Les Paul DIY kit (Part IV (b): even more Tru-Oil finish)

This is part four (b) of my Les Paul DIY kit build history, and it deals with applying more of the oil finish to the whole guitar.

I'm currently at 9 coats of Tru-Oil finish for the "ebony" front, and 7 coats for the neck and the mahogany colored parts of the guitar (back/edge of the body). Buffing and applying more oil is now very easy, because the surface is more or less smooth all around. Only very little oil is needed now for each surface.

It doesn't get much better than that. Cat approves. For food.

There were a few places where the wood stain was not absorbed properly because of a drop of glue or something that was allowed to drip on the surface during manufacturing. These and a few places where my buffing was a bit too vigorous during the early finishing stages left bright spots in the dark surface that I was able to make almost disappear with the same black felt tip pen that I used to cover defects on the headstock.

Unfortunately, I've found more defects with the guitar body: there's a series of hair-line cracks at the bottom edge that I cannot seem to be able to cover by the oil finish (I think I mentioned these already), and opposite the neck cracks appeared between the wood blocks that the body is made of. If you buy your kit from Gear4Music, and I suggest you don't, you should perhaps apply some wood filler at the edge and bottom parts of the body, sand it smooth and then spray paint the lot. You can still stain and oil the top.

I'll do a few more coats on the body (front and back) and then leave it at that. I'm preparing for wiring the electrical stuff and assembling the guitar. That will be part five of my construction log.

RAM Cartridge for the Yamaha DX7 Synthesizer (Part I: Introduction)

When I was a teenager I spent hours on end in the keyboard section of music instrument shops and played those keyboards and synthesizers that I knew from the back of album covers, where musicians used to list the equipment they used. Of course, the famous flagship synthesizers like the Roland Jupiter-8, the Oberheim OB-8 and the likes were completely out of my price range. Finally, a friend of mine who owned a small monophonic synthesizer himself told me that there's a new synthesizer that's perfect for me: the Yamaha DX7. A few weeks later my mom drove me across the border into Germany where I bought a DX7 for under CHF 3000. Despite being over 30 years old, it still works perfectly, and I still play it frequently.

The Yamaha DX7 was the dominant synthesizer of the 1980s with its idiosyncratic sounds such as the electronic piano, bass, and marimba voices. If you happen to see a music video of that era and watch closely what keyboards the guys with the strange hairdos mime playing on, 9 out of 10 times it will be a DX7.

The DX7 has internal memory for 32 voices, which even for the 80s was relatively little. It has an expansion slot, however, where cartridges can be plugged in to provide direct access to further 32 voices. The DX7 shipped with two ROM cartridges, each containing 2 preset voice banks (2 x 32 voices) selectable by a switch on the cartridge. At the time, Yamaha also sold RAM cartridges onto which single voices or the full contents of the internal memory could be stored, sort of an external RAM extension. Unfortunately, the cartridges are very hard to find these days, and even the used ones sold on eBay are very expensive.

The publicly available circuit diagrams [PDF] of the DX7, e.g. on Dave Benson's DX7 page, reveal that the cartridge design is very simple. It is really only an external memory chip, and the pins on the cartridge slot are just the address, data and signal buses to control the reading and/or writing of data from or to an EEPROM.

The simplicity of the circuit suggests that it should be possible to build oneself such a memory cartridge. EEPROMS with 64kbits (8k x 8), that's room for 2 voice banks, can be found for less than USD 5. The other parts (resistors, switches and an AND gate for the combined chip enable lines) cost perhaps a dollar or two. The PCB is another story, but there are prototype PCB manufacturers like OSH Park that do them for USD 10 apiece or so. Don't even ask about the enclosure.

As you can guess, I'm going to try to design and build such a cartridge. In the following weeks I will be reporting on the progress of this project. Peek preview: The prototype boards have already been sent away for manufacture.

Update [19.08.2014 08:42 CEST]: I just got a notice from OSH Park that the PCBs have been shipped!

So stay tuned!

Les Paul DIY kit (Part IV (a): more Tru-Oil finish)

This is part four (a) of my Les Paul DIY kit build history, and it deals with applying the oil finish to the back/edge of the body and the neck.

After having had quite a success with the black (or "ebony") top of the guitar, I proceeded to apply the oil to all mahogany stained parts of the body and neck. Having seen how the body absorbed the wood stain at all those parts of the edge where the wood is cut across the grain, I expected the oil to be sucked in likewise. The first coat on the back of the guitar went very well. It was absorbed neatly but still with only a few more helpings. Same with the first coat on the neck. But when I started applying the oil at the edge, I thought that I must have used up half the bottle when I finally had rounded the edge. Well, at least the second coat would need less. I was wrong. I could hardly keep up with the wood absorbing the oil, and I applied it generously.

After two coats I started buffing the surface with steel wool where the surface was smooth and (gently) with 400 grit sandpaper where it wasn't. The next coat went far easier, finally leaving a smooth and shiny surface everywhere. I'm now at coat number 4 and I can see the end of the tunnel. I'll do two or so more coats at the mahogany surfaces, and at least another three to four at the ebony top.

Back of the guitar after four coats of Tru-Oil. Cat decidedly unimpressed.

Applying the oil where the wood stain had already darkened the wood far beyond mahogany levels made it even darker. It's now nearly black, and I hate it far less than I should.

Les Paul DIY kit (Part IV: Tru-Oil finish)

This is part four of my Les Paul DIY guitar kit build drama, and in this episode I'm writing about the oil finish. Having seen this video by Fred Yen and followed the debate on gearbuilder.de [German] about what oil to apply and how, I finally decided to go with the Tru-Oil. It seemed easy enough to apply and would result in a nice glossy finish.

I let the stain dry for 48 hours before I dared applying the oil. I cut an old t-shirt to pieces for the rags, and then applied a small amount on it and started rubbin' it in. The oil soaked into the surface like there's no tomorrow, but I knew that and didn't bother. It took a few helpings to cover the front of the guitar. Remarkably little of the stain rubbed off. Once I had covered the front I let it dry for 3 to 4 hours before applying a second coat. I think it's better not to buff the surface between the first two coats as the oil is just too thin and likely wiped off together with some of the stain.

After the second coat had dried I buffed it very gently using industry grade 00 steel wool. The idea is really just to get rid of the shining in order to have a dull surface ready for the next coat.

After 4 coats I already had a pretty hard satin finish. But I wanted more! Much more!

After 6 coats it really started to take off. Buffing becomes very easy and unproblematic. The oil is  hard and thick enough to protect the stain. Also the grain started to show really nicely. This part of the project, i.e. oiling the surface, is really the first part that I consider a complete success. It looks way better than I imagined.

Having protected the top surface well enough I proceeded to oil the remainder of the body and the neck. But I'm not inclined to push my luck and therefore I'm going end this report here. I'll defer that to an other installment of this series. After all the disasters I think I deserve a happy ending for a change.

Les Paul DIY kit (Part III: Staining) - Disaster Edition

This is part three of my Les Paul DIY guitar kit construction log where I'll be reporting on my attempts to turn a lump of repeatedly sanded wood into a nicely stained guitar. It's going to be a story of misery and desperation.

When researching various looks I quickly found that I don't really like sunbursts. Instead, I decided on an ebony top and mahogany bottom, especially after having stumbled across this Supreme Electric Guitar Transluscent[sic] Ebony Electric Guitar Mahogany Body Electric Guitar from China on AliExpress that looks awesome. I stained and spray lacquered a piece of junk wood to get an idea of what I was going to achieve.

If you look closely you might notice that the black surface has a slight brownish tint at the lighter parts. In order to accomplish that I added a few drops of mahogany to a slightly diluted black water-based wood stain, both made by Clou. I shouldn't have. When I started to stain the surface it rather soon became clear that I made a bad mistake. The blended stain seemed to be of a dark violet color. But having started I couldn't just stop but instead had to finish staining the whole body. Sometimes colors change after having dried. Well, it did. The result of my staining efforts was a grayish violet -- very much like blackberry yoghurt left unrefrigerated for two weeks.

There was only one solution, and it rhymed with "sanding". Actually, it was sanding, and lots of it. I sanded the surface thoroughly hoping not to destroy the veneer. Finally, the surface was light enough that I needn't expect it to show through when I stained it black.

Second attempt. This time I used unmolested (neither diluted nor color blended) black stain, and the result was quite pleasing, particularly with the grain nicely showing. I seriously considered ruining it with a botched sunburst finish after all!

Before proceeding to staining the back of the body I wiped down the surface with a wet sponge in order to lighten it up a bit and also to make the grain stand out a bit more. When I was pleased with the result I tore off the masking tape ... and this was the result: the masking tape ripped off pieces of the edge of the body.

I don't think I have seen anything like this in any of the dozen or so YouTube videos that I've watched before embarking on this project. That is one #@§&% dodgy kit! At this point I considered the project a failure, and I was close to dumping the kit. After some deliberating, though, I decided to simply stop bothering and just finish the kit already.

Alright then. I sanded the edge down to mitigate the damage, and then stained the edge of the guitar, the back and the neck using a water based dark mahogany stain. While the back of the guitar and the neck took the stain quite well, the edge absorbed the color like a sponge, resulting in a very dark edge. This was neither expected nor totally unwelcome. I stained the top of the headstock using the same black stain that I used on the surface of the guitar. The two spots where there were glue drops and hence the stain was not absorbed, I later colored using a black felt tip pen. Not bothering anymore simplifies construction a lot.

After letting the stain dry for a day or two I also wiped the mahogany color down using a wet sponge, lightening up the back and the neck, but not having any effect on the edge. Not bothering anymore really simplifies construction a lot.

Next installment will be on the finishing using Tru-Oil gun stock finish. I ordered a 240ml bottle on eBay, and it has already arrived!

Les Paul DIY kit (Part II: Sanding)

This is part two of my Les Paul DIY guitar kit build diary. I made a video where I explain some of the issued found with the kit. Also, there's a cat!

The guitar body is cut and pre-sanded, but to prepare the guitar for staining, I wanted to sand it some more. I started very gently using a 180 grit sandpaper. The veneer at the surface is very thin and easily sanded away. I then proceeded using 240 and finally 320 grit paper.

After wiping body and neck down using a sponge and warm water to raise the wood fibers and then let it dry thoroughly, I sanded everything lightly using 320 and finally 400 grit sand paper. I repeated this cycle two more times and ended up with a smooth top and bottom surface. I didn't manage to smooth the curved sides of the guitar beyond a certain point, especially where the wood was cut across the grain. Also, small fissures appeared at the bottom edge of the guitar, perhaps because of the watering -- or the cheap build.

When trying to pre-assemble the guitar, I found that the neck didn't fit into the neck pocket. I had to sand the sides of the neck's bolt-on block quite considerably until I got a snug fit. The same happened when I test-fitted the pickups. I couldn't set the pickups until I had filed and sanded down the corners of the cavities.

There were also a few places where during manufacturing some wood glue was allowed to seep or drip onto the surface of the guitar, especially at the sides and the headstock. It soaked into the wood and could not be removed by sanding. I can already tell that the guitar is quite shoddily manufactured. If you want to build your own, perhaps you want to find a higher quality one, even if it's a bit more expensive.

Anyway, the guitar is now as ready for staining as it's ever going to be.

Les Paul DIY kit (Part I: Unboxing)

The other day I stumbled across a video log by a guy named Fred Yen wherein he records his building a Les Paul-type guitar from a kit. I don't play guitar, and to be honest, I don't even know where to blow into this damn thing to make a sound. But after having seen him building it, the idea to build one myself seemed just too irresistible. Unfortunately, the kits that appear of a certain quality like this one by Albatross Guitars sold via Amazon are unavailable for people outside the US, because Amazon doesn't ship outside the US. I ended up buying a cheapo New Jersey kit from Gear4Music that has the following features:

• Bolt-On Neck
• Basswood Body
• Maple Neck
• Rosewood Fingerboard
• Die-cast Chrome Machine Heads
• 628mm Scale, 22 Frets
• 2 Volume, 2 Tone, 3-way Selector
• Covered Humbucker Pickups
• Tune-o-matic Bridge
• Chrome Hardware

As it seems customary now that we have YouTube, I made and intend to continue to make some videos logging my build progress. Or lack thereof. Here's the unboxing video. With cat!

The background music, by the way, is a little quick-and-dirty tune made on a Yamaha MOX6 synthesizer using a preset performance, an electric piano and an acoustic guitar voice.