Caustic Soda Vs One Shot Sulphuric Acid

Absolutely not!!!!!!!! A serious explosion could result, covering all & sundry with nasty stuff.

If the drain doesn't unblock, try the caustic again or use rods. There will still be a highly alkaline presense in the drain, so the acid will react with it.

Dave

In my experience caustic soda is good for fatty deposits - kitchens etc, and sulphuric acid is good for hair balls - baths & showers. Beware that sulphuric acid will stain baths and shower trays so be very careful how you pour it.

AWEM

It's nothing to do with time - if you left it full of sulphuric acid for, say, a month, and no water at all went down the drain, then you'd potentially have a BIG problem if you shoved caustic soda in there. However, alternatively if you were able to flush away all traces of the acid using copious amounts of water, then it would be safe to use the alkali within a few minutes. So it all depends on how effectively you can get rid of the acid.

David

When you mix solid caustic soda and water, the mixture gets hot. It can get very hot, and boil. When it boils, it can and will spit hot caustic soda granules/boiling caustic solution all over the place. If you pour boiling water onto solid caustic soda, the temperature of the water will probably immediately go up a bit, to above boiling, and it can and will

The above is why it is recommended to mix the caustic into cold water, carefully, to avoid being showered with caustic. Read the side of the tub for more info.

You should avoid being showered with hot (or cold) caustic, use eye/skin protection, and keep some vinegar and a pail or two of cold water handy to wash in if there's an ewmergency.

If anyone tells you that the above isn't true, then they're fools.

Make sure there's no caustic in the system before using acid, or it will cause a violent reaction. Flush it with water first.

Quite frankly, I think you'd be better off dismantling the system to do a proper job. Good Luck and take care.

"Chris Bacon" wrote >

Similarly, conc. sulphuric gets very hot when diluted. If attempting to dilute sulphuric acid *always* add acid to water, *never* the other way round. That way, if it boils and spits you are more likely to get splashed with dilute acid. Eye protection etc. is a must.

Steve S

Hmm but do you reckon he's going to able to buy sulphuric acid stronger than 1M anywhere? Seems unlikely to me. It's difficult enough finding hydrochloric acid for pavement cleaning.

Personally I would pour the acid in now, then run like hell!

I'm sure the resulting explosion will unblock the drains, and it might bring down the rest of your ceiling as well, which is a GOOD thing.

Did you try blocking the WM waste, flushing cold, then slowly pouring lots of hot and detergent before flushing with warm or more cold?

If you have to call someone out, it would be good to tell them before they start about the chemical soup in the pipes.

Similarly if trying to flush the blockage again, take care so you don't get a face full of caustic.

If the bath/shower drains and loo are running fine the blockage is most likely in the branch to the kitchen sink.

cheers, Pete.

I demonstrated this to one of the kids over Xmas. One part caustic, one part water, and stir. I predicted it would melt the yoghourt pot, but it didn't. Didn't boil, didn't spit. Hand hot I'd say. Why people bother with acid or alkali drain unblockers is a mystery to me. Most blockage respond to the smaller diameter garden hose (with a flow of water if necessary)

In future, tip a cup of soda crystals down the plug hole, followed by a pint of boiling water. Repeat this every week of so and it keeps the drains clear.

sponix

Theres also the option of a flexible wire rod. Screwfix sell them for about =A315 or so.

NT

Just had a thought, are you sure it isn't blocked with the polystyrene tiles that fell down? If so, pour down some diesel fuel. Make sure it doesn't catch on fire, not with all those flammable tiles around.

HCl at 10% is readily available from s/fix under "Patio Cleaner" I use it for general descaling. It's quite as strong as brickwork cleaner (travis perkins). The local PM has Hcl (strength unknown).

The H2SO4 in the one shot drain cleaner is "94%" It seems pretty strong it fumes and discolours many things.

Could well be worth a go. You could "borrow" some "curtain wire", or use a bicycle cable, just for an experiment....

Even I wouldn't do that.

You use caustic to braak up organics - especailly solidified fat - and sulphuric to smash through limescale.

Mixed togrther they neutralise each other.

After a short period of pyrotechnics.

High school chemistry suggests that sodium sulphate and a LOT of heat will be the result.

I am not sure if I know ANYTHING that sodium suplhate is good for..

If you had used brick acid (hydrochloric) you could at least have made some salt....:-)

When doing anything with caustic, once the blockage has cleared always flush with gallons of fresh water. The public drains can handle mild alkali in quantities better than a gob of conentrate going past, which can get trapped and cause problems.

Despite dire warnings, I once again used castic and hot water to clear the christmas grease out of the U bend, and can report that as usual I did not end up in hospital.

Use of _boiling_ water from a kettle is a bit of a last resort, and you do get superheated alkali vapour and a lot of splashing, so do that carefully and test outside first with glasses and old clothes on so you know what to expect.

Splashes on skin will burn and need washing with lots of cold water fairly immediately. The skin will feel soapy, but no lasting damage ensures. Eyes are a different matter. lots of hot water and off to A & E weher they can at leats give you pain killers - corneas do redrow, but hurt like sin while they do. Ive never had alkali in my eye, but I have had branches and throrns scratch the cornea and cause an extremely painful condition, and infection too.

Splashes on cloths bleach them totally and generally rot the fabric too. . The secret is to get hot caustic to the site and let it stay there and do its work., If the drain is totally blocked, this may not work.

What I do in cases of dire ncessity is this.

I open up the sink plug, and fill it to the brim with solid castic soda crystals.I keep adidng them until the whole drain is as full as it can get.

From a distance, I pour boiling water from a kettle on,. a little at a time, at arms length, because it is a VIOLENT flash steam generator, and

If the drain doesn't clearr, I repeat as often as is necesary until the high concentration hot caustic has travelled to wherever the blockage is.

I'd say this brutal technique works 90% of the time.

However there are exceptions.

- I have had 'female waste' blocking low fall sewage systems outside to a septic tank, with high ground water levels leadng to high tank levels. Here I used reverse flushing from a manhole - pushed a hose up the pipe and probed the turdiness until all the big bits had floated past.

- I have had an old toilet so scaled up that female waste and turds and bog paper got stuck in its U bend.Here caustic made short work of the turds, but some industrial acid from a friend - sulphuric IIRC - left in over night dissolved what scale there was - we ended up pushing HUGE chunks of turd and urine and scale composite down the drain in due course. Once that was done the other problem did not reoccur. The loo also looked sparklingly new again.

- I have seen tree roots push and fracture old clay pipes, and then get inside. This is really bad news. It can happen with plastic too - the joints may spring, and the roots then charge off towards this lovely nutrient and water supply. Sometimes chemical attack helps keep it at bay, but really, having dug one up in that condition, I'd say that is the only real answer.

Thats essentiall what I do to any drain the seems not to be draining as it should.

With showers, I pull the thing up from the trap and clean that first. Usually they work once all the pub(l)ic hairs are removed. But a dose of hot casutic (I don't use boiling water unless I have to. Caustic geysers are fun, but they do case localised damage to hands and clothes, and sometimes othere localised objects).

All the bollocks about 'never add water to caustic, always do it the other way' applies to chemistry lessons, where what you want is a safe reliable way to dilute the stuff. And you are dealing with testosterone infused teenage brains scarcely able to concentrate on what they are doing, and whosw parents will sue if little jonny gets a nasty hurty splash on his yummy tum.

WE are looking here for the most violent pressure generating way to get scaldingly hot caustic in a soil pipe.

The only serious danger is to your eyes. That is really really serious, and needs massive cold water instantly.

Otherwise skin gets scalded, and cold water will reduce that to a minor itrritant in a minute.

Respect your caustic. Like your circular saw, your router, your chainsaw, your consumer unit, its capable - not of killing you at least where the others WILL..,but of damaging your eyes...but on a scale of dangerous things I have done its well down the list ..

Acid is actually more dangerous.,especially in eyes.

Amminia is more instantly incapacitating.

The nearest I have cimne to killing msyelf is petrol used to start a bonfire. Hint. Being 8 feet away on a hot summers day and ligthting the match there to light a bit of paper to throw at it, is no help. Petrol vapour is dense and heavy and travels a LONG way on te ground..

The second near miss was failing to let the router bit stop turning before allowing it to swing back into my jeans. Fortunately the jeans stopped it a couple of mm from the femoral artery. Jenas are more replaceable ...

Chuck keys left in lathes are another one I remember.

ALL DIY is potentially dangerous and also lethal. Falling off ladders, electric shock, severe trauma from power tools - ask your A & E..hernias from lifting sacks, back pain...tetanus and other raging infections from scratches splinters and cuts in the garden...

Caustiic burns? I doubt they see one a year.

diesel is useless, Use celluose thinners.

That will dissolve the plstic pipes as well, with luck :-) Oh, sulphuric and hydrochloric make short work of congealed PLASTER and cement waste..

A mild laxative I believe (Glaubers Salts)