AJI125 

Background: I picked up a 72/73 Fuji Finest from bikemig . Stem was stuck as I knew (first picture below is from bikemig, I didn't even take a before of course...).

So I read up on several ideas and approaches, and started with some mechanical efforts, not much luck. Quickly moved on to lye. A couple soaks later and lye was no longer effective from what I could tell - a blackish green layer on exposed surfaces of the old stem remnant - possibly something from the other components of the alloy used? Anyways, as you can see in the very bottom pictures, the lye wasn't reaching the stuck surface anyways, as there's still shiny aluminum there where it was in contact with the steerer.

Next I resorted to expanding the hacksawing already done, takes a bit of patience of course. Eventually got the right tool for the job after fiddling with a freehanded Jr blade. Each time I walked through the garage I dripped a little PB Blaster around the outside, was good for flushing out the debris and maybe helped in the end. With enough hacksawing, I got through one side eventually, and was pretty confident to move on to the Freeze-Off approach since I now could be sure the stuck stem could be squeezed smaller than the steerer with the slot cut out. First application, voila! Little banging down and up, twisting with the vise grips and it was out!

I'll let the pictures and captions tell the rest of the story.


Before photo (courtesy bikemig)

Lye starting to work

After Lye Soak #1

After Lye Soak #2 (had checked in the middle of the soak, no change from overnight, so called it quits)

Hacksaw #1, Jr blade, not very efficient

Hacksaw #2, much better

The final solution... One 15sec application, waited the minute or two, and hammered down (using an old chisel) and the stem moved!

After freeze-off, flipped the stem and hammered from below (wedge was still stuck in bottom, and here it's actually jammed into the stem again, so just had to bang it back down to get the stem out)

That bad boy was stuck in there tight! Confirmed one side was fully cut through, not sure it would've come out without that.

Steerer after a quick swab (still filthy)

bikemig 

Very cool. I’m impressed. I gave it a good try but I gave up when I found another 70 s Fuji Finest in my size. I took the path of least resistance by going with n + 1, 😀

zandoval 

Bravo... "We shall never surrender..."

Chombi1 

Great job!
Freeze Off was also the only stuff that worked for me when I had to take off the stuck stem from hell on my Vitus Plus Carbone 7.
I tried all the other chemicals suggested in the forum and they all did not work, despite soaking the stem and steerer tube in the penetrants for more than two weeks. Then, by chance I came across a can of Freeze Off at a small hardware store and figured I try one last product, before I break out the hacksaw blade and destroy the rare Vitus pantographed stem.
Well, it only took a couple of minutes for the Freeze Off to break the stem from the steering tube! The seized BB cups on the frame also came right off also using the Freeze Off on them, after that.
Now I use it the free any metal things I have that's stuck or seized from corrosion.

smoothness 

I'm sorta surprised that you felt the lye did not work. What was your ratio of lye to water?

AJI125 

I didn't precisely measure it out. I was using an old vase (thanks RJ the bike guy for his video) and a bored block of wood to support on top. I used about a third of a 1/3 cup scoop (I have a bunch from old protein powder containers), so about 2 tbsp, and just eyeballing the picture again, maybe 16-20oz water? Just enough to get up over the stem portion of the steerer. Started with a bit of remaining undissolved powder both times. First time through, lots of immediate reaction, with debris from the aluminum, and all the lye powder dissolved. Second time, 24h of soaking, hardly any debris, not much reaction, and extra lye powder did not dissolve (but dissolved fine when I rinsed the container after). I should also mention I bored down the surface a bit with a 1/2" drill bit before lye, but didn't feel I had enough control to do much more. I also didn't think a spade bit was a good idea (only thing I had bigger that wasn't a large hole saw), and didn't want to drive around to the area hardware stores looking for a 5/8" or 3/4" bit.

When I rinsed everything and brought the fork back in, the stem was blackish green, changing to charcoal grey with a tinge of green when it dried. Just some quick google searches indicated it might be the alloy remnants left after the aluminum dissolved, but I don't know for sure. I brushed it a bit with the nylon brush I could get in there and WD-40, but it didn't come off. I do wonder if I could've used some abrasive on it to scour the outer layers back off to expose more aluminum so the lye would've worked again. When I snapped off the top pieces seeing if I could wiggle it at all, they were still shiny on the interior. You can see from the "after" pictures of the stem above I got no lye solution penetration to the lower contact areas where it was stuck against the steerer (still shiny). Would've had to fully dissolve from the inside out. I'll add another picture of what it looked like wet, post lye. The hacksaw picture above shows what it looked like dry (and shiny spots where pieces snapped off).

I think if I did it again, I'd probably try the hacksaw through one side (assuming I could reach all the way without having dissolved/snapped off the top inch or two) and then Freeze Off. But the lye definitely did some work and dissolved some aluminum.

RustyJames 

I need to look into Freezeoff. I had a piston REALLY stuck into the barrel of an old motorcycle and I tried everything short of dynamite (Kroil, PB blaster, olive oil, flowers and candy, whispering sweet nothings, etc) and nothing. Final result was some “persuasion” - big hammer and drift - and it came free. I felt like a caveman but it was a result. The rings are still fused into that old piston FWIW.

zandoval 

Here's an interesting link to information on basically how this method works...

Google Answers: Effect of heat or cold on expansion of steel and aluminum.