Sanding grits

[Reed Gray]

Well, I also posted this over at WC, but have to ask here as well. With the advances in abrasives, I am seeing grits of 260 and 280 in the fine range. After using them, I don't really like them. They do fit into the next grit up formula (that grit number plus half as in 180 + 90 =270). Main reason is that whenever I step up from 180 to the next grit, I always seem to find some 120 scratches. They come out fairly easily with 220. Some turners even go from 120 to 220 without using 180. Problem with the 260 - 280 is that it is very difficult to get those scratches out.

Any one else run into this?????

robo hippy

[Don Alexander]

my normal progression is 150, 220, 320, 400, 600 though lately i have taken to using 120 to start on some of the rougher tearout then on to 150 etc i use Klingspor's J-Flex sandpaper i can get it pretty cheap ($3 /lb) from their bargain bin and i like it better than anything else i've used
other than Abranet and obviously Abranet is alot more money

never use 260-280 grit and have seen no need to try it scratches have been alot less of an issue since i took Wally's advice and started wet sanding with some oil (i have been using clear Danish oil as it doesn't darken the wood like BLO) i also lightly sand cross grain on woods where scratches are problematic HTH YMMV

[Dennis Ford]

I sometimes find scratches a couple of grits coarser than what I am using. When that happens, I go back a grit level to get them out.

The 280 grit that I have seen is P280; switching between regular and the "P" grades is confusing because the numbers don't mean the same thing.

[Kyle Iwamoto]

Are "grits" standard? By this I mean is 3M 220 and Norton 220 the same as Abranet 220? If you were to switch brands, that could be a problem. The reason I ask, is that Norton seems "sharper" than the same grit of 3M. They both, when new, seem sharper than the Abranet. Even 3M wood seems sharper than 3M wet or dry.

[David E Keller]

I've never heard that formula for choosing the next grit, Reed, but I don't generally make large jumps like that in lower grits. My starting grit varies from 80 to 150 depending on the wood and how well I did with the tool. Beyond 150, I go 180, 220, 280, 320, 360, 400, and sometimes 600 or even 800. I haven't had great luck skipping ahead, and I find the process faster with more grits than with less.

Kyle, there doesn't seem to be a real consistency among grits of different brands in my experience... I just use Vince's discs now.

[John Hart]

I've had that problem Reed, but I think I've resolved it with less pressure. Like when I'm using the heavier grits, I have a lighter touch. Works for me anyway.

[Jeff Nicol]

Reed, I use 240 inbetween the 220 and then 320,400,600,800 and that is about it most of the time for me unless I am really shooting for a glowing near flawless surface that I will wet sand up to 2400 grit and oil. I find the 240 purple paper from 3-M is incredible for removing just about any marks that are left from previous grits. But just like most things there are always exceptions but it is when I try to sand out a stubborn spot or some tearout.

More patience I guess,

Jeff

[Don Alexander]

there is so much of the turning process from start to finish that varies depending on the touch/feel of the individual turner sanding is definitely
one of the areas where a slight change in pressure can drastically change the results also the consistency of the grit on your sandpaper makes a big difference

i think its cool that there are so many different techiques , tools and styles that can and do effectively produce awesome pieces that , like the piece of wood itself, are truly one of a kind

[Reed Gray]

My usual grit progression is 120 (some times 80 is required, but 80 grit scratches are the most difficult to get out, even more so than some tear out and tool marks), 180, 220, 320, and 400, at least for my bowls. I just have noticed that when I jump to the 280, and not the 220, I am finding more residual scratches. Hate having to go back. I do use light pressure (the weight of the drill max) and slow speeds on the drill. No hand sanding on my bowls. I have a good light (Blue Max, or Ott lights are another one that the people who do fancy hand sewing use) that is very close to natural sun light. Maybe I need stronger glasses.

robo hippy

[Bill Bulloch]

Sanding your turnings -- who-ever-heard? I'm going to have to try that.

[John King]

See American Woodturner, Journal of the American Association of Woodturners, October 2010, vol 25, no 5, p 25, Sandpaper, The Nitty-Gritty by Art Scott. It's all you ever wanted to know. - John

[Reed Gray]

Seems like sanding technique is as varied as turning technique. Biggest problem is getting all of the previous grit scratches out before advancing. Good light, patience, stronger glasses.

robo hippy