Lignum vitae i might go up to 600. P400 sandpaper only oil finishes like tung oil teak oil require the surface to be finished to this level.
The first time i used an oil finish i was disappointed that it lacked the attractive sheen of a film finish.
Sanding fine woodworking for oil finish. In fact the photos illustrate this being done on apparently unfinished wood but many authors including in the pages of fine woodworking have argued against ultrafine sanding because it can interfere with the subsequent finishing process. Be sure you sand the whole surface with the same grit paper. If i m going to varnish a wood like walnut or maple 180 grit on the bare wood is fine.
Do the initial sanding with medium fine paper and finish with one or more of the finer grades. Oil finishes you can create a fairly smooth oil finish by sanding between coats using very fine grit sandpaper 320 grit or finer. Where oil has only one ingredient varnish contains resin and solvent.
First dried dye looks dull and ugly don t be alarmed keep going. Oil and oil varnish blend finishes have no measurable build so any roughness in the wood caused by coarse sanding telegraphs through. Do not use steel wool when preparing wood for water based finish as steel particles may cause rust spots.
If i m working a wood as hard as cocobolo for an oil finish i might sand up to 400 grit. But until adam godet discovered the right way to apply an oil finish he was getting lackluster results. And it s also not a requirement for all wood working projects that use those types of finishes.
Sanding oil onto the wood surface with wet dry paper helps fill pores with the swarf oil slurry you create and it can result in a smoother finish. Be sure to allow each coat to fully cure which means leaving overnight in a warm room. Some oil finishes such as watco danish oil and deft danish oil instruct to apply coats within an hour or two.
He advocates sanding through 500 grit and then polishing the wood further with 0000 steel wool. Repeat dye sanding until you re happy with the shade. He soon discovered the secret to getting an oil finish to shine can be summed up in three words.
But these finishes can be made ultimately smooth simply by sanding between cured coats or sanding each additional coat while it is still wet on the surface using 400 or 600 grit sandpaper. To speed the process or create a slurry to help fill open pores sand the oil into the wood with fine wet dry paper. For something like a knife handle i might even polish it on a buffing wheel.
Let it dry then lightly sand with a fine grit sanding sponge to knock down raised grain and to even out the color a bit. Also wet sanding will generally use 320 as this practice requires a very fine grit as well. If you miss a spot the stain will be darker on the rougher areas.