There is a cool vid of Simon Anderson finishing a CNC shape for Adam Robertson (rooky that took 2nd at Bells).
For those CNC shapers that are Skill planer challenged. I know, it ain’t the ‘real thing’.
U tube vid down the bottom. Question: what grit papers did he use?
Nice video: Looks like he is using a block made out of BLUE XPS with 40 grit Klingspore to knock downs the machine grooves.
Clean the stringer and finish with 60 grit Klingspore before screening.
The shapers that are finishing boards for the large factories are very skill shapers raw blank or machine cut.
An unexperienced shaper can ruin a machine cut. It still takes skill! Notice how Simon was careful not to over shape!
Also he trued up the nose and tail before proceeding.
I use predominantly 80 grit for finishing PU pre shapes. Sometimes a bit of 40 grit doesn’t go amiss either. If you were going to airbrush it then you would probably want to go to 150 grit before “passing it on”.
It’s hard to come by but if you can get it 220 Brown Japanese screen cloth is amazing stuff. After 40, 60, then 120 screen and a light pass of 220 Japanese cloth and the finish is perfect for a high end airbrush job. I used to use 80 when I first started shaping. However I found that 80 would leave imperfections. I have a Japanese shaper friend that is a perfectionist and use some of the same tools. The problem I have is that other shapers take all my cool planners and sand papers to the point that I don’t have them anymore? I keep my sand paper under lock and key. When I find the Japanese planes that went missing I will keep those under lock and key as well. You being in NZ gives you access to all kinds of cool tools. Japan is a quick trip from Auckland. Try the wood working districts for all kinds of cross over tools. Simons Sanding blocks are pretty cool. I have some XPS sanding blocks as well and their so light while still rigid that they make sanding a breeze. I also use a Balsa wood block with a piece of 2mm neoprene that I wrap a sheet of 60 grit to knock down any high spots before screening. The key is no to produce any distortions. I’ve seen a lot of different shapers finish boards perfectly. All very skilled and all using different methods. In the end I guess it’s whatever your most comfortable with?
I will keep an eye out for the Japanese stuff and thanks for the tip. I’ve been pondering the idea of tossing my foam shaping blocks in favour of just plain 'ole wood and sandpaper for a lot of the work. Will still be using sandpaper to finish the rails but I’m leaning towards hard tools for removing the machine marks and a lot of the blending. Have tried using a wooden concrete float a couple of times now and it fits most places pretty good. It also has the advantage of a handle already attached. Just take a couple of self adhesive sandpaper discs and stick on. When they’re worse for wear just peel off and apply new paper. For the tighter areas just use a narrower block of wood. Seems to be working pretty good for me so far.
I was thinking it might be something like 60, 120 and 220, so not too far off. Most hand sanding I have seen was using one of those big rubber pads, but I can see the advantage of having a sanding block with less flex to clean up a machine cut.
Computer designed boards are a lot more complicated than they first appear, but that’s another thread.
60 grit to take down the grooves would be way to slow. 40 grit is faster. Some shapers use a 7" sander with a soft pad to knock down the grooves. I don’t do it any more and I take an extra five minutes and block them out by hand. The key is not to distort the preshape.
i use 40 spray glue onto eps or xps
be careful with eps blocks they can drop a bead that will fck everything up