Jason's Refin

[erikbojerik]

Thanks u-r-b.

I am not a big scraper guy, this is really the only time that I typically use one. I could certainly invest in a set (and tackle the sharpening-burnishing learning curve....), but I've already got a bunch of razor blades kicking around, so....

 

[erikbojerik]

So, one of the most oddly-challenging things about this refinish proj is that Jason wants his rear cavity cover attached with magnets instead of the existing small Phillips-head screws. I was able to fill the screw holes fine, but the challenging part has been that the original cover was too thin to support a magnetized attachment.

We still wanted the grain to match the original swamp-ash, so I decided to try to build the cover thickness up from the bottom using more swamp ash, and that worked fine.

But then this required me to deepen the recess for the cover...time to break out the trusty overhead router.

With the front of the body registered against a piece of 3/4" MDF on either side of the neck, I could rout off a very specific thickness from the cavity cover recess.....but after the first pass I could tell this was not happening, I was removing more material toward the center of the body and less toward the edges of the body.

Turns out the body is not of uniform thickness, it gets thinner by maybe 1/10th toward the edges. So the only thing to do was to hand-sand a "tilt" into the cavity cover, this took some doing to match up the thickness, but I got it to match up.

After that, I was able to hand-sand the edge of the newly-thickened cover and have it match the roundover of the body.

 

[erikbojerik]

So after each layer of clear-coat, I am level sanding with a small plywood block backing 400-grit paper (after knocking down the runs with my razor-blade scraper). Edges that require less aggressive action get the Norton 320-grit yellow sanding sponge (which, since it is well-used, actually sands more like 600-grit paper).

The idea is to knock off the "shine" so that the next coat has some texture to bite into (unlike nitro which has a chemical bite-back and doesn't need this). In the above photo, the back of the headstock has been sanded but the neck has not.

If you look closely at the above pic, you'll see a few small recesses that are still shiny, these are areas where the grain is not yet filled in and the surrounding coat MUST be sanded down level to the bottoms of all these little low-spots. EVERY shiny dot must be removed (and the whole thing wiped clean with lacquer thinner) before shooting the next coat.

Here's another common challenge when shooting clear, namely "solvent pop". Here's a shot of the top of Jason's bass, which is cocobolo (now nicely sealed! ).

Upon close inspection, you can see very tiny white dots or "pinholes" in the finish, they are filled with the white dust left from sanding with 600-grit. These holes are generated when the solvent is trying to gas off from the finish, but is prevented by a dry skin that can form over the finish if it flashes too quickly. In this case, I was using un-thinned conversion varnish, and because I was shooting in direct sun, it skinned over *just* before the last of the solvents could get out, so they collected and formed these tiny bubbles underneath the skin.

No biggie at this stage (the dust is blasted out with compressed air and wiped off with thinner, and the next coat fills them in), since I am trying to build coat thickness to fill completely the grain in the cocobolo. With this product (Chemcraft Plastofix), I was able to shoot 3 coats in one day, with level-sanding between each coat (after 90-minute dry-time). After that, all the grain was filled!

 

[erikbojerik]

After the grain has been completely filled, I now shoot coats that are thinned with 15% of the slow reducer; this lengthens the time for the clear to flash off, which allows it to flow out into a nice even layer with a minimum of sags and runs. For this, when I shoot the neck I hang the instrument vertically, and when I shoot the body and headstock, I lay it so that the surface that receives the coat is flat (horizontal).

Here is a shot of the headstock shoot; the neck and back of the instrument have already received their final coats, so they are taped off to avoid overspray.

Here's a closeup of the flow-out on the headstock with this thinned conversion varnish, 5 minutes after shooting. The reflection is the trees in my neighbor's yard.

 

[erikbojerik]

Here's the body flow-out 5 minutes after shooting, reflecting the trees again.

 

[Rickett Customs]

Erik,
Daggone man, as good as this thing is looking, you're not gonna
charge me a storage fee are you?

Awesome work and pics.

 

[erikbojerik]

"Storage fee"....???

I think that's what the rest of my family tries to extract from ME when I take up half the garage, and then suggest that they move their crap out into the driveway so I can have the other half.

 

[Darkstrike]

*Drools*

 

[Rickett Customs]

Erik,
BTW, this is what the outside of the top and bottom of the case for it looks like at this point:

 

[erikbojerik]

Second (and last) application of Mirror Coat. Again the trees reflected...

This will sit for the recommended cure time (5 days) and the entire instrument will be ready for buff-out next weekend.

The case is coming along!

 

[Rickett Customs]

Second (and last) application of Mirror Coat. Again the trees reflected...

This will sit for the recommended cure time (5 days) and the entire instrument will be ready for buff-out next weekend.

The case is coming along!

I also realized that I had to clean my lcd on my laptop, It was looking spotty for a second, then I realized it wasn't the picture

 

[erikbojerik]

OK so here's how I levelled the fingerboard last week. I start at the nut end, where there's always a little meniscus that runs up against the nut. That is filed down and levelled along with the rest of the real-estate between the nut and #1, using a fine file.

Then out comes the trusty leveller, a slab of polished marble (left over from a bathroom remodel) with 240 grit stuck on the smooth side.

That is run over the fretboard to rough-level the works, it is easy to see part-way through what's still low and what's level.

 

[erikbojerik]

After that, its 600-grit dry with a random-orbital sander, then 1000-grit Abralon pad (wet) by hand.

Again the trees reflected...after the 1000-grit by hand. It will buff up considerably more with 2000-grit when I start on the clear-coat buff-out for the rest of the instrument.

 

[erikbojerik]

OK, so one of the tricky parts of an epoxy fretboard is on the edges, where the epoxy ends and where the rest of the finish begins. For this instrument, I actually applied a thin layer to the edge of the fretboard with the rest of the neck taped off, so that the edge between the two is right at the fretboard glue joint. This will make life easier if anyone needs to remove the fretboard for a future repair.

But of course, when you pull the tape there is a little "edge" where the epoxy sits ever-so-slightly higher than the rest of the finish. This is where the razor-blade scraper comes in handy again, knocking this down to the same level. Here in this photo, you can see where it has been scraped down near the nut, and where it's still sitting high. This is scraped all the way down the neck, then sanded smooth with 600 wet->1000 wet.

 

[erikbojerik]

Buff-out happened this past weekend. After the last coat of CV sets for ~5 days or so, it is levelled with 600-grit wet on the curves, and 600-grit dry on the flat surfaces. Then the entire instrument is worked over using 1000-2000-4000 grit Abralon (wet). I use a dilute solution of water and Ivory hand soap, the soap is important to keep the abraded finish suspended and off the surface. The neck is left at 2000-grit for ultra-smooth feel.

REALLY important to wipe the entire instrument clean between grits.

Then the buffing, I use a StewMac foam pad chucked into an electric drill, which is held in a vise clamped to a workbench. This way I can hold the instrument with both hands. A separate pad for 3M Perfect-It II (fine cut) and Meguiar's #9 swirl remover 2.0 (cleaning thoroughly between). Here it is buffed-out and awaiting the hardware.

Happy-boy reflected in the buffed-out finish.

Importantly....NO evidence of cocobolo oil seeping through the finish , as was the case with the original oil finish. These kinds of catalyzed clear-coat products are the only finishes I've seen that are able to seal off cocobolo and keep it from weeping oil.

 

[Rickett Customs]

Erik,
I tried calling you yesterday, to see how it went over the weekend, I don't know how bad the rain was in your neck of the woods on saturday, It was horrible most of the day around my parts.

Looks like it's on the up and up , extremely nice shine to it, I look about as happy as that boy in the last picture

 

[j3ss3]

dang that bass is a nice one!

 

[Darkstrike]

Looks incredible!

 

[WesW]

Oh my.

So - what do you charge for this service? That bass looks awesome! Great work.

 

[erikbojerik]

WesW, it depends on a lot of things; what kind of original finish and whether or not it needs to be stripped, neck-thru vs set-neck vs bolt-on, satin vs glossy, etc etc. PM me.

All the hardware is on and the bass is set up, but because we've lost a little volume in the control cavity from making the cover thicker, I need to shave off a few mm from one side of the cavity to make room for the 9V. There's plenty of room.