Removing circular marks after polishing

[Don Nethercott]

Hi Folks,
I am unable to remove the circular polishing marks in the bottom of my bowls.

After turning I sand with 80, 100, 120, 150, 180, 240, 320 and 400 (Hermes)
I then use some stuff that looks like Scotchbrite and comes in 3 grades, 600, 800, 1200. I don’t know what it is but I got it from the old Southern Woodturning in Canberra when I was last there. It’s now Carba-Tec and I can’t find it in their catalogue.

I then use Shellawax to polish. I press as hard as I can and run the lathe at 1140 rpm.

Any ideas as to what I am doing wrong and how to correct it.

Don

[Zsteve]

If all else fails - read the instructions

[Don Nethercott]

I have a copy of the UBeaut instructions which I follow. The only reference I can find to my problem is -
Q/ I am using Shellawax. I sand up to 1200 grit, but the finish on my bowl always has lines in it that look like sanding marks. Why?
A/ You should be using Shellawax Cream. It is designed to stay on the surface of the timber during application so it can be worked into the wood with heat from friction. Shellawax, as a liquid, soaks in to a bowl too quickly meaning you have to apply a heavier coat which will in turn pick up the weave of the material it is being applied with and will create those sanding type lines.

I only use Shellawax Cream.
Maybe you have a different set of instructions!!??

[Shane Watson]

I'm no turner but sounds to me like your not sanding properly in the first place. Personally I would stop using the synthetic steel wool and use abrasive paper through to 1200g making sure when you change up to the next grit you've sanded out any lines left from the previous. Frankly all I ever use the synthetic steel wool for is for inbetween coats and usually only on turned parts of furniture (eg legs).

But like I said, I ain't a turner so it could be all different to what I know, but you did post this in the finishing forum and well I am a finisher, or so that piece of paper in the bottom drawer tells me anyway!! :eek:

Cheers!

[rsser]

Think Don may have it, if you've been careful to sand thoroughly before moving to the next grit (tho one tip here is to wipe out any dust from your bowl and remove any residue from your paper each time you change grit - the aim is to get rid of loose grit from the process).

When applying Shellawax, make sure you use a soft close weave cloth and don't put too much on.

I often get marks when applying a second coat so I aim not to. If I have to, I cut the first coat with the finest paper I used in sanding and apply only a small amount. Usually I just top the first coat with wax.

[RETIRED]

Seein as how the Grand Poobah ain't here.

Sand up to 400, then use EEE and remove all traces of it. Make sure that the cloth is a tight wad like a french polishing rubber. Lathe speed shpuld be as fast as it will go without fling the bowl off. Use a clean surface to ensure that you are removing the EEE. The colour is the timber not the wax.

Stop lathe. Apply a light coating of Shellawax Cream all over the bowl. Start lathe. If it drowns you, you put too much on. Let it fling off. Now the tricky bit.

Using the cloth tightened into a ball or rubber apply great pressure and starting from the centre move out maintaing pressure the whole way. It is a FRICTION polish and requires heat to work at its best.

If you get a line in it start from the centre and start again. Do not use a new section of cloth.

The best way of sanding bowls is with a Vic Woods Rotary sander also available from Ubeaut.

Hope this helps.

[Cliff Rogers]

G'day.

Adding to what said, & I quote...
"Turn the lathe on and with the cream moistened portion of the rag
apply a steady heavy pressure to the work whilst slowly moving
the rag over the entire piece."

Use the same rag that you applied the cream with to do the polishing.
The bit of solvent(?) moisture left in the rag helps to stop the buildup
of dry/set wax/cream from caking & leaving heavy lines in the finish.

If you do "cake" it & leave heavy lines in it, you can redampen the rag &
try again or you can polish out the "cake" using EEE.

I find that I have trouble getting a truly 'even shine' on a large surface
using Shelawax Cream & will often use the EEE to polish the cream finish
to give an even satin finish instead.

[ubeaut]

To eradicate all traces of sanding get a Rotary Sander (http://www.ubeaut.com.au/rotary1.htm) you will be left with a copmpletely line free sanded surface. Stop using the scotchbrite stuff (probably Webrax if it is grey). It, like steel wool, is really designed for use on metal, not wood, and yes I know they say you can use it on timber but it is definitely no substitute for using the real thing.

You may also find that the scotchbrite stuff is partly burnishing the surface and almost case hardening it and thus will give uneven penetration of the polish. If you look in the book on page 46 (latest edition) you will find Webrax info and it says "I would not be inclined to use it on raw timber."

Only start using the EEE at 400 grit if the surface has been sanded using a Rotary Sander (http://www.ubeaut.com.au/rotary1.htm) otherwise you are best to sand up to at least 600 and preferably higher.

If you are working on a surface larger than 80mm you would be best to use Shellawax Cream or a mixture of the cream and liquid for sizes over about 250mm. This should stop any lines from the polish.

It is possible that you are either using too much or not enough of the cream. Not enough will give bright and dull patches. Too much can create lines in the surface. These are put there because you get a small wave of the polish building up on the back edge of the rag when burning the polish into the timber and if you happen to pick up some of this wave you are then trying to lay down new stuf onto the surface after the original has already done its work. This in turn will set up a series of lines and marks on the surface that aren't easy to remove.

Using just the right amount is one of the best tricks you can learn, it does take a little time to get right. Keeping the rag in a tight wad and using the same section all the way through the application is also another trick that is easily learned by some but not by all.

Hope this is of some help.

Cheers - Neil :)

[Don Nethercott]

Thanks Neil, , Cliff Rsser & Shane,
I'll try your suggestions .
Possibly I am using too much wax.
I do have one of your rotary sanders, but can't seem to get it to spin properly in the centre of the bowl.
Strangely I only seem to get these lines in the centre inside of a bowl, rarely on the outside.
Thanks for your help,
Don

[ubeaut]

Try working very slowly over the inside centre as the rotation speed is almost nil compared with the speeds attained as the work progresses towards the outer reaches of the bowl.