The Hossenfeffer II Build

[Gilmourisgod]

Sparkle Inlay Test #2:
I realized that any bubinga showing through the MOP would show up as a jagged line along the edges of the 1/8" triangle routs. I've used this stuff before, Envirotex Lite, its a polyester resin that dries water clear, and since its polyester, I realized I could use marine gelcoat tint to get it white. I also got a jar of a much finer grade of crushed MOP to use as a base coat, adhered to white tinted resin painted into the recesses. I wasn't sure how much of the gelcoat tint I could add without screwing up the polyester cure, so my first coat into the recesses wasn't quite opaque. If it seems like its curing out OK, maybe I can add more tint. If not, I'll just have to apply two or more coats. Science!

Here it is with one base coat of tinted Envirotex, and the finer grind of MOP flakes. I'll use the bigger flakes seen in the first attempt to the right, applied with a submerging coat of Envirotex, to get the real "sparkle" look.

You can see in this shot, I didn't get the vertical edges of the recesses opaque white enough. The Envirotex is thin enough that it seems to run down off the edges as it levels out. The edges really have to be white, or the bubinga will show through as a ragged edge under the transparent infill. Might have to apply more of the white tinted stuff right before it starts to kick off.

 

[Gilmourisgod]

Sparkle Inlay Test #2
Just for yucks, I tried my admittedly geriatric West System epoxy with slow hardner. Awful! Incredibly pee-yellow amber and full of bubbles. I assume the amber tone is just because it's old, but the bubbles rendered it cloudy as hell, even using a torch to try to get them to pop. The Envirotex Lite is excellent, dries water clear, pretty thin, so it levels nicely, and hitting it lightly with a propane torch popped all the bubbles. We have a winner! I will have to be careful not to have any MOP flakes on the side walls within about 1/16" of the surface, a couple MOP flakes gravitated upwards on the test, they'd be exposed by the time I radius this sample.

Finally got the triangle inlay recesses cut, I suck at this, must have taken me 4 hours of excruciating careful dremel and chisel work. I'd forgotten how HARD Bubinga is. Got the obligatory couple of small chip-outs, which I was able to CA glue back in place.

And here's the first coat of white tinted envirotex in the slots to build up an opaque background under the MOP flakes. The Envorotex isn't ideal for this, its so thin it tends to run off the vertical slot sides before it sets up, so I kept touching it up. This will take at least 2 coats, I'll use the second coat to glue down a thin layer of the fine crushed MOP, then submerge the bigger flakes, adhered just to the bottom. The Envirotex takes about 72 hours to fully cure, so it's a slow process, but thats why it dries with no bubbles.

 

[ctmullins]

Yay, that’s exciting!

 

[Gilmourisgod]

Snuck in a little Turkey Day Luthiery amongst the Gluttony and Sloth. I laid down a first layer of fine ground crushed MOP as my base layer, still a little transparent. In hindsight, I got too hung up about tinting the epoxy as a background paint. By the time you get enough colorant in it to be opaque, you can screw up the chemistry of the cure. If I ever do this again, I'll just paint the slots with a pearlescent acrylic paint and have done with it prior to MOP flakes. I think I'll put in one more layer of fine MOP, then go for the bigger flakes for some real bling, submerged in Envirotex clear. Happy T-Day, hope you arent reading this instead of hanging around watching football!

 

[Wes275]

This is looking fantastic!

 

[Aceonbass]

I'm done eating turkey, and I don't watch football. This is far more interesting.

 

[ICM]

Snuck in a little Turkey Day Luthiery amongst the Gluttony and Sloth. I laid down a first layer of fine ground crushed MOP as my base layer, still a little transparent. In hindsight, I got too hung up about tinting the epoxy as a background paint. By the time you get enough colorant in it to be opaque, you can screw up the chemistry of the cure. If I ever do this again, I'll just paint the slots with a pearlescent acrylic paint and have done with it prior to MOP flakes. I think I'll put in one more layer of fine MOP, then go for the bigger flakes for some real bling, submerged in Envirotex clear. Happy T-Day, hope you arent reading this instead of hanging around watching football!
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Those look spot on; amazing work!

 

[Gilmourisgod]

And here's the final layer of larger sized MOP flake bling prior to submerging in Envirotex. I can't have any of the larger flakes adhering to the sides of the slots, as they might poke through the surface when I'm radiusing the board. This is where they really start to look like the old school sparkle inlays. Once this hardens up for 24 hours, I'll pull the blue tape and mask off the sides and ends of each slot with foam double stick tape to act as a dam to get the resin slightly proud of the fingerboard. P.S., you are literally watching polyester resin dry at this point, so that qualifies y'all as Luthiery Geeks for watching this. Or maybe just Ric Geeks.

P.S.
If anybody else wants to try this, let me know. I'll still have about 99% of the MOP flakes in fine and coarse sizes left after this. I'll mail em' to you for postage.

 

[Fat Freddy]

P.S.
If anybody else wants to try this, let me know. I'll still have about 99% of the MOP flakes in fine and coarse sizes left after this. I'll mail em' to you for postage.

What with this^^^^^

and this vvvvv......Well....astonishingly good all 'round...

 

[Gilmourisgod]

Aaaaaannnd.... here it is (finally) with poured resin. The foam double stick tape acting as a dam all around, so the resin ends up slightly proud of the board. This stuff has about a 25 minute working time, so it wasn't too stressful. I followed the directions to the letter, pre-heating the resin a little, mixing two minutes, then tranferring to another cup, mix another minute, etc. Bubbles form as you pour it in, but the resin is thin enough they rise to the top and can be popped by just breathing on it, or as I did, using a grille lighter waved over it. The carbon pops the bubbles. Two of the inlays developed flaws, not sure what happened, it almost looks like cracks in the resin, not sure what happened there. I'll have to see how it looks when it's cured, worst case scenario is I'll have to route them out and try again. PITA, but per usual I'm betting the farm on an untried technique, so it would serve me right. You cant see them in the photo, but its visible up close. The resin really is water-clear, so even a tiny flaw sticks out like a sore thumb. Sigh....

 

[Rôckhewer]

Very pretty.

Might have to try something like this with the crapload of leftover shell scrap from my current build.
Got a bunch of pieces not even big enough for a headstock logo, ... but still can't bring myself to throw any of it away. (Was way too expensive)
Just have to figure out how to break it down to semi uniform flake size.

 

[Gilmourisgod]

I was wondering if one of those turbocharged little coffee grinders would do it? Science! Really @Rôckhewer , if you want some already ground into flakes, I probably have enough left over for 20 guitars, and this is almost certainly a one-off for me, so it’s just going to sit on a shelf otherwise.

 

[Gilmourisgod]

The foam double stick tape came off pretty clean, and left a nice meniscus of resin proud of the board. The two flaws at 7th and 9th fret marker can be seen in these photos, some kind of filament debris got into the resin, but It looks like its right at the surface, in which case it will get sanded away when I radius the board. I got a couple of tiny bubbles right at the surface, should sand out too. The mistake I made was pouring a bit of leftover resin into a couple inlays that were fine already so I didn't "waste" it, classic "polishing a turd" maneuver. I think the resin had already started to kick. Hopefully I got away with it. I'll call this a real success if I can sand it and buff it back up to gloss, but it looks pretty hopeful for now. I'll let it harden up for a couple days before attempting that, though it feels like hard plastic now after 48 hours cure. Got the day off from work, but wife and kids all gone for the day, Yeehaw! Shop Time!

 

[ctmullins]

Sweet!

 

[Wes275]

Looks great. Wish there was a local luthier i could go get some hands on exp with. Someday Ill venture out there. Haha

 

[Gilmourisgod]

@Wes275
You don’t have to go an apprentice route unless you really want to go pro. Lots of self-taught ( with a lot of help from YouTube and TB) amateurs doing amazing work, and some generous pros willing to offer advice. It’s harder than it looks, but there’s nothing like playing an instrument you built yourself, even if it isn’t perfect.

 

[Wes275]

Oh i will at some point. I just know how costly mistakes can be. A safety net would be nice. Haha

 

[Jisch]

Oh i will at some point. I just know how costly mistakes can be. A safety net would be nice. Haha

Not to push the point, but mistakes are rarely costly unless you're using super expensive wood (using expensive wood on your first instrument would be a mistake). You're likely not going to mess up pickups or hardware, which could get expensive. Worst case you wreck a piece of wood and start over, which may be a huge waste of time, but under $50 in actual cost.

 

[Matt Liebenau]

Nice job on the inlays and kudos for correct ( I think) use of meniscus.

 

[Gilmourisgod]

Flush trimming the fingerboard to the neck beam...... WHEN THIS HAPPENED.

I just plain lost my attention for an instant and BZZZZTTTT! After the urge to wrench my own eyeballs out by the roots passed, and the swearing petered off to a dry wheeze, I packed up my tools and walked away to wait for a cooler head. It's bad, but fixable with some rework. It looks deeper in the photo, but the gouge in both neck beam and fingerboard is a fat 1/32" or so. The nut width is 1-5/8", standard Ric/P-Bass size. If I recut the taper on the neck beam by the fat 1/32" both sides symetrically, I'll end up with a nut width somewhere between a Jazz bass and a Ric, around 1-9/16". Not that I have any choice, but I think I can live with that.

The real PITA is that the revised taper has to carry into the headstock wings, which will trash my nice cream binding, at least for sections closest to the nut. I'll have to fair the headstock wings into the new neck beam width at the nut, route the two sections of binding off, re-cut ledges, and re-bind. That will suck, but I can't see any alternative short of scrapping the neck and fingerboard, and that ain't happening. Any tricky alternative suggestions appreciated, but I can't see a better fix.

I laid it out on my CAD drawing, I'll set a straight edge up zero'd to the beam width at the bridge end, and around 1/32" in from existing on each side at the nut. The actual change in neck beam dimension is tiny until you get all the way to the nut, hoping I won't have to touch the pup routes. The only other downside is that the pre-slotted Ric sized brass nut I bought probably won't work, the E and G string may be too close to the edge of the nut, not sure yet. There may be other unintended consequences I haven't thought of, which will surely make themselves known eventually.