smoothness 

first: i am not a chemist
second: see first

I consider myself pretty handy, and smart enough to know that I am not really smart. So I figure I'll take one of the most caustic things ever, and try melting an aluminum seatpost stuck in a steel frame. Because Science!

I've so far spent two hours trying to figure out the optimal way to plug up an open seat tube top (pro tip: there isn't one - it will ALWAYS leak), and accidentally splashing lye on both my arms, my head, and my boots. Despite wearing safety gloves, and a a full chem mask + goggles.

I've poured in about two rounds of 2:1 lye solution so far; I can't see any progress (due to the wrapped seatpost), but I hear noises. Apparently it's doing something beyond trashing my paint.

I also need to buy a new bottle of concentrated lemon juice, because I was freaking out about the lye eating through my skin (and the leather on my boots), so I sorta sprayed it everywhere. My hands are still slippery (read: mostly inert lye sitting on my hands despite repeated rinsing), and I'm still able to see and smell. So I've got that going for me.

Anyone else have some stupidly dangerous science project going on?

ridelikeaturtle

Could you have someone filming this and upload it to YouTube? Priceless...

ramzilla

Does it sorta look like the volcano experiment with soda powder & vinegar?

smoothness 

HEY NOW. If i'm going to suffer for hilarity, I don't want Alphabet/Google/Youtube making any more money. Also, at least I had the cognizance to not try to selfie-video myself while doing this stuff. That's how people get hurt...wait a minute.

oddjob2

Hope you will be okay, otherwise this will give new meaning to the term Zombie Thread.

CliffordK

Wash the lye off with copious amounts of water. You don't need to use up the entire US Stockpile of lemon juice. Vinegar would also work.

How much post do you have sticking out? Any?

I don't think the goal is to completely melt the post, but rather to get it loose and pull it out.

smoothness 

it totally sorta looks like the vinegar baking soda volcano. except full of melty aluminum slurry.

due to many mechanical attempts of removing the post, all i have left is about 1 cm worth. and it is very sharp. ask me how i know. so i'm basically hoping to melt the whole thing out, rather than try to pry it.

Chris W.

I had to resort to this method on a Trek 520. It took several days for the Lye to do it's thing, and the heat produced by the chemical reaction ruined the paint! Very dangerous, hope I never have to do it again.
Cheers,
Chris

ridelikeaturtle

That's why you get someone else to hold the camera, so you don't get lye all over it.

I tip my hat to you, if it weren't for the adventurous out there, what a boring world we'd live in! It's great stuff, and this should work - I'd just love to see it happen.

CliffordK

Less paint to ruin with the fork.

So far I've never had to deal with such issues, although on a crazy whim, I bought a bike with a stuck bottom bracket, and the previous owner had already started making a mess out of it

thinktubes 

Why, yes! (Thanks for asking)

A few days ago, I started noticing a "vinegar" smell in my car. I though maybe an apple had escaped from a grocery shop and rolled under a seat. A search came up empty, so I popped trunk and discovered the source.

I had been carrying around the old battery from my wife's car. I needed to take it back for the core charge, but who has time for that? Anyhow, it had leaked all over the carpet in the trunk. Anything metal was covered in salts and the smell was overwhelming.

I read that the way to deal with this is to spray everything down with a baking soda solution. I must say I got some pretty good volcanic action localized to the trunk of my car.

once the acid was rendered inert, I shampooed the trunk and now my car smells like a taxi.

yipyipyip

Do not use acid to neutralize the base! Just dilute with lots of water.

smoothness 

Just for clarification: I used the lemon juice AFTER i had doused myself in water. I still felt slimy, and even though I knew the water took care of a lot of the lye...I just wanted to make extra sure (and smelling lemony fresh at the same time!)

Warning: neutralizing a base with an acid can cause an exothermic reaction, which can cause serious burns. do not do it if you get it on your person.

Update on the melting: I accidentally dropped a fair amount of lye slush outside of my drip bucket and onto my pressure-treated deck...which is one story up. Let's hope the floor doesn't melt away from me. The original idea was to use the eyelet as a gauge to see when I had poured enough lye; unfortunately, I didn't think it'd sprinkle out like an eye-talian fountain.

ridelikeaturtle

This is turning into a lost episode of "Breaking Bad"

Darth Lefty 

This doesn't sound dangerous enough, you should hook it up to a starter battery or maybe a welder

smoothness 

things i've used on this frame:

MAPP torch
Louisville slugger (baseball bat of freedom)
Sledgehammer (soviet hammer of submission)
Six-foot breaker bar ("it's all about length, baby")
more MAPP (bored)
Dry Ice (application error on my behalf - did not get frame hot enough, and ended up just creating a dry ice volcano inside a bicycle frame. also threw a lot of it at my lab assistant)
...
and just general whacking it on my cross-section of a tree trunk (it brings stumping to a whole new meaning)

I would have tried tig, but I don't have access to a welder. if I did, I would have just tried to weld it to a sheet of metal and extracted via tow hook on a car.

I can't really see how I could use the starter battery...except for maybe making a ghetto welder. BRING ON THE AMPS.

UPDATE ON MELTY GOODNESS:

The cork I put in the seat post is no longer functioning as named, and should now be named Sveltey McSievey, of clan Slippery. Surprisingly, it hasn't melted to nothing yet. The oxide coating on the exposed bit of seatpost is definitely melting away with each application; the only issue is whether any of the solution is getting between the tube and the post. I've run halfway through my solution of lye, and my boots are definitely ruined.

ridelikeaturtle

Can you entertain us with some photos at least? This sounds like the project of the year!

artclone

I'm confused about stuck stems and posts. (Probably because I've never run into one.). But wouldn't the obvious way to get these out be to drill and then, if needed saw or chisel? And if you don't have an appropriate bit or other tool, to bring it to a machine shop?

Does something about drilling not work?

smoothness 

@ artclone:

the issue with using a needle file/rat tail/triangle is that you can't get enough leverage far down the seat tube for any worthwhile effort. the same goes with hacksaw blades - you'll be there forever. you can't drill either, unless you've got a drill press that's tall enough to accept a frame, and the skill to drill only through the seat post, and not through the seat tube as well. finally, machine shops are expensive, and lye is cheap.


and because people were curious, here's a few pictures (the order goes: original, cold, then hot, then melty hot)

eschlwc

if you pour the lye in your eyes, you'll be heroic, just like hazel motes.

Gerryattrick

A last resort of course, but strangely satisfying.

CliffordK

I think someone had posted a photo of adding a wire to the back of a bare sawblade to give it a bit more pressure down towards the end of the seatpost. But, still a lot of work to saw it out, with the risk of cutting too much.

cs1

I actually went back to the OP to check the date. You fooled me there!

exmechanic89

Coolness..

Fahrenheit531 

The BEST kind of madness. Good luck and here's wishing you some survival!