Dubbeld French Polishing Kit
- 500ml screw top air tight mason jar for storing used pad/rubber – don’t let it dry out!
- raw cotton wadding
- cloth wad covers
French polishing is the process of applying shellac using a French polishing rubber. The rubber is made by wrapping a piece of worn, lint free, cotton cloth (old white t-shirt material is best) around some cotton wadding or cotton waste.
The purpose of the rubber is two fold. Firstly it acts as a reservoir to store the polish and secondly it is the applicator used to transfer the polish to the surface.
Place a hand full of cotton wadding into the centre of the cotton rag, bring in the four corners of the rag and then twist to form a pear shaped pad, ensuring that the base of the pad is flat and free from creases or defects as shown. The size of the rubber can vary according to the user or the size of the job to be completed.
Depending on whether an open grained or filled grain finish (or anything in between) is desired, will determine whether we fill the grain prior to french polishing.
For an open grain finish, sand to minimum P400 and remove all dust from the surface, then go straight to bodying up.
For a grain filled finish, do not remove the fine dust as this will mix with the shellac, along with a filler such as pumice powder, which is also a very fine abrasive.
I do not recommend using coloured fillers as timber changes colour and filler does not.
Apply the pumice by wrapping a small amount in a Chux type cloth and dusting the surface.
Charge (soak) the rubber with a 1lb cut shellac, backing off when the surface of the rubber is not immediately absorbing. Tap the rubber on the palm of your hand (use gloves) or a paper towel to flatten the surface. The polish should not squelch or run. If it does, squeeze the excess out.
Work the surface of the timber in circular motions. The amalgamation of dust, pumice and shellac will form a paste and as it is worked will both abrade the surface and begin to fill the pores of the timber. Repeat this until the desired level of filling is achieved. After a few layers of shellac, a couple of drops of lubricating oil such as paraffin or mineral oil will allow the rubber to move more freely. Apply it in drops from a squeeze bottle or with the tip of your finger. Take care not to apply too much oil as it will have a smearing effect on the surface and will need to be removed later.
Once the surface is dry (preferably overnight), with P600 or P1200 wet or dry paper with a hard block and water as a lubricant, scuff the surface with the grain. A little dishwashing detergent or pure soap can be useful as a wetting agent.
Hints and tips:
- Never allow the rubber to stand still on the surface as the polish will melt into the previous coats
- The rubber must be used in a constant flowing motion while it is on the timber
- Keep a check on the face of the rubber to make sure it is clean. Clean as necessary with a clean rag and alcohol
- Regularly flatten the rubber by tapping on the palm of your hand
- Make sure the face of the rubber doesn’t wear through. Reposition the wad as necessary
- Do not let the rubber dry out. Add a few drops of polish as needed
- Never work the rubber too wet. Squeeze out excess as previously mentioned.
This is the process of building up the polish. Ideally, if we wanted to apply 100 coats, they would be applied in 3x 30 coat sessions, allowing a few hours between sessions for the coats to gas out or sink. The application of the shellac is in the same way as grinding except no pumice is used. The rubber must not be overloaded as excess shellac will ridge up with the circular motions and will not flatten out. Try to never use a new rubber for bodying up as it will hold too much polish.
Applications are made by using the rubber in circular and then figure of eight motions. Again, apply a few drops of paraffin oil to aid as a lubricant. The surface will tell you when it has had enough shellac because it will start to pull. Many factors will affect this, especially the temperature and humidity of the work space and the cut of the shellac.
The final pass in a session goes with the grain, passing fairly quickly and lightly over the surface. Always finish the session in this way. The rubber should always be slid onto the work from one side and off the other during the polishing stroke. Placing the rubber on the work and then starting the stroke will create a mark, which will be very difficult to remove. Likewise the same problem will arise if the rubber is stationary on the surface; this is because the alcohol will immediately start to reactivate the previous coating.
- Never let your rubber dry out. Always put it in an air tight jar (supplied with french polishing kit) when not in use, even if only for a minute.
Spiriting Off/ Buffing to a high gloss (piano finish)
Once a sufficient layer has been achieved on the surface, spiriting off can commence to produce the final high gloss finish.
Scuff the surface with P1200 or higher to remove any high spots. A new rubber must be charged with only a couple of drops of polish and twice the amount in alcohol and applied lightly and quickly over the surface with the grain (no circular motions) to remove the oil and achieve a gloss finish.
Alternatively forego the rubber and use a fine cutting compound (6000 grit or higher) and buff the surface to gloss.
The above mentioned practised and applied correctly, will result in what we call a piano finish. This is the highest shine and clarity of any finish and regarded universally as the best finish of all. However, if this is too bright for your liking ,dulling down is the removal of the high gloss and can be done in the following ways:
- method 1. Take some 0000 steel wool and rub into some paste wax. Rub in the direction of the grain up and down the surface until it is dulled to the required finish, then buff out with a clean soft cloth. The problem with this method is that it is inclined to leave fine scratches in the surface.
- method 2. Take a dulling down brush that has fine, tightly packed bristles. These may be hard to find but a shoe polish brush will work. Sprinkle fine pumice powder on to the bristles of the brush and rub briskly up and down the grain to the required finish. Wipe off with a clean soft cloth. This method, I believe, is the superior of the two and gives a soft patina to the surface.