Tool Restoration – William Marples Hibernia Mortise Gauge

This is a little bit of a long winded story, but bare with me, it’ll be worth it.  Quite some time ago, I wrote about a trip that the family and I took to the Royal British Columbia Museum in Victoria, Canada.  You can read that post HERE if you wish.  Go ahead, I’ll wait…  No, okay… Well while there, I found a display of old woodworking tools and one of them was identified as a William Marples Hibernia Mortise Gauge.  I was thrilled to see the tool identified, as I had the exact same tool in my collection.  However, on mine, no manufacture’s marks were readable.  I didn’t know exactly what I had until the trip to the museum.

Well after reading the above mentioned post, my good friend Gerhard Marx of http://www.jenesaisquoiwoodworking.com/ fame, sent me an email saying that he would really like one of these mortise gauges.  Gerhard resides in deepest darkest Africa, and told me that he figured his chances of ever stumbling across one of these in the wild was next to nil.  Hippos… quite likely, antique hibernia mortise gauges… not so much.  He asked me to keep an eye out for one whenever I’m out browsing garage and tool sales.

I bought my mortise gauge on eBay UK.  It is often cost prohibitive to do this from the US as international shipping is often more expensive than the tool.  To avoid the costly English international postal rates, I had it sent to my mother-in-laws house in England and picked it up on my next trip there.

Well, knowing that Gerhard wanted one of these I couldn’t resist.  Within a few weeks, I searched on eBay UK once more and found one that I managed to grab a good deal on.  I had it shipped to my brother-in-law.  Last summer, we met up in Jamaica for a family vacation and he brought it to me there.  I brought it home to Washington.  Wow, this quite a well traveled mortise gauge.

My plan was to promptly restore the gauge and send it off to Namibia.  Unfortunately, my small summer project of building a chicken coop spiraled into idiotic proportions and I’ve only just finished it.

With the coop and run finished, I turned my attention to the gauge.  Better late than never I suppose.  Here’s the gauge before I started any restoration work:

As purchased from eBay UK.

I know it looks rough, but these mortise gauges are a joy to behold.  I just love them. They are very heavy in the hand, and you know you’re dealing with a solid, top quality tool the minute you pick it up.  The head is made from ebony (although I’ve read they can be found with rosewood) and brass.  The stem is brass and has a hidden steel screw running through the middle.  This screw adjusts the distance between the two pins.  The head is also locked to the stem by use of another steel screw.  This screw bears against a small brass plate that in turn presses against the stem.  This acts as a clamp and locks the head. The stem has a small groove running down the length of it, and the small brass plate has a corresponding tab in it.  This stops the head from rotating on the stem. Sounds confusing, but the pictures below will clear things up.

I like that both of the adjustments need a screwdriver.  For some this might seem a negative aspect of the tool, but not to me.  My experience has been that I set up a gauge once and lock in in place for the duration of a project.  I have multiple gauges and if I have a different mortise to lay out on the same project, I’ll set up another gauge.  This is usually quite helpful, think of them as mini story sticks (until you adjust them).  I want to be able to set a gauge, snug the screws down, and know that those settings are going to stay put.   Somehow psychologically, locking the settings with a screwdriver just seems more permanent.  I’ll leave the psychological issues for Gerhard to delve into.  🙂  Also, once set, there are no little fiddly bits or wing nuts hanging off the side of this tool.  It is sleek and simple.  Most importantly, it does its job exceptionally well.

It’s pretty rough and dirty.

Most of the screw slots were filled with years of accumulation of crud.  The groove along the stem was also fairly full.  The pins of the gauge have been sharpened and filed down to nearly nothing.  They are going to have to be changed.

The pins are shot and will have to be replaced.

The tail screw (which adjusts the distance between the pins) was in great shape.

It looks as though it has spent some time rolling around in a toolbox.  It is all cosmetic though and is going to clean up beautifully.

You can see a previous owner’s stamp on the head.

Before I get started on the restoration, I suppose I should mention my philosophy on making old tools usable and beautiful.  Serious die-hard collectors would cringe, but I want to make the tool both beautiful and usable.  This gauge is not being preserved in its current condition for all eternity and put on a shelf.  However, I don’t intend to make really old hand tools look factory new.  Some of the tiny dings and owner’s stamps, give the piece character and speak to its age.  When I’m done, the tool will be clean, shiny, well oiled, and functional but some original marks will be there.  The shine will fade in a few months to an even patina.

To get started, I used a dental pick to clean out the screw heads.

A dental pick is a great tool for removing all the gunk from the screw slots.

Once the screw slots were cleaned out, I was able to take apart the gauge.

To polish the stem, I began with sandpaper.  Working from 320 grit up to 1500 grit.

I started cleaning the stem with 320 grit paper.

I moved up to 400 grit paper.

I also sanded the head of the gauge.  I sanded both the ebony and the brass at the same time.

Then 800 grit.

Better put all these little pieces in a bag before anything gets lost.

As you can see below.  The stem is clean, but there are still small little dings that show some use and age.

I finished sanding with 1500 grit paper.

I’ve been meaning to change the buffing wheel on my bench grinder for some time.  It’s fairly worn out, but it will work for this job.

My grinder with a pretty manky, worn out buffer wheel.

One cool thing about ebony, is that it is so hard you can buff it on the grinder like brass. The same extra fine green buffing compound that I used on the brass really made the ebony shine.

After polishing.

Next the pins.  These are used up and need replacing.  I tapped them out with a small hammer on the anvil of my bench vise.

This pin is used up and will have to be replaced.

Now I needed to find replacement pins. I had a good search through all my nails, but all were either too thick or too thin.  I’ll have to take a thick one and make it thinner.

Checking a nail for size.

To do this, I took a nail that was slightly too thick and chucked it up in my drill.  With the nail spinning, I used a file to start thinning it down.  I periodically checked it against the hole in the brass plate.

With the nail spinning in the drill, I took a file to it.

Once it got close to the right thickness, I switched to 100 grit sandpaper.

Using 100 grit paper to finalize the thicknessing of the nail.

While still in the chuck, I also started to file flat knife points onto the nail.

With the nail securely held in the chuck , I started to file it to shape.

Filing the pin to a point.

Side profile view.

I refined the edge on an oil stone.  Now that the pin in the correct size and shape, I want to harden it.  I’m doing this in the hope that it will wear longer and need sharpening less. I poured a little oil into a tin and got out my blow torch.

Getting ready to heat treat the pin.

While holding the nail in a pair of pliers, I heated the tip until it was glowing bright.

Getting the nail red-hot.

And then quenched it.

I quickly dropped the still glowing nail into the oil.

And let it cool for a minute.

Once the nail had cooled it was black and nasty.  I touched up the cutting edge on the oil stone once more and cleaned the shaft of the nail with some 320 grit paper.

After heat treating.

Cutting the pin down to length.

I used a hacksaw to cut the pin to length and then installed it in the brass mounting plate that screws into the stem.

The new pin tapped into the brass mounting plate.

I then repeated the above process and made a second pin for the other part.

Both new pins installed in their mounting plates.

Time for re-assembly.  When I went to re-install the brass plates in the stem, I found that the new pin had very slightly bowed out the sides of the plate.  This made it just a little to tight to re-install.  I very slightly sanded the sides and they then fit fine.

I very slightly sanded the sides of the brass mounting plate.

So here it is all put back together.

The end result.

The new pins.

Using a very fine jewelers file, I fine tuned the pins so that they cut to the same depth in a test piece.

I’m happy with how the shape of the pins came out.

Some of you may not like how shiny the gauge is.  I have received comments in the past that the bright shine looks out of place.  Fear not, the shine will dull in about 6 months (sooner with a lot of use) and will revert to a more-even dull luster.  In the below picture, I show my gauge on the right which has already dulled, and Gerhard’s gauge on the left.

I shall leave it up to Gerhard as to whether he wants to maintain the high polish or let it fade.

Above, Gerhard’s is on the left, mine is on the right.

When the shine dulls, it takes on a nice even patina.

Well, it’s finally finished and only about 10 months after I bought it.

I packaged it up in lots of bubble wrap and sent it off to Namibia.  I hope that Gerhard gets many, many years of good use out of it.

For those interested, it turns out that shipping to Namibia takes forever.  I finished writing this post on March 16th, a few days after dropping the package off at the post office.  It was not until today that I got an email from Gerhard saying that it had arrived.  I think it must have gone by horse and sail-ship.  I am very happy that it arrived safely though.

– Jonathan White