Search found 706 matches

by bigmack
31 May 2023, 12:27
Forum: Biology, Physics...
Topic: Disposal of used agar plates
Replies: 33
Views: 14817

Re: Disposal of used agar plates

When I first started , I was told by my off sider to store them in the fume hood until the GA lit a fire to burn off excess green waste then bring them over and chuck’m on the bonefire . I knew no better but after about 6-9months I was asking when was the bonefire ment to happen . Discovered that th...
by bigmack
25 May 2023, 15:02
Forum: Sourcing Materials & Eq Repairs
Topic: Bromine
Replies: 9
Views: 3426

Re: Bromine

elaruu wrote: 25 May 2023, 09:52 Hmmm. He says it is an essential part of the curriculum.....
I’d say he’s talking out is bottom.
by bigmack
24 May 2023, 16:42
Forum: Chemistry and Labware - General
Topic: Burettes
Replies: 2
Views: 1999

Re: Burettes

Is all of them or just one or two ? Sounds like you have done pretty much all you can . If they are the ones with Teflon tips , I’m thinking the tip is damaged . You could try slicing a small bit off the end as parallel as you can with a Stanley knife . Failing that , the round filing cabinet might ...
by bigmack
24 May 2023, 13:10
Forum: Biology, Physics...
Topic: Spectrum Tubes
Replies: 8
Views: 2540

Re: Spectrum Tubes

Yes I would always recommend having a spark gap set to the widest setting where it will still arc consistently while using anything connected to an induction coil . If the device connected requires less voltage then the spark will stop . That is OK .
by bigmack
23 May 2023, 15:23
Forum: Biology, Physics...
Topic: Spectrum Tubes
Replies: 8
Views: 2540

Re: Spectrum Tubes

I got one of these power supplies for ours . https://www.chemtalk.com.au/viewtopic.php?p=48804#p48804 I was looking at your holder and it reminded me . We got one of those in our set of tubes from serrata ( MTA) . Teacher whinged that all the tubes were glowing . She was kinda right . If the probe w...
by bigmack
23 May 2023, 10:35
Forum: Biology, Physics...
Topic: Spectrum Tubes
Replies: 8
Views: 2540

Re: Spectrum Tubes

Annette , care to throw up a picture of the induction coil and even the tubes
by bigmack
16 May 2023, 11:14
Forum: Recipes and Pracs
Topic: Silica gel for chemical garden
Replies: 7
Views: 3747

Re: Silica gel for chemical garden

LOL , I’m playing house husband until I can find a job .
Still pop in when I can .Miss the job and the forum .
by bigmack
15 May 2023, 22:34
Forum: Recipes and Pracs
Topic: Silica gel for chemical garden
Replies: 7
Views: 3747

Re: Silica gel for chemical garden

Edit : one less step in the process , but also reduces risk as no Sodium Hydroxide needed . ….. although Sodium Silicate is Corrosive anyway . Hmmm ,this just reminds me . Our retired Chem teacher left a gas jar full of Chemical garden in his display cabinet in his class room. He knew what it was ,a...
by bigmack
15 May 2023, 17:57
Forum: Recipes and Pracs
Topic: Silica gel for chemical garden
Replies: 7
Views: 3747

Re: Silica gel for chemical garden

Whenever we did it,we just used Sodium Silicate solution that was in the Chem store .IIRC ,ours come from Silform .
by bigmack
04 May 2023, 22:03
Forum: Safety with Chemicals
Topic: Melting Plastic
Replies: 2
Views: 2399

Re: Melting Plastic

I've been told it will not give off any fumes. Then there should be no problems then …… other than who has to clean to saucepans :o Most milk bottles are HDPE . It melts around 120°C Apparently HDPE shouldn’t produce toxic fumes even when burned . So a bit of melting should be fine . Whats the purp...
by bigmack
03 May 2023, 18:58
Forum: Recipes and Pracs
Topic: HELP
Replies: 17
Views: 8887

Re: HELP

Metho is fine Rosalie . Trick is getting the right distance between the spirit burner flame and the star . Blocks of wood etc work but are a pain . We ended up getting some adjustable jacks to lift the burners up under the tripods . You can buy them from usual suppliers for about $70 .-$100 each . I...
by bigmack
03 May 2023, 17:53
Forum: Chemistry and Labware - General
Topic: electrolysis of water
Replies: 8
Views: 4482

Re: electrolysis of water

Sounds like there is a break in one of the electrodes Rosalie . When its working , there should be a fury of bubbles coming off each electrode . It looks like fizzy drink . Can you check the continuity between the platinum and the bare copper wire on both .A multimeter or simply a light bulb and a p...
by bigmack
16 Mar 2023, 09:10
Forum: Sourcing Materials & Eq Repairs
Topic: Reduction Tube
Replies: 3
Views: 1978

Re: Reduction Tube

mtg wrote: 14 Mar 2023, 10:33 I have a stack of copper reduction tubes, never used in my life time, they are a glass tube, roughly 11mm in diameter, with a bubble (sort of) in the middle, about 30mm wide, 180mm long all up.
Any chance of a pic mtg ?
by bigmack
16 Mar 2023, 09:06
Forum: Sourcing Materials & Eq Repairs
Topic: trundle wheel
Replies: 13
Views: 3677

Re: trundle wheel

Kathryn I'm also in the market for another one but agree that all the plastic junk available from our regular suppliers wouldn't last five seconds with our lot . We have an old Lufkin one and it's still going . Have found them available from Total tools and other big tool shops .Not the cheapest @ $...
by bigmack
09 Mar 2023, 13:54
Forum: Sourcing Materials & Eq Repairs
Topic: Wheatstone bridge
Replies: 14
Views: 3257

Re: Wheatstone bridge

Each one is a basically a Rheostat. You need two to make a wheatstone bridge .
Could do same thing with normal Rheostats .
Bridge.jpg
by bigmack
09 Mar 2023, 10:35
Forum: Sourcing Materials & Eq Repairs
Topic: Wheatstone bridge
Replies: 14
Views: 3257

Re: Wheatstone bridge

probably someone that appreciates Steampunk stuff would love them Where would I find such a person? (Or is that a joke that flew over my head??) Not a joke Rosalie. Steampunk is quite a passion for some folk . They love old school Wood,brass,copper Leather etc . Some are quite artistic with it . No...
by bigmack
09 Mar 2023, 09:04
Forum: Sourcing Materials & Eq Repairs
Topic: Wheatstone bridge
Replies: 14
Views: 3257

Re: Wheatstone bridge

probably someone that appreciates Steampunk stuff would love them
by bigmack
08 Mar 2023, 12:05
Forum: Sourcing Materials & Eq Repairs
Topic: Wheatstone bridge
Replies: 14
Views: 3257

Re: Wheatstone bridge

Is it these things Rosalie ? .
Dragged out from the back of the Physics cupboard. Couple of variations , but they all do the same thing .
Wheatstone 2.jpg
There's a piece of Nichrome wire on the ruler .
Wheatstone 1.jpg
No ones ever asked for them while I've been here
by bigmack
28 Feb 2023, 11:33
Forum: Safety with Chemicals
Topic: printers
Replies: 9
Views: 2885

Re: printers

I have a B/W laser printer in Staff room which is a reasonable walk but most of the time I'm needing Colour stuff and have to walk 4 flights of stairs and the other side of the school . I have to ring the Printroom , see if they are using the Colour printer and then make sure the Bypass tray is not ...