Plumbers are a nightmare in my area. I give some details in other replies. I am also a nightmare for them because my screwed up town gives them nowhere to park. So they often don’t even want to come. Their fee just for showing up is about what I spent on tools and chemicals.

Where do you live that sulfuric acid is illegal?!

I think it’s like this in all of Europe. I know in the US you can get 32 oz. of it at Menards for $8. But that’s not an option here. I have no idea what people do if they need to build a battery. The stuff I got would be different than what’s in batteries. Probably the battery acid is more pure. What they sell to pro plumbers is a bottle labelled as /drain cleaner/ with sulfuric acid as a main active ingredient. It likely has a cocktail of additives to optimize it for drain pipe usage or perhaps make it inconvenient for other usages.

What if you do that? Illegal to buy, own or both?

I doubt it’s a possession offense. They are controlling the sales. If you go to a pro plumbing shop and try to buy it, they will require proof that you’re buying on behalf of a company that was constituted for the purpose of plumbing.

Exactly… that was constantly on my mind. Last time I hired a plumber to fix a leak while I was away, the plumber was incompetent. Did not find the leak (which was in /exposed/ pipework), charged 200 cash and ran with the money. The plumber actually charged 4 times as much as I paid a doctor to make a house call.

Some plumbers can legally buy sulfuric acid for this purpose. So in fact by law I was essentially being forced to hire a plumber, in effect.

My way of thinking is that I’m going to learn something & my tooling costs will be less than a plumber. I’ll “own” the problem for the next time. This one about drove me to the edge, considering I was about to experiment with borderline parasites.

A pro would have had an expensive snake cam… so there’s that. I would not want to put my own snake cam down the pipe because it’s not made for such filthy environments… would likely ruin the cam.

I blame whatever plumber installed the drain. They used many hard-right 90° fittings that hinder snakes. Then they installed no clean-out. And no vent. I also suspect the pipes under the floor may be goffred (accordian-like). So the lesson here is that snakes are not always the answer if the pipes are lousy.