Update:
We are now in the
staining phase.
We are using a Vaton "dark brown" indoor wood stain, sprayed with an inexpensive $35.00 HVLP sprayer, off our 2hp 39Litre air compressor.
Good results with 60%/40% stain/paint thinner.
For a look at our sprayer, go to amazon.com and this keyword:
Tool Force A-C1 50 PSI 2-in-1 HVLP Spray Gun
(Another company to look at is "Advanced Tool Design" (at
amazon or
spraygunworld). Nice color, we are happy (we ended up not using the regulator that came with the gun, as our air tank reg works perfectly well).
Gloss finish
We are unhappy that in Japan at least in our area, while spray can acrylic lacquer is plentiful, a commercial size (3.5L would be fine) is unavailable. Frustrating. The common thing here is to spray polyurethane, and we are likely forced to do this to get a gloss finish. A benefit also is that the unit is less likely to degrade or shift in any way -- one benefit of poly though is the super-hard, acoustically reflective surface, plus joins (between faces and fins) will be filled or smoothed by the poly (if we shoot it to our satisfaction).
Glue
We do have some white glue drops on some pieces. If we could do it again:
Once you are sure of your frame size length, assemble & glue the faces on at the same time as fins are assembled, not later.
And if possible, get the glue into a caulk tube or find a way to apply it directly with (something like) a caulk gun. This would have solved our issues (mistakes). Also we found out a bit late that if you keep wet-damp rags around and use them liberally on missed glue, you can wipe it off wood pretty well, if done immediately.
In the USA, liquid nails or constructive adhesive in caulk tubes may be the better choice, though I can't say for price. I think white glue works very well in the build, I like that we can bungee and tighten our frames overnight, and that the glue remains flexible for some hours. If a more targeted application method is found, it would be perfect.
From an
engineering standpoint, we have all well depths within 2mm and many within 1mm of spec, and the widths are spot on (due to the foam being a stable 40mm width).
Spray materials use
It's way easier to stain/seal last, the sprayer works great, with a little help from a stain-soaked rag for deep areas and smoothing. We go with one spray coat, then wait about 15 minutes and do some spray touchup if needed. An N23 uses between 300cm-350ml of stain, so it's pretty economical. Spraying a unit takes perhaps 10 minutes, and touchup another 5. The time involved is in setting up an outdoor spray station, pouring and mixing, getting the gun set up right. We had no experience shooting stain before, and it wasn't too hard to figure out. We also shot polyurethane, which isn't that different.
For costs, we costed our N23 at $49. each. In Japan stain and poly aren't cheap.
$60. for 3.7L of stain (x2?) $120.
$45. for 3.5L of poly (x2?) $90.
$ 9. for 3.5L of paint thinner (x3) $27.
$237. (and a lot of stain and some poly left over). We built 14 units (4 are N19s) so altogether we add $17. to the cost of each unit, bringing the cost up to $66.USD per unit. (We have enough extra to build the remaining 4 N23s for the mix room ...)
I don't have pics yet, but soon --