Crawls Backward (When Alarmed)

IconProjects, musings about guitar builds, guitar repairs, vintage tube amplifiers, old radios, travel, home renovation, and other stuff.

Vintage Princess Banjo Mandolin Crack Repair

Now that the Princess banjo mandolin is lying in state pieces on the workbench I can start fixing the cracks.

First one is this crack on the heel cap.  The cap is a nice pice of birch I think.  It looks like the laminate in the center of the neck underneath began to crack and took the cap with it.

This shot is a little out-of-focus, but still illustrates the point.  You can see the split where the laminate piece - I think that's birch also - began to crack.  Since the cap is glued to that, it also cracked.

So I got some hot hide glue into my syringe.  I'm using a 0.9 mm needle.  I had to thin the glue down - it's not quite water-thin, but close.

The glue has to be thin or it won't pass through the needle.

I squirt the glue into the crack until it starts coming out of the top.

Then I clamped it up in a vise with come cork-faced cauls.  The white paper you see is waxed paper, so the glue won't stick to the cork.

It's hard to tell, but I think the crack on the cap isn't closed all the way.  We shall see what happens.

The next crack is this one on the maple trim piece that covers the laminations on the rim - see the arrow in the picture.

I was gently pulling on the crack to see how far the piece was pulled off the rim.  A couple inches...couple more.  Then, small crack noise and the whole piece popped off.

It's actually better that it came off.  Now I can reglue the whole piece and know it will stay on.

I glued the ends of the trim piece together and clamped them down to dry overnight.

Then I'll be able to attach the piece onto the rim as one assembly, rather than try and deal with the crack at the same time.

The round trim piece is sort of 'springy' and isn't exactly the same size as the rim.  In other words, I have a bit of play in terms of it.

So I'm going to glue a small section at a time so it will line up properly.

Brush some hide glue on the rim...

...and align and clamp down that section.

I left this piece to dry and the next night did another small section.  And I started thinking: this is going to take a week at the rate I'm going!

I kept thinking to myself: "self, if you only had a bunch of spool clamps to do this, you could do the whole thing at once!"

Then it hit me: I don't have spool clamps (yet...) but I do have rubber bands!

So I used rubber bands to hold the rim down, with clamps in a couple of recalcitrant sections.

It worked great.  Got it lined up all the way around.

Do you remember the crack in the heel cap?

My first repair closed the crack in the heel itself, but only tightened up the heel cap a little.  I thought that might happen.

So I used my Crawfish Instruments Bridge and Veneer Removal Iron™ to heat the cap.

Careful use of a seam separation knife gets the veneer right off.

Now I can fit the two pieces back together properly.  Which is what I should have done the first time.

Here is is glued up (again).  Should be much better this time.


 
 

ca. 1935 'Princess' Banjo Mandolin Restoration

Who woulda thunk it?  Two mandolins in two weeks?

And this is not just any mandolin - it's royalty! 

Not only that, it's a banjo mandolin.  As if a mandolin wasn't loud enough to start with.

This is a sort of mystery-make banjo mandolin.  I'd guess it dates from the late 1920s maybe up to 1940 or so.

Told you it was royalty!

It's a 'Princess.'  Very nicely made - 5-ply maple rim, three piece maple and rosewood neck, and what appears to be a rosewood headstock inlay.

I suspect this was made by Regal or one of the other Chicago makers - there is a plate covering the rear of the tuners that sure looks Regal-esque.  Plus, the name could be a play on 'Regal' as well.

At any rate, it belongs to a friend of mine and I'm going to do a little fix-up and get it going again.

There are a couple of cracks to fix, I'm going to put a new head and possibly a bridge on it as well.

First order of business is to take the head off.  I'm using my new 'MyBanjo' tuning head wrench.  Pretty neat and handy - three common sizes on one wrench.

The lugs were pretty loose - virtually no tension on the head.

I need to take the neck off in order to remove the head.  There is a lug at the strap end that attaches to the coordinator rod.

The rod isn't adjustable, but it's not made of wood, so I think the proper term is coordinator rather than 'dowel.'

OMG.  I am speaking banjo language.  We're in trouble now.

You can see how I just used the lug itself to turn the nut that attaches to the rod.

Here's the lug detached from the pot and the rod.

I'm leaving the other lugs on for now.  I'll polish them, and I think it will be easier if they stay on the banjo pot.

Closeup of the MyBanjo tool.  I believe it's an English design.  This should fit 95% of the banjos in existence I would think, since there are three nut sizes - 1/4, 9/32 and 5/16.  Imperial measurement still lives!

If you have one of these, you will be able to tune the head on virtually any banjo on earth.  That, my friend, is power.  Use it carefully.

I bought this and the new head from Elderly Instruments. And ironically, my friend, whose banjo mandolin this is, worked at Elderly in the early 1980s.  Small world.

Okay.

So now we can just pull the neck away from the pot.

When I did this, I thought of another good friend who says "Banjos are easy to work on.  They're just a bunch of parts."  And so they are.  And it's pretty logical as to which part goes where.

The internal rod just slides out from the bigger coordinator (or is it just a rim?) rod.  There's a thread that goes into the neck heel.

With all of the tension lugs undone, it's a simple matter to pull the tension hoop up off the head.

And the head just comes up off the rim.

There was a spot at the heel end of the neck where the fingerboard was pulling up off the neck.  So I just gently tugged on it, and the whole board came off.  Better now than when my friend is in the middle of some fingerboard-burning solo.

The frets are really sticking out from the fingerboard, so it will actually be easier to dress them back with the board off the neck, I think.

Check out the beautiful black and white pearl "moon" inlays.  Very nice.

Next, I'll work on those cracks I mentioned.

 
 

Cleaning and Polishing the Finish on the 1919 Gibson A-4 Mandolin

I am proceeding cautiously with cleaning and polishing the finish on the A-4 mandolin.  I did some research, and read about polishing varnish-shellac-or-whatever-mystery finish is on the mandolin.  I want it to be clean and shiny, but I don't want to damage the original finish at all.

So I first cleaned it with soft towels and naptha.  Naptha is a good gentle cleaner, and it evaporates very quickly.

If you do use naptha for cleaning an old instrument, do it outside.

Some dirt came off, and it's starting to have a nice gloss and more clarity.  You can see the beautiful grain on the spruce top.  The finish is quite transparent.

I usually use (and swear by) Virtuoso Cleaner and Virtuoso Polish.  The cleaner is especially amazing.

So I tried some cleaner in some inconspicuous spots.  It worked very well.

Here's a sample of the dirt I got off a section of the top where you arm would rest.

I saw no damage, lifting, bubbling, at all with the cleaner and the polish, so I used it on the whole instrument as I would with a lacquer finish.

Now, just because it worked well on this particular instrument means it's safe for anything.  I'd still be cautious on any finish.

Look at the gloss on the back!  There was an area near the center with a lot of hazing and it came right out.

The finish looks like glass over red tint over the maple.  It has terrific depth and clarity now.

Top looks good too.

It was really hard to photograph due to the glare from the gloss.

There are a couple of wear spots that are a little less glossy, but it still looks good.

I polished up the tailpiece hardware, and put it back on.  Did the screw heads too.

After a couple of years, they'll get their own patina just from being exposed to the air.  But in the meantime, I got all the tarnish off.

You may recall from a previous post that the tailpiece cover didn't look so good.  (Note the top finish also).

Here it is back on the mandolin after being polished.  Night and day difference.

The headstock cleaned up nicely as well.

Love that fleur-de-lis inlay.

After I strung it back up, I put on my homebrew Kawika Hula Girl Shaker break in tool.  My trusty Hacker Hunter RP-38 is driving it.

I'll give it a couple of days treatment.  From what I understand, the mandolin hasn't been played since about 1967, so it can benefit from being 'woken up' again.

Here's a close up of the 'shaker.'

You can also see how nicely the finish cleaned up.  It's amazing that the finish is 95 years old.  A real tribute to quality work.

I need to take the mandolin outside and get some beauty shots soon!

 
 

Fingerboard Cleaning, Fret Dressing, and Tuner Lubrication on the 1919 Gibson A-4 Mandolin

So, the cracks on the Gibson A-4 are fixed.  Now I can clean the fingerboard, do a bit of fret dressing and clean and lubricate the tuners.

You may have read elsewhere on this here blog about my experiences cleaning old fingerboards.  My old Martin ukulele was about the worst.

This one isn't too bad.  First I like to do a cleaning with Simple Green and a toothbrush.  Not too much, just enough to lift the surface dirt off.

Then I use Dunlop Fingerboard Cleaner & Prep.  This stuff is great.  The downside is that on a dirty board, it takes numerous passes to get everything off.  This one took 8 or 9 passes.

I can't seem to find this sold in a larger size.  I'd like to buy a quart (about a liter) of it.

A lot of times on vintage instruments you see "fret sprout," where the fingerboard has shrunken up due to changes in humdity.  Then the sharp fret ends stick out a bit from the board.

This mandolin's frets were not sticking out at all below about the 10th fret, but the ones above that were.  I probably won't spend much time playing there, but I wanted to dress those fret ends anyway.

So I made a few passes with a fret end bevel file. Notice also how dull the frets look.  We'll fix that too.

That takes care of the frets sticking out from the edge of the board, but there are usually still some sharp edges on the edges of the bevels.

So I go back with a small fret end file and just touch those edges up - two or three file strokes does it.

Now you can run your finger along the length of the fingerboard edge and it's nice and smooth, no rough or sharp edges.

The final touch is to go over the frets with the magic 'Fret Erasers' from Stew-Mac.  Start with the 150 grit and work up to the 1000.

The frets wind up super shiny and smooth.

There is a touch of wear on the first couple of frets, but it just didn't justify recrowning them.  These frets are small to begin with, and I don't want to take off any material.

Here's the finished fingerboard.  I've been using Stew-Mac fretboard finishing oil for the last year or so instead of lemon oil and I love it.  The board winds up with a beautiful natural glow and is super smooth.

My container of this stuff will last for years.  It just takes a small amount on a fingerboard.

This board is ebony, and now you can see the beautiful brown streaks here and there.  They were invisible before the cleaning.

The tuners on these old Gibson mandolins are notorious for being hard to turn.  A couple of them on this mandolin were virtually impossible to move.

So I used a drop of Tri-Flow lubricant on the moving parts.  They've freed up nicely.  One or two of the tuners still have a place in their rotation where they tighten up a bit, but they're much better overall.

I polished up the base plates a bit with metal polish, just enough to take a bit of the tarnish off, but not super shiny.  I think they look good now.




 
 

Crack Repair on Top of 1919 Gibson A-4 Mandolin

When I worked on the side crack on the Gibson mandolin, at some point I noticed this crack in the top.  I just didn't pay much attention at first, until I realized it was the center seam and it was a crack that needed attention.

I'm actually holding it open a bit in this picture.  It wasn't quite that bad looking and open in reality (maybe that's why I sort of missed it even though it was plainly visible...).

Anyway, I set about fixing it.  Top cracks are generally the most straightforward body repairs on an acoustic instrument, since they're the most accessible.

The process is: hold the crack open, work some hot hide glue into it, then gently but firmly clamp it down to close it as much as possible.  This crack closed up nicely with some pressure in a couple spots along its length.

I discovered my cam clamps were too big to get into the soundhole, so I improvised with this cast iron c-clamp.  I just stuck some cork on the bottom with rubber bands so it wouldn't damage the inside bracing of the mandolin.

Here's a simulation/test of the actual glue application.  Heat the surface up a bit with a heat gun to help give the glue a longer working time.

Then I reached in from the end pin hole with some long tweezers with an angled end and pushed up on the top.  Then brush some hide glue on, while working the crack up and down gently.

And repeat from the soundhole end - with fingers inside the mandolin.

What you see above is just a test with some glue.  I wiped that off with a warm, damp cloth before the actual operation.  When I did the actual repair, I was able to get the crack nicely opened up and glue worked into the seam.

One of the things I really like about hide glue is that it's so easy to get excess off, even if it dries.  In this instance, I put a pretty liberal amount on, then wiped the excess off quickly before I clamped it up.

Work the glue into the crack, then quickly clamp it up.  I used a couple pieces of thin plexiglass as cauls.  They're strong enough to hold the crack down, and you can see your progress through them.  With the clamps on, the crack closed right up.

I won't bother cleating this from the inside.  The crack will be pretty tightly closed up, and the hide glue tends to pull the crack together as it dries, making for a strong repair.

I only cleat when absolutely necessary - meaning when a joint needs support.  This crack will be solid.

Here's the seam after repair.  I still need to clean up a little glue squeeze-out, but it looks good.   And it's much less noticeable in person.

My guess is the seam has been open for quite some time, so I'm happy with the way it closed back up.

Love that sunburst!  Much more subtle and natural than Gibson's 1950s sunbursts, I think.

 
 

Side Crack Repair on 1919 Gibson A-4 Mandolin

When we left our vintage old Gibson A-4 mandolin, it was waiting for yours truly, the awful of this blog, to cook up a caul to use to press down the side to fix a crack.

Let's get with it, shall we?

You may recall my trusty jamb saw from the adventure I had last summer fixing a rotted piece of a wood pillar on the outside of my house.

The top of the mandolin is lower than the fingerboard, so I'm making a caul with a triangular section of a wood block cut out to allow it to sit on the fingerboard, but also have a part that also sits on the top - basically two levels at once.

Since I don't have a bandsaw, I used the jamb saw to make one vertical cut for the long side of the triangle.

And then I made a horizonal cut with the saw to cut away the triangle section.

You might see where this is going.

The piece I cut off allows the caul to sit up on the fingerboard and also has a section that will contact the top.  I decided to cut it on an angle so it would fit along the neck better and not want to slide off under pressure.

I thought I'd want pressure on both surfaces when I clamp it up.  Pressing down on the fingerboard alone doesn't close the crack on the side much.

I like to use cork on the surfaces that will touch the instrument, so the caul won't damage the finish, and it also helps it not to skid out of position.

So I glued some cork to the bottom surfaces.  You can see that, ironically, I used another caul to help clamp the cork down.

Almost ready.  I just need to trim that excess cork on the belt sander.

I'm also going to round the edges a bit more...it looks more finished and not so crude that way.

I actually like making cauls.  You get to be a bit creative and use the problem-solving part of your brain at the same time.

Sanded flush.  You can see the triangle section clearly now.

Trial fit on the mandolin.  Should work fine.

If you're wondering about that bad spot on the side, well, I did sand that smooth later.

You can see that there will be pressure on both the end of the fingerboard and the top, which we need in order to close that crack on the side up as much as possible.

Aside: lookit how tarnished the tailpiece cover is.  I need to polish that thing up.

Now back to our crack repair.

I used a couple of my removal spatulas to open the crack up as much as possible to get glue into it.  Sorry about the bad picture - it's hard to take a shot with my tool in one hand and the camera in the other.

The plan is to warm up the crack a bit with the heat gun, to give a little more working time with the hot hide glue.

Then I'll hold the crack open with the spatula, get hot hide glue into the joint, then clamp it up.

Good luck to me.

We brush hot hide glue into the joint.

This is actually a little staged - I did use the spatula to hold the crack open more.  I just couldn't get a picture off while holding both the brush and the tool.

But you get the idea.

You have 60-90 seconds to get the glue in and the repair clamped up before the glue begins to gel.  Have to work quickly.  I always do a dry run or two to make sure everything's read to go before I use glue.

All clamped up.  You can see the new caul on the top.  There's also a flat rectangular caul on the bottom - note the waxed (aka paraffin) paper on the caul in case glue gets on it.  Don't want to glue the caul to the mandolin!

I was able to get the crack mostly closed.  It's a wide crack, it's been sitting for decades, and there isn't much movement overall.  We do what we can.

Here's the finished repair.  It's solid, but as you can see, there is still a bit of open crack.  Not worth losing sleep over...the main thing is that it's not going to move any more.

Note the green arrow - I inadvertently took a chip of wood out with a spatula.  Dagnabbit!

I suppose I could fill it with sawdust, but to be honest, compared with that old patch repair above it, it's not that bad looking.  I can always go back and finish it.

So we now have a stable, repaired crack.  Guess what?  I found another crack on the top that needs to be repaired!  Onward.