Seat post stuck in the frame

Hello lovely people

I have a single speed built on the Tokyo Fixed frame which was purchased new around 3 years ago (as in the frame only).

Sadly after 3 years of riding and me not servicing the bike, the seat post has rusted inside the frame and can't be taken out manually. The guy at my local bike shop suggested removing it using high temperature, however apparently this will definitely damage the paint...

Any ideas/suggestions please? I'm looking to sell the bike to my mate but I realise that with the post stuck in it's virtually worthless.

Thanks in advance.

Zofia

https://www.lfgss.com/conversations/128127/newest/

Buy a bottle of plusgas and soak it, heating the seat tube and if possible, cooling the seatpost at the same time will free it.
But plus gas and a vice should do it. Otherwise get an old saddle to don't mind bending and clamp it tight. Wedge between two immovable objects and use the leverage of the whole frame to twist

I'm assuming that the seatpin is alloy? If it is then heating won't work, the alloy will expand much more than the steel frame. A method I've used successfully in the past is to immerse the seatpin and top of the seat tube in a bucket of crushed ice for half an hour or so, clamp it up nice and tight in a vice, wrap a rag soaked in boiling water around the seat tube (use gloves!) and twist immediately. If it doesn't move then repeat. If you can get some movement, no matter how small, you are winning and the pin will, eventually come out.

There are specialists out there for just this type of thing who things such as pouring liquid nitrogen down the seat tube area via the now empty BB into to seat tube to cool it. Nothing worked for mine, but then I am never selling the frame so giving up didn't matter too much.

I've successfully used cokedown the upside down seat tube before.....probably fucked the frame from the inside out though!

Apparently the man at the bike shop has tried using frame as a levarage. Also probably doesn't help that i haven't got a vice!
I'll think of alternative...

Yes it's an alloy I believe.

Will try out as soon as I find something I could use as a vice in my flatmates world of tools!

Yeah I was told that by doing this you fuck up your frame significantly and make it essentially worthless. So was gonna try out some DYI first and seek opinions here!

Thank you all, will let you know what worked in the end...

Yes, please keep us updated.

I've tried both the heat and coke solution to no avail - and honestly, you could end up doing some damage to braze-ons and the seat tube if you're not careful.
One method I've heard of, but not yet tried myself, is drilling a hole in the bottom bracket (good for drainage purposes too) and then wacking the seatpost from below with a long rod and a hammer. Possibly after having soaked it in penetrating oil.