Operation Caustic - Completed

[FZRIP]

92 Kilauea with an immovable seat post, went for chemical attack after everything else failed.
It came out this afternoon.
Well chuffed.

 

[GTLoz]

I may have to resort to this myself on a fire mountain. I know this is probably a daft question but could you explain how you went about this. Many thanks.

 

[ishaw]

Looks like you did a great job no ruining the paint too.

 

[FZRIP]

I may have to resort to this myself on a fire mountain. I know this is probably a daft question but could you explain how you went about this. Many thanks.

It was all a bit Breaking Bad…
Here’s a pic of the set up, I messed around a bit to get a system I was happy with. I was desperate not to damage the paint, it’s already a bit iffy but good enough to keep.
I used caustic at around 35/40g to 200ml water.
Bunged up the end of the seat post with blu-tac or plasticine. Poured the caustic into the seat tube via a funnel piped to the bottle cage mount. Once the tube was full to the bottle cage mount then allowed the pipe/funnel to rest (lower than the fluid height) over a Pyrex jug with water in it. I then bunged up the seat tube hole in the bottom bracket with a bit more blu-tac, this meant the gas created was vented out of the funnel and no bubbling juices came anywhere near the paint if escaping from the bottom bracket.
There was a fair bit of bubbling/frothing/steaming/spitting and everything got rather warm as the reaction progressed.
The mucky liquid which bubbled out of the funnel was cooled and diluted immediately as it dripped into the water in the Pyrex jug.
The frame was suspended over a seed tray with water in it, to catch and dilute anything that I might spill or drip.
The reaction time was about 3 or 4 hours, once everything has college and stopped bubbling I removed the plug from the top of the seatpost and the inside of the bottom bracket. Drained the remaining fluid /sludge (if anything was left) before repeating.
It took 3 days, probably dosing it 2 or 3 times per day.
I did initially try a stronger solution, but the reaction was too powerful, all the solution bubbled furiously out of the pipe within an hour, quite violently. The weaker solution seemed to give more reaction time with the solution in contact with the aluminium to do the job.
I kept plenty of water on hand to make sure any spills of accidental contact could be washed immediately, off both me and the frame.
Very impressive result.
Patience and preparation are key.

 

[GTLoz]

It was all a bit Breaking Bad…
Here’s a pic of the set up, I messed around a bit to get a system I was happy with. I was desperate not to damage the paint, it’s already a bit iffy but good enough to keep.
I used caustic at around 35/40g to 200ml water.
Bunged up the end of the seat post with blu-tac or plasticine. Poured the caustic into the seat tube via a funnel piped to the bottle cage mount. Once the tube was full to the bottle cage mount then allowed the pipe/funnel to rest (lower than the fluid height) over a Pyrex jug with water in it. I then bunged up the seat tube hole in the bottom bracket with a bit more blu-tac, this meant the gas created was vented out of the funnel and no bubbling juices came anywhere near the paint if escaping from the bottom bracket.
There was a fair bit of bubbling/frothing/steaming/spitting and everything got rather warm as the reaction progressed.
The mucky liquid which bubbled out of the funnel was cooled and diluted immediately as it dripped into the water in the Pyrex jug.
The frame was suspended over a seed tray with water in it, to catch and dilute anything that I might spill or drip.
The reaction time was about 3 or 4 hours, once everything has college and stopped bubbling I removed the plug from the top of the seatpost and the inside of the bottom bracket. Drained the remaining fluid /sludge (if anything was left) before repeating.
It took 3 days, probably dosing it 2 or 3 times per day.
I did initially try a stronger solution, but the reaction was too powerful, all the solution bubbled furiously out of the pipe within an hour, quite violently. The weaker solution seemed to give more reaction time with the solution in contact with the aluminium to do the job.
I kept plenty of water on hand to make sure any spills of accidental contact could be washed immediately, off both me and the frame.
Very impressive result.
Patience and preparation are key.


View attachment 884396

Thank you for the very comprehensive response. Looks like quite an undertaking. How did you get the tube to stay in position on the bottle cage mount?

 

[FZRIP]

I found an aquarium airline connector, with a bit of fettling I managed to screw one end into the cage mount, leaving the other end sticking out for the funnel pipe work.
I was desperate to avoid paint damage, otherwise it’s very straight forward.
Safety precautions are just sensible. There’s some dodgy stuff on YouTube…
Happy to help more if I can.

 

[GTLoz]

That's brilliant thanks, like you I really want to avoid paint damage. Completely agree with the safety precautions. Looks like I'll have to put a shopping list together. I had been trying penetrative fluid but read recent that will not work with bimetallic corrosion.

 

[ishaw]

You could try using a bleed screw from a brake in the bottle boss to hold the tube.

I've got a stuck seat post in a frame, caustic will sadly eat the carbon so not an option for me. It's actually my first ever stuck post, and I've only got myself to blame as I bought it like this.

 

[TSP]

Great (scary & comprehensive!) job