Showing posts with label Glues and Gluing. Show all posts
Showing posts with label Glues and Gluing. Show all posts

Monday, January 18, 2016

Irish Bouzouki - The Rosette

I managed to complete the rosette this morning. There's no hint of chipping which has frustrated me in the past, thanks to a tip I picked up from a long-forgotten source.

Prior to routing the inner and outer purfling channels that border the rosette, which I complete after the inner tiles have been glued in place, I applied Titebond to the soundboard in the immediate vicinity of the rings and let it dry overnight. The rationale for doing so is that the wood fibres of the soundboard are less likely to tear or chip when the channels are routed as they are supported and stabilised by the glue. I believe the original suggestion involved the application of shellac in the vicinity of the rosette, but as I'd already managed to smear some Titebond on the soundboard when gluing the inner tiles, I figured it would achieve the same goal. Mission accomplished!


Cheers
Pete

Monday, December 9, 2013

A Guitar Back is Born.

A half hour here, an hour there, and before you know it, a guitar back has materialised. I've been making a concerted effort to make progress on this guitar after work throughout the week, when I would typically be less than productive where guitar building is concerned.


The back halves were joined with Titebond as usual, but I thought I'd attempt to use hot hide glue wherever else I can on this instrument. Apart from its great strength and resistance to creep, I enjoy the fact that it's so easy to clean up once the parts are joined and clamped. After allowing a short time for the squeeze-out to gel, most of it can be easily removed with a chisel-shaped scrap of spruce. A sponge dipped in the hot water from my glue pot, wrung almost dry, removes the remainder of the glue pretty effectively.

Attaching braces to the soundboard would seem to be a realistic goal for the week ahead. We'll see whether Murphy's Law allows me to achieve it!

Cheers
Pete

Saturday, September 3, 2011

The Fingerstyle Guitar - Gluing the Soundboard and Back

There are several commonly used methods of clamping the soundboard and back as they're glued to the rims, but the technique pictured here is the one I've adopted; it works very well, and I feel no need to explore other options. I use thin bungee-cord to apply the necessary clamping force, with a caul made from masonite and cork sheet in place to distribute pressure evenly around the guitar's perimeter. The caul focuses clamping pressure on the edge of the back or soundboard, preventing any deformation of the top or back plates which the tightly stretched cord might otherwise cause. It also serves to protect the delicate soundboard wood from damage where the cord breaks sharply over its edge. I trim the top and back plates to within a few millimetres of their final dimensions prior to clamping; there's minimal overhang and therefore no leverage brought to bear by the bungee-cord on the edge of the plates.

Gluing guitar soundboard and back

Gluing guitar soundboard and back

Gluing guitar soundboard and back

I haven't become anywhere near proficient enough with hot hide glue to consider using it to attach the soundboard and back plate to the rims, and in any case, I'm not convinced of the benefits of doing so. That being the case, I'm happy to continue using Titebond Original, applying it the gluing surface of the linings with a 1 inch foam roller after the rim assembly has been securely clamped in the outside mould. The roller allows me a high degree of control over the quantity of glue applied and, if I've judged it well, there's negligible glue squeeze-out at the intersection of the linings with the top and back plates and therefore little need for clean-up inside the guitar body. I attach the back first, the advantage being that once the bungee-cord has been secured, I can flip the entire assembly over and inspect the interior of the guitar through an opening in the base of the mould, cleaning up what squeeze-out there is with a damp sponge.

Click any of the photos for a larger view.

Cheer
Pete

Sunday, June 26, 2011

The Fingerstyle Guitar - Fun With Hide Glue


This has been my first attempt at using hot hide glue, and although there were some tense moments - including one abortive attempt at attaching the bridge plate - major disasters were averted.

Because hide glue begins to gel quite rapidly once it cools, it's important to apply it and have the piece being glued clamped in position before that happens. Before I glued each brace, I found it useful to have several practice runs without glue to establish the sequence of steps I'd follow and to make sure I knew in advance where and in what order I would position the "go-bar" clamps. Despite the benefit of those dry-runs, I wasn't able to remain cool, calm and collected at all times and I still managed to make a gooey mess on a couple of occasions.  Thankfully, of all the glues I've used, hide glue is by far the easiest to clean up. As I found out on my first attempt at gluing the bridge plate, the worst that can happen is that the soundboard, brace or bridge plate need to be cleaned of glue with a little warm water, ready for a second attempt when things have dried out. The advice I've read repeatedly - and with some relief - is that using hot hide glue gets easier with practice!

Cheers
Pete

Wednesday, June 15, 2011

Hot Hide Glue

In an effort to find out first hand why so many luthiers favour the use of hot hide glue when modern alternatives are so readily available, I've finally ordered (and received!) some high clarity 192 gram-strength hide glue granules from the U.S.  I'm sure my Titebond, epoxy and superglue will remain indispensable for many tasks, but I'm keen to introduce this most ancient of glue types into my building process, particularly when it comes to attaching braces to instrument soundboards and backs.


My initial order was intercepted by Australia's occasionally-vigilant quarantine service and ultimately destroyed by them (despite my protestations), but it seems they were distracted by other matters while my second order was entering the country.  I'd be feeling a little guilty right now for having circumvented our quarantine laws, except for the fact that other Australian builders report that their shipments are routinely inspected by quarantine personnel before being sealed up and sent on their way without a fuss. If one-pound packages of hide glue posed any real threat to national security I'm sure they would be confiscated on a more consistent basis!

It's been a long time since I've had any need for a baby bottle warmer; the cheap model pictured will see out its days as a handy glue pot.

Some useful links:
Frank Ford - Using Hide Glue
Luthier's Mercantile - Granular Hide Glue
Wikipedia - Animal Glue


Cheers
Pete

Friday, February 11, 2011

Glue Clean Up

With the advent of the soundport, the standard of workmanship inside the guitar body is more easily scrutinized and there's perhaps an even greater incentive to clean up surplus glue as the various component parts are assembled - not that I've neglected this previously. If some vintage instruments can be taken as a guide, it seems this wasn't always a priority, even for well-respected manufacturers. Times change though, and as I inspected a new Martin in a local music shop not long ago, I must say I was impressed by the meticulous attention to detail within the guitar body including the fact that all traces of excess glue had been carefully removed from the intersection of the back plate with the linings and back braces. I vowed then and there to emulate this in my own instruments to the best of my ability in recognition of the fact that it's often the little things that make a big impression.


There are several approaches to cleaning up excess glue once clamping pressure is applied to a freshly-glued joint. Regardless of the method used, I always try to plan ahead and give some thought to the arrangement of clamps to ensure unhindered access to glue squeeze-out after they're in place. I'm also careful not to apply an excessive amount of glue in the first place. A 1-inch foam roller is helpful in that regard, with the added advantage that an even coverage of glue is more quickly and easily achieved.

I know that the preferred approach for many builders, whichever glue is used, is to leave glue squeeze-out undisturbed, letting it partially set or gel before attempting to remove the excess. I use Titebond for the majority of gluing tasks, and find that a flattened plastic drinking straw with the end cut at something like a 45 degree angle is a good first step towards removing unwanted glue as soon as clamps are in place. This approach works particularly well when gluing braces to the soundboard or back. The straw is pushed cut-end-first along the freshly-glued joint and much of the surplus glue finds its way inside the straw which is then discarded. It helps of course to have several pre-prepared sections of drinking straw on hand.  Chisel-shaped slivers of spruce or cedar, moistened Q-Tips (cotton buds or ear buds) or a moistened sponge can also be useful as a follow-up and, using a combination of these methods, it's usually possible to remove every last vestige of excess glue without compromising the joint itself.


When gluing braces to the back and soundboard, I exercise patience and generally glue one - or perhaps two - braces at a time. Not only does this slow and steady approach give me ample time to clean up after myself, but I have the luxury of a clear view and unobstructed access to squeeze-out.

Another strategy which contributes to a clean look inside the guitar body is to attach the rim assembly to the back first, rather than to the top. I find it helpful to have a second chance to tidy things up before the top is attached and while the various nooks and crannies which will remain visible after final assembly are still easily accessible.

Cheers
Pete

What's In a Name?

The back and sides of this guitar are of narra, which is an alternative name for a wood that's most often marketed here in Australia as ...