Sciencemadness Discussion Board - Best materials for chemical work surfaces?

Best materials for chemical work surfaces?

Draeger - 6-2-2020 at 14:27

So, basically, I want to build myself a sort of enclosure designed sort of like a fume hood in structure. I am planning to make it fire-proof.

I was wondering; what would be a good material with both good chemical resistance and good temperature resistance, that's also not too costly?

I know there's the fume hood thread, but I didn't really find anything referencing a good material. Might have missed something, though. Sorry if I did.

Heptylene - 6-2-2020 at 15:31

Kitchen tiles. Very chemically resistant, probably fire resistant too. Not too expensive, but a lot of work to put together and probably heavy.

Other materials could be polyethylene or PTFE sheet, stainless steel, ... but plastics are not fire resistant and stainless is expensive.

How fire resistant does it have to be? Do you plan to have things burning inside the fumehood, or is it a safety measure?

Abromination - 6-2-2020 at 16:32

Test different materials for its chemical resistance by exposing it to conditions you expect to find in a fume hood. A lot of primers are very resistant to corrosion.

DavidJR - 6-2-2020 at 17:34

Stainless steel isn't exactly stainless in a lab environment. I wouldn't make a fume hood out of it (unless it was covered with something else).

j_sum1 - 7-2-2020 at 03:59

Well, my workbench is painted plywood. Not the best but defininitely not as bad as you would imagine. I have a large piece of kitchen granite that I use from time to time. I also use bathroom tiles. Cheap and disposable is not a bad combination.

I have not decided for the interior of my fume hood. I will probably glue down a sheet of polycarbonate and then continue to use the granite slab on top of that if I feel it is needed. Tiles or glass are other possibilities. One thing to consider is that hard surfaces are not too friendly to glassware. Or maybe 3mm ply that gets replaced on a regular basis...

Edit
I should add that chemists worked on varnished wooden benches for decades.

A bit depends on what evil you are going to be subjecting it to.

[Edited on 7-2-2020 by j_sum1]

Herr Haber - 7-2-2020 at 05:07

Kitchen tiles are probably the best but as mentioned a lot of work to put together and prepare the surface.

Not only do they meet your criteria, they also meet one more you forgot: they are easy to clean !

I also use 30x30 PTFE slabs (3mm thick) I got from Germany to protect an area temporarily. My hotplate sits on one of those. They are expensive but immensely versatile.

Heptylene - 7-2-2020 at 07:35

Quote: Originally posted by j_sum1

Well, my workbench is painted plywood. Not the best but defininitely not as bad as you would imagine. I have a large piece of kitchen granite that I use from time to time. I also use bathroom tiles. Cheap and disposable is not a bad combination.

I have not decided for the interior of my fume hood. I will probably glue down a sheet of polycarbonate and then continue to use the granite slab on top of that if I feel it is needed. Tiles or glass are other possibilities. One thing to consider is that hard surfaces are not too friendly to glassware. Or maybe 3mm ply that gets replaced on a regular basis...

Edit
I should add that chemists worked on varnished wooden benches for decades.

A bit depends on what evil you are going to be subjecting it to.

[Edited on 7-2-2020 by j_sum1]

Good point about hard surfaces, tiles are pretty bad in that regard. My work bench is also a wood. It's a kitchen countertop. I applied some linseed oil to make it waterproof, which works to some extent, but it does get stained a little bit over time.

12thealchemist - 7-2-2020 at 11:44

I've put some thought into this myself from time to time, and recently distilled my thoughts when needing to ask workshops at the university to make a Schlenk line scaffold. The previous one was wood painted with a fire-retardant paint, however, the paint was not at all solvent resistant. The solution they came up with was a specialised plastic material called Trespa, but that's not cheap and probably difficult to get hold of for you or I. The main benches are varnished wood, and despite being a little stained or darkened, they've held up well for several decades (the building is in need of a revamp).

I believe commercial fumehoods use ABS as their floor, which is pretty heat (300+°C from flamed glassware) and obviously solvent resistant. My lab surface at home is an old kitchen counter which is melamine-coated chipboard, and has stood up fairly well - though the tiny lithium fire wasn't so kind.

I've considered a glass sheet covering a wooden bench, but that is susceptible to cracking and breaking very easily. Granite and slate are fire and chemical resistant, but expensive and heavy. Though price could be circumvented by using a cast-off kitchen counter.

Overall, I'd say varnished wood is the best option - difficult to actually burn, chemically resistant (particularly solvent), and is less likely to break your glassware when it falls, unlike stone (eg tiles, granite, slate).

DavidJR - 7-2-2020 at 13:46

Quote: Originally posted by 12thealchemist

I believe commercial fumehoods use ABS as their floor, which is pretty heat (300+°C from flamed glassware) and obviously solvent resistant.

I very much doubt that. ABS is not very solvent resistant at all. It dissolves in acetone, for instance.

Swinfi2 - 7-2-2020 at 15:32

I kind of like the idea of coating Stainless in a thin layer of alumina, I remember seeing a paper with some easy-ish sol-gel methods fairly recently but can't find it now.

But that might not be so easy to accomplish with larger sized sheets of metal.

draculic acid69 - 8-2-2020 at 06:33

Abs sounds like a terrible idea.acrylic would be superior to abs in so many ways

unionised - 8-2-2020 at 08:18

Quote: Originally posted by j_sum1

I should add that chemists worked on varnished wooden benches for decades.

[Edited on 7-2-2020 by j_sum1]

In my day they were waxed, rather than varnished.

ABS has lousy heat resistance.

Tsjerk - 8-2-2020 at 08:32

Go for kitchen tiles. They are easy to clean and I haven't met a chemical that damaged them. The stuff you use to secure them with is another story, I did spill some acid once and the filler started to bubble, but then again... the filler is easy to replace after a couple of water rinses.

12thealchemist - 8-2-2020 at 10:30

Quote: Originally posted by DavidJR

Quote: Originally posted by 12thealchemist

I believe commercial fumehoods use ABS as their floor, which is pretty heat (300+°C from flamed glassware) and obviously solvent resistant.

I very much doubt that. ABS is not very solvent resistant at all. It dissolves in acetone, for instance.

That does sound much more sensible. I must have mixed up some acronyms then. Any thoughts on what that plastic is then, anyone?

morganbw - 8-2-2020 at 11:18

For an amatuer, I would have no problem using an ABS tray(translated to a floor) to catch mistakes.
Just me maybe, somethings in life wind up disposable.

During my career job, our lab did have a fume hood. I have no clue of the floor material (except that it was black and likely a composite material). We made some efforts to catch spills with some sort of tray/containment method under reactions.

If you visualize air flow within a fume hood vapors should not be a problem with floor materials.

Amatuer (translate this to your kitchen/spare bedroom/deck.
Do the best you can with the knowledge you have and what you can access.

Abromination - 8-2-2020 at 11:19

Quote: Originally posted by 12thealchemist

Quote: Originally posted by DavidJR

Quote: Originally posted by 12thealchemist

I believe commercial fumehoods use ABS as their floor, which is pretty heat (300+°C from flamed glassware) and obviously solvent resistant.

I very much doubt that. ABS is not very solvent resistant at all. It dissolves in acetone, for instance.

That does sound much more sensible. I must have mixed up some acronyms then. Any thoughts on what that plastic is then, anyone?

Perhaps a phenol formaldehyde resin? I think this is used on the black colored lab benches.

DavidJR - 8-2-2020 at 11:34

Maybe. Also epoxy benches are used but these are expensive.

DavidJR - 8-2-2020 at 11:43

Quote: Originally posted by morganbw

For an amatuer, I would have no problem using an ABS tray(translated to a floor) to catch mistakes.
Just me maybe, somethings in life wind up disposable.

My issue is less that it would be damaged, and more that it will end up as a nasty sticky mess if you spill a random solvent on it. ABS is a styrene copolymer and has similar solubility to polystyrene.

My lab bench is now topped with varnished plywood. The first varnish I tried was some kind of water based stuff that was unsuitable because it dissolved and became sticky in pretty much every organic solvent including alcohols. I quickly sanded this off and revarnished with a traditional smelly polyurethane varnish. This is much more solvent resistant and does not dissolve in any solvent I have spilt on it so far. However, it can still be damaged by some solvents, but this results in parts of it peeling/ flaking off, not it dissolving to make a sticky mess.

Boffis - 8-2-2020 at 15:02

Porcelain bathroom tiles, you can obtain them up to at least 90 x 60cm, about 10mm thick, semi matt or high gloss, heat resistant, non-porous, virtually indestructible and fairly cheap. Tile shops will often have a few odd ones laying around from demonstration samples that you can often get cheap providing you are not too fussy about the colour.

CharlieA - 8-2-2020 at 16:38

My lab surface is made with porcelain kitchen/bath tiles. I used a regular tile adhesive, and a silicone-based grout. Seems to work well, but I am finicky about spills (both having them and cleaning them up immediately).

Ubya - 9-2-2020 at 05:03

i made mine with kitchen tiles, they are pretty much untuched by everything i spilled.
as a filling between the tiles i used an epoxy based filler, it is chemical resistant and liquid proof, not cheap but you really don't need much. i used less than half of the tiles fron the package (they sell a minimum number) so i just use them to test stuff, as a heat resistant base dor beakers and hot glass, even as boiling chips, i still have around 20 of them.

ps it's not that hard to place tiles, it was my first time and went pretry well, the hard part is cutting the tiles, but you don't have to if make your measures in advance (i designed the base for 10x10cm tiles, but i later found out that i couldn't find any, so i had to buy 15x15cm tiles, and cut some if them to fit)

Draeger - 9-2-2020 at 05:12

Thanks everyone for your answers. I think I'm going to try the kitchen tile + epoxy filler approach.

monolithic - 9-2-2020 at 05:56

Soapstone is the "classic" chemistry bench top material.

rockyit98 - 9-2-2020 at 16:20

cheap and most reliable way is to change the surface for the situation.i have a granite plate that have a mass about 40 Lb it is good for most chemicals and fire but i also use a gypsum board coated with Silicone sealant that rated for 250C ,easy to clean up portable and disposable.

Sulaiman - 9-2-2020 at 22:44

Whatever the work surface is, I recommend using a sheet of silicone rubber on top of it.
e.g. the first I found - not the cheapest https://www.ebay.co.uk/itm/Red-Black-White-Silicone-Rubber-S...

Resistant to most chemicals but 68% HNO₃, 35% H₂O₂ etc. will stain it,
but not significantly damage it if contact is only for a few minutes.
The rubber mat is easily washed and it encourages glassware to bounce rather than shatter.

Any 'bouncy' material could be suitable ... rubber, plastic, softwood etc.

draculic acid69 - 10-2-2020 at 03:23

That black builders plastic that comes in rolls is pretty inert to most stuff I've spilled on it this week including concentrated h2so4,DCM, xylene, cyclohexanone and assorted bromo compounds.it smells like bong resin though for the first couple of days.

download (1).jpeg - 4kB

[Edited on 10-2-2020 by draculic acid69]