Aluminium window parts seized

[chrishscorp]

I have a 50 year old portlight, the glass is cracked I would like to replace it, it is in an aluminium porthole and held in place with an aluminium screw ring which after 50 years is locked well solid. there is a rubber seal close by so dont want to use heat as i will struggle to get a new seal.....

Is there anything the hive mind can suggest to free up these parts, sensible suggestions gratefully received

 

[Concerto]

Hi Chris

If the portlight is original, the interscrews Westerly used are made of chromed brass. To break the sealant from the gel coat use a cheese wire. If the inner rim has seized, then use a steam gun to "crack" the "welded" joint.

Roger

 

[chrishscorp]

Its the portlight on a centaur, so no such luck with interscrews, it is a 4 1/2'' diameter aluminium ring that screws into the round portlight and holds the glass in

 

[DinghyMan]

Try soaking it in white vinegar, it will dissolve the corrosion

 

[Refueler]

Coca Cola (original) ... Vinegar .... Citric Acid ...... Dilute Phosphoric Acid ...... each of those were old remedies for freeing up parts like this.

Immersing in hot but not boiling water to get the metal to expand ....