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onzenuub

Dissolving a stem that cannot be removed from the crown

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onzenuub

And another useful tutorial from Francisco

 

First, I would like to thank all the forum members that helped me to discover this technique.

 

Some times the stem may break itself in the way that following picture shows:

 

4064994045_bdebbc8cca_o.jpg

 

As seen, there is no enough room to take the stem and to unscrew it from the crown. Therefore, it seems impossible to remove the stem. Hence, a new stem should be bought, what could be sometimes very expensive.

 

In other cases, it is possible to unscrew the stem, but the rest of the stem is too short and the stem is expensive or spares are not available. In such cases, if the broken part is the threaded part, a stem extensor can be used. Next picture shows a stem extensor.

 

4065744440_5b6c57e534_o.jpg

 

The broken stem would be screwed in the small tube. However, in our case, a stem extensor is not useful, as we cannot remove the broken stem form the crown.

 

What we are going to do is to dissolve the stem. This is possible because crown is made of a material much more resistant to corrosion than the stem.

 

To dissolve the stem we will use alum powder. If you cannot find it in a local store, it can be easily found at Ebay. Follows one example:

 

4064994221_755b5215ab_o.jpg

 

I bought this one:

 

4064994305_428d79f88a_o.jpg

 

We put quite alum powder in a small glass.

 

4064994357_fdea5a5e59_o.jpg

 

Really, I did put twice quantity than the picture shows. The alum powder is dissolved in water.

 

4065744754_3ef40cbda2_o.jpg

 

The crown is submerged in the water. Moreover, I added an old stem to see the effect of the alum powder on it.

 

4065744838_c56c80ac7e_o.jpg

 

This is a very slow process. The time needed depends, of course, of the amount of stem to be dissolved. I recommend shaking the glass every couple of days.

 

In this case, as I wanted to see the effect on the old stem, I wait quite a long time. Last picture was taken after 9 days. It is possible to see small pieces of the stem on the bottom of the glass.

 

Alter two weeks, the crown is free of the piece of the stem. In addition, the old stem shows this horrific aspect. Please check that one part of the stem is open.

 

4064994605_c002beb592_o.jpg

 

Now it is time to check whether the hole of the crown is truly free of small pieces from the stem, and if a new stem can be screwed. It seems so:

 

4065745292_1e2f707390_o.jpg

 

As next picture shows, there is no any problem to screw a new stem. Therefore, the crown has been repaired.

 

4065745414_ffc9ca2a44_o.jpg

 

Thanks for reading,

 

Francisco

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jameo210369

Great addition Onze

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omni

I can add that my jeweler sped that dissolve waiting time down to 2 days by heating the alum solution up.

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sconehead
I can add that my jeweler sped that dissolve waiting time down to 2 days by heating the alum solution up.

Good tip Omni... :irish_dance:

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KeNnY

Amazing ! GOing to try it out asap !

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gran

WOW!!!!!!

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Dr Yan

If Johng was doing this he would use nitro-hydrochloric acid ;)

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narikaa

Salts of Alum

 

 

Little used and seldom found

 

 

Has a myriad of uses

 

 

;)

 

 

 

 

.

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DR3M3L

I broke mine today :s does anyone know where to get a stem?

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Member X

RWG shop ;)

 

Or Ofrei in the US, or CousinUK in the UK.

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DR3M3L
RWG shop ;)

 

Or Ofrei in the US, or CousinUK in the UK.

 

Thanks mate!

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Nikosaldente

Great tutorial!

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chrish8

couldn't one just use this

 

Basic_Wire_Cutters.jpg

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flyr

couldn't one just use this

 

Basic_Wire_Cutters.jpg

Not much good when the stem is snapped off inside crown and there is nothing to get a grip on. :sad:

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flyfishng2

excellent tip. another technique for my toolbox

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GenTLe

I used vinegar and got same results in around 10 days :)

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