For final shaping, I think the key is to go slow and inspect frequently so that you creep up on the target shape.
I have found that even if I happen to have a block of wood that matches the dimensions of the nose block, it’s easier to work with one that’s laminated from 3 or 4 pieces of equal thickness so that I can use the laminations “seams” as a visual guide. If you have an even number of laminations you get the benefit of a one of them being your centerline. This build’s nose block did not have a centerline lamination but the center slab was narrow enough for eyeballing the symmetry. If you want to get fancy, you can build your nose block in such a way as to get a centerline seam as well as an equatorial seam, plus any other's you might want. When sanding, I use a hard backed sanding block so that the glue seams don't stand proud of the surface. As I get closer to the final shape, I continue with the hard backed sanding block but I use very light pressure.
Also helps to use a single light source when checking your work so u have a reliable shadow line to check for unwanted waviness. I 'm constantly re-orienting the noseblock/fuselage so that I'm alwasy sanding on the terminator transition between light and shadow.
A big one I often forget when I’m in a rush is to hold the fuselage so I’m looking at it head-on. The top of the fuse becomes a curved horizon. Slowly tilt the fuse nose up while observing this horizon. Obviously the horizon will form an increasingly tighter curve as it creeps up to the tip of the nose. Be on the look out for unwanted left/right asymmetry as welll as other inconsistencies in the character of the curve. Do the same for the bottom by slowly tilting it nose down as you observe the bottom horizon
Great stuff!
I have carved many fuselage plugs and other parts to make moulding plugs. All this advice is very relevant.
With careful work, you can make a laminated plug with incredible accuracy, easily +/- 0,5mm (0.020")and lower, with careful sanding and frequent glancing/measuring the lamination shapes and lengths. Make sure your wood laminations are the same thickness, though.
For the wood sanding tape trick, I made a vertically adjustable sideboard type of block for the abrasive paper side, and always keep a roll of smooth electrical tape around when sanding. You can always put masking tape over the end of a sanding block, too, in order to give you a lot of adjustment for doing thin edges such as this.
Another trick is to use spray adhesive and put abrasive paper in two grades on each side of a basic 'plank' sanding block. Do the rough sanding and then flip the block for most of the finer passes.
On harder balsa, you can actually polish the wood after fine sanding to, let's say, 320 grit with Scotchbrite-type scouring pads taped across a small block. Here, we have many different grades and densities, but I'm not sure in the USA. The Scotchbrite also seems to remove a lot of the dust from the grain line grooves. Before the first cost of dope or sanding sealer - or epoxy, the finish is pretty smooth almost instantly as there are very few dust particles.
I learned many of these tricks from my wooden yacht builder father before fibreglass came along and put him out of business. I make Chinese furniture now just for fun, so I have a lot of chances to use what I learned.
By the way, my dad became a production manager at Hawker Siddely Aviation after he gave up the yachting side - and that wasn't bad for learning stuff, either!
Doc.
