Bizman62

As I'm no expert either I was hoping the same but since none of the more savvy active ones has chimed in and corrected my answer I guess the advice of using nitro on nitro has silently been accepted.

Guess I meant "level" rather than "flush". No bubbles or drips. Nor sanding marks.

Hi and welcome! To answer your question I don't know for sure but for what I've heard and read nitro keeps shrinking forever. And I really mean forever, like decades. Just look at the crackled vintage guitars! Also, unlike 2-part stuff, the drying of nitro is based on evaporating the solvents. So you'd have to wait at least until there's no smell - I just read about a guitar that had the smell after a year! Obviously, if the underlaying nitro keeps gassing it will try to push the epoxy layer off. Doesn't the above sound like "no"? As said, I don't know for sure but knowing that certain coats don't work together (like oil based wall paint over latex) I'd be very cautious with nitro. A nitro clearcoat would be the safest bet and give a similar lustre and if stored properly it would also last.

If I'm not totally wrong the primer should be sanded flush before painting. That should also blend any height difference in before applying the black paint. Also, you can mask the bottom side and apply some clearcoat on the rim of the top. Then you can mask the top including the rim before applying the black paint. That should give you a nice crisp line. The clearcoat on the rim will also prevent the black from staining the edge of the top and if some black gets under the tape (that's unavoidable!) you can easily scrape the paint off the clear! Was that clearly enough told? My broken English is sometimes so repetitive that I can't understand it myself!

Me too! Isn't it funny that such gorgeous looking pieces of ebony were considered as waste not too long ago. Some people still only accept the darkest ebony. Us connoisseurs know better!

Now as the doorstep scrap'o'caster is more or less finished, it's time to start a new project for next winter. This time something more ambitious. We all know the Gretsch sound, don't we? And it's different to any other sound, isn't it? A year ago Santa brought me a pair of Bigsby style whammies which led me to get a pair of Artec Filtertron type pickups. I also bought a 4mm thick bookmatched figured maple top (or bottom?) intended for some sort of acoustic stringed instrument. And I have a pile of spalted alder that has been drying on the upmost shelf of the workshop all winter. That might work for the base of the body. So here's the alder. It appeared that some of it was way too soft so I cut it into firewood for the Saturday night sauna! The thinner blanks seem to be quite solid and they are wide enough for a LP style body. However, the pieces are of different widths and the narrower one is too narrow for half a body so the centerline will be off. Unless... What about making a three piece body with a centered strip! That might look better with the bookmatched top with the seam along the centerline, don't you think? A quick and dirty mockup about the hardware: And of course I won't make an LP with Gretschy hardware! A Jet is larger than an LP but the maple top is a bit on the short side so I can't make it as long as a Jet. But I can make the upper bout wider in the style of the Jet. Also the lower bout may get a bit more of a drop shape, the waistline on the drawing is a bit plump but I ran out of time to redraw it.

If the surface feels rough when you wipe it with your hand - similar to having shaved your chin silky smooth in the morning but in the evening there's that certain roughness - go very lightly with a fine grit paper. 400 should be good but you can go finer. The most important thing is not to use any pressure! You'll just be knocking the fibers that the moisture of the stain has raised. Steel wool might work for scratches but there's also the risk of sanding the dye away. Also any remains of steel may rust so a nylon abrasive felt might be a safer option. But I repeat, after staining you should only go very lightly over the top so you don't sand the dye away. Or, if the sanding lines really bug you, prepare for sanding it all clean and start the colouring process over. That's not as bad as it may sound, a random orbital through various grits will do most of the job in no time. Agreed, that's a bit blotchy. If you're going to use black paint, there's no need to sand that colour away as black paint has the best cover ratio of all, it will hide anything. Also the dye doesn't prevent the paint from sticking. That said, you should do a similar light sanding before painting. Also notice that any scratches in the wood will be emphasized both with the black paint and with the clearcoat! After the black has properly dried, you may want to sand it satin before applying the clearcoat. Again, any imperfections will become magnified under the clearcoat so be patient when preparing for the clear. One more hint: When sanding wood, wipe with a moist cloth and let dry before changing to a finer grit! That will raise the grain. After the finest grit moist the surface again and go lightly over it, repeat that twice for the smoothest possible base for both staining and coating.

A combination of sawing and spindle sanding is also a valid method.

Don't know if it's the preconditioner or what but it sure looks like you've splattered something here and there with a wide brush. And that that "something" absorbed the dark stain better than other areas and made it blotchy. Black paint is a valid option and after all, paint is just clear with pigments. And basswood doesn't have too fancy of a figuration anyways so hiding it is no big sin. The top looks great. Actually a solid black back may be a good option to highlight the top so let's hope the back turns into a happy accident!

And for my liking not shiny on the neck!

From "Oh shit!" to "Oh wow! - at least in this spot" is my preferred method, requiring going back for fixing a scratch left from two-three grits earlier. Gentle wipes with frequently cleaned abrasive repeated a million times, that's the best tutorial about fine sanding from me.

The ones I've bought have always had the padding but the ones you tighten with the screw tend to lose the protective caps. The top covers split and the rotating caps wear from the inside as the 'bearing' doesn't rotate too smoothly.

I tend to do the same to prevent marks on the surface. But as you said there'll be another layer to hide them. Let me suggest you a workaround combining the best of both worlds: Attach cork pads to the clamps! For the upper jaw of the F you can simply glue that on the iron (after having cleaned the glue squeezeout remains off, that is). For the round rotating parts you may want a big larger diameter pads which should become sturdy enough using 3-6 mm thick plywood (Nordic Birch) under the cork.

Glad to see you again! When clicking the 'Next unread topic' link it opened somewhere in the middle of the page, showing your headstock and body design, seeing them felt like coming home from a journey. Is it really almost a year since your last update? Man does time fly!

I've used a random orbital on flat surfaces and it may help leveling without major scratches. But if you've already got somewhat of a gloss it might not help too much. According to what I've heard and learned through experience is to choose a grit less coarse than the depth of the scratch and sand across until the scratch vanishes. Then change direction again and sand with a finer grit, change direction and use a finer grit etc. until the spot blends in with the surrounding gloss. And in case I've forgot to mention, don't use any pressure! Look at @ScottR's Green One for reference. Those pads look similar to the 3m pads I've bought at the car paint shop. The foam can hold lots of water which makes them ideal for wet sanding.

Isn't it somewhat counterintuitive to see how well even a fine grit sandpaper/mesh/whatever cuts through the surface, leaving a satin sheen without scratches with much fewer strokes than you'd think? Seeing that miracle happen is always fun, seeing the faces of other people after having instructed them not to use pressure for best results is hilarious!

Wax or oil don't behave well under any coat. Shellac should work as a middle man but you won't know until having tested with your stuff. Also, when mixing different coatings one thing to remember is to let the previous layer cure properly. Any fumes that may emit from the previous layer can do things to the next one. I was going to say "less desirable" but then I remembered crackling which used to be very popular among house decorators not too long ago. Fun projects with kids are the best. Looks nice too! As they say there's many ways to skin a cat.

Shellac is said to be compatible with most anything. I'd say 2k is guaranteed compatible with 2k. The question that now popped into my head is, were you going to spread the 2k by hand of from a rattle can? If the latter, then I'd consult the vendor to ask if they could add some pigment to it. After all, 2k paint is just 2k clear with added colour!

Ahh yes... Did you know there's stain/dye in rattle cans? I didn't until I googled for such. You may even let a car paint shop make a coloured mix of 2k and semi-transparent pigment into a rattle can.

Is this the final stage? Or will I reseat the neck at an angle, continuing this saga sometime in September? Time will tell... Having decided to follow Veijo's suggestion to lower the trapeze I started by carefully marking the bridge location for intonation and the area to be modified. The low angle plane seemed to be just right for the job but like all blade tools in the workshop it didn't chew material off, at least not in a manner I could control. A rough file didn't seem to work either, the oil treated pine is surprisingly hard to carve! So I taped a loose saw blade on the top for an angle guide and taped the end of the sanding block as well and it seemed to work better. Still not too happy. But then I remembered I had bought an Iwasaki rasp and that made things happen in the pace and accuracy I liked! After having finished the slope I then re-inlaid the trapeze endpiece and bent the bottom end of it to better match the roundover of the bottom of the body. A drop of oil blended the newly revealed surfaces to the existing finish. And as no guitar is finished until the strap buttons are installed I decided to get rid of the hook. Notice the real leather pad: Salvaged some leather from the trash bin of the workshop and punched a dozen of pads out of it. Has the angle changed at all, it's hard to tell. But now everything has been done at that end so if need be resetting the neck for a taller bridge is the only option left. The neck feels nice and nothing rattles or squeaks, not even when bending the dusty frets so guess that can be called a working guitar. And here's a final view of the entire instrument:

Has the plan changed? Couldn't find any other than that, then again this flu makes my eyes jump the obvious.

I've sprayed a burst using 2k poly once, following the advice of our tutor Veijo who is a trained Master Luthier and has been in the business since the mid eighties so he should know. Anyhow, the procedure was as follows: After having sprayed a layer or two of poly and sanded it level up to some 400 wet I sprayed another thin layer of the 2k. Then when it was still wet I sprayed alcohol based dye for the burst. And while that was still wet I noticed that the overspray was way too intense so I took a rag soaked in solvent and wiped it all off! Much, much easier than sanding back to the first clearcoat! So, reapplied a mist of 2k to provide some grip for the dye, cleaned the spray gun (model very cheap, sub €20) and sprayed the alcohol based dye. This time the result was pleasing so I continued with 2k, wet on wet, to seal the dye between layers of clear. The last layer of clear has to be thick enough for level sanding without fear of sanding through the burst. Wet on wet was the trick, allowing the previous layer solidify just enough to prevent runs but not too long to build a skin. That would not be a major issue, though, it just means you'd have to wait for the 2k dry properly and sand it matte for subsequent coats. Later I've learned that you can also mix 2k and solvent based dye in which case you don't need the mist coat to start with.

Nicely done! You now have a tool that's nice to use without fear for fingerprints.

Gave some further thought to it and you're most likely right. An egg has one of the most durable shapes and it's all about the curvature. Or at least I haven't seen any braces inside eggs.

What would you think about making a flat top with braces heavily radiused to the inside? Lacking the words let me draw it: Would that be enough to keep the top from sagging or do you think the overall curvature with braces radiused against the top (and maybe bottom too) would be more rigid?