New Site

Hi Guys, 

 

Just to let you know that the blog has moved to http://www.bigfootguitars.com 

Come follow it over there, and plenty more content to come up on the site in the coming months.

 

Cheers

Karan

Day 8 – Working the Sides

Now that the sides are bent, they need to get shaped a bit to take on the final form. The first bit is to place them in the body mold and trim the length down to final size. Once this is done, blocks of wood is glued onto the join at each end. These are called the Neck and Tail blocks. The purpose is to strengthen the joins, and also to provide a larger gluing surface for the top and back later on.

The blocks are measured and cut, and carefully glued on.

Gluing the Head and Tail Blocks to the Sides

The blocks after gluing

 

 

 

 

 

 

 

 

 

 

 

As you can see in the picture to the top right, the blocks are not level with the length of the sides. This is deliberate, and the sides will now be planed down on each end to the height of the blocks. This will create a curved surface on the sides, and the back will be glued on to this, creating the back arch for maximizing sound resonance.

This is a delicate process and cannot be hurried. Care is taken to ensure that the sides are of even height on both sides, so that the back is not glued on at a tilt.

If you recall, I had mentioned in an earlier post that the sides are 2mm thick, and this is a very narrow surface area to glue the top and back. To counter this, a lining is glued on to the inside edges of the sides, broadening the gluing surface, and strengthening the joint. Strips of wood are used to make this lining (Kerfed lining is also popularly used).

Gluing the inside linings to the sides

 

Top view of linings

 

 

 

 

 

 

 

 

 

Yes, they look weird! Small spring clamps are used to keep the lining in place while the glue dries. There should be no gaps in the join, otherwise the purpose of the lining is kind of defeated! The lining strips don’t naturally bend this much, they need to be sprayed with water and bent to shape on the bending iron.

 

Side Linings Glued

Full View – Linings

 

 

 

 

 

 

 

 

 

 

Once the glue dries, the linings are sanded down to match the sides, head and tail blocks.

Next up, putting it all together!!

 

 

 

Day 7 – Side Bends!

I finally move to more technically challenging work – bending the guitar sides!

The Situation – The guitar sides are around 32″ long x 4″ wide x 2 mm thick. Yupp, thats 2mm!

The initial challenge is to plane the sides down to thickness by hand, given the fact that thickness sanding machines are almost impossible to find around here! So a long, traumatic bit of planing later, we have the sides ready

Here’s where it starts getting exciting. There are a number of ways to bend the guitar sides. The oldest method is to use a pipe with a heat source inside it (heat softens the wood and makes it flexible, but can also scorch the sides!). As of now, I don’t own the traditional bending iron as it is called, so will need to use the Side Bending Jig I made a few days ago http://bigfootguitars.wordpress.com/2012/07/05/weekend-projects/

 

Heated Side Bending Jig side view

This strange looking contraption, otherwise called a Jig, is a heaven sent design courtesy of a really creative luthier back in the day. Essentially it sandwiches the sides of the guitar in their final shape between two thin aluminium sheets, and 200 watt bulbs under it help dry the wood out in the required shape. This method reduces side-splitting and cracks because the wood is tightly sandwiched.

Anyhow, to the sides are soaked in water for a few hours to make them supple and then fitted into the mold.

 

 

 

 

The bulbs take about 45 minutes on low heat to dry out the sides, and then they are taken out of the Jig and placed in the main body mold. On the inside of the mold, I have placed 2 turnbuckles (also called spreaders). These press the sides outwards and hence once again sandwich them so they retain the form. I leave them like this overnight.

 

 

 

 

 

The sides in the body mold with spreaders in place

 

 

 

 

 

 

 

 

 

And of course, here are the sides after coming out of the mold the next morning!

The Sides

 

 

 

 

 

 

 

 

 

 

Another view

 

This process is (for the novice) usually accompanied by a lot of anxiety, because one split in the sides would mean starting a fresh set of sides from scratch, and that is NOT a very pleasant thought! Glad these turned out alright

 

 

Strat – Repair Work

Part of last weekend’s work was sorting out an old Squier Stratocaster for my young friend Zubin Mitra. He’s a budding guitarist and a great singer, all the ripe old age of 15! The guitar was handed down from his uncle, and hadn’t been used in a while. He took it to a couple of stores and was told that the neck was twisted and would take major repair, so I offered to look at it. It was in need of a thorough cleaning and setup before anything else!

The Strat taken out of its case for inspection

The first step was to check the action on the guitar, using a straight edge. Straight up it was evident that the action was way to high to really play anything after the 5th fret comfortably. To fix this, I tried to tighten the truss rod by a quarter turn, but it was too tight to move. Evidently the neck had bent over the years and was too stiff for any further adjustments. Many people at this stage make the mistake of forcing the truss rod by turn it further, but this can lead to the rod snapping inside the neck, thereby ruining the neck and leading to VERY expensive and tedious repair work.

Here’s a close up view of the action at the 9th and 12th frets

the crazy high action at the 12th fret!

I removed the neck from the guitar and clamped it onto a table, applying pressure behind the 7-9th frets, in order to straighten the neck a bit. This eased the tension on the truss rod and made it easier to tighten safely.

Once this was done, I moved to the bridge and adjusted the height of the same to match the fingerboard radius, ensuring a smooth playing feel. All in all it reduced the action from 6mm at the 12th fret down to 3mm!

The next step was to clean the age old dust of the guitar and wipe down the fingerboard with a rag soaked in zippo fluid.

Lastly, gave the volume and tone knobs a good cleaning and checked the pickup wiring to make sure everything was in place and we’re good to go!!

Here’s to the happy owner with his baby

Back in action!

Weekend Projects

Hi All!

This past weekend was a little off track, in the sense that I spent it making a couple of Jigs and things that I need to help with the guitar building process. The agenda for the week was to get the sides bent to shape. This is rather terrifying for a first attempt, since I’m essentially taking 2 strips of timber, 2 mm thick and 3 feet long, and bending them to match the sides of the acoustic guitar. There is a lot of stuff that can go wrong with this process – the sides can crack and split, or get shaped incorrectly, all of which will seriously impact the look and structural stability of the guitar. But then again, when you have a workshop and extra timber lying around, you gotta experiment at some point!

There are a couple of ways to bend sides -

1. The bending iron – Traditionally, the bending iron has been used to do side bending. It is essentially a hot pipe, approximate 2.5″ in diameter, on which wet wood is placed and bent. The water in the wood turns to steam when it makes contact with the pipe. This helps to soften the wood and makes it flexible. Bending on an iron is a time consuming process, and involves continuous checking to make sure it is done properly. However, there is one slight problem – I don’t own a bending iron – YET! (a friend is kindly carrying one down from the US next week!)

FYI this is what a bending iron looks like

Bending Iron

 

 

 

 

 

 

 

 

 

 

This brings me to option 2 – Making a Heated Side Bending Jig. This involves a little more work than sending credit card info online to aStewMac!!! I got hold of the plans from http://www.ultimate-guitar-building.com (great website by the way, for most things guitar building related) and decided to put them to use. Using sheets of Ply wood, I cut out the various pieces and put them together. This jig works in a pretty interesting way – there is a guitar shaped mold on which the sides are placed, after being soaked in water for a while. The sides are then clamped to the mold so they take the shape of the final guitar sides. Under the mold lie 3 bulbs (200 watts each) which are kept on for around 40 mins to assist in drying the sides. After that time, the sides are removed from the jig, and if everything has worked out as per plan, the sides should be ready! This method is also more fool proof (even though it sounds complicated!) because it reduces the chances of splitting the sides or making incorrect bends, as long as the mold is perfectly made.

 

Heated Side Bending Jig side view

So anyhow, I got to work, and after a little while, this is what I came up with

The springs are used to hold wooden blocks which clamp down on the two ends of the side pieces. You can see the mold placed in the center of the jig, with aluminium sheets on top. The side pieces are placed inside the aluminium sheets – this helps with the heating / drying process. The yellow glow at the bottom is from the bulbs at work! Pretty proud of the end product I must say

 

 

And another view

Heated Side Bending Jig – Front

 

 

All in all, that’s a pretty sweet time saving contraption, and I definitely recommend it for side bending!

Stay tuned to see how the sides turn out

 

Day 6 – Brace Yourselves!!

I’m sitting here with my Guitar top with the rosette inlay done, top sanded down to 3mm, with a slightly off center sound hole cut out and wondering what to do! After a brief period of mourning for the sound hole shape, I decide to move on to completing the rest of the sound board (this WILL come back to haunt me later).

The plan is to prepare the braces for the sound board. It is a rather technical part of guitar construction (isn’t it ALL??) as these braces will impact the tone of the guitar, and simultaneously provide strength to the 3mm thick top. To give you an idea, the guitar strings exert a force of 100lbs on the bridge, where they meet the body. Now imagine a 3mm thick piece of wood dealing with that stress!!! It’s at times like these that I wonder why people didn’t just start with inventing the amp and electric guitar straight up. But then I think about the sound of a pure acoustic, and nothing else seems to matter too much. Worth all the effort

All bracing marked out on the inside of the Soundboard

 

 

 

I begin with drawing out the location of the braces on the inside of the sound board. These are carefully measured, and yes, there is a reason that they look funky. The primary one being that if one can make life hectic for a luthier, then mission accomplished!

So all the markings are made, and the braces are roughly cut to size. Now it’s time to get the hands dirty. Hola Fevicol, my old friend. Let’s get gluing.

 

 

 

 

X-Braces being glued to the Soundboard

 

The picture to the right shows the primary X-Brace being glued on to the sound board. This brace will need to be a perfect fit, as it provides the maximum support to the sound board. It is also positioned strategically so that it doesn’t interfere with the placement of the bridge plate (a thin piece of hardwood that lies under the bridge for support) .

 

Once the braces are glued, they are shaped with a small block plane and sandpaper. I honestly thought this would be the toughest part of building the acoustic, but to my surprise I ended up REALLY enjoying the process, and got into it full power!

The following pictures will give a better idea of what the end product looks like.

 

Planing the X-Braces

 

 

 

The X-Braces have been scalloped using a chisel, round file, and a hand plane. Tough, but rewarding!

 

 

 

 

 

 

Scalloping the braces – This is something that (I think) was made popular by Martin & Co. and has over the years become a kind of standard for bracing. The scalloping allows the mass of the brace to reduce without impacting the strength of the join. Also, it is said that the scallops help the sound of the instrument – this is up to you as a reader / builder to accept and use. I personally think they make the braces look REALLY COOL  and that in itself is worth the trouble.

Another view of the X-Braces

 

 

 

Come on! Tell me that doesn’t look sweet?

 

 

 

 

 

Gluing the Tone Arms

 

Now that the X-Brace is done, I move on to the tone arm braces. These will also be scalloped and sanded later to add to the sexy curves on the braces. I am so tripping on this. It’s quite incredible (and I know I’m repeating myself, but it just is) to see the guitar taking shape, knowing that you’re in charge of every little thing that goes on with a piece.

Also, this journey has made me start respecting my guitars a lot more, now that I know how much effort goes into it

 

 

Here’s a view of the sound board once all the braces have been glued and shaped. All the scallops in full glory.

Scallop Bracing view

 

 

 

The flat, dark strip of timber in the center is the bridge plate I mentioned earlier. This is stuck on in a slightly different manner, because it needs to be an even, tight fit, and is glued onto a slightly arched surface.

 

 

 

 

Home Made Go-Bar Deck

 

 

 

 

It’s a home made version of what is called a Go Bar Gluing Deck. Essentially dowels (wedged between a low ceiling and the soundboard) are used to apply pressure on the plate, helping it to stick evenly. I had a few deep throat clamps handy, so I mixed and matched them with the dowels. Picture below.

 

 

 

 

 

Here’s the top, completed

Top Bracing Complete, little clean up required!

 

 

 

Now, till I figure out how to go about bending the guitar sides without a bending iron, I’ll get started on the neck!

 

Thanks for reading, and as always your comments / suggestions are welcome

Day 4 – Time for some Body Building!

Now let’s get to the exciting bit! Here’s the timber for the back and sides – Indian Rosewood. (pic)

Rosewood for the Back and Sides, and Sapele for the Headstock Veneer

The Guitar Back – glued, planed and sanded down to 2.5mm. Talk about manual labor!

To get started, I need to glue the 2 book-matched (pieces which have been split, so when opened like a book they show a beautiful, symmetrical, matching grain) Indian Rosewood back pieces, which have been hand sanded down to 2.5mm. This is a slightly tricky process, as the wood is really thin, and the glue joint needs to be perfect so it doesn’t split later on. The pieces are held together with little wooden blocks on either side to prevent sideways movement, and a piece of timber is clamped length-wise over the join. This is to prevent any upward movement. After a couple of hours, I remove the clamps and sand off any excess glue on the joint.

The clamps are carefully put in place to ensure the radiused braces don’t move while being glued to the back

The shape of the guitar back is drawn onto the Rosewood piece, using the guitar mold, and then roughly cut out. The right markings are made, and the Back Braces are laid out. Here is where the going gets a bit tricky. This is the mathematical equation:-

The final back has an arch in it + The braces are flat = One confused Sardar luthier.

A lot of sanding takes care of this problem, and then the braces are ready to be glued onto the back. The back and braces are clamped onto the body mold, so to help ensure the arch in the back, and then glued. Yes, I know this  looks like a weird, colorful, metal spider, but somewhere in there is the back and the braces!

Full body view of the bracing.

Once the braces are done, they are hand planed into interesting pointy shapes for various technical reasons, and then sanded to a smooth finish. Here’s what they look at once that bit is done. The white strips are regular masking tape, to protect the back from getting scratched while planing and sanding out the shapes. I’m already getting excited about what the final piece will look like! woohooooo

Notice the angles that are formed on the braces

For now, the back is done!  Over to the next step!