3D Plasticaster Build

OK, so this might be number 4 on the simultaneous build list, but with a difference - one that most of the wood working purists may be disgusted by ..

It's 3D printed.
For the record, it's not my design, it's using a design at https://www.thingiverse.com/thing:1068688
What the final product could look like:
Attachment 41390
Why?
I like 3D printing though I'm not a 3D nut nor am I good at it. I just like producing functional things. Also.. because I can?
I'm using this design because I'm not entirely convinced about the result and making my own design is a lot of work. I don't mind work if I know I can achieve a result.

But it's a Les Paul?
The shape of the body is yes, but be damned if I'm going to put that name on something with single coils.

Mods?
I'm going to fill the cutout for the trem and use a hardtail instead. I tend to think that PLA isn't that strong of a material to cope with the neck tension + additional tension from a tremelo.

Budget?
$50 - basically two rolls of PLA + the cheapest half decent neck I can find. Maybe $80 - I might hit up Pit Bull and see if they have any less than perfect seconds/returns floating around when I'm about ready. . Everything else is coming from what I have laying around. I don't expect this to be anything more than a conversational piece that works rather than something I'm going to want to actively play. I can't imagine that it's going to have any particularly fantastic tonal or sustain qualities.

Challenges?
Heaps. Firstly the design has a number of pieces that quite simply don't fit on my print bed, so I've had to carve them up. Getting them to match up might be.. interesting.. It also adds more points of failure. I've already had to learn some new things to get the parts cut down to printable size.
The pattern adds a pretty complex surface area to sand and paint. I've also dumped a logo on the body that has fine enough detail to make life quite simply miserable trying to tidy up.

I mentioned that I don't think that the PLA material is necessarily strong enough to handle this much tension. My backup plan should the centre look to be too weak will be to replace that section with some timber - whatever I can find that's reasonably strong and replicate the plastic design straight on wood. I'd prefer to avoid this, but it's a backup plan.

Current status:
Lower tail printed successfully (about 30 hours print time) and semi sanded. Back plate currently printing as the roll is low and each of the major pieces requires about half a kg (1kg rolls) of filament. Once the back is done I'll swap rolls and get on the upper tail. I don't like having the printer sitting there doing nothing, so I'm likely to push on with getting all the parts printed fairly quickly. Getting them sanded and assembled is a long way down on my priority list. That's something I'll potter away at as time permits.

Interesting.

I'm not sure the finished body is anything like a Les Paul, it's more a Strat with cut-back horns to me.

The centre section between the neck pocket and the bridge is the section that needs to be strongest, and if your PLA is quite brittle, then I'd make that section far more solid. At least they've gone for a fixed bridge.

With so little body mass, it may be quite neck-heavy.

Sound-wise, it could be fine. Plenty of decent sounding plastic guitars in the past. But only time will tell. You've certainly made things harder for yourself by not being able to print it all in one go, but I suppose it does allow you to incorporate some strengthening elements within the body as it's sectionalised.

I wish you well and will watch with interest.

Quote:

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Originally Posted by Simon Barden

Interesting.

I'm not sure the finished body is anything like a Les Paul, it's more a Strat with cut-back horns to me.

The centre section between the neck pocket and the bridge is the section that needs to be strongest, and if your PLA is quite brittle, then I'd make that section far more solid. At least they've gone for a fixed bridge.

With so little body mass, it may be quite neck-heavy.

Sound-wise, it could be fine. Plenty of decent sounding plastic guitars in the past. But only time will tell. You've certainly made things harder for yourself by not being able to print it all in one go, but I suppose it does allow you to incorporate some strengthening elements within the body as it's sectionalised.

I wish you well and will watch with interest.

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Thank you.
The mid section is actually cut for a tremelo though I'm not sure the designer ever installed it. I'd rather just infill it.
Most people that have built it have suggested it's using around 2 rolls of filament, which is 2kg + electronics. Hopefully that's enough to counter the neck if I go with something that's fairly trim.

The original design is actually still 6 sections that need to be glued + a back plate. There is a complete version, but if I could afford a printer big enough for that, I'd have a wall full of Gibsons ;) I've just increased it to 8 sections. The upside is at least that the small sections are easier to manage with sanding.
I did make the mistake earlier of sanding with 400 grit without a dust mask on. I don't think I'll make that mistake again. Assuming I ever stop sneezing :D

Pretty sure the guy that built this wound up at NAMM with it a few years ago, so I hold out some hope that this can be achieved!

“so this might be number 4 on the simultaneous build list”

Only 4? 🤣😉

Have you considered having a bash at your own guitar neck? A bolt on strat style is not that difficult. Scarf joints are a wee bit more challenging but can be done with as little as a sharp saw, clamps, a few clamping cauls and a router.

This should be an interesting build to follow, please keep us updated on progress as it happens ever so slowly...

I have heard PLA can be strengthened through "annealing" in the oven, but I also hear tolerances get thrown about when you to this.

If in the end it doesn't work out as hoped, you can always use it as an excuse to try your hand at lost PLA casting and turn it into an aluminium body... But that might throw the budget out the door.

Your backup plan for core strength should at least make a playable guitar, strengthening the strap points the the centre might even be possible with a long custom made steel rod or two.


Looking forward to see how it progresses in any case

Quote:

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Originally Posted by FrankenWashie

Have you considered having a bash at your own guitar neck? A bolt on strat style is not that difficult. Scarf joints are a wee bit more challenging but can be done with as little as a sharp saw, clamps, a few clamping cauls and a router.

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For a Strat or Tele style neck, with a big enough bit of wood, you don’t even need to make a scarf joint. A bit wasteful, but easier. It’s far less wasteful if you get a wide plank and make several neck blanks at a time, arranged top to tail. Which mean you need several bodies at a time, and you end up like FrankenWashie.

Quote:

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Originally Posted by andybanks

This should be an interesting build to follow, please keep us updated on progress as it happens ever so slowly...

I have heard PLA can be strengthened through "annealing" in the oven, but I also hear tolerances get thrown about when you to this.

If in the end it doesn't work out as hoped, you can always use it as an excuse to try your hand at lost PLA casting and turn it into an aluminium body... But that might throw the budget out the door.

Your backup plan for core strength should at least make a playable guitar, strengthening the strap points the the centre might even be possible with a long custom made steel rod or two.


Looking forward to see how it progresses in any case

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Will do. It's a long slow process and I disconnected the light in the print enclosure to run the buffer over the Samick earlier, so it's dark in there now.

Never heard about the annealing process. Worst case I could always use PLA+ which I've heard is better.

I'm hoping the strap points are adequate given the fairly low weight of the build, but that's a good idea if it looks to be problematic. The outer stuff is surprisingly solid even with a 60% infill. I suspect it's thick enough and solid enough that it should be OK as long as it doesn't get too hot. The pattern on the outer body is printing at 8.5mm thick, so it's pretty decent. My DAW PC is under my desk with a set of 3mm thick brackets. A little flimsy, but still holding, so PLA isn't completely useless :P

Quote:

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Originally Posted by Simon Barden

For a Strat or Tele style neck, with a big enough bit of wood, you don’t even need to make a scarf joint. A bit wasteful, but easier. It’s far less wasteful if you get a wide plank and make several neck blanks at a time, arranged top to tail. Which mean you need several bodies at a time, and you end up like FrankenWashie.

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Not sure I even have enough tools to have a crack at my own necks. Interesting idea though. I did see a video of a guy with a fretless electric recently and it sounded awesome. My own necks would be one way of doing something like that. This could be dangerous. I need to stop thinking about this now. :cool:

Quote:

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Originally Posted by lunaticds

My own necks would be one way of doing something like that. This could be dangerous. I need to stop thinking about this now. :cool:

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That’s right, stop thinking, start doing. Let loose your inner Ig0r!

Quote:

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Originally Posted by Simon Barden

For a Strat or Tele style neck, with a big enough bit of wood, you don’t even need to make a scarf joint. A bit wasteful, but easier. It’s far less wasteful if you get a wide plank and make several neck blanks at a time, arranged top to tail. Which mean you need several bodies at a time, and you end up like FrankenWashie.

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I did phrase those separate concepts rather poorly didn’t I? Thanks Simon.👍🏾

Quote:

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Originally Posted by FrankenWashie

That’s right, stop thinking, start doing. Let loose your inner Ig0r!

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Ha! My bank account has been adequately drained this fortnight lol. I've spent way more than I've made ;)
That said, I've amassed a router and a jigsaw in the past week so I'm starting to get the wood working tool collection up. Dunno about scarf joints yet though. Been a long time since woodwork in high school. I might have a crack at assembling some set neck kits before I take that leap.

I'm starting to get the impression that I'm not the only person here who'll stray far from the beaten path just for the sake of carving ones own path.

Progress shots.
This is the bottom tail end.
Attachment 41401Attachment 41402
The whole dinosaur/Jurassic Park thing is **long** story, Yes it will factor into my builds..

I've attacked various ridges and other sharp bits with a file. I've done some cleanup around the logo though it needs more work. I hit it briefly with 400 grit early this morning, but I really need to hit it with something a bit coarser to clean up the layer lines. I'm not to worried about the inside, but the outside will definitely need to be smoothed out.
Once it's ready, I'll pull the last support off and spray the inside while I still have reasonable access to do so.

Looking promising.

It's probably too late, bit have you thought about leaving some cavities with covers that you can fill with little sand bags old used batteries to balance the weight out if needed? The PLA should be strong enough, because you have some geometry on your side, but I worry it might flex a bit. Hopefully it won't impact the final product.

I'm keen to see how this goes, because I might be tempted to do version 2 once i see all the tricks of the build.. I did quarter cut some gum last weekend, but it is only 600mm long so won't quite support a neck and headstock. Dang!

I do have a much larger felled tree down the back of my property that I might needs to see if I can source a long enough piece for this sort of experimental build.

Remember, If nobody tries anything different, nothing will ever change.

Oh this gone be good. RE: rigidity, have you considered carbon fibre and epoxy wrap?

Looking forward to seeing the updates, maybe I'll print one myself!

Another couple of pieces printed this morning, so the whole lower section of the body is now printed.

I hit the first part with the sandpaper for a while this morning to see if I could knock out some of the layer lines that were present. I don't want to go too hard on it or I risk loosing some of the texture around the gaps. I threw it in the makeshift spray booth and hit it was some paint just to see how it'll come up. Will know more once it's dried off.
Attachment 41428

That's looking pretty good. Sanding PLA can be tricky, you could hit it with a primer filler first to fill in the layer marks, and then sand the filler back, it might be easier to sand and will be less risky of burning through to the fill pattern.

Probably not the worst idea. If it wasn't for this damned lock down, I'd sneak out and buy some primer. The can I'm using at the moment has primer in with the paint apparently.. One of those 2 kids driving me nuts at Bunnings 30 minutes before lockdown came into effect and me not being able to find what I actually wanted kind of purchases lol.
I've just sanded and sprayed another piece. 2 coats seems to be enough to fill in pretty well from I can see in the garage light. I might get the other piece finished off later and see how it's actually looking in daylight.

Lockdown does add a new level of complexity don't they. I'd probably look at Supercheap before Bunnings for something like this, it tends to be more auto body repair than home repairs sort of stuff. Can you still do click and collect?

P.s. I get the kids thing, I don't think I've had a phone call in a month where I didn't have to stop and manage one of my kids mid sentence.

https://www.supercheapauto.com.au/p/...0g/105782.html

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Originally Posted by andybanks

https://www.supercheapauto.com.au/p/...0g/105782.html

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Cool cheers. I will hunt down some if I look to be running into trouble. Should be able to do click and collect, but I'm gonna have a tough time explaining why I had to drive that far across town :P
Looks like this stuff will be useful for other projects too.

Yeah, fair call. I'm running lower and lower on stock around the house as well.. might have to order a big batch to be delivered soon.

Quote:

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Originally Posted by andybanks

Yeah, fair call. I'm running lower and lower on stock around the house as well.. might have to order a big batch to be delivered soon.

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I couldn't even find anywhere that would do delivery for it... I'd load up on paint as well if I could. The black I've been spraying it with is destined to be the base coat on my Jurassicaster build. I might scrape by. Maybe.

I found somewhere to order a filler primer from and have a couple of cans on order.
Looking at the state of the plastic even after sanding, it's gonna annoy me, so hopefully this helps take the edge out.

Progress update:
All of the patterned outer components are now down.
Waiting on:
- Centre - currently printing. At 100% infill, this is about 390grams of plastic alone.
- Centre neck. That's next. It's bigger and heavier, and I'll need to change filament before I do this bit.
- Glue. It's coming. The original build guide suggests gluing from the centre out, so I'll go with it that way.
- Neck. I may have ordered a black neck that's in transit. Oops.
- Headstock logo. I'm gonna try something different and have a raised logo and axe name on the headstock. I'll 3D print them in white, lay down a coat of polyurethane and see if that'll hold it. Then I'll see what happens if I add a few extra coats over the top. A little experimentation involved, but it should be super light so I imagine if I put it down as soon as I've put on a slightly heavy coat, it might be enough to hold.

I hope the centre prints work out well. Every time i have printed dense parts of any significant size, i get warping, but that is more likely to do with the lack of a cabinet and variations in temperature than the machine itself. I'm crossing all my fingers and toes for you. :-)

Quote:

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Originally Posted by andybanks

I hope the centre prints work out well. Every time i have printed dense parts of any significant size, i get warping, but that is more likely to do with the lack of a cabinet and variations in temperature than the machine itself. I'm crossing all my fingers and toes for you. :-)

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Cheers! Yeah, had my fair share of those kinds of dramas. I wound up buying an enclosure which has helped. On long prints I leave it unzipped a bit as it gets too hot in there, but it certainly helps. Mines in front of a window and under the central heating vent, so it was copping it a lot before I did that.

My biggest concern at the moment is that I can see a support being printed in a really, really bloody difficult spot to pull out. Time will tell I guess!.

Oh dang! Hopefully something you can get at with an old guitar string or a Dremel if needed.

Quote:

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Originally Posted by andybanks

Oh dang! Hopefully something you can get at with an old guitar string or a Dremel if needed.

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It looks like it's directly behind a pickup, but has a solid back behind it. Only ways in are through the pickup hole (its single coil), or around a 90 degree bend. It'll be fiddly enough to get a pup in. It's filling the entire cavity so its bigger than the pup hole. I should be able to get a sharp pair of cutters through the middle and get a few layers out. Usually enough to grab with the needlenose pliers and start trying to break it up (something the rest of the print has made me familiar with). As long as I can do it cleanly it should be OK.

I did just glue together the pieces that I had to cut to print. Some slight gaps between them so I've just packed them with a little more of the plastic glue. It's a 2 part that apparently cures in 30 mins. I'll leave it tonight and if time permits tomorrow I'll clean up the excess glue with some sandpaper and try to get it in a reasonable state for spraying.

I'm assuming that the logo I've printed on to this, given its fine detail, probably should be given a wide berth with the filler primer?

Yeah, I'd spend the time on the logo getting it as good as possible first, a small amount of primer filler might not hurt, but it will require even more fiddling around to finish it off.

I'm excited to see it all coming together. Are you tired of listening to the printer in the background?

Quote:

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Originally Posted by andybanks

Yeah, I'd spend the time on the logo getting it as good as possible first, a small amount of primer filler might not hurt, but it will require even more fiddling around to finish it off.

I'm excited to see it all coming together. Are you tired of listening to the printer in the background?

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Noted.
Printer doesn't bother me. Only time it's really stopped in the past 3 months or so is when the change from PLA to PETG back to PLA kept causing some clogging issues so I replaced the bowden tube and had to wait for a couple of weeks. I seem to keep finding things I need, so I keep printing :)

Awesome. [emoji3]

Centre piece complete:
Attachment 41460
Printed with stressingly bugger all filament left on the roll and the wifi on the Octopi box playing up so I had no way to pause it.

You can see on the right the scratch marks from where I had to work at removing the supports that covered the pickup slot.
On the far left you can see a bigger block - in the original design thats wide open for a tremelo. I've filled it with a solid block given that I'll use a hard tail.
Thinking about the strength of this section, there was probably some balance achieved using a trem.. given the pressure on both sides. I may experiment with building a solid support or two that can be glued in if I can find a way of being able to shoehorn a pair of pickups around them.

I'll aim to strip the single coils from the Samick over the weekend and work on how to fit them in this section, and sort out the supports.

The neck section is printing. That'll be a few days out. Most people are saying they need to modify a bit, so that'll have to let that sit until the neck arrives.

Pieces sitting roughly together:
Attachment 41461

I've just resized the pickup holes slightly to get the covers through snug, but without being so tight it'll be impossible once I put a support under there. Screw holes drilled.

The neck mount looks to have around 2 days left printing. Printer has been running 24x7 for a week on this job so far, so a couple of days longer is hardly a concern. Once it's done I can get on to the custom bits I still need - the support for behind the pups and an edge mount enclosure for the output jack. It'll be down behind the logo somewhere and blackwired back to the control cavity so it doesn't stand out too much.

The existing glue joins vary between awesome and woeful. I've attempted to file and sand off a lot of the excess that came from using it to patch the gaps. Some of it I'm hoping will just add to the texture. I have a few gaps left in some of the joins that need a little TLC. I don't really know how effective the primer/filler stuff is yet to know how much it will hide for me.

The neck heel part has finally printed - it's taken around 2 days and finished around 3am.

https://youtu.be/wfyGT8vgG48

Over 400g of plastic went into it, so it's a fairly heavy chunk of PLA. The supports were a bit of a pain to get out of the pickup cavity, but I managed after messing around for half an hour or so.

I've since made a jack box to mount on the side. It's going to be a little fiddly to get back into it once it's glued in, so when the wiring kit bits arrive, I'll put it all together then glue it in.

I'll likely glue the centre pieces together at some stage today then I can probably move on to attaching the upper body parts.

Attachment 41525
Body is together, has gone through a couple of rounds of filler/primer and on to its first full coat. I don't have a lot of back satin left, so I'm going to avoid another full coat and just worry about hitting the areas that need a touch up - mostly the areas where the primer is still coming through.

I've learned a lot thus far:
- The filler/primer cracks up over parts that had been painted previously despite sanding. I think more effort went into trying to deal with that drama than I ever spent sanding the PLA. The control panel has some fairly deep cracks despite a lot of sanding time. I've decided I might just live with it. A few cracks add to the texture.
- The filler is fun to sand. It makes a lot of mess. It also smells. A lot.
- I need better gear to put bits together while glue dries. Limited clamps made it a challenge.
- This concept has a massive surface area that is quite simply too hard to completely prepare.
- I really should have put more effort into fine tuning my printer to reduce the layer lines and done more testing to avoid using as many supports. There are a lot of mesh areas inside the sections that the supports had adhered to that are too hard to get to. If I'd have been less focused on making this low budget, I suspect I'd have printed enough pieces to make 4 guitars instead of 1.

This is definitely not perfect. A lot of the join work is crap, some due to the additional layers added where I've cut the sections up to fit, where things moved while the glue cured and so on. There is a gap to the right of the centre - you can see it near the bridge. There is a whole area that doesn't have a side in the design to adhere to the section with the control cavity, so there isn't a lot of room for adhesion.
I wound up with two sections to put together, and this was where they joined. Initially they were near perfect, but it become clear soon after that where I'd anchored other areas (I resorted to cable ties), that it was trying to flex. When I let it go, that gap developed, so I let it go. It doesn't seem to make a lot of sense to create a whole lot of pressure over an area that doesn't have a lot to adhere to. Once the back plate is on it shouldn't stand out too much I hope.

The neck arrived yesterday. Surprisingly straight. The finish is a bit average and there are signs that the clear coat has come over to the fret board.
I've thrown on a coat of lemon oil to start trying to bring up the fretboard, and I went through and gave the frets a quick level, dress and polish.
I 3D printed the Plasticaster logo, laid down some polyurethane on the headstock and managed to get it to stick. This needs some more work - it's coming up a bit bubbly - I imagine the coolness of the garage is probably a bit too cold for it. Once it's dry I'll try to sand it back and wait until it's a bit warmer to give it another coat. I don't really care to do too much more to the headstock other than get that logo stuck there with a couple of coats over it to help keep it there, and otherwise bring the finish back to an acceptable level.

I've got the electronics all ready to go when the body is ready.
The hardware however is a different matter; it's all kit bits from the ST-1 which is still in transit (since 20/8).

Very interesting build. What's the body weight?

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Originally Posted by McCreed

Very interesting build. What's the body weight?

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A tad over 1.4kg at the moment.

Hopefully I'm somewhere near getting a full coat over this thing now. I go in and move it occasionally and just do patch jobs where required. I'd very much like to not need to put much more time into that body if I can avoid it. There's a lot of "little things" that are too time consuming to fix that I'd rather just ignore for the sake of this being more of a prototype rather than something I want to make awesome. I suspect I could put a few hundred hours into this body trying to get it where I want it only to still wind up with a guitar that doesn't really justify quite so much effort.

Doing the TB-4 at the same time, working on the timber I feel a distinct relationship between what I'm doing, what I'm try to achieve and the material. It behaves and it's enjoyable to put time and effort into.
I'm struggling to have the same thing working with plastic. I suspect a lot of it is just due to the sheer amount of surface area and limited accessibility to so much of it. It was a massive undertaking to print and its taken a lot of sanding and filing to get the body almost to what someone with a better printer setup would have achieved straight off the print bed. The filler is incredibly messy to deal with - useful, but given its behaviour over the sections that had already been painted and the complexity of the surface area it was another set of problems - though I must say, it has taken out some of the need for aggressively sanding the PLA back to reduce the layer lines.
Possibly it's skewed by my relationship to 3D printing - I've never really put any effort into it beyond design.. things print, I use the thing for whatever purpose. It's always been the final step of production rather than the half way point.

I've been looking at a 3D printed bass design - one that lacks the body complexity and instead just provides nice, flat surfaces to work with. That might be a one day future project.

Attachment 41529
Headstock is a bit pockmarked with the last spray. Having a lot of trouble getting a consistent coat over it. Thinking I perhaps need to get a couple more layers over it, let them sit for a day or two so they get hard then try to sand them down till they're flat, recoat then hit with a finer grit paper? I've never tried to finish clear coat from a can before, so not terribly familiar with how to deal with this.

It's looking pretty good to me. :-)

I would be surprised if it would be possible to get a perfect finish from the printer, and since there are so many internal and hard to get at surfaces, it would take a massive effort to clean it all up to make it look nice. There might have been an opportunity to use plastic welding to fill some of the bigger gaps before the filler, but it is pretty tricky to not burn through the thin shell of the printed parts and screw it all up. I have probably about a 50% hit rate on that sort of thing.

If you look back at the original picture you posted of your inspiration, you'll notice the finish is also not perfect - in fact I think they may have wrapped it in vinyl, but they have definitely hidden the imperfections by using a matte finish. Reflective surfaces (especially dark colours like black) always show up the imperfections, so it will be harder to get a super clean look with the gloss black. If you can live with it, it is still pretty cool... Just stand back and squint a bit. :-)

I am still really keen to see how this works mechanically and how it responds to string tension. Will it stay in tune? will it resonate somehow unexpectedly? Pretty keen to see how it functions. :-)

p.s. I think you are on the right track with the clear, let it go off for a day or two, and then have another crack at it. Apparently the weather is only going to be almost nice in Ballarat tomorrow..

Quote:

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Originally Posted by andybanks

It's looking pretty good to me. :-)

I would be surprised if it would be possible to get a perfect finish from the printer, and since there are so many internal and hard to get at surfaces, it would take a massive effort to clean it all up to make it look nice. There might have been an opportunity to use plastic welding to fill some of the bigger gaps before the filler, but it is pretty tricky to not burn through the thin shell of the printed parts and screw it all up. I have probably about a 50% hit rate on that sort of thing.

If you look back at the original picture you posted of your inspiration, you'll notice the finish is also not perfect - in fact I think they may have wrapped it in vinyl, but they have definitely hidden the imperfections by using a matte finish. Reflective surfaces (especially dark colours like black) always show up the imperfections, so it will be harder to get a super clean look with the gloss black. If you can live with it, it is still pretty cool... Just stand back and squint a bit. :-)

I am still really keen to see how this works mechanically and how it responds to string tension. Will it stay in tune? will it resonate somehow unexpectedly? Pretty keen to see how it functions. :-)

p.s. I think you are on the right track with the clear, let it go off for a day or two, and then have another crack at it. Apparently the weather is only going to be almost nice in Ballarat tomorrow..

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Cool cheers. The paint is satin, but it seems particularly glossy, and does absolutely show everything. I'm just resigning myself to the fact that the imperfections are cool.

Weather, nice, Ballarat? You mean we're gonna have one of those 3 days a year tomorrow? Awesome. Saves me checking the weather. :P

Clear either needs to go on as flat a surface as possible, or you need to use countless coats to build up enough depth to sand it back flat. It will just follow the contours underneath it, it won’t just fill up any dips first but also cover the bumps. You’d need a very thinned paint indeed for it to pool in the pits and even then, as mist of that liquid would be thinners, it would still dry out leaving a smaller pit, and the paint layer would be even thinner. A standard spray can is probably 30% paint/lacquer, the rest is propellent and thinners. Increase the amount of thinners and the paint content goes down considerably, so you’d need maybe 3x the number of cans.

Plus, too much thinning affects the paint finish and of course on anything but a horizontal surface, it’s just going to run off and not stick. So, getting the surface as flat as possible first is the ideal solution.

For the bass idea, as it would also have to be in parts (unless you get a new 3D printer), maybe you could make a full solid body bass in a jigsaw-style, so the pieces slot together nicely, provide mechanical strength for the joints and provide lots of glue area? You could also highlight the jigsaw effect if you wanted by having the pieces slightly different heights.