Woodworking Talk banner

Hand Sanding Question

1K views 13 replies 4 participants last post by  Labow 
#1 ·
Hey everyone.
My ROS has an issue, so I've been hand sanding a slab that I'm working on. It's a piece of cypress endgrain (cookie), about 2'x3'. I am using a block with some cork taken from a bulletin board glued to the bottom, and with the sandpaper attached.
I've sanded it to 400, and spent what I feel like was adequate time, but when I get down close to the piece and hold a light low and look at it, I'm seeing scratch marks. I believe what I'm seeing is the marks from the 400 grit paper. So, my question is, will you always see lines when hand sanding? Or do I just need to keep going at it? Maybe they're more apparent on endgrain vs a piece where you would sand with the grain?

Thanks.
 
#3 ·
Thanks for the response. Maybe I didn't sand enough with a lower grit, cause I went through all the grits (80, 100, 120, 150, 180, 220, 320, 400). Or maybe something got in the sandpaper and caused the scratches. I'll drop down a couple of grits and see if that takes care of it.

Any benefit to changing the direction I'm sanding with each grit? I've been sticking to the same direction throughout.
 
#5 ·
Here’s what i dont get: If you sand with 80 grit you leave 80 grit scratches, then you sand with 100 grit to get rid of the 80 grit, and leave 100 grit scratches, which you then sand with 120 grit...and so on. Following that logic l, when i sand with 600 grit i’m going to get rid of the 400 grit scratches, but leave 600 grit scratches, and so there’s always going to be something. Or is 600 so fine that you cant see the scratches?
What if i only sanded a piece to 220? Wouldnt there be a lot of scratches showing?
 
#8 ·
You will eventually reach a point where you cant see the scratches - but this is not necessary nor advisable.
The finish you use will normally specify which grit to use as the final. In most cases it will be 180 or 220. If you go beyond that, you are reducing the surface area that the finish has to stick to.
 
#6 ·
End grain usually "shows" a little more than face grain when it comes to scratches and finishing. That said, usually once you get above 240 grit, scratches become imperceptible if you did it properly. While youre not "inaccurate", moving to higher and higher grit turns more into burnishing than "sanding". If youre applying oil, I usually go to 400, but with finishes, I stop at ~240, not much point in going further.
 
#11 · (Edited)
Oh, also, Tony, why is getting rid of all the scratches not necessary? .............
Because there is a point that your eye cant see them anymore. If you take a real dense wood like rock hard maple, it will actually shine with a 2000 grit paper and look like you have a finish applied when in actuality you dont.

When I first started woodworking, since i had no one to ask questions to, I just experimented on my own to verify stuff.
I dont remember the exact numbers but you will get the general idea. I sanded several pieces of the same wood, starting with 120 grit only, on the first piece. The second piece I sanded 120 and then 150, the third piece I sanded 120, 150, 180 and so on and so forth. progressing upward I think I went up to 2000 - dont remember for sure.
So now I have a bunch of pieces of wood with each one sanded slightly higher than the previous one. Again, I dont remember the exact number buy just stay with me. The first piece sanded with 120 took 5 coats of poly to look smooth and the sanding marks became invisible The next piece with the 150 grit took only 4 coats of to get the same results. The next piece, the 180 only took 3 coats and the 220 only tool 2 coats to get the same results. anything above that only too 1 coat. Then when I reached probably 1500 and above the NO finish looked like the finished pieces. This was with poly because that is what i used in my beginnings. And thats why as a general rule, it is not necessary to remove scratch marks above 180 in a dense wood.
Oil finishes will probably go a little higher, but there too there will be point that the wood, especially dense woods, will not absorb the oil or finish beyond a certain point.

What I am going to ask is that some of you duplicate my experiment with oils and let us all know how that works out. And remember RTFL. Labels are important. The manufacturer of finishing products wants you to succeed.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top