Bass build/bass mod - Lockdown Edition!

[KaiHern]

Hi all!

Hope all is safe and sound in this season of life. I have recently graduated, with nothing to do. The lockdown has made nothing to do so unbearable! So I have decided to modify the only bass I had, a recent Steingeberger Spirit. Have never done any woodworking whatsoever, but I hope lurking in Luthier's corner had imparted nuggets of wisdom in my project. It could very well be the greatest regret of my life; who knows.

Starting this thread to document my progress and learnings, feel free to stick around to critique or advise ) It is gonna be a rolling project, plans will be made on the fly, according to whatever mistakes i make along the way.

Progress:
This is the first day, where I stripped the thick poly shell with a scraper, heatgun and some PPE. Studied chemical engineering, and have got this habit of wearing PPE. All woodworking tools I purchased online, thank goodness for e-commerce and delivery services!

My mistakes and learnings:
(1) the heat gun has 2 temperature settings, 500C and 700C. Never ever use 700C, it will lead to the charring of wood. It was only later on when I checked that the surface temperature required for wood to char is at 150C (some research paper somewhere).

(2) be gentle with the scraper. There are multiples times when I gorged the wood, and removed some material, hopefully later on in the project i get to fill it with some epoxy or CA and fix it up with some sanding.
(3) poly is some toxic stuff, there was plenty of fumes generated from the heat, and dust from the mechanical scraping. Purchased a 3M respirator 6200 and organic vapour cartridge 6001 for protection. Figured since it was mandatory to wear these at chemical plants during my internship, I should wear this here too. Not sure why it was so difficult on this bass. Unlike other projects I see around here where the surfaces peel off, I had to ram the scrapper hard just to remove small bits of the poly shell.

Gonna continue to remove the sides tomorrow. I know I am new to this. Please guide me!

 

[GMC]

What kind of finish are you going for? If it's painted, I would have just sanded back the existing a finish a tad and sprayed over the existing paint.

 

[KaiHern]

I plan to chamber the body, so I had to remove the finish blocking the way. You do have a point. I'd just sand the neck and cover everything with acrylic laquer once I'm done.

 

[Jon Clegg]

When I used a heat gun to strip Poly from a bass, I found that keeping my other hand near the area I was blasting with the gun was an effective means of controlling the temp -- about the time I REALLY needed to move my hand, the poly was starting to peel without charring the wood. YMMV.

 

[KaiHern]

Progress updates:
Started on the sides. This was a set neck, so I was rather worried with the glue joints that may fail under heat. Yesterday the joint was quite hot form the heat from the heat gun. Today I tried 'shielding' the neck and fretboard using paper, works very well, the neck was cool to the touch. Should have insulated the neck earlier this way...

Spent some time sanding the neck joint nicely, since I am not stripping the paint on the neck.

Learnings:
(4) I learnt to always protect the neck joints from heat, a simple piece of paper was able to deflect the hot air from heat transfer.


Now, for the electronics I was thinking of getting a alumitone humbucker with and audere preamp. Not sure about the compatability between these 2

 

[Matt Liebenau]

I thought those were neck through. I know the older Corts and Hohners were. Could you post a picture of the back once the paint is off?

 

[KaiHern]

Here's the front of the neck heel, there's a horizontal line cutting thru, exactly like how Gibson makes them. In fact this was made by Gibson hahaha

 

[Matt Liebenau]

Could be. I do t know how they’re being built now. That’s why I had asked about a pic of the back. The one from the front sort of looks like it could be neck through. I’m mostly curious. Like I said, I know the old ones were definitely neck through. This is an old Cort that’s been “modified.” Either way, keep us posted. I’m interested to see what you come up with.

 

[KaiHern]

Some updates to my progress. The plan was to thin the body down, and then chamber it. After chambering, I'll cover everything up with a 3/16" piece of basswood to seal everything up.
First I sanded the neck, using @GMC's recommendation, and also to avoid splitting the wood joints in the neck.

I used a drill guide attachment and a frostner bit to remove a depth of 1.5cm, and then chiseled the remaining. All in all, stripping of paint took me 6 hours, while the drilling and chiseling took me another 6 hours. I guess because this was my first time with power tools, I had to be slow and steady and safe.

Will continue the leveling using a hand plane tmr.
Have also decided on getting a lace deathbucker and an audere 4 band combo for the internals.

 

[KaiHern]

Could be. I do t know how they’re being built now. That’s why I had asked about a pic of the back. The one from the front sort of looks like it could be neck through. I’m mostly curious. Like I said, I know the old ones were definitely neck through. This is an old Cort that’s been “modified.” Either way, keep us posted. I’m interested to see what you come up with.

View attachment 3831749

Wow that's a beauty!, could you also share the front of the bass? would love to see it!
and also after the drilling and chiseling, I can confirm that it is a set-neck. A close up picture just for you )

 

[KaiHern]

So the past few days i have
1) sanded the back flat, which took plenty of hours to ensure everything is level. If I had the right tools it could be much faster

2) drilled some threads into the neck joint, in between the interface of the maple neck and basswood body. I then filled it up with epoxy. The idea is to strengthen the joint as the epoxy soaks into the wood. Not sure how effective this is though. But im sure does not weaken the joint. Will have to wait till everything's done before installing the strings.

3) Chiseled and drilled an alternative hole for the jack, and filled the previous with epoxy.

4) Routed a small battery cavity for a future preamp if i ever want an upgrade. Would like to know a method to make the route nicer? How can I remove the dimples formed by the bits, without using epoxy again haha.

5) Ive got a thin layer of basswood that I cut to cover the cosmetic damage of the woodworking (I had initially planned to do so). Since I do not have a router to make the lip for the cavity, I made the cavity hole of the veneer to be larger to form the lip to hold the cavity cover in place. It is currently curing, will have updates tmr!

If all goes well, tmr I will string it up and install alumitone deathbuckers that came in the mail today! Guitar finish can wait till next week

 

[KaiHern]

Hi all, was wondering how I may do a belly cut on the body. Knives first, followed by sandpaper?
Weighing between keeping the rectangular paddle board shape vs comfort of the bass.

 

[Beej]

I do a belly cut with a farrier's rasp for the rough shape, surforms to bring it to a smoother edge, followed by files to cut to flush and a scraper to make it smooth. Final sanding can prep it for finish. I use the hard edge tools for shaping though as you're much less likely to get a wavy surface which can happen with shaping through sandpaper.

 

[KaiHern]

Stringed it up and added some new upgrades!
Before any modifications, the guitar weighed 3.28kg (7.23 lb)
Now it weighs 2.35kg (5.18 lb), a reduction of 28%
Overall body thickness reduced from 4.1cm to 2.8cm (1.1")
The alumitone deathbucker weighed 60g compared to the stock soapbar of 141g

3D printed a synapse hook, and did a small little cavity to have the hook flush to the body.

Wired the alumitone deathbucker as passive, and wow it really sounds better than the stock pups. Could hear more finger dynamics.

Here's the front and back of the guitar right now. At the back you can see the lip around the cavity to hold the cover in place. I felt it went quite well!

Thanks for following through with me

 

[A9X]

Now, for the electronics I was thinking of getting a alumitone humbucker

Please do so as it's the one that most interests me for my Hohner B2V.

Really butchering it would be adding a headstock.

 

[SlickaBass]

Thanks for sharing pictures and pickup ideas.

If it were me I would have considered moving the bridge 6mm (1/4") towards the nut. Glad to see there is scope. Why? Well then even the original Steinberger strings should fit. The new Gibson ones are longer and to me sound bad. I managed to get some Ken Smith's to fit on my non modified one and that was an instant tone upgrade.

As for PUPs are the Lace ones still 3.5" or did you route new sizes?

Glad to see your experimental results.

 

[A9X]

^^ Huh? Never had any trouble getting KS or Status strings to fit my Woodbergers.

 

[KaiHern]

Thanks for sharing pictures and pickup ideas.

If it were me I would have considered moving the bridge 6mm (1/4") towards the nut. Glad to see there is scope. Why? Well then even the original Steinberger strings should fit. The new Gibson ones are longer and to me sound bad. I managed to get some Ken Smith's to fit on my non modified one and that was an instant tone upgrade.

As for PUPs are the Lace ones still 3.5" or did you route new sizes?

Glad to see your experimental results.

Thanks for the advice! Right now I have my bass stringed with flatwound chromes, and the saddles are almost maxed out after intonation. It could be that the flatwounds are stiffer, and would require a little longer scale length. The bridge pickup I installed is a lace deathbucker in guitar humbucker shape. The original routes were guitar hunbuckers, so I stuck with that.

Ooo, would like to know more about the Ken smith's. I have got the adapter that can take single end strings

 

[KaiHern]

Please do so as it's the one that most interests me for my Hohner B2V.

Really butchering it would be adding a headstock.

Yup! It's installed. Compared to the original stock emg selects, I could hear more finger dynamics. My amp doesn't have a tweeter, so can't say for sure about the nicer highs that other people hear from their alumitones.
I plan to get an audere 4band with this, they sell a version that is modified to pair with alumitones.

 

[Peteyboy]

Dude, you're like a mad scientist! I absolutely can not take my eyes off any part of this process!