Unscrewing wooden bell pushes - UK Vintage Radio Repair and Restoration Discussion Forum

TonyDuell · 26th Mar 2018, 7:02 pm

Among the items I brought home from the BVWTM sale yesterday were a few old wooden bell pushes. They consist of a wooden base with a male thread onto which screws a wooden cover. There are 2 contacts on the base, the button fits into a hole in the cover. I am sure you know the sort of thing.

Anyway, I can't unscrew the covers on two of them, and I wonder if anyone has any tips/tricks for separating stuck wooden threads. If it was metal I'd have a few ideas, but not for wood.

So far I've tried to grip them with a 'Boa' strap wrench, I've tried to tighten them slightly, and I've run a knife blade round the join on the outside to remove any paint/varnish. Nothing has helped.

Mike Phelan · 26th Mar 2018, 7:25 pm

Heat the screw with a soldering iron?

emeritus · 26th Mar 2018, 7:29 pm

Try putting it in an airing cupboard, which will make the wood shrink slightly.

TonyDuell · 26th Mar 2018, 7:35 pm

Quote:

Originally Posted by Mike Phelan

Heat the screw with a soldering iron?

It's not a screw as such, it's the screwed joint between the 2 wooden parts (base and cover). No metal screw that I can put a soldering iron on.

TonyDuell · 26th Mar 2018, 7:35 pm

Quote:

Originally Posted by emeritus

Try putting it in an airing cupboard, which will make the wood shrink slightly.

Thanks, I'll give that a go.

robin coleman · 26th Mar 2018, 7:46 pm

Tony I to bought a few and have used a hair dryer on then.i have ised small amounts of vegetable oil applied in the gap with s strange to lubricate the thread.Ineeded some to go with the two flag indicator box I have from a late relatives house.
Regards
Robin

tealandsilver · 26th Mar 2018, 8:12 pm

Also try tightening slightly before untightening. I've used that technique often for all sorts of threads and surprisingly it often works!

ms660 · 26th Mar 2018, 8:34 pm

If at some point the whole has gotten damp it might be due to uneven drying or acclimatization, the outer (think of it as a nut) will have a lower volume than the inner (think of it as a screw) so it will dry out faster and shrink on to the screw, dry the whole lot out very gently (no direct heat) over a week or so then give it another go.

Lawrence.

Boater Sam · 26th Mar 2018, 8:41 pm

Its a very coarse thread turned on both parts. Dry it out thoroughly and it will release, it may take quite a long time but do it slowly to avoid splitting.

Graham G3ZVT · 26th Mar 2018, 9:28 pm

How about putting the bell-push in a plastic bag and placing it in the dry environment of a freezer few days?

I recently put a large wooden TV cabinet in the freezer for a week, in order to kill woodworm. It came out completely undamaged.

Yes, I'm amazed that SWMBO allowed me to too.

26th Mar 2018, 7:02 pm	#1
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Unscrewing wooden bell pushes Among the items I brought home from the BVWTM sale yesterday were a few old wooden bell pushes. They consist of a wooden base with a male thread onto which screws a wooden cover. There are 2 contacts on the base, the button fits into a hole in the cover. I am sure you know the sort of thing. Anyway, I can't unscrew the covers on two of them, and I wonder if anyone has any tips/tricks for separating stuck wooden threads. If it was metal I'd have a few ideas, but not for wood. So far I've tried to grip them with a 'Boa' strap wrench, I've tried to tighten them slightly, and I've run a knife blade round the join on the outside to remove any paint/varnish. Nothing has helped.

26th Mar 2018, 7:25 pm	#2
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Re: Unscrewing wooden bell pushes Heat the screw with a soldering iron? __________________ Mike.

26th Mar 2018, 7:29 pm	#3
emeritus Dekatron Join Date: Jan 2012 Location: Brentwood, Essex, UK. Posts: 5,337	Re: Unscrewing wooden bell pushes Try putting it in an airing cupboard, which will make the wood shrink slightly.

26th Mar 2018, 7:46 pm	#6
robin coleman Hexode Join Date: Oct 2011 Location: Portsmouth, Hampshire, UK. Posts: 354	Re: Unscrewing wooden bell pushes Tony I to bought a few and have used a hair dryer on then.i have ised small amounts of vegetable oil applied in the gap with s strange to lubricate the thread.Ineeded some to go with the two flag indicator box I have from a late relatives house. Regards Robin

26th Mar 2018, 8:12 pm	#7
tealandsilver Tetrode Join Date: Nov 2017 Location: East Lothian, Scotland, UK. Posts: 66	Re: Unscrewing wooden bell pushes Also try tightening slightly before untightening. I've used that technique often for all sorts of threads and surprisingly it often works!

26th Mar 2018, 8:34 pm	#8
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Unscrewing wooden bell pushes If at some point the whole has gotten damp it might be due to uneven drying or acclimatization, the outer (think of it as a nut) will have a lower volume than the inner (think of it as a screw) so it will dry out faster and shrink on to the screw, dry the whole lot out very gently (no direct heat) over a week or so then give it another go. Lawrence.

26th Mar 2018, 8:41 pm	#9
Boater Sam Banned Join Date: Dec 2013 Location: Middlewich, Cheshire, UK. & Winter in the Philippines. Posts: 3,897	Re: Unscrewing wooden bell pushes Its a very coarse thread turned on both parts. Dry it out thoroughly and it will release, it may take quite a long time but do it slowly to avoid splitting.

26th Mar 2018, 9:28 pm	#10
Graham G3ZVT Dekatron Join Date: May 2010 Location: Greater Manchester, UK. Posts: 18,711	Re: Unscrewing wooden bell pushes How about putting the bell-push in a plastic bag and placing it in the dry environment of a freezer few days? I recently put a large wooden TV cabinet in the freezer for a week, in order to kill woodworm. It came out completely undamaged. Yes, I'm amazed that SWMBO allowed me to too. __________________ -- Graham. G3ZVT