Rubbing leaving tiny ridges

[Green]

I restored a set of family dining chairs (circa 1910) via attending french polishing classes last year. They finished up a treat. Success went to my head and I've taken to restoring a sideboard which has large surfaces areas, unlike the chairs. I'm having trouble applying the shellac as patterns are being left in the polish after each rub.
Could my rubber to small? (no jokes please)
Could the mix too thin or too thick? or,
Is this just normal and I need to fine sand or steelwool between rubs?

forever Green

[Duncanmck]

The first coats of shellac can be applied to the timber in a circular motion. This is allowed to dry 24 hours sanded with 500 - 800 grit wet & dry paper with a turps/linseed oil as a wetting agent. The remaining coats should be applied with the grain of the timber and not in a circular motion. You should be able to apply about 4-8 coats per session. (a coat is a single pass of the rubber over the timber). Allow to dry 24 hours and again 500 - 1000 wet & dry with linseed/turps as a wetting agent.

1. You always need to sand between coating sessions.
2. Application in a circular pattern is only for the first coating session, if at all. Others only apply rubbings with the grain and no circular motion.
3. Shellac should between 400gm shellac per 1000ml metho and 200gm shellac and 1000ml metho. (if your mixture is too thick though it should also be drying on the rubber and leaving a buildup on the outside of your rubber cloth)
4. Assuming shellac is correct viscosity, then the other reason is that you have too much shellac in your rubber and hence are applying it too thickly.

Some photos of the markings would be very helpful if this does not answer your queries.

[ubeaut]

G'day Green - It is common for fine patterns to be left on the work by the rubber, this shows that the polishing is progressing, however if the patterns are very pronounced then it is most likely that your rubber is too wet and/or the polish too strong.

The size of the rubber shouldn't make too much difference however for a reasonable size flat surface it should be something that fits nicely into the palm of your hand and won't cuase you to cramp up with use. The working face of your pear shaped rubber, when flattened should be around 30mm wide by 60-70mm long, depending on the size of your hand.

Idealy when you go to a french polishing class you should take a flat piece to work on and not a chair, as all you basically learn to do with a chair is apply shellac, not to french polish.

I don't know what sort of french polishing Duncanmck is referring to but it bares no resembelance to any I have ever heard of. That is just shellac application.

Apply the shellac in varied patterns with the rubber, circles, figure 8's, ovals to the left ovals to the right, back to circles etc, etc, after enough applications straighten out by going up and down the grain with straight strokes, if done correctly there should be no need to sand between coats.

By varying the pattern of the applications you basically rub out the previous pattern and don't allow a build up of patterns to form, straightening out finishes that session and eradicates any fine pattern marks that may still be on the surface.

Do not just go straight up and down the grain without varying the pattern or you will be left with train tracks and tram lines on the surface, which will have to be sandad out.

Better still Click here and get the book. It will solve all your problems.

Cheers - Neil

[ozwinner]

Buy the book, it will all become clear.

Al

Disclaimer, I dont care if you think Im getting a kick back from Ubeaut. Which Im not, so why am I writing ths dribble.

[Green]

Neil - That all makes sense, right down to the lessons NOT learnt by taking the wrong item to the classes. My rubber is way too small and I'm sure the tracks are the result of shellac oozing out the sides of the rubber (like bow-waves).

What exactly do you mean when you state that the polish is "too strong". Do you mean that the mixture is too thick or that I'm putting too much on the rubber, or something else?

Green

[ubeaut]

If your polish is being used at full strength it is too strong, initially you would need to cut it at least 50/50 with meths and then continue to cut it with metho as the polishing proceeds until towards the end you are almost using pure alcohol with just a touch of shellac. Not quite as simplified as that but you will find that out as you go.

The rubber should be fully charged with your shellac mix then pretty well all of the excess squeezed out till there is nothing coming to the surface until a reasonable force is placed on the rubber. The face of the rubber should feel ever so slightly damp when rubbed on the palm of your hand, yet carry enough polish to lightly wet the hand.

Begin your circles, etc with light pressure on the rubber, as you continue you will need to exert more and more until towards the end of a session (as the rubber begins to dry out) you will need to exert a pretty heavy downward pressure on the ruber as though you are trying to drive it through the top of the work, and whatever happens during the application, never let the rubber stop its movement, not even for a split second.

Hope this is of a bit more help to you.

Cheers - Neil

PS You will also need a bit of paraffin oil as the polishing continues as lubrication for the rubber. Like I said, get the book http://www.ubeaut.com.au/book.html and you won't go wrong.