Sanding prior to staining
I've just been reading a tin of commercial stain. The recommendation is to sand with 120 grit sand paper and then to sand again thoroughly with 400 grit paper before applyng the stain. Really? I have never even seen 400 grit paper, but judging from P240 it must feel like photocopy paper (smooth)... What o others here think? Does anyone know what dressed timber of the sort that you get in the hardware stores is finished to? Sanding must be the least rewarding part of any job... but if you don't do it right, well....
What effect do yo want? That determines the level of sanding
Quote:
Originally Posted by
GarciaJ
So I started out with P240, and then changed to P360. The P360 defintely feels rougher on pine... so I figure that one of the previous commenters is correct. How fine to go must depend on the timber, even when using oils.
Also I looked this up on Wikipedia, and some of the grit sizes being quoted here are just off the charts. The finest I could get at the local hardware was P240 on normal sandpaper. The finer grades can only be found on emery paper, and described as being for metal finishing. Yet some of you are describing 4000 grit and even higher... surely we are talking about different roughness scales.
The wikipedia chart stops at P2500... which is american grit 1000. The average particle size is only a few microns. At these grit numbers. Yet some of the responses here talk about serval thousand grit.
Many of the people that I know do not sand below 320 grit, and are happy with that. Fine, if you are happy with that, but it is not a fine quality IMO. However, what you need to consider is that a finish from a sharp hand plane or scraper is more akin to a 10,000 grit because it is sooooo fine.
If you need/want to sand then a really fine finish requires a really fine grit. Before I French polish I sand to 1000 or 1200 grit wet and dry, even on a soft timber like Australian cedar (Toona ciliata) and it makes a real difference in the finish. Harder timbers like Blackwood can cope with 320 to 400 grit, but do not deliver a fine finish, IMHO.
Hard work and fine sanding produce better finishes. I leaned to polish from an Austrian cabinet maker. He was taught to polish timber for two days (20 hours) with metho and pumice powder before any shellac was added. THAT is fine quality polish. What we do is pretty rough by comparison.
However, as i have said elsewhere, if you are matching an Australian antique finish then much lower polish levels are appropriate, so it is horses for courses.