LumberJocks

Why won't it work for me????

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by George M posted 08-09-2011 01:21 AM 1220 views 1 time favorited 9 replies Add to Favorites Watch
View George M's profile

George M

118 posts in 2230 days


08-09-2011 01:21 AM

So I just started doing some lathe turnings again after 30 years. I have been working on a couple sets of peppermills and am going nuts trying to get a good sanded finish.

*Why can’t I get rid of the sanding lines??

I’ve read blogs on sanding turnings. I’ve watched videos. And I still end up having to sand by hand with the grain to get a good finish.

I have used slow speed. I have used high speed. I make sure the paper isn’t stationary and always moving. I have used grits from 120 to 150 to 180 to 220 to 320. I don’t know what else to try.

So what is the secret? How can I get a great sanding finish just using the lathe?

-- George, Parker Colorado


9 replies so far

View hairy's profile

hairy

2384 posts in 2998 days


#1 posted 08-09-2011 02:14 AM

I use something like this in a cordless drill. It really works.I usually start to feel safe around 150 grit that it won’t sand away detail, below that and you need to be cautious.

http://www.woodcraft.com/Product/2003740/33563/2-Hook-and-Loop-Pad-with-14-Shank.aspx

To get a good finish right off the tool takes a lot of practice and sharp tools, cutting , not scraping.

-- stay thirsty my friends...

View lew's profile

lew

11343 posts in 3221 days


#2 posted 08-09-2011 02:32 AM

Does your lathe have a reverse function? That may help. Also I have heard of turners dampening the surface with water to help raise the grain prior to sanding. I haven’t tried either method.

When you think of it, a pepper grinder is usually just a big spindle so when you sand it on the lathe, you are actually sanding across the grain. Something you wouldn’t do on a flat board. So some scratches seem inevitable. I usually sand- with paper- with the lathe turning. Turn it off and look for scratches. If there are deep ones, I sand some more with the same grit trying to get consistent scratch marks. Then move on to the next grit until I get to about 180. At that point, after sanding with the lathe on, I turn it off and sand “lengthwise’ with the grain where possible. Same for 220 grit. After that I switch to Abralon pads and go to 5000 grit, with the lathe running. Now, grab a big handful of shavings, left over from the turning, turn the lathe speed to about 75% of max RPMs and then hold the shavings against the piece. This final step polishes the wood. There still may be some very fine scratches but they almost always disappear with a poly finish.
Sanding and finishing are really my weakest skill. I keep trying, however.
Hope this helps.
Lew

PS, As I was writing, Hairy added a great accessory. I use it also. In addition, on larger pieces- like a rolling pin, I put sanding discs on my random orbital sander and use it while the lathe is turning.

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View George M's profile

George M

118 posts in 2230 days


#3 posted 08-09-2011 03:44 PM

hairy – I’ll look into that part. Does it work well for both spindle and bowl turnings or just bowl?

Lew – Yes, it is the cross grain sanding that gets the marks. However I keep seeing videos of people that only sand with the lathe and get no marks. That is what is frustrating me. Do the Abralon pads get rid of any existing marks? I had forgotten about the polishing with shavings. Will mark that down.

-- George, Parker Colorado

View Bluepine38's profile

Bluepine38

3341 posts in 2551 days


#4 posted 08-09-2011 04:16 PM

I use the 3m roloc discs with variable speed drill and low enough rpm on both the drill and the lathe that
I do not have to worry about burning the wood. Flap wheels also help in some area and leave a smooth
surface with the finer grits. I just used scrap pieces of wood to practice on until I got the sanding down
a little bit. A dust collection and air filtration system make it easier to concentrate on the sanding also.

-- As ever, Gus-the 77 yr young apprentice carpenter

View George M's profile

George M

118 posts in 2230 days


#5 posted 08-10-2011 02:45 AM

Bluepine, good ideas. I’ll look into the flap wheels.

cr1 – The wood I have been working with are Cherry, Maple, and Walnut. I must admit I do not always get a new piece of sandpaper. Also I do need to wipe the work better between grits. Thanks for the heads up.

-- George, Parker Colorado

View hairy's profile

hairy

2384 posts in 2998 days


#6 posted 08-10-2011 03:31 AM

It is easier to use on bowls.

I normally hand sand along the grain between grits, it’s just part of the process for me. Wipe or blow off your workpiece between grits.

-- stay thirsty my friends...

View peteg's profile

peteg

3857 posts in 2289 days


#7 posted 08-12-2011 12:41 AM

I presume you are cutting with the grain & not thru or across?
With most spindel turning you should be able to get an almost “of the lathe” finish prior to sanding, you may need to play with your tool selection, a good quality Skew would be my choice for a pepper mill type turn.
As far as the sanding goes,
Use only aluminium oxide, or wet n dry type papers (ie good quality)
go thru the grades & dont skip a grade,you can’t remove 150 grit scratches with a 320 paper, if you notice scratches after a size then go back & redo
use a bit of parafin oil with each size, cuts down dust & softens the cutting, wipe with a paper towel between each application,
Yes fwd / rev does help, but is not esential for a good finish
you know, sometimes you get a piece of timber that just doesn’t want to play ball no matter what
Good luck hope it comes right for you

-- Pete G: If you always do what you always did you'll always get what you always got

View George M's profile

George M

118 posts in 2230 days


#8 posted 08-12-2011 03:20 AM

Actually it is all across grain for a pepermill. That is why the scratches are so problematic. I think part of my problem is I have to get better with my tools. I used mostly gouges and scrapers. I have just started practicing with the scew. Of course I have to use the gouges on concave areas.

I must admit also that I use dry sandpaper – not wet/dry. Maybe I will try that also.

Thanks for the info.

-- George, Parker Colorado

View Carl Fisher's profile

Carl Fisher

53 posts in 1941 days


#9 posted 08-17-2011 06:57 PM

Your pepper mill is a bit larger than the pens I typically turn, but it should be about the same process.

The trick I’ve found is between grits, stop the lathe and sand lengthwise with the lathe off. This should help to remove the sanding lines around the circumference and prepare the piece for the next grit selection.

A skew will get the piece smooth enough that you could start with a much higher grit than a scraper or gouge.

-- Carl Fisher, Fort Mill, South Carolina --

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com