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old screw heads

NutmegCT

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Restoring a mid-19th century French organ (harmonium).

Alexandre arrival 20 Nov 22.JPG


How the heck do you remove those old single slot screws??? None of my screwdrivers fit - keep twisting out of the slot. Screwdriver blades won't even go all the way to the bottom of the slot. Never experienced this before.
Tom M.
 

waltesefalcon

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Tom, do you have access to gunsmith's screw drivers? The blades for many of them are hollow ground rather than tapered, allowing them to seat better in some types of screws.
 
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NutmegCT

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Picture? Vwalah!

IMG_1375.JPG


The screwdriver blade just barely goes into the slot. It's like the slot is too shallow, or the screwdriver blade "V" is too fat to go all the way into the slot. The screw slots deform easily (ask me how I know ...). Only thing that goes fully into the slot is a mini screwdriver, but that's not strong enough to turn the screw.

Thanks for any help!
Tom M.
Edit: Walt, never saw a gunsmith's screwdriver. Is there any appropriate substitute? Maybe grinding or filing down a standard screwdriver blade somehow?
 

Basil

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Edit: Walt, never saw a gunsmith's screwdriver. Is there any appropriate substitute? Maybe grinding or filing down a standard screwdriver blade somehow?
That’s the first thing I would try. Find an old, relatively thick screw drive and grind/file to fit.
 
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NutmegCT

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Thanks for the suggestions, which I'll try tomorrow. There are over 100 screws, of various sizes. Patience ... I must have patience.

By the way, here's a similar instrument after a complete restoration:


Very different sound, capable of much more expression, compared to the typical nineteenth century American reed organ.
 

waltesefalcon

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I agree that grinding the head a regular screw driver is likely your best bet.
 

waltesefalcon

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I have the large 'professional' set of Chapman drivers and bits in my shed, a small one for my range bag, and I have bought a small set for two of my boys.

Now I also have a set of Grace bits and a driver for single actions because they have deeper holes on the grip frame and you need a bit that is longer than the Chapman set.

Both are American made brands and are very high quality.
 
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NutmegCT

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For anyone needing a sleep aid, here's a link to photos of my (slow as molasses) restoration work, day by day.


The instrument was built to be relatively simple to disassemble; each "layer" lifts out to reveal the next layer. Stop rail, keyboard, pallet board, wind valves, bellows system, etc. Fortunately, most layers have few screws to mumble and fumble with.
 

waltesefalcon

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That's a very cool harmonium Tom. Keep us posted.
 

JPSmit

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interesting pics - yet no notes. :ROFLMAO:
 

70herald

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Restoring a mid-19th century French organ (harmonium).

View attachment 83566

How the heck do you remove those old single slot screws??? None of my screwdrivers fit - keep twisting out of the slot. Screwdriver blades won't even go all the way to the bottom of the slot. Never experienced this before.
Tom M.
My parents had an American pump organ of similar vintage when I was a kid. Had about 2X more pull knobs. Probably weighed 1000 lbs and was very difficult to give away when they moved. It apparently came from a church and if you pumped quickly it could put out some serious volume!
 

LarryK

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I bought some old wooden handle screwdrivers from a flea market vendor. Fit all the old screws. Gun screwdrivers will work but might twist under extreme pressure. Kind of like pulling the screws out of the 50s Jags with all those slotted screws rusted in place.
 

DrEntropy

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I have the large 'professional' set of Chapman drivers and bits in my shed, a small one for my range bag, and I have bought a small set for two of my boys.

Now I also have a set of Grace bits and a driver for single actions because they have deeper holes on the grip frame and you need a bit that is longer than the Chapman set.

Both are American made brands and are very high quality.
Small Chapman set here, #9600 from the early '70's. For the small stuff (Japanese lenses in particular) I have a set of Vessel screwdrivers made to fit the profile of the Japanese fasteners. Jewelers' sets for watches and cameras. Swiss files, too. Hard to do a proper job without the right tools! If there is an American made equivalent, it's what gets bought, but some of those things just aren't readily available. For a time in the late seventies it was difficult to find US made micrometers!
 

waltesefalcon

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Most of my fine stuff is American, like my set of mics and most of my measuring devices are Starrett. I do have a mix of American and Swiss watchmaking tools. I use a modern set of Bergeon screw drivers but my staking set is an old K&D set from about 1915.

Usually I buy used tools because I can typically afford better quality. In the shed I mostly have Mac because that is what my dad had. I've bought some Mac where I could, but I also have some old Thorsen and Craftsmen from the 50s and 60s.
 
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