Removing a crown to replace a stem

[AP1875]

What’s the best way to remove a crown from a stem?

i have it in a pin vice but can’t break the seal of the loctite/glue when twisting it.

 

[Rafael]

Usually there should'nt be any glue/loctite but you can try heating it/dripping some acetone into the thread and see if this will work.

[AP1875]

Something must be holding it because it won’t twist off.

I think acetone will ruin the rubber inside the crown.

[Tudor]

Unless it's newer than 15 years old, you need new rubber seals anyway. 

Pull the seal with a dental pic. Acetone will eat the locktie and alternatively, heat the stem with a soldering iron which will also break the bond.

[Rafael]

1 hour ago, AP1875 said:

Something must be holding it because it won’t twist off.

I think acetone will ruin the rubber inside the crown.

You don't have a lot of options given the circumstances. Better have a ruined rubber seal than a broken stem inside the crown.

Edited September 28, 2020 by Rafael

[AP1875]

If anyone else reads this asking the same question my solution was to grip it with a set of water pump pliers.

[clockboy]

Normally just a bit of heat (I use a soldering iron) and they just twist off. If it is really tight the danger will be breaking the stem.Perhaps a soak in Acetone might help. Before you apply force make sure a replacement stem is readerly available.