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Luke Maddux
15th May 2015, 11:47 PM
I mostly turn faceplates. As such, I got a sanding pad and set to learning to power sand my bowls. I got grits 120 - 400 and, up until recently, have always power sanded through those grits and then moved to hand sanding on the lathe, typically to 600 minimum.

I have, however, recently stopped power sanding. I just reached a point where I said "wait a minute... what am I accomplishing here?"

I was always under the impression that it was A: faster and more aggressive and B: creating some kind of orbital effect which helped eliminate sanding marks.

A: is obvious. It's more aggressive.

But B:... I just don't get it. Yes, it results in fewer CONCENTRIC sanding marks, but the marks are still there, they're just askew from round. If I just use little pieces of sandpaper in my hand, I can still get rid of the previous grit, and I still end up having to do a bit of sanding off of the lathe if I want to get that gallery-quality, zero sanding mark finish.

I know the tricks that people talk about. Sanding in the correct quadrant of the workpiece, keeping it moving around, only using the edge of the sanding pad, changing pads regularly, etc. etc.

So I've reluctantly determined that power sanding is worth neither the hype nor the money nor my time.

Someone drop some knowledge on me and prove me wrong.

Thanks in advance,
Luke

Mobyturns
16th May 2015, 08:10 AM
I much prefer the passive sanders over power sanding. I come from the school of thought that it is far better to spend a bit extra time in perfecting the cut from the tool than sanding. Excessive sanding introduces its own set of problems especially with woods that have differing densities in the blank creating uneven surfaces.

On my spindle work and bowls if I can I always take the opportunity to hand sand with the grain before moving to the next grit on sections of the turning that allow me to do so. :D

Christos
16th May 2015, 08:25 AM
I don't power sand often as I am not setup to. So when I resort to power sanding it is because I have some tear out that is causing me grief. I don't power sanding to the higher grits.

george mavridis
16th May 2015, 08:35 AM
I much more prefer hand sanding to power sanding. I am a bit outcast at my club.

rtyuiop
16th May 2015, 10:31 AM
I am a beginner still trying to figure out my preferred sanding routine, but so far I am getting best results with using coarse grit power sanding to deal with any problematic torn grain (maybe only necessary because I can't get a consistent clean cut for the life of me!), then switching to an inertia sander and moving up the grits.

smiife
16th May 2015, 05:57 PM
Hi luke,
Power sanding is much quicker than hand sanding,
I don, t think there is much wrong doing it either way
depends what you are comfortable with.
When you power sand how fast is your lathe running
and is your drill flat out?
I have never had a problem power sanding, but i do
sand to 800 grit and use an inertia type sander i have
found it to be very good, also once to 800 grit then use
EEE paste , it gets rid of the fine scratches and gives
the piece a great finish, then finish off with something
like glow to polish the piece,,,, hope this helps:2tsup:

Luke Maddux
16th May 2015, 11:48 PM
Smife: typically around 1000rpm and yes, flat out drill.

Moby: yeah, I've had a lot of luck hand sanding before switching grits. I think there is some good science/physics to support this being a smart practice. Unfortunately the grain or nature of the piece doesnt always allow, but when it does it's good stuff.

I almost bought an inertia sander from McJing today at the TWWW show. Maybe I'll go back and buy one... I can always use an excuse to buy another ticket.

brendan stemp
19th May 2015, 10:16 AM
I much prefer power sanding over sanding by hand. It is quicker and gives a better result; no doubt in my opinion. The redgum bowls I sell get sanded to 240. No further. Not necessary. No noticable sanding marks.
When power sanding I slow the lathe down to approx 400 rpm. But this varies according to size of the piece on the lathe. But generally speaking, slower is better.
My next preffered option is the inertia sander.

mick61
21st May 2015, 12:52 AM
G`day Brendan I agree with 240 for red gum no point going any further. With hard acacia`s[ there aren`t any soft ones ] sanding up to 2000 is worth the effort. power sanding Is good if you have the room on the piece to do so. You can`t power sand fine beads on a lidded container.
Cheers Mick

Luke Maddux
21st May 2015, 12:54 AM
I much prefer power sanding over sanding by hand. It is quicker and gives a better result; no doubt in my opinion. The redgum bowls I sell get sanded to 240. No further. Not necessary. No noticable sanding marks.
When power sanding I slow the lathe down to approx 400 rpm. But this varies according to size of the piece on the lathe. But generally speaking, slower is better.
My next preffered option is the inertia sander.


If you're able to get ZERO visible sanding marks after 240 grit then I'm doing something very, very wrong, or we have drastically different ideas of what sanding marks are.

I obviously need to revise my technique some.

Drillit
21st May 2015, 06:11 PM
If you're able to get ZERO visible sanding marks after 240 grit then I'm doing something very, very wrong, or we have drastically different ideas of what sanding marks are.

I obviously need to revise my technique some.

Hello Luke Maddux,
With power sanding my way (static using sorby type revolving sanding head)
(1) speed down to no more than 400-500 rpms.
(2) sand in single quadrant, moving & sanding from bottom to top.
(3) start with 150, 180, 240, 320 & 400. I find that is enough.
(4) remember to try and get your best finish off the chisel.
(5) after starting with the 150, the subsequent grits are designed to remove any marks left by the previous grits as you go through the grades.
(5a) when you are finished I wet down with water spray and paper towel and let dry. That will leave raise the grain and leave a nap. I then re-sand with 400. I would use this procedure also without a sanding head.
(6) if you using high speed sander on an electric drill or grinder etc, I reduce lathe speed further to no more than 250. I do not use grits less than 120 ever and would not normally use EEE, as a matter of choice only.
(7) You will also find that with green wood, the sap will clog up the paper very quickly. If using electric drill etc. you can use a cleansing rubber to remove clogged abrasive paper. Having said that, some timbers are more difficult to sand and you need to resort to hand sanding with the lathe off, particularly some end grain in bowls or where it is a bit punky.

Hope that helps, Drillit.

Mobyturns
21st May 2015, 07:22 PM
If you're able to get ZERO visible sanding marks after 240 grit then I'm doing something very, very wrong, or we have drastically different ideas of what sanding marks are.

I obviously need to revise my technique some.

Luke, Different timbers require different sanding & finishing strategies. 240 maybe all that is req'd for some & 2000 for others.

The most important factor with sanding is that the next grit up (240) removes the sanding marks from the prior grit (150) before moving to the next (320). You must sand out the next lower grit sanding marks before moving on as no amount of sanding at higher grits will achieve that.

hughie
26th May 2015, 10:43 PM
I much prefer power sanding over sanding by hand. It is quicker and gives a better result; no doubt in my opinion. The redgum bowls I sell get sanded to 240. No further. Not necessary. No noticable sanding marks.
When power sanding I slow the lathe down to approx 400 rpm. But this varies according to size of the piece on the lathe. But generally speaking, slower is better.
My next preffered option is the inertia sander.

Totally agree with Brendan. I have quite a selection of both power and inertia sanders. The finish especially on inertia sanders is always a few grits higher the the grit your using IMHO.
The only difference is with the inertia you need speed to drive the sander, other than that I wouldnt be with out mine.