parlour guitar renovation

As a hobby maker, I like to try new things, learn new skills and generally enlarge my interests in instrument making. Over the last few months I’ve taken to collecting and renovating guitars from the 20s and 30s.

These are cheaply made instruments by unknown makers so I don’t feel I have an obligation to preserve them in their original state. I am happy refinishing them albeit in shellac not lacquer.

These instrumenst could be termed parlour guitars, are ladder braced, usually with a pin bridge and usually arrive with light gauge steel strings and occasionally with nylon strings.

Cracks and loose braces are the usual problem, though a neck reset is sometimes necessary. I have no issues with modifying the braces or thinning the tops where I reckon the instrument is over braced. Back removal is usually necessary and done with heat, a suitable tool and some patience.

Here is my latest project. There’s one soundboard crack, the neck dovetail is loose, and 2 of the back braces are loose. I could have tried fixing this without opening the box but I propose replacing the ladder bracing with an X brace system as used on a similar period Martin parlour guitar. (photo below) I expect it to sound better and will only find out by trying this modification.

Note how crudely its made! There’s a large resin pocket in the main soundboard brace: why would a competent maker have used this piece of wood? Note also there’s no reinforcing patch under the pinned bridge.

greenscoe said:

why would a competent maker have used this piece of wood? Note also there’s no reinforcing patch under the pinned bridge.

Click to expand...

Maybe because they never thought anyone would look inside and find out. Surprise! The buried body has been found!...

There are nearly 300 visits to this thread so I think that means there’s interest in renovating a guitar! On that basis here’s some more information.

This is a Meinel and Herold Wiener (Vienna) model from Klingental, Germany.

I think this is from 1920-30 but that’s really a guestimate-maybe someone can tell me?

I’ve cleaned up the one-piece maple back and reused only 1 brace: the other 2 are new spruce. The originals were far from quarter sawn and not symmetrically curved.

Removing the 2 ladder braces from the soundboard may seem straightforward but it's easy to split or mark the soundboard or undo the glued centre joint. For this reason, I proceeded carefully with small saw and curved gouge whilst protecting the soundboard with scrap wood. Scraper and sandpaper completed the job. Heat, steam and boiling water don’t always easily separate a glued joint without causing unintended collateral damage. The pros no doubt would do it in a flash.

I’ve never yet made an instrument with X bracing, so my modification to this guitar is based on the Martin photo in the original post. I may have over braced: the braces could have been a little narrower. I’ve already pared down a fair amount whilst tapping and flexing and I may do a little more work. I know what a tenor uke soundboard sounds like when correctly done but am not sure with a guitar especially since the bridge is still attached. The new braces are in perfectly quarter sawn spruce and the reinforcement patches are in mahogany.

The sides are of maple (average 2.5mm thick) and are not bookmatched. The linings are solid maple too of similar thickness. The binding is narrow ie the same depth as the top thickness. This indicates the top is typically 3.5 mm thick but as thin as 2.7mm at some places along the edge.

I may add a few side reinforcing strips before I close the box. Side cracks are quite common on old instruments though this one has only damage at the waist from when it was poorly bent.

As a hobbyist maker myself, I love this kind of stuff. Please keep posting.

After watching several videos on Youtube about X bracing/scalloping and tap tuning, I added some secondary braces and further reduced the existing bracing. When struck a soundboard should be musical, some say bell-like: I like to think of wooden Xylophone bars (notes) that ring out.

Gluing on the back can change the neck alignment. Since the action was high on this instrument, the opportunity was taken to correct this whilst gluing the back. This ‘cheat’ avoids having to do a neck reset.

This instrument was initially shellaced and the sides had a thick/rough varnish finish more recently applied. Paint stripper and then meths using wire wool and scotchbrite pads were used to remove these.

240 grit paper then sanded the back/sides flat but left some dark staining: I didn’t want to heavily sand the sides which were quite thin in places. The pale maple was ‘coloured’ with repeated application of a weak potassium permanganate solution. The colour is now that of dark walnut which masks the grain of the non bookmatched sides. It is fairly even despite the residual stains.

I like to apply a several coats of shellac over a few days, topped off with more coats of Tru Oil. This is then knocked back with 0000 steel wool when all is cured. It gives it a deep warm aged appearance rather than a perfect modern looking high gloss (some might also add a waxed finish on top of this). The guitar finish will also darken and warm even more over subsequent months.

The photos below shows the back as received and after the first few applications of shellac. It will be a couple of weeks before its finished.

The fretboard on this guitar was worn at the frets 1 to 3. The easiest way to rectify this is by filling using CA adhesive and fine sawdust of the appropriate colour. This is then scraped level with a stiff backed razor blade and sanded with 600 grit. (The stiff backed razor blade is very useful. A burr can be applied with a hard metal tool and its then used as a mini scraper). Apart from a little shiny patch, there’s no sign of the repair, and this is not noticed when the strings are added.

Sometimes the fretboard is made of an ebonise light coloured wood and the black surface has been worn away. I have found the easiest way to fix this is to use Indian Ink which is water proof and colour fast.

On one instrument I replaced the whole fretboard because several frets were incorrectly placed and the instrument had terrible intonation.

Necks on these older instruments are usually black. I believe this is called ‘piano black’ shellac. My quick solution to restoring this black finish is to use blonde shellac on top of a matt black waterbased paint (Blackboard paint in UK).

The machineheads on these slotted headstock instruments are sometimes damaged. Modern m/heads use 35mm centres which was not always the case. On this instrument it's 30mm centres and one worm gear/button has been replaced at some point in the past. The alternative to retaining the old m/heads is to use 6 off modern single m/heads, an option I try to avoid.

I too am following this with interest. There is a lot of satisfaction in renovating older instruments. One thing concerns me:- the distance from the zero fret to the first, looks less that first to second. Could be a photographic effect, but it does look rather obvious.

John Colter.

ukantor said:

I too am following this with interest. There is a lot of satisfaction in renovating older instruments. One thing concerns me:- the distance from the zero fret to the first, looks less that first to second. Could be a photographic effect, but it does look rather obvious.

John Colter.

Click to expand...

Frets are positioned correctly on this one-it must be just a photographic effect. Glad you are interested John. My intention in posting is, as always, to encourage others to have a go!

Very nice. Parlour guitars are great.

I think that was originally made for gut strings. It may be 1920's but it could also be earlier although it's based on much earlier 19 th century romantic guitars. There were countless thousands of such guitars made in the area around Klingenthal and SW Germany/ Czech. A real instrument making centre but more famously known for violin making. It was largely a cottage industry with whole families involved in the making of guitar parts. Often something like the soundboard might be made by one family and the necks by another. They were throwing these things out by the dozens - every week. They are never (or rarely) named. If they are then it's likely a stamp or label of a dealer.