Irksome screws unscrewed

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pennymachines
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Irksome screws unscrewed

Post by pennymachines »


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Your first attempt is your best chance of a clean extraction, so make it a good one. As in all restoration work, a bit of preparation can save a lot of perspiration. The vital thing is to ensure the screwdriver doesn't slip and mangle the screw head as you try to turn it. The first thing is to clean the slot with a needle-ended file. You can apply a dab of gripping agent to the screwdriver tip (expensive stuff, but sometimes it just gives you the edge). Insert a tight-fitting screwdriver and whack the handle with a hammer a couple of times to bed it into the slot and help break the screw's grip.

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Penetrating oil followed by heating the screw head with a soldering iron several times, causing the screw to expand and contract can break the grip of even the most stubborn rusty screw. However it has taken me an hour or two to free one screw! Patience is the restorer's greatest ally. Failing that, one can dig the rusty thread out, which often reveals little more than a stump, then drill out the hole and fill it with a plug of the same wood, matched as best you can with the grain orientated the correct way.

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The impact driver is best used on heavier jobs. It allows you to apply maximum turning force to the screw head in one short sharp burst. It can be great for quickly releasing beefy bolts etc., but the downward force applied makes it unsuitable for more delicate work involving wood or fragile castings.

If a screw head offers no purchase, the screw extractor can sometimes come to the rescue. You drill a hole into the top of the screw, insert the extractor and twist. The extractors come in a range of sizes, but I've not had much luck using this method on small screws. There's just not enough metal in which to embed the extractor.
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coppinpr
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Re: Irksome screws unscrewed

Post by coppinpr »

very good and clear advice Mr P !!THUMBSX2!!
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special when lit
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Re: Irksome screws unscrewed

Post by special when lit »

This stuff is also really good at freeing stubborn bolts etc.
https://www.halfords.com/motoring/engin ... 21533.html
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tallstory
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Re: Irksome screws unscrewed

Post by tallstory »

I find the application of a little heat works well. I use a heat gun to apply heat until the metal is too hot to touch. Then as Mr PM says, an impact hammer usually gets them out. As a last resort I drill them out but this often causes problems when trying to centre the drill on the screw head (and missing!).
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badpenny
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Re: Irksome screws unscrewed

Post by badpenny »

When I apply heat to a screwhead I use a soldering iron in order to concentrate the heat and keep it off the wood.
tallstory
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Re: Irksome screws unscrewed

Post by tallstory »

I should have been clearer. My suggestion of applying heat with a heat gun was for a metal screw (or bolt) seized in metal not wood.
My restoration of a Brenner Ball past the arrow has certainly given me lots of practice!
pennymachines
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Re: Irksome screws unscrewed

Post by pennymachines »

pennymachines wrote: Mon Oct 02, 2006 10:41 pm Penetrating oil followed by heating the screw head with a soldering iron several times, causing the screw to expand and contract can break the grip of even the most stubborn rusty screw.
Déjà vu.

This post came from a long disused section of the Archive called Restoration. Finally copying them over here.
sparkymike
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Re: Irksome screws unscrewed

Post by sparkymike »

I have found that if you hold a cross head screwdriver at a 45 degree angle to the screw and then tap it with a hammer from different directions, that might be enough to break the rust that is preventing the removal. I have used a freeze spray aerosol that shrinks the screws/bolts etc. and have had some luck with that method. There is a screw extractor kit that you have to drill a hole and then a special drill is used in a battery drill in reverse direction. I have found these work quite well. (Not to be confused with the tapered screw extractors that just seem to enlarge the broken screw/bolt etc. and don't work. (in my experience.)
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Re: Irksome screws unscrewed

Post by sparkymike »

This is the type of extractor that I have found works ok.
It is double ended. You use the countersink and first in normal direction then use other end for removal.
Mike.
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