Kinetic water ram... Google it.

Never use acid in a totally clogged drain.

My guess is your pipes are choked from many years of grease. You may have to cut the section(s) out and replace them.

I had a similar situation this spring, tried pan of boiling water, Drano, 25' drill snake, 50' Industrial snake, nothing. The only thing that worked was a Sewer Jetter (basically a pressure washer nozzle/hose you run through your pipes). May be able to rent one for a day, that's what I did....... Also, be careful with that liquid fire, it's caustic enough to damage some plumbing materials. Especially if they are corroded or pitted really bad. Good luck!
https://www.sunbeltrentals.com/equipment/detail/974/0730022/elect-sewer-jet-1500-psi/

Try dumping a container of Battle Born trap cleaner down the drain.

Sulfuric acid will clean out almost anything

You would likely , in the long run, be further ahead, if you just . Go ahead and replace the drain , with pvc. Especially if you , are handy, and can do it yourself. That copper drain is many years old . Put extra cleanouts in the new system, so you can clean out if needed , later on. Take those copper pipes , and cash them in, copper , is a good price now. Good luck. old243

Well this may seem too simple but worked for me for the past 49 years on my kitchen sink drain. I have a very long drain that makes a right angle turn in my basement before going into the sewer line. It must be 20 plus feet and about half of it is a 2 inch metal pipe. Anyway about every two years there gets to be enough grease buildup to where the sink will hardly drain at all. All I do is dump a BUNCH of Dawn down the pipe once the pipe has slowly drained itself and then dump pot after pot of BOILING water down the sink drain. I mean I get the big pot on the stove and get it literally boiling. I will also use the plunger in conjunction with the boiling water but be careful not to get scalded. One time in the summer I took off the trap and ran a garden hose down the pipe and plugged around it with a rag and turned the water on full blast. That also worked well. Good luck with whatever you can get to work for you.

my first throught would be how hard would it be to put in pvc to replace the copper

I had a 1 1/2 inch galvanized drian line in my basement dating back to probably about the time of the first washing machine

I tried all sorts of stuff and eventually cut it out and replaced it , when I cut it I could see it was very plugged with grease from years and years and years of washing cloths and the shower that pumped into it was hard and nothing was touching it long enough to make a difference

there was maybe 1/2 inch of room left in the pipe which is why it it would drain slooooooowly

I cut it al out and replaced it ,been good since that was probably 16 years ago

a stick of pvc is what 15-20 dollars and the boots about 5-7 each for less than a box of non toxic shot and an hours time after dark you can replace at least a good section of it which will allow you to clean out the other parts more

and get back to the important thing in life hunting

Turn your water heater up so its scorching hot, then run the whole tankful down the drain. (turn it back to normal before your shower )

I had a similar problem with the 2" pvc pipe that ran from my kitchen sink into the basement and then into the sewer pipe. The total length of the pipe was around 30'. About 10' from the end that goes into the sewer pipe I cut the pipe off. There was no blockage in that last 10'. So, I knew it was in the remaining 20' that came from the kitchen sink.

I use Pogo anchors which are nothing more than washers. I cut a slot in the end of an 8' drowning rod to hold a washer that would fit inside the pvc pipe. I had a length of 3/32nd cable attached to the washer which entered the pipe flat. I pushed the washer into the pipe as far as it would go. Then I pulled on the cable which opened the washer up allowing it to pull out all the sludge.

I could see why I had a blockage. It looked like mostly greasy gunk that had accumulated over the years. It ran great after that.

I almost forgot. I bought a rubber sleeve at a hardware store to put the pieces of pipe back together. I used hose clamps to secure the rubber sleeve. If I ever have another blockage all I have to do is take the sleeve off to clear it in the future.

In response to some of the suggestions you have gotten, remember that in systems with septic tanks and drain fields, do not put any chemicals(including left over anti biotics) into the system that you could not safely put into your mouth. Your entire system only works because it is filled with tiny living things that break down the organic wastes you feed them. Obviously, pressure cleaning, hot water that would cool before reaching the tank or replacing the clogged sections would all offer safe solutions.

just hit it with yeast or rid -x after you get done. Copper and drain cleaners don't go well. BUT copper scrap is high sell it to help pay for pvc and don't look back.

Had a friend who had a blockage in his yard. He pushed a garden hose down the sewer pipe to the clog, then turned the water on wide open. Had to do this about every 12 months.

Well, figured I had tried everything and went down to pull the cleanout plugs. I must have been a much stronger and younger man when I last put them in about 20 years ago and they would not budge no matter how hard I tried.

Ran over to Menards and got a couple Fenco pipe couplings (best thing since sliced bread and canned beer by the way), came home and grabbed the sawzall and sliced the copper above where I was guessing the clog was. Ran the snake down both sides. Between the cut and the main sewer pipe I ran into a couple places I had to work pretty hard to get the snake through. I pretty much took a sludge shower through this whole thing but I think I beat it! Put the Fenco fitting in and ran the water for a good long time and it seems everything is holding fine.

Thanks to all for the advice on this thing! Now I am going to have a beer while sitting around waiting to see what's going to happen next.

Moosetrot

Fernco......amazing product fer sure.

Portable air tank with 3/4 hose and valve

Nessy would say fenco couplah
Good job on the fix.

Fernco couplings are great , yes , but have you considered putting a clean out plug where you just added a Fernco ?

My thought is if it clogged there once , it may clog there again years down the road. Easier to open a clean out plug than a Fernco that may have been in place for some time and may now be very hard to remove. Just don't tighten the clean out cap too much this time.

That is actually a great idea. After all this time I wanted to do whatever I needed to do quickly and get our drain working again. Just really glad to get it up and running again. Tomorrow will be spent putting the final touches on my second duck boat and just maybe I can be on the marsh in the afternoon!

Moosetrot