Australia's Science Forum

I don't know about you guys, but for years it's driven me nuts that when pracs use our waterbaths, & the kids are using small beakers, some invariably tip or get knocked over in there, & if they're heating milk or similar I have to empty & clean the bath before it's needed for the next lesson

They're doing the junket prac this week, & I was determined to have clean waterbaths at the end of it so I played around with a few things & came up with this:
It cost $10.90 for a huge piece of polystyrene from Clark Rubber, & I found the short length of downpipe from Bunnings to cut the holes for $1.99.

Just cut the styrene to rough size with a hot knife, trim for a snug fit inside the waterbath, then heat the piece of downpipe in a bunsen & cut a few holes at a time. Took about an hour to do 4.

6 classes have used it so far & no spills

It, you're so clever. It's great when an idea works. I'm always looking for ways to keep equipment clean.
Diana

What a wonderful idea! Well done

Brilliant - well done!

I've pinched so many recipes & ideas from you guys at Chemwatch, I just wanted to give something back, & for once I had an idea that worked - hallelulah!
The best bit is if they get busted it's super cheap to make them again. Also occurred to me that any shape or size for beakers/flasks etc would be easy as long as you find a 'cookie cutter' that's the right size.......more trips to Bunnings in the future I think

Good idea. Where did you get the water baths from in the first place. We use a hotplate and beaker etc. Not very successful I can tell you.
Estelle

Depending on how big your waterbaths are you could make them even cheaper by getting foam boxes from the supermarket to cut up. They usually have them going free if you ask someone in the fresh food section. They look great I wish we had a waterbath... well, we have an old one that was donated but the thermostat doesn't work so we have to put a data logger in to moniter the temperature and it can take a day or two to make it right, so it's hardly worth it!

They're Grant waterbaths & we got them about 17 years ago from Selby Scientific, but they're not in business anymore.

I have never seen that tech trader website before. I started looking but when I add something to the enquiry list it won't go back to the original list so I have to click the link again each time! Very frustrating... Does anyone else have this problem?

Having said that, it is working now! No explanation...

at my school they do the junket prac in test tubes and I use a plastic test tube rack to hold the test tubes.
Matchstick

great idea Bindibadgi
very clever indeed.

Does the polystyrene cope with boiling water?

R-S

Our waterbaths only go up to 90 degrees, so we set the temps at 20, 40, 60 & 80, & they also use the fridge & freezer to get down to 10 & 0.
The styrene coped fine with 80.

We did try using test tubes a few years ago, but our little darlings (& the teachers as well) complained that it was too hard to decide when the end point happened.

Another Cheap and simple one...
How to seal a bag and make it air-tight!
Cut a disposable water bottle on the neck of the bottle and keep the neck , top and lid only.
Insert the plastic bag through into the cut part of the neck and pull the end of the bag up and out through the original opening where the lid screws on.
Fold the bag over this – and screw lid back on to seal.
great for short term and for camping..

[wish i could post a picture easily.!]

Noona emailed the explanation and photo to me today (and a few others)
so if you want a copy of it, just PM me here with your email address and i will forward it to you