×
The Power to build a Community (22 Nov 2019)

Do you wish to set up a STEM club? Maybe you have an idea for a professional discussion group or maybe you want to collaborate better with the members of your Area Technician group. Then why not check out the TecHKnow GROUPS area now. We give you the power of TecHKnow in your hands to manage your personal GROUP. Check it out now by clicking on the main menu.

× General discussion, news, views, opinions regarding daily working around the school science preproom and laboratory area

Question Brass weights

7 months 6 days ago #41339 by Kasey
I've found 16 sets of brass weights - and they are absolutely filthy.

Washed them in water and washing up liquid which has brought most of the labels and blu-tac etc off, but they still look terrible.

How do I clean 160 brass 100g weight quickly? Without resorting to cleaning each one with a scourer?
Not after bright and shiny, just clean.

Please Log in to join the conversation.

7 months 6 days ago #41340 by SteveKeys
If you have a dishwasher, bung them in with the next load.

If you don't have a dishwasher, sell the brass and buy one

Steve

Please Log in to join the conversation.

7 months 6 days ago #41341 by Kasey
Considered Steve's reply, then common sense took over and I realised I haven't any room for a dishwasher.

Had a look on google and the most common method was tomato sauce.

So I stuck them on the acid bath for a couple of minutes and then gave them a quick was, and they look a lot better.

Please Log in to join the conversation.

7 months 6 days ago #41343 by bsimmo
and are a bit lighter too :-)

Make room for a dishwasher, make it a mission.

Please Log in to join the conversation.

7 months 5 days ago #41344 by Kasey
Judging by the amount of muck that they carried they probably weight about right now ....

Believe me I have thought long and hard about a dishwasher and it comes down to one thing. It would have to go where the food fridge is now. Which means moving the fridge. Due to lack of power points I would have to run it of an extension lead somewhere. Favourite is moving the bin and glass bin. Then I would have to find somewhere for the bins.

Get the picture?
:) :) :) :) :)

Please Log in to join the conversation.

7 months 5 days ago #41345 by bsimmo
We have two dishwashers :blush: :whistle:






(irony being Food Tech do not have a dishwasher <shush>)

Please Log in to join the conversation.

7 months 4 days ago #41346 by Kasey
:angry: :angry:

Please Log in to join the conversation.

7 months 20 minutes ago #41347 by AndyG
We had two dishwashers - one went wrong so we asked for it to be dumped and they dumped the good one :-(

Please Log in to join the conversation.

6 months 4 weeks ago #41348 by anna17
Soak them in sodium carbonate solution, it's the main constituent in cheap DW tablets. If I put my copper bottomed saucepans in the dishwasher,at home, the copper comes up lovely!!
The following user(s) said Thank You: Kasey

Please Log in to join the conversation.

6 months 4 weeks ago #41349 by Baldilocks
I have always wondered just how much a cleaning process affects the weight of these things. As a result I was pretty anal about not letting my calibration weights get dirty, or even touched, so that I wouldn’t have to clean them.

Brass weights get a patina of ‘brass oxide’ which is presumably heavier than the brass on its own. Cleaning this will remove some brass as well as the oxide giving a nice shiny weight but one that is lighter.

Has anyone done the experiment to see how much effect this has?

Ian

“Do not believe everything you read on the Internet.” -Abraham Lincoln

Please Log in to join the conversation.

6 months 4 weeks ago #41352 by Kasey
Not done the experiment.
But at the level we work at I don't think it matters much. :-)

Please Log in to join the conversation.

6 months 3 weeks ago #41357 by AndyG
And lo! The experiment was cobbled up ... Mass dusted then
Before stupidly excessive clean: 99.9468g
After stupidly excessive clean: 99.9303g

So not a lot (it was a very old and very dirty brass mass) but it's enough to give a result in a 2d.p. reading.
I stress that this level of clean is not something I'd do normally - the mass wasn't even boxed. However, I don't think calibrating a balance to 100g (if it was) using a mass with a 0.016% error would influence the students' results ...
The following user(s) said Thank You: Baldilocks

Please Log in to join the conversation.

6 months 2 weeks ago #41361 by Kasey

AndyG wrote: And lo! The experiment was cobbled up ... Mass dusted then
Before stupidly excessive clean: 99.9468g
After stupidly excessive clean: 99.9303g

So not a lot (it was a very old and very dirty brass mass) but it's enough to give a result in a 2d.p. reading.
I stress that this level of clean is not something I'd do normally - the mass wasn't even boxed. However, I don't think calibrating a balance to 100g (if it was) using a mass with a 0.016% error would influence the students' results ...


LOL! :laugh:
The following user(s) said Thank You: Baldilocks

Please Log in to join the conversation.

Moderators: TheOtherSeamusTecHKnowD.B.FergusonDampSquibBaldilocks
Powered by Kunena Forum

Latest Forum Posts

More Topics »