pfretzscher plywood bass

[Mat Roop]

I have not worked on very many basses... but a 1/2 size, apparently with a buzz, showed up in my shop yesterday... 3 questions... because if the problem buzz is with the bass bar it will not be worth it to open up the instrument.

 

1- This bass is a student Pfretzschner plywood bass and the client got it as a donation  from a school who said they thought that the bass bar was loose causing a buzz. I have inspected the bar thoroughly with good light and mirrors while tuned to tension. There is only one short area where the glue seems to have a small crack, but it does not seem to move under pressure and it is near the center of the bar on the bass side. The ends seem firmly fixed. It seems unusual that the bar would be loose in the middle and not the ends.... is it likely or even possible that the buzz can come from here. There are lots of loose slivers and pieces of ply around the edges that to my mind are the source of the buzz. 

 

2-Do all tailpieces follow the standard sizing?... ie this unit has a Thomastik 4 adjuster style tailpiece that looks monstrous... but it is only 287 mm long compared the the standard 1/2 size tailpiece length of 310mm. The standard length of a 1/4 tailpiece is 290mm.  I could not find sizing info on the underside of the tailpiece. so I am wondering what size of tail piece is this?

 

3- The tuning gears are in serious need of lubricant... what is appropriate to use?

 

 Thanks for all your help!.... Mat

 

[Christopher Jacoby]

I use graphite and beeswax on machine tuners. I think, with basses, that improvisation is in order. I haven't gone this far into the dark side (yet), but a friend of mine had a similar repair he had to make on another nigh-throwaway bass, and he drilled through the top on either side of the bassbar, got glue under the bar, and looped wire down and under the bar and pulled it up. Twisted it tight to clamp, then dowelled the holes.

Not endorsing; just saying...

[captainhook]

I've used paraffin wax on tuner gears, and Chris' suggestion sounds even better, but if they are too worn it may not help much.

[Mat Roop]

I use graphite and beeswax on machine tuners. I think, with basses, that improvisation is in order. I haven't gone this far into the dark side (yet), but a friend of mine had a similar repair he had to make on another nigh-throwaway bass, and he drilled through the top on either side of the bassbar, got glue under the bar, and looped wire down and under the bar and pulled it up. Twisted it tight to clamp, then dowelled the holes.

Not endorsing; just saying...

Why graphite?? ... would that not make things messy and black ? What about straight beeswax.. I've got lots of that.

 

BTW... I found a split in the back centerbout seam... likely the source of the buzz...

 Thanks for all your help!... Mat

[Greg Olwell]

I'm a bass player, not a professional luthier, so I'm only able to speak from my own experiences with instruments. But in my time, I've owned a few plywood basses and in my experience with them, the buzz is more likely to come from the wood de-laminating than something like a loose bass bar. It happens all of the time to older plywood basses, whether they're Kays or European-made. Now, I'm not saying that it's not a loose bass bar, those things happen too, but it's probably not in the top three causes of buzz. If the strings aren't old and damaged and they fit reasonably well on the bridge and nut, it's probably time to play it and listen to where the source of the buzz is coming from. With a bass this can be a two-person job.

 

Now about geared tuners. These things are machines and typically the best thing for them is some decent lubricant for metal. On my bass, I keep a towel handy to wipe up any possible excess, but a small, controlled drop of Tri-Flow on the worm gear and between the large gear and the brass plate makes tuning much easier. One small drop on either location is enough, but again, keep a towel handy just in case.

 

[This may go without saying, but: Don't use WD-40, unless you're cleaning the gearing. It's not lube, it's for breaking lightly frozen joints and clearing out water so that real lubricant can be added after the preparation.]