Clean burnt Sugar from glassware

[Labbie]

One lovely teacher, has some burnt sugar in our new test tubes, about 22 of them. Any ideas how to remove this mess

I have tried really HOT HOT water, & soaked over night with oxalate acid. Help

[RosalieM]

Haven't had to deal with that problem, but bi-carb soda or napisan seems to work for just about anything. Worth a shot! Good luck
Rosalie

[Ocean Breeze]

just soak them is some Na OH overnight. They will just rise clean in the morning! No scrubbing required

[Lyn]

What strength NaOH would you recommend? I have several evaporating basins with charred remains from a jelly crystal prac which no amount of scrubbing is moving.

[dime]

1M or 2M max NaOH should do the trick. It will loosen just about anything. Even melted (sublimed?) sulfur from test tubes or deflagrating spoons. Might need to leave them for a couple of days, just keep soaking till the stuff lifts off. Have a nice weekend all :

[Labbie]

I had forgotton about Nappy Sand, Silly me, but we have run out of that. So I will have a go with Sodium Hydroxide, I have some Old 3M which I could use up, as a cleaning Acid. Thank you again

[ellice]

We keep a stock of small test tubes (7x1cm) for burning sugar. Then I just throw them away!

[Labbie]

Yes so do I, but this teacher helped him self. He did'nt ask, just went ahead and did it.

That Nappy San is really good.