|
Cabinet and Chassis Restoration and Refinishing For help with cabinet or chassis restoration (non-electrical), please leave a message here. |
|
Thread Tools |
12th Nov 2016, 9:27 pm | #41 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,010
|
Re: Immobile Woodscrews!
One trick I've found works well is to use a screwdriver which has the metal-bit run all the way through the handle ( these have a special name which I forget: the ones I have also have a hex section on the shank immediately below the handle which is great because you can use a spanner to turn it while pressing the blade into the screw-slot with your other hand ).
Put the screwdriver straight in the slot then give the metal-bit-protruding-through-the-handle a good whack with a hammer. The shock - being conducted down the metal blade - does its thing to loosen the grip between the screw and the wood. Doesn't always work though: I have a 160-year-old house with a lot of oak used in the construction. Over a century or so the tannins in the wood corrode all iron nails/steel screws to utter irremovability! I use the same "shock" trick when faced with socket-headed grubscrews in bakelite control knobs - though don't tap the allen-key too hard or it can snap off inside the socket of the screw.... |
12th Nov 2016, 10:22 pm | #42 |
Guest
Posts: n/a
|
Re: Immobile Woodscrews!
I am wondering if the screw in post one is now undone?
|
12th Nov 2016, 11:36 pm | #43 |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
|
Re: Immobile Woodscrews!
|
13th Nov 2016, 12:12 am | #44 |
Heptode
Join Date: Jul 2014
Location: Boston, Lincolnshire, UK.
Posts: 995
|
Re: Immobile Woodscrews!
|
13th Nov 2016, 12:50 am | #45 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,108
|
Re: Immobile Woodscrews!
As G6Tanuki says Oak is a special case- You would think that galvanized fixings would be ok, but no- it eats through zinc as well.
|
13th Nov 2016, 7:41 am | #46 |
Dekatron
Join Date: Sep 2011
Location: Rugeley, Staffordshire, UK.
Posts: 8,835
|
Re: Immobile Woodscrews!
Oak is the devil's wood. Many years ago before I knew how tough old oak was I tried fixing an old, loose oak chair using a few nails. The nails would literally not go into the wood at all, it was like trying to drive a nail into metal. So hard is old, seasoned oak.
__________________
A digital radio is the latest thing, but a vintage wireless is forever.. |
13th Nov 2016, 9:15 am | #47 |
Heptode
Join Date: Mar 2008
Location: Forest of Dean, Gloucestershire, UK.
Posts: 648
|
Re: Immobile Woodscrews!
|
13th Nov 2016, 9:32 am | #48 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Immobile Woodscrews!
Oak's OK, you need to use the proper fixings, stainless steel, phosphor bronze, oak pegs etc. For nails and screws pilot and clearance holes are essential, for oak pegs you should drill offset holes for the draw.
Lawrence. |
13th Nov 2016, 11:08 am | #49 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,768
|
Re: Immobile Woodscrews!
True - the high tannin level in oak reacts badly with steel screws, which will turn the oak black and over time, the screws will be next to impossible to remove.
Taking the thread a little further off the original topic, this blackening phenomenon is used by woodturners and woodworkers to advantage for ebonising oak, whereby 0000 grade steel wool is dissolved in vinegar over a few days to make an ebonising stain. (The steel wool must first be washed with detergent to remove any oil which will be present due to the manufacturing process). When applied to oak, and to a lesser extent walnut and cherry) it turns the wood to a dark colour - in the case of oak, it looks rather like ebony, due to the reaction of the iron acetate with the tannin in the oak. Fine, if that's the appearance you're seeking, but not useful if you want to avoid staining a wooden cabinet through the use of steel screws. See: http://www.popularwoodworking.com/te...ebonizing_wood https://www.youtube.com/watch?v=fUWw...#t=154.4116863 Very unwise to use wire wool for finishing oak radio cabinets prior to applying a finish such as oil or varnish as tiny fragments will lodge in the grain, can't then be removed, and over time, will react with the tannin in the oak. Use a cabinet scraper or say 240 - 600g wet and dry, or Mirka 'Abranet' which doesn't clog.
__________________
David. BVWS Member. G-QRP Club member 1339. |
13th Nov 2016, 5:35 pm | #50 |
Octode
Join Date: Nov 2011
Location: Manchester, UK.
Posts: 1,875
|
Re: Immobile Woodscrews!
What a great thread. I really enjoyed post #32 - thanks David.
I'd echo the idea of hanging onto an old-style carpenters brace for undoing tight screws, and keeping screwdrivers with broken handles to make bits for it - and hollow grinding the tips for a good fit. Actually, I have a short screwdriver bit with the big diamond-shaped lump on it which you see on old-style wood bits, which fits the jaws in my brace as first intended - so this is an idea which has a long pedigree. A while back I inherited several boxes of Nettlefolds No 6 bronze 3/4 wood screws (ex Ferranti, oddly) and now I know to keep them for if I ever make something in Oak! (Oh - and valve grinding paste works for getting a firmer grip, as does fine emery cloth (rough side in) under Stilsons (careful!) if you ever have to get hold of something smooth 'around the outside'). ...just to add, in the spirit of post 32, one more I found on another forum which really made me smile: HACKSAW: One of a family of cutting tools built on the Ouija board principle. It transforms human energy into a crooked, unpredictable motion, and the more you attempt to influence its course, the more dismal your future becomes. |