Mechanics and wrenches,,,, has anyone heard of wd40 having adverse effects on CF frames?? This is the picture I acquired this CF bike for cheap, 105everything ,the hiccup, seat post stuck fast in seat tube, I've tried all basic maneuvers not budging , so now I get this brain storm,,, take seat off plug up the Thompson elite post,turn frame upside down remove bottle cage screw and fill frame with wd40 let set overnight or longer depending on information gathered here about possible damage caused by wd40 on CF for some time,, to let the wd40 soak in real good,, any comments? The part about brainstorm I was very liberal with that fact is I'm working with minimal gray matter,,,,

WD-40 is not great as a penetrant, get yourself some Kano Kroil or PB Blaster instead.

Now you know why they dumped it so cheaply.

What is the seatpost made of?

I have a frame with a CF post and an aluminum shim that the previous owner got the post stuck, and cut off flush.

The consensus was to get something like a PVC pipe reamer and cut it out. The aluminum shim should give the frame a slight amount of protection.

Cutting inside the frame still sounds dangerous, but I think that will be the the way to go.

I can do that,,, any concerns about the effects of the fluid and the CF? Reason being appears Mr Sheldon Brown frowns on that , something about petroleum products on CF for extended time,,,, my concern as well ,,

Thompson elite is aluminum,, but I don't get the concept of the shim, I'm sorry limited brain cells,,, someone also suggested cutting seat post and hammering down into frame at least six inches?

My frame was made for a 28.0 seatpost which is a rather uncommon size. So, someone installed and shimmed a 27.2 post which apparently got stuck and broken.

Carbon + Aluminum is a bad mix, at least for seatposts.

Here is a discussion about Lye, Ammonia, and various solvents.

Corroded Seatpost Removal

I think the OP went with PB Blaster, but never reported back whether the frame was destroyed, or they got the post out.

Keep in mind that at least a little grease gets on CF without any damaging consequences.

Ok I'll look for the pb blaster and continue with the plan ,sounds similar to the one someone else has tried,,, thank you for all input ,,, we'll see what happens,,, there's always a hitch with the good deal only thing seller told me about it before hand and I made the decision to proceed with the good deal,