Drain unblockers

so as i've seen people have mentioned the use of stuff like drain unblocking fluid / crystals to "eat" away stuck alloy bits to free them from frames, i'm wondering if anyone know where i can buy that stuff? the drain in my kitchen sink is blocked and i need it, tried B&Q and that huge asda on old kent road they don't sell it...

jiust buy some caustic soda

basically all you need is something called Sodium Hydroxide. you can buy commercial cleaners but its mo' moneh.

thanks i know that, anyone works in a school lab can nick me some?

anyway, back to my question... WHERE can i find it?

hardware shops.

caustic soda is indeed what you require.

local old school hardware shops are best

Hardware shops carry that stuff

I had the same problem with my shower earlier this month, didn't have time to find a hardware shop, so I poured a shit load of bleach straight down the drain and left it from morning until evening, then flushed it out - it worked!

Try to get a plunger, an old school but effective way - if you can't find one, run some water, put you hand over the plug and make a cup shape with your palm, then push up and down quickly, making sure to keep a seal (water helps with this). It's not ideal, but it can help - I'm not taking the piss, by the way!

Mr Muscle Sink & Plughole unblocker - like Ronseal, does exactly what it says on the tin. Available at most branches of most supermarkets for about a fiver.

thanks guys for the tips... i'm already surprised that the drain survived eating my flatmates' tea leaves and assorted greasy gunk for 2 years until it started coughing up.

sano, i've got a plunger, but the blockage is rather bad it wont work.

caustic soda in the cheapo shop selling plastic containers and mops and all sorts next to the bookies on hoxton st about £1.20

This'll do the business:

http://www.diy.com/diy/jsp/bq/nav/nav.jsp?action=detail&fh_secondid=9271679&fh_location=%2f%2fcatalog01%2fen_GB&fh_search=plunger&fh_eds=ß&fh_refview=search&ts=1195674655678&isSearch=true

Far better than pouring a chemical cocktail down your plug hole. You'll get an instant result, too. Whether you're using a plunger or a gas cartridge, make sure that you fill the sink before you try to unblock it. The plunger has to be well under the water level for it to work well.

One Shot. My local DIY store sells it. It's basically neat sulphuric acid and is the best stuff for burning through the shit in your drains

caustic soda is sodium hydroxide btw, and its much more efficient than all those mr muscle etc. shouldn't think acid would be particularly efficient at removing grease...

any one pound shop will have it ;)

boots sell caustic soda me thinks.

Does caustic soda actually dissolve aluminium? Could I use it to munch a crank arm off a pedal axle (steel)? I have a very sweet pedal that is fused to a crank and would dearly love to remove it!

hacksaw, the end of the crank

31trum hacksaw, the end of the crank

Done that! Dremelled a few slots as deep as I dare before hitting the pedal threads and got nowhere. I have actually now taken a wedge out of the end by trying to lever the sides of the slots apart to loosen the threads. Heating and cooling hasn't got me anywhere either. I need some magic alu munching liquid that won't harm the steel!

Momentum

Get your self a center punch.

Face the back of the crank towards you. Get a small drill (2 mm ish) and place it a the join of the pedal axle and the crank. So the drill is on the axel half is on the crank.

Drill away from the pedal axle at a slight angle. You should find due to the softer nature of the the pedal axle the drill will pull more into the soft alloy.
Only do this a mm or so in to the crank now you should beable to re position the drill to drill parallel to the axle and very close to the threads. Be careful not to twist the drill as you may snap it.

Repeat this process round the axle, eventually you should have more or less completely released the axle. A little twisting with a spanner + vice or pipe grips may still be needed but due to the fact that you have less material around the axle it should move. The center punch may come in usfull when trying to start your drilling to to keep it where you want to drill.

It can be quite difficult to do and you have to be careful. If you end up damaging the threads a bit all is not lost. A thread file can really sort out some bad threads. 20 tpi is what you would need, personally I should not buy one as they are quite expensive but go ask at a bike shop or local garage, they tend to have them. Pro blet you use it for free or a drink.

That sounds like a workable idea, although I think I'd need a vice to do it properly. Current workspace is either a g-clamp on a chair or held in hand/under foot on the floor!

I quite like the idea of just chucking it some magic liquid that dissolves all the aluminium but leaves the steel fine and ready to thread into some other cranks!

Look what I found on physics forum http://www.physicsforums.com/archive/index.php/t-105538.html

random internet physics dude I didn't think NaOH dissolved aluminum. We've used it in the past to dissolve hard anodization off of parts and it seems to leave the base metal untouched...

[cite]other random internet physics dude[/cite]It takes a while to dissolve the aluminum, but it does eat it all up. Does nothing to copper, brass or steel though.

[cite]yet another random internet physics dude[/cite] At the beginning, and with a non-hot solution, the reaction is very slow. After the thick layer of aluminum oxide has been removed by the NaOH, the reaction proceeds fast.

Seems like its time to get some sodium hydroxide, a suacepan I don't care about and some rubber gloves!

The reaction creates hydrogen and "noxious fumes" so prob won't have a fag while I'm doing it.

Interesting, sounds like a good idea, you have done some good researching!

May be one do do ina well ventilated area.

Or I could try and collect the hydrogen to run my ipod!

Definietly need good ventilation - an interesting point that I read is that the ventilation needs to be at the top of the space, otherwise the hydrogen will gather at the highest point in a pocket until a spark comes along...

It's also a pretty exothermic reaction once the oxide comes off and the sodium hydroxide is pretty unfriendly to skin, eyes, etc. Will try it on the street outside my flat with some rubber gloves I think.

Will report back once I have done this (and will hopefully be able to show you a pair of these babies on my bike):

I remember you picking those up at Herne Hill for a ridiculously small sum. £1.50?
Maaaaan you get all the bargains! Have you thought about a side-line as a personal shopper for 'fixed-riding hip urbanites'?

They do look good. What era are they from?

1986?

haha