Friday, June 3, 2022

Chemical class to solve seized aluminium seat post

Safety notice << Pls wear safety googles and gloves. Its pretty hazardous.  Do it at ur own peril. 

The good of mucking around with old discarded stuff is that u can experiment and learn. After 2 weeks of penetrating oil and light tapping and hard wrenching.. the thing is really stuck. I even tried to use saw blade to split the tube... its hopeless. So the "nuclear" option remained. 
u can find in lazada or hardware store. Be careful with it.

its not cappuccino 
Triple sealed and wrapped... and it still dribbles abit. 
I told u.. it will be messy. So cover ur space well 
This is all that remains after 2 days of soaking. I think it could be shorter. I literally soaked it to death

I found that caustic soda, lye can dissolve stuff. And that means aluminium. The thing is it is controlled item and the work around is to find pipe declogger like the above. Look at the chemical/ safety information. Look for Sodium Hydroxide/ lye/ Caustic Soda. Or "do not use in alumimun fittings as it can damage" << Get that.

#1. Strip ur bike out as much as u can
#2. Seal the BB part with tube/ tape or what ever. U are going to make a vessel out of the bike tube. 
#3.  Saw off the seat post, find a small funnel. The idea is to slowly pour the Sodium hydroxide solution to let it do its thing.
#4.  Suitup/ Googles and gloves. Line the floor with news paper and work outside ur home. There will be some fumes. 
#4.1 Get a small cup fill with 1/2 water. Then add in 2 spoon granules of the declogger. Give it a slight swish and u would probably see some bubbling reaction. And then the solution gets hotter... 
#5  Pour it in and observe. The frame will feel abit hot and if it doesn't spill over. Do up another batch and pour in. Do it slowly and observe. It helps if u have a clamp or bike holder. 
#6. As the solution reaches the top of the seat post, u will see foaming and bubbling. Like u are doing some cappuncino. That's meaning the chemical is working.  
#7. It can take min 3-4 hours before the solution eats up the seat post and delodges it.  I use a scrap tube and put into the solution as a gauge to see the reaction time. 
#8 - The seat post is freed!!

Its really interesting to see all the bubbling. But becareful, wear PPE. 
The solutions does eat away the paint - at least the bike I experimented. But the Steel material is not affected. SO DONT DO THIS ON UR ALU bike 
So have you tried this and if there is another way to solve it? Do share in below comments? Happy DIY! 
IT does affect the paint 

How it looks after the Caustic soda solution soak 

Maybe a "RAW"Color scheme? 

Seat post cleared and one frame saved

Keeping this as a souvenir of this chemical experiment 


No comments:

Post a Comment