics used for flexible consumer products.

1 Attachment

Glue and duct tape.

JB Weld - remove the old glue, re-glue and allow to set, add more to form a 'collar' around the join, possibly incorporating structural splints.
Possibly alternative - a carbon fibre repair kit?
Much will depend on aesthetics and the replacement cost of your headphones as any repair will be weaker than the original...

Yeah if it’s snapped the band you’re best off neatly wrapping it in a reinforcing bandage. A bit of carbon or glass woven tape and epoxy resin. It won’t be the prettiest repair but it’s about all you can do.

If the contact area is small, then I'd be inclined to drill holes into the opposing surfaces and glue in a steel pin.
ETA - Accuracy in getting the holes exactly opposite each other isn't as important as you might think. If you give it your best shot, use a pin that's narrower than the holes you've drilled, and the adhesive will fill in the gaps.

Often wondered, after I complete a bike ride, why is the ascent stat recorded on my Garmin always higher than the ascent stat on the same Komoot route?
e.g Today I did a 53 mile loop, Komoot says its 3650ft, Garmin says 4534ft. Why such a disparity?
Presuming - hopefully - that the GPS figure is the one to rely on..?

Presuming GPS is the one rely on

GPS is terrible for altitude measurement due to geometry, so most Garmin units use a barometer instead. The barometric altimeter on a Garmin is pretty good in general for counting ascent/descent, but it can't measure absolute altitude and is fooled by changing weather, so it attempts to re-zero periodically by GPS.

Your Garmin is probably using air pressure to work out elevation gain and kamoot is working it out from the GPS/map data

Thanks all on the headphones, think it is going to be some different glue and wrapping in tape as the first bodge

e.g Today I did a 53 mile loop, Komoot says its 3650ft, Garmin says 4534ft. Why such a disparity?
Presuming - hopefully - that the GPS figure is the one to rely on..?

I did the same 200km ride with 2 other people with Garmin GPSes. We had three ascent figures of 1400m, 1800m and 2200m.

The ride distances differed by +/-10km too. All of us rode together the entire time, no-one left their GPS running whilst leant against a wall or at a food control or anything.

tl;dr the cumulative error on GPS measurements adds up quickly...

Garmin says 4534ft

You can correct the Garmin if you have access to weather observations. For a short closed loop route, a reasonable estimate is obtained simply by comparing the altitude reading at the start and finish, which should be the same, and applying any difference as a slope correction to the data to compensate for any pressure drop
https://www.youtube.com/watch?v=QKacmwx9lvU

(With reference to Shimano). Am reading that 11 speed chainrings with a 12 speed chain is fine, but want to know what exactly is the difference between 11 and 12 speed chainrings and chains? Reading vague conflicting things.

Is the gap on 12 speed chains thinner?

If so assume the 12 speed chainrings are thinner?

Is the space between the chainrings on a 12 speed crankset different to the spacing of the chainrings on an 11 speed crankset?

And ultimately, have an ultegra r8100 chainset. What is actually changing when I switch the outer 12 speed ring to an 11 speed ring? (Keeping the 12 speed inner)

Updated DNS stuff on godaddy over the weekend to change hosting from Skyline to Webflow, didn't realise but it also ballsed our email. I've since re-activated it and seems to be working fine now but haven't received anything sent to/from work accounts between this 10am when it was resolved and midnight Saturday when it was triggered. Is there a way to recover those - are they clogged up somewhere or no chance? Just on the vague off chance a distant great uncle bequeathed me a time-sensitive million quid or something.

I want to buy chemicals, mainly for cleaning stuff. Citric acid, IPA, caustic soda, limonene, etc.

Can anyone recommend some kind of chemical supply company that will sell to individuals, or shall I just pick some random site on Google? Or do I just have to live with basic bitch repackaged supermarket versions?

Are supermarket versions of these things more expensive or cheaper than proper chemical supply stuff? I presume the former but I don't know

Will I get put on a watchlist?

Will I get put on another watchlist?

There's been various Karcher window vac chat on here over the years and I may buy one. Having just looked them up though there seem to be about 6 different models, anyone able to tell me the one to go for so I don't have to wade through loads of specs. Ideally I'd just like to get the cheapest one but no idea if the expensive ones are way better.

Just get the cheapest one, I've got the cheapest and the one above, had to buy another because I lost the plug and couldn't get a replacement at the time.

The more expensive one has a wider wiper and is a bit more powerful but I can't say it makes a massive difference.

Citric acid, IPA, caustic soda, limonene, etc.

I tend to get from either Amazon or https://mistralni.co.uk/ I could check when I get home where the oxalic acid came from as I have a feeling it wasn't either of the above.

Supermarket formulations are generally overpriced and often contain not much of chemical you're after.

Will I get put on a watchlist?

Not for anything on that list. Buying toluene, sulphuric acid and nitric acid all at once might invite questions🙂

My parents had the small one and for some reason or another it was replaced under warranty with the big one. The big one is too big for some of their smaller windows*. We have the small one, haven't felt any need to upgrade.

* just seen they sell a narrow nozzle because of this. Can't really see why you'd need the big nozzle in a normal household use case.

I suspected Amazon would probably be full of dropshippers who just overcharge for stuff that's come from a proper chemical supply company. Thanks for recommending Mistral

Supermarket formulations are generally overpriced and often contain not much of chemical you're after.

That was my suspicion, thanks

One Shot, available from hardware shops, is 91% sulphuric acid. 1 litre for about 9 quid.

Cheers all, cheapest one it is.

You can get all that on eBay too, if you don't need laboratory grade.