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jonathan evans
11-01-2009, 9:54 PM
I have a rehab question I'd welcome any advice on. I picked up an old ugly-looking combination mortise gauge off a junk table this weekend, suspecting there's a gem beneath the grime & corrosion. I was right--it's either rosewood or some other dense, dark wood; brass wear strips, brass thumbscrew, and a brass sliding adjustment -- which freed up easy enough with some WD40 & judicious urging.

Here's the problem: the single pin on the marking side, and the two pins on the mortise side were rusted and worn down to just little nubs level with the surface of the stem. How to get the nubs out so I can replace them? They were just flush with the surface -- nothing I mean nothing to get hold of even with the finest nippers, etc.

On the marking-gauge side, the nub sticks directly into the wood of the stem; on the opposite side, i.e., the mortise side, one pin, or what's left of it, is staked through the brass slide close to the end, while the other pin is stuck in the wood and comes through the brass plate on the end of the stem.

As I said, the problem is what to do. I want make it usable if possible but don't want to mangle it in the process. The pin staked at the end of the brass slide will probably be easy enough. It's the other two I'm stumped by. I thought about driving the nub ends down deeper into the wood of the stem with a tiny pin punch and then retrofitting with new larger-diameter pins, which would probably seat okay in the resulting holes. Drilling out the old ones doesn't seem like an option -- any tiny drill bit would slide off center and just bore a parallel hole alongside the remains of the pins.

No doubt some would advise that I should just clean it up & put it on the mantle as a decoration and buy a new Marples one. But there's something of a challenge to this which I hope fellow Neanderthals will appreciate. Much obliged for any suggestions.

Jonathan Evans
Athens, Ga.

James Scheffler
11-02-2009, 10:11 AM
You've probably looked at this already, but I'll throw it out there. Are you absolutely sure that the pins don't go all the way through the stock, so that you could punch them out from the other side? I've seen a few examples of gauges where the pin went all the way through. It's possible that you might not see the hole because it was filled and now it's covered with grime.

Jim

Matt Stiegler
11-02-2009, 10:18 AM
And if the pin holes don't go all the way through, maybe you could drill through from the back so you can punch them through.

jonathan evans
11-02-2009, 7:23 PM
Right, I wondered if it's not a single pin running through from one side to the other; I won't know till I center a pin punch over one nub and try to drive it out. I guess if it's two shallow pins seated on the two sides, the worst that would happen is I'll just drive the one deeper in like I mentioned -- well, the worst is I'll hit too hard & split the shaft. Otherwise what I need is about a 1/32" Forstner bit to drill out AROUND the nubs . . .

Jonathan Evans

jonathan evans
11-03-2009, 10:25 PM
You've probably looked at this already, but I'll throw it out there. Are you absolutely sure that the pins don't go all the way through the stock, so that you could punch them out from the other side? I've seen a few examples of gauges where the pin went all the way through. It's possible that you might not see the hole because it was filled and now it's covered with grime.

Jim

Thanks Jim you were right--a few taps with a very small nail set (which had the requisite concavity or dimple on the end to center over the pin nub) and the nub end on the opposite side came far enough out to get hold of with a needle-nose pliers. It was indeed all one pin driven through from one side to the other. Now all that's left is to find a short length of tool-grade steel the right diameter to file sharp, drive through, and sharpen the other end and voila it's again a usable mortise gauge--just in time for a series of mortise/tenons I have to make.

Jonathan

Richard Darjes
11-04-2009, 11:14 AM
Drill bits are made of tool steel.

Rick in Oakville Canada

Paul Atkins
11-04-2009, 12:09 PM
If you are thinking of a slightly larger pin, maybe you could make a hollow drill with the I.D. the same as the pin. I have done this for small screws, but not that small. Time to learn watchmaking.