Friday 29 April 2011

New Dot Markers

George is a 'Man Of ROCK' - as a result he has problems seeing his position markers at dark gigs.
 His bass is black and the markers small, not a good combination.





So when he brought his bass in with a broken headstock (I told you he's rock'n' roll) I took the opportunity to replace the side dot markers with slightly larger ones.
 I've decided on 3.2mm white plastic markers.
 I custom make dot's using the drill press.
 The first stage is to grind the butt end of a 3.2mm drill bit flat.


I clamp a block of mild steel to the drill press base and drill a hole in it using the drill bit.






Then without moving the steel block I take the drill bit out and turn it around so the butt end is facing down.





 The drill is an exact fit in the hole and lines up perfectly. You can see I've used this block before.
 I've made a press to punch out dots.





I use an old piece of pickguard material. While I'm about it I punch out 50 or so - won't need to do this job again for a while.





I enlarge the existing holes in the guitar and glue the dots in with superglue gel.





When the glue's dry I shave it flush with a sharp chisel and the job's done.

With any luck he'll be able to see what he's doing now.

George also runs The Killingroom rehersal space here in Auckland - www.thekillingroom.com - my band uses it, why don't you?


Cheers
    Glyn



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Wednesday 2 March 2011

Guitar cutting out

A number of things can cause your guitar to cut out but the number one most likely is the jack socket.
 If a guitar hasn't been plugged in for a while or been left in a damp environment it can often develop electrical problems. Electrical component can oxidize and cause contacts to become intermittent or fail completely. The most common problem is with jack sockets.


The inside, ring part of the jack becomes 'dirty' with oxidization and no longer makes correct contact.The result is loud humming, crackling or cutting out.
 The answer is very easy:
 Take a rolled up piece of wet-n-dry paper (about 600 grade) and clean the jack with it.


You can see dirt that came out of this Les Paul's jack.
 The process can be made a little easier by spraying contact cleaner into the jack as well to help dissolve the dirt.


Contact cleaner dissolves the 'poo' and then evaporates away so as not to attract dirt.
 The job is quick and easy. I always keep some 600 grade in my gig bag just in case - it could save a lot of embarrassment on stage.
 All guitars are susceptible to this problem - it doesn't matter if you play a vintage Strat, a new Les Paul or a real cheapie, eventually the jack will need a clean.
 If symptoms persist get it checked out - the jack may need replacing or there could be another fault.

Cheers
    Glyn


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Saturday 12 February 2011

Battery compartment for EMG's




This is most definitely a ROCK guitar- it's a Dean Dime-o-Flage.
 The owner has decided to swap the stock pickups for EMG's and has gone for the classic 81,85 combination. 


He's going for the 18 volt option which gives the pickups a little more headroom He's fitted the pickups himself and intends to wire in the EMG pots etc. but has a slight problem:


There's no space for one battery let alone two. So he's brought the guitar to me to route a cavity and to fit a battery compartment.
 We're limited as to where it can go. The guitar has a narrow waist and the pickup cavities have been routed from the other side - I don't want to route through to one of those. I need to be able to drill a hole from the new cavity to an existing one to run the wires. We decided to put it just above the string anchor points.


Routing is not a job for the faint hearted  - if you've never used one and fancy giving it a go - get some tuition. I used to tell my students "no one ever had a minor accident with a router", not strictly true but it focused their minds.
 I'm using my 1/2" shank Makita router for this job.


 I'm using a 1/4" cutter and a 10mm guide bush to follow the template. My template is cut 2mm oversized to allow for the difference in size between the cutter and the guide bush.


 The template is made from 6mm clear plexiglass, it's hard wearing and being able to see through it helps with positioning it accurately.


I first route a test run on a piece of scrap to make sure it will be the right size for the new battery box. You can see I've used this piece of scrap before.


Routing is noisy and dusty and there can be flying chips - I never take any chances.


 I put masking tape over the area and mark the exact location on it. I align the template and clamp it in place.


 I check it after the first pass - all looks good. Then it's a case of gradually increasing the depth down to 33mm in this case. This guitar body is made of basswood so it's easy going for the router. I'm quite a fan of the loose, open sound of softer hardwoods like basswood and alder and of course they are kinder on the tools.




It's a big hole.


Here's the finished battery compartment. I've drilled a hole through to the control cavity and fed the wires through. The rest is up to him.


Glyn


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Monday 24 January 2011

Gibson Songwriter - neck break

I got back to the workshop after my xmas break, the phone rang and this became my first job of the year.





 Ugly isn't it!
 The head has been broken in a fairly typical way - I see this a lot and it is a routine job.
But this one has been 'repaired' badly and the glue has failed. Then they tried bolting it together and the result is obvious from the photo.



 The bolts were tight enough to crush the face of the headstock - Its all a bit of a mess.

 The unsuccessful repair makes it more complicated. I can't glue it back together - sticking failed glue to failed glue just isn't going to work.
 I decided to cut out the damaged area and replace it with good wood.
 I called the owner with my solution to his problem and he was a little reluctant at first (quite understandable). But in the end he gave me the 'go ahead'.


 I made two saw cuts to define the section to be replaced and started removing mahogany with a sharp chisel. You can see one of the cuts on the left of the picture. I use a Japanese Saw - they're very accurate.
 I'm going to leave the veneer on the front face of the headstock to give extra support and glue surface area. This makes it a lot harder but I think its worth it.



You can see the truss rod exposed in the middle of this picture. Sometimes things have to look worse before they can look better. This is not a job for the faint hearted - it is a Gibson after all.



I carve a block of mahogany to fit the area I have cut out. I glue and clamp it in place.

 


The new piece does look a little incongruous - there's a touch of Frankenstein's monster to it.


Here I've started to carve it. It's a sharp chisel job - it has been pointed out to me how much I go on about sharp chisels in this blog but I just can't help it.
Now its just a case of shaping it so it looks like a guitar neck again.




 So here's the finished article. The owner didn't want any spray job (the cost can be quite high) so I just gave it a couple of coats of clear lacquer to seal it.
 I'm pleased with it - saved a nice Gibson neck from the scrap heap.

   Glyn



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I am no longer repairing guitars - since covid 19 I now work full time making pickups

Friday 3 December 2010

Too hot to handle

 Its officially summer here in New Zealand and the weather is warming up. The acoustic season has begun - there's nothing better than sitting out on the deck strumming a few chords, dog by your side and a cold beer on the go.
 There is a downside to it all - in the last week I've had two guitars in the workshop with the bridges clean off. They had been left in cars. 
 You wouldn't leave your dog or your kids in the car for hours on a sunny day and your guitar will be just as unhappy.
 Guitars are put together with 'heat reversible' glue (usually an alaphatic resin). This makes it possible for me to do my job. If I need to take your guitar apart I can by carefully applying heat. If you leave in the car too long a guitar will dismantle itself.


  This guitar is a nice, Spanish made classical guitar. It spent the afternoon in its case in a car with the outside temperature about 25C. Of course it was a lot hotter in the car.


 Whan the case was opened the bridge was off.


 As you can see, the glue has failed - there's still glue on both surfaces.
 The first thing I did after taking the strings off was check the internal braces. It is very common with repairs like this for there to be more damage on the inside than the outside.
 Everything was fine inside to I imagine the bridge came off before the string tension pulled the top too out of shape.


 I remove most of the old glue with a sharp chisel.
 Incidentally, I measue the sharpness of my chisels by testing them on the hairs of my left arm.


 That's a nice bald patch with no rash - a sharp chisel.
 Now you know how to spot a luthier.


 I use the belt sander to clean up the underside of the bridge.



 This bridge has a slight warp that I take out with the sander.



 I score the underside of the bridge to help give the glue a key.


  I mask off the bridge area on the body. This helps with both alignment and glue clean up.


 I use five long reach clamps to attach he bridge. The glue is Titebond Alaphatic resin.
It is very important to use a reversible glue. If this bridge had been held on with epoxy in all likelyhood it would not have failed. If it hadn't failed the top would be warped, there would be untold damage to the braces and the result would be a much more involved repair.

  As it is the guitar is ready to play again with no visible evidence.

 

Sammy doesn't like being left in the car either  - he'd rather be showing off his catching skills on the beach.


  Glyn



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Tuesday 16 November 2010

Hofner Pickup re-wind

I had a visit from Paul Crowther the other day (always a pleasure to see him). He's rather a legend for amongst other things his 'Hotcake' overdrive pedals and the 'Prunes and Custard' (my favorite for theremin).

http://en.wikipedia.org/wiki/Emlyn_Crowther

 He wanted to know if my coil winding machine was up and running -  he had an interesting pickup for me to wind.


 Its an old Hofner pickup which I guess is from the 50's. The guitar has 3 of them and this one has a break in the windings so needs to be re-wound.
This would normally be a straight forward job except for the design of this pickup.


 This is the inside of it. The windings (around the outside) are not wrapped around a bobbin. They are just sitting in the pickup and have been wrapped in tape to protect them. In the middle you can see the magnets sitting in a hard putty. There are incidentally only 5 magnets.
 So the problem Paul left me with was how to wrap about 5000 turns of extremely thin wire into a coil and therefore make a pickup.
 After a long brainstorming session with Sheena we came up with a plan.

 We figured that the wire had to be wound around a bobbin and then somehow the bobbin removed.



 So I made this bobbin. The sides are plastic from a Strat pickguard (white) and the centre has been carved from candle wax.



The bobbin bolts together and is attached to another plastic plate which in turn fits to the winding machine.
 The idea is to wind the pickup on this and then warm the completed coil up and melt the wax. The wax should seep into the coil thus potting it as well. Then the sides can be unbolted and voila a copy of the original coil.


 Winding the coil wasn't any different from any other pickup - so now for the tricky bit.


 I warm the coil ever so gently with a heat gun. I put my free hand next to the work to judge the temperature - if it gets too hot the plastic will melt and I'll be starting again.



 When I see some wax oozing out I ever so gently remove the top plate.



 With the wax exposed I can apply more heat and watch it flow into the coil and as it cools becomes solid.



Then I wrap tape around it to hold everything in place. I cannot emphasize enough how fiddly this is. There are a few stray wires and if any of them break I'm starting again.


It may not be much to look at but its taken hours. The slight curve is to match the shape of the pickup casing. I've tested it and I'm pleased with it at 5.5Kohms.
 In the background you can see the magnetic lugs - I had to dig them out of the putty.


 I put the whole thing back together using 'friendly plastic' instead of putty then fill the casing with wax, solder the back on and its finished.

 Its been quite a task but I'm happy with the result.

   Glyn



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