Thread: Henry Disston No 93 Mortise gauge question

Originally Posted by GARY47#

I have a Henry Disston No 93 Mortise gauge. Does anyone know how to remove the fixed scribing point? There is no screw visible and the brass mounting plate is firmly fixed to the wood shaft.

If your able, some Pictures might help us.

Cheers Matt.

Gary

Welcome to the Forums.

As Matt has said some pix might help a little, although I am not sure about how quickly you have picture "rights" as a new member.

Having said that i was about to question whether you had mistaken your particular gauge for a No.83 as I had not been able to find anything in the catalogues. Then I chanced upon this from 1918:

Disston No.93 Mortice gauge. 1918 cat..jpg

I don't know if that helps you any (probably not). Perhaps just for curiosity's sake.

Regards
Paul

Ive not taken one of those apart but I have seen a fair bit of brass fixing to wood before on vintage things and antique furniture. Gluing brass to wood never really worked to well but it was done on some things just by itself. Pinning the plate to the wood was used when it really has to stay. That plate probably has the steel scribe pin fixed through its hole and peened from the back of the plate first into a sort of boss or thickened part maybe. The plate would then be fixed to the wood by drilling holes, turning those holes into square tapered holes with a punch. Then brass tapered pins are made by cold forming them on the end of a rod or wire on an anvil with a hammer . These are chopped off the rod then with the plate positioned on the wood, the wood is drilled to take the pins a fraction smaller . The pins are driven in and the piece is likely glued as well .

Hide glue with Garlic added I was told once . The rough thick ends of the pins is now filed off flush to the plate and they disappear completely. If you skew the pins slightly it stays put. That's how most well fitted brass plate decoration was done.

The pin could be fitted after the plate was fixed onto the marking gauge by just drilling and inserting into a tight hole. Id try grabbing and twisting first . If its broken off then drilling it out with a dummy plate fitted over the top to stop the drill wandering should work . A steel plate with a hole drilled that's clamped in position to stop the drill wandering off course. If the brass plate has to come off though , heat and a fine sharp chisel tapped from three sides to try and start to lift the plate away.

Rob, I doubt the pins are peened on the inside, I'm pretty sure they are a press-fit - a slightly tapered steel pin will lock in brass like it is welded in, no need for anything more. I'm not sure if that's how it was always done, but it appears to have been how the pins were attached on a 77 (the model with the internal slider), that someone asked me to fix years ago. The pins were mere stubs with just enough left to grab with pliers & gently twist/pull them out. Plan B was to drill them out, which would have been quite a bit more difficult, and I'll keep your suggestion of a dummy guide hole in mind in case of future need!). However, as I recall, they came out cleanly with no apparent damage to the brass. Since all of the old pins I've come across were quite soft & easily filed, I just found a nail that was slightly larger than the hole, chucked it in a battery drill & tapered it slightly, tapped it in firmly, then clipped to length & sharpened it.

I use hardened pins and cutters on the gauges I make - hardened cutters make sense, mild steel loses its edge a bit too quickly, but it's probably overkill for pins, you can't sharpen them with an ordinary file (but a diamond "paddle file" does the trick nicely).

I've seen the garlic treatment for preparing metal for glueing recommended in a couple of places, but it was a very long time ago & can't remember where I've seen it. You don't add the garlic to the glue (though it might improve the smell of the stuff ), you use it to clean the metal. Both garlic & onion contain a substance that combines readily with oxygen & de-oxidises the surface (& is highly toxic to dogs which is why it's not a good idea to give the left-over stew to your dog!).

Cheers,
Ian

Originally Posted by IanW

Both garlic & onion contain a substance that combines readily with oxygen & de-oxidises the surface (& is highly toxic to dogs which is why it's not a good idea to give the left-over stew to your dog!).

Cheers,
Ian

Ian

Compost worms also are not overly fussed about the Alliums.

Regards
Paul

Originally Posted by IanW

Rob, I doubt the pins are peened on the inside, I'm pretty sure they are a press-fit - a slightly tapered steel pin will lock in brass like it is welded in, no need for anything more. I'm not sure if that's how it was always done, but it appears to have been how the pins were attached on a 77 (the model with the internal slider), that someone asked me to fix years ago. The pins were mere stubs with just enough left to grab with pliers & gently twist/pull them out. Plan B was to drill them out, which would have been quite a bit more difficult, and I'll keep your suggestion of a dummy guide hole in mind in case of future need!). However, as I recall, they came out cleanly with no apparent damage to the brass. Since all of the old pins I've come across were quite soft & easily filed, I just found a nail that was slightly larger than the hole, chucked it in a battery drill & tapered it slightly, tapped it in firmly, then clipped to length & sharpened it.

I use hardened pins and cutters on the gauges I make - hardened cutters make sense, mild steel loses its edge a bit too quickly, but it's probably overkill for pins, you can't sharpen them with an ordinary file (but a diamond "paddle file" does the trick nicely).

I've seen the garlic treatment for preparing metal for glueing recommended in a couple of places, but it was a very long time ago & can't remember where I've seen it. You don't add the garlic to the glue (though it might improve the smell of the stuff ), you use it to clean the metal. Both garlic & onion contain a substance that combines readily with oxygen & de-oxidises the surface (& is highly toxic to dogs which is why it's not a good idea to give the left-over stew to your dog!).

Cheers,
Ian

I don’t won’t to take this thread of track,

But this Garlic idea has me intrigued, can someone start a new thread, I’m going too get a crucifix made anyone know any Wood workers.

Cheers Matt.

Originally Posted by IanW

Rob, I doubt the pins are peened on the inside, I'm pretty sure they are a press-fit - a slightly tapered steel pin will lock in brass like it is welded in, no need for anything more.

Ian . I did suggest that but down the bottom part . I started thinking more as I wrote and didn't bother putting the most likely method up top . Ive seen "Bosses" I think they are called, in brass casting where threads need to go through. To give better body to the part needed and at first I was thinking that'd be the best quality way of making it.

Is that how the Garlic is used . I actually tried adding it to the glue 25 to 30 years ago and it didn't seem to do anything . It did smell more like a kitchen cook up. These days I guess Poly glue is the best glue for brass to wood application. That Poly glue stuff is great!

I'm assuming the OP has a pin that needs replacing which is why drilling it out may be needed. But it probably is hardened steel so drilling may not work so easily. Some guys mentioned here years ago old gramophone needles were good for marking gauges. I have also replaced with nails but they wore out fast being soft. If I need harder stuff I'm usually grinding down modern screws when I need hard steel for pins. Or Allen keys. Or screw drivers. Which is one reason I collect rusty steel when I see it free or cheap. As we all do .
Rob

Originally Posted by auscab

I'm assuming the OP has a pin that needs replacing which is why drilling it out may be needed. But it probably is hardened steel so drilling may not work so easily. Some guys mentioned here years ago old gramophone needles were good for marking gauges. I have also replaced with nails but they wore out fast being soft. If I need harder stuff I'm usually grinding down modern screws when I need hard steel for pins. Or Allen keys. Or screw drivers. Which is one reason I collect rusty steel when I see it free or cheap. As we all do .
Rob

Rob

Broken twist drills (the shank portion) can be useful for this too, particularly in the smaller sizes, which tend to break quite easily.

Regards
Paul

I replaced the pins in a mortise gauge recently and it was fairly straightforward. I used nails, tapped through the brass and works well.

Originally Posted by auscab

..... I have also replaced with nails but they wore out fast being soft. If I need harder stuff I'm usually grinding down modern screws when I need hard steel for pins. Or Allen keys. Or screw drivers. Which is one reason I collect rusty steel when I see it free or cheap. As we all do .
Rob

Me? Collect old bits of steel? Never!! Well, that's almost truthful because I've got tins of bits & pieces of hard or harden-able steel that "might come in useful sumday..." and my time to use 'em is running out, so I've resisted adding more to the collection (for at least 6 months now...)

Rob, for someone like yourself using your gauges constantly, I suppose nails are a bit soft, but for the average amateur they should last many a year in pin gauges. Mild steel is too soft for cutters, for sure. There are lots of sources of hard steel, I was going to suggest broken drill bits but Paul beat me to it,. Old HSS sabre saw or jigsaw blades can be very useful for the flat style of cutters & marking-knife blades.

When I was making too many marking gauges a few years ago, I bought some lengths of O1 steel rod, which came annealed & easy to shape, then hardened them with a torch. Pin & cutters.jpg

It worked very well on the 4mm rod I was using for cutters, but the 1/16" or 2mm rod I used for pin gauges was a bit hit & miss. I found it too easy to over-heat it in my efforts to get it hot enough not to cool below critical temperature before I could get it in the oil. I had to have the oil sitting dangerously close to the flame, which isn't the most clever idea....

Cheers,

Originally Posted by IanW

Rob, for someone like yourself using your gauges constantly, I suppose nails are a bit soft

They are Ian.
I got sick of having to re file worn ones after about ten years of using them and repairing some with nails . Ive got a few gauges and my favorite has a blade not a pin.

Rob, I use both cutter & pin gauges all the time - cutters for cross-grain marking & cutting deep lines for hinge housings etc, and pins for long-grain. The reason for the latter is that pins leave a more distinct mark that my ageing optics can see...

I also like using a pencil gauge for making erasable marks. These are my "daily users":

Pencil cutting pin.jpg

I do have a few others:

b gauges.jpg