Second Build

[Detour]

OK a little late to the party, but here's the first progress shots of an ST-1JR 3/4 I'm putting together for my son. This is my second build, the first being a 335 kit from somewhere else. The requested theme was "Ice Wing", which is apparently some sort of dragon made out of ice from a book he's reading. The head I carved out on a bandsaw to resemble a dragon tail, and then tried to put a paint job on it resembling ice crystals. The last piece will be to put an engraving of a dragon into the pick guard.

For the paint, I started out with a metallic blue acrylic paint as the base coat. I applied it with a foam brush which worked OK, but I didn't want to clog up my sprayer with whatever flakes were in the paint. Topped with polycrylic and sanded to 320. Then I made some urea + dish soap solution following instructions on the internet, and sprayed that on with a spray bottle. After it dried, it looked horrible so I wiped it all off and tried again. Then I did that 3 more times before I was happy with it. Then I topped that with some gloss black enamel. Let it all dry, and then scrubbed back some of the black with scotch-brite and water. Then lots of polycrylic over top of that using spray gun. Polished with micro mesh by hand, then followed up with plastic polish and a buffing wheel on my drill.

The overall effect wasn't quite as "crystal" as I was shooting for, but the customer is happy so I'm not going to start over hoping for better. I maybe could have gotten a better effect if I had purchased the $200 off the shelf crystal paint solution instead of $8 of urea fertilizer from amazon. Or maybe it was my prep work. Probably my prep work. Couple things I learned - the urea solution is not a supersaturated solution as I tried first. When I did that, the urea crystalized immediately on contact and didn't leave a crystal pattern but instead built up in a sludgy layer. I watered it down until it took a few minutes to crystalize as the water evaporated. I couldn't get it to take longer than a few minutes - probably due to the extremely low humidity here. I tried several things to get it to leave a thick layer and so leave bigger crystals, and in the end a couple squirts of dish soap worked the best, but still not great. The black paint also didn't scrub off as neatly as I was hoping - possibly/probably I should have used a rougher grit sanding of the clear coat before spraying down the urea so as to get better adhesion between the clear coat and the black. It might also have to do with the mixing of chemistries - I used acrylic for the base, acrylic for the clear coat, but my black coat was oil based - I probably should have gone back out to the store and picked up some black acrylic instead.

I decided I wanted something darker than the rosewood or "blackwood 2" or whatever it is for the fretboard, so I hit it with some general finishes espresso gel stain which got it to a nice dark tint that matches the paint better. Time will tell how well that wears. I still need to polish some of the stain off the frets, but it came off with just my fingernail where I made an attempt, so it shouldn't be an issue.

Attached the neck to the body. I notice that there's still a gap just big enough to put a piece of paper in between the neck and the body that wasn't there when I dry fit just before. Maybe I can close it up with more torque. Or I might just scratch it all to hell in the process. Given how much he scratches his acoustic guitar through inattention, not sure it matters. LOL.

Next steps:
1) Just noticed that the output jack hole was not pre-drilled. So I'll need to drill that, hopefully without messing up the paint. Test fit your hardware, friends. Somehow I never tried to put that piece on the body before I started. Oh well.
2) Paint the cavities with something conductive.
3) Make a new pick guard. The white one doesn't really match. I have some clear cast acrylic on order. I ordered from a local company so it gets here faster, and after they take my money I get a note "that's in our Houston warehouse so we'll put it on the next transfer shipment and it will get here in a week". Grrrrr... The plan is to run it through the CNC to shape, then v-carve an "Ice Wing" dragon into the underside of it. I'll paint it to match, with the paint on the underside so it doesn't all get scratched off by an over-eager 10 year old shredding some AC/DC.
4) Replace the covers on the pickups and switches and knobs with something black. I wish they offered a black hardware option on this unit.
5) Install all the hardware.
6) Plug my ears

[JohnH]

Looks great!

Weird about the output jack hole though, what a bugger

[Detour]

Thank you John!

Today, while I was supposed to be working:
1) Hit the neck screws with my impact driver - another 1/2 turn or so and the neck is fully seated, and no new scratches!
2) Painted the cavities with conductive paint. After 3 coats per the instructions on the can, I read about 20-30 ohms per inch. Not as low as what some folks were reporting, but I think it will do. That stuff settles fast - I found I had to stop and stir it back up in the middle of a coat as a thick layer of the graphite and carbon black would settle out. I plan on putting copper on the backside of the pick guard to finish off the cage.

[dozymuppet]

Some very cool details have surfaced there. And I love the headstock shape.

I'm also about to start an ST project for an offspring that wants something book-themed, so this is a cool reference (though I won't be submitting myself to the same pain )

Sent from my Pixel 4 using Tapatalk

[Detour]

@dozymuppet - it wasn't too bad once I got the rhythm down for spraying the clear coat. The rest of the paint was all a one-ish time application and so wasn't too bad. I ended up with a lot more orange peel than I wanted, but without a dedicated spraying booth I got lazy. I either had to move the cars outside and spray in the garage with a full kit on and hope that not too much spray ended up on my wife's shoes about 20 ft away, or try and spray outside. In Colorado a day without wind is rare, so that meant waiting days between coats. In the end I got on just enough to get by and then called it a day. I did end up burning through the clear coat in a couple of places (mostly on the neck where the corners are sharper and I sanded a bit more), but with the "aged" look of the whole paint job even I have to look for them, and I know where they are. I'd never sell it like that, but it's not for sale

Today I drilled out the hole for the output jack. I used a 7/8" forstner bit to drill it out. I was able to drill it out hand held without destroying the paint. 7/8" is about the biggest hole I could get and still have the cover plate hide it. It's not quite big enough for the posts on the backside of the jack though.

By the bend in the jack plate, it looks like it was supposed to be drilled out more towards the right side of the curve since that's where it matched the curve of the body. I didn't like how that looked though so I brought it back out to right about at the corner and by hand put a bit more bend in the plate to match the new location.

After drilling in until it just broke through to the cavity at the corner (coming in at an angle like that it doesn't line up any more), I followed up with a hand chisel and opened it up until 1) the posts cleared the inside of the hole, and 2) the opening between the cavity and the new hole was big enough to easily run the wires. I managed to stick the chisel through my left index finger in the process - just a recommendation, but apparently it's not a good idea put your finger in the hole you're actively running a chisel through. It's just a flesh wound though, so I should be back to playing in a few days. I'll go back through this afternoon and touch up the inside a little to smooth it out and then apply more conductive paint to the new hole.

[Detour]

I've been waffling over drilling the mounting holes for the bridge for two days now. Where does everyone place their bridge? I've seen lots of conflicting information. The most believable source I've found so far says to move the saddles all the way forward towards the neck, and then mount such that they're at the scale length so that they have their full travel back to the tail for adjustment. The assumption there is that the adjustment will always be back, but will it be enough? How much delta between scale length and final saddle position is to be expected?

[Simon Barden]

That's basically what I'd do, but saddles almost all the way forwards with maybe 1-2mm of spare thread showing if you can get the scale length set like that.

Top E will go back by around 1mm, bottom E maybe up to 2-3mm. Wound strings are a bit less consistent in the positioning than plain strings. Heavier strings will need the saddles moved back a bit more than lighter strings. The higher the action, the further back the saddles will need to go. With a higher action, you add more string tension pushing the string down at the 12th fret to fret it which makes the string sound sharper, so you then need more string length to lower the pitch again. So it's hard to give definitive distances.

There will also be very small variations in string thickness/mass along its length, which will affect the intonation position for that string. Similarly as the string wears, corrodes and gets a gunk build up over time, then the mass/unit length of the string over its length changes, and the intonation will start to drift out.

[Detour]

Thank you Simon - I got it drilled out, and at first glance it appears I didn't screw it up!

For reference for others, the scale length on this guitar is 576mm, not the 571 advertised. I've seen others post the same observation, so it doesn't appear that I got a wonky neck.

To get the holes nicely drilled out I 3D printed a drill guide which worked very well in keeping the holes aligned nicely.

[Detour]

While I'm waiting for someone to draw the dragon for the scratch guard for me, I figured I'd test my process by making the back plate. Good thing I bought extra acrylic - it's upside down! I like the process though. The photo doesn't do it justice, it's got a cool 3D look to it.

The process is to V-Carve the image into the back of the acrylic with a CNC, and then paint it from the back. When the plastic is peeled off, you get this. To give it a little more texture, I dry brushed black into the carving first, and then painted the metallic blue matching the guitar over top. I haven't decided yet to go with blacking out the acrylic after painting the back (so it's a gloss black with the blue art on top), leave it clear like the photo, or go with a tint somewhere in between. I've got some automotive vinyl tint on order to try that out. If I do go with transparent or tinted, I'm going to have to completely redo all the wiring - the harness that came with it is definitely not visible grade.

[Detour]

I took a couple weeks off to take care of some new puppies. I'm working on the scratch plate finally this week. I finalized the drawings and made some test cuts out of MDF to make sure the new plate fits and the pickups are all in the right place. The mechanical components I drew by literally tracing the plate that came with the kit, then tweaking it until I liked it. I payed a guy on fiverr to draw a dragon that will be engraved into it. I ended up making a dozen test prints out of paper and another half dozen out of MDF before I was satisfied, but I think I'm zeroing in on it.


I started on the final plate today, and I'm running into a few issues that need working out with the engravings I'm doing. Since these are on the reverse side I need to make sure they're crystal clear, and the 30 degree bit I used is not giving me that. It looks like too much heat is trapped inside the cut, resulting in some of the shavings melting back in. In my test cuts with a 90 degree bit I didn't have that problem, but I need the extra detail that the 90 degree bit can't provide. My plan right now is to leave the pin striping as is, convert the dragon to a 60 degree bit, and hope for the best. With the way I'm doing this I can't QC anything until everything is done, so... we'll see what we get. I have lots more acrylic, so all it will cost me is time if I need/want to re-do it.

That said, the plan is still:
1) cut a clear acrylic blank to size, peel off the back layer and paint it gloss black.
2) mount it front side down on the CNC, engrave the pin striping and eye. Paint the pin striping metallic blue, fill the eye with red synthetic opal and CA.
3) engrave the dragon, remove from the CNC and spray paint it metallic silver.
4) re-mount on the CNC front side up. Cut the mechanical holes.
5) cut the outside edge bevel, then finally cut the piece free.

Glamor shot of the blank bolted into place. I made a job specific waste board to hold it with symmetrical threaded inserts so that I can take it on and off the machine without losing my zero. They're symmetrical so that I can flip it from front to back and still keep things aligned. If I do lose zero (stuff happens...), I machined crosshairs at the bottom left and top right of the scratch plate to let me re-establish it referenced to those inserts.


Shot of the blank after cutting and painting the pinstripe and eye. The painting is messy, because who cares? It will all be covered up by another coat of silver spray paint and then copper tape later. I didn't take a photo of the not-glossy inside of the cuts. The eye is barely visible at the top left inside the pin striping. Hopefully it will pop from the front side...