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Finishing Woodwork

I have been refinishing old woodwork in pommy cars for most of my life. As I approach the 60 years of age barrier – [on the low side you are middle aged the high side you are geriatric] I have been approaching paint manufacturers about their products and the finish I could expect to use on woodwork.

Most urged me towards two pack finish techniques. From experience in the commercial industry this was not the way I wanted to go. Most two-pack systems are carcinogenic [cause cancer] and the finish looks like plastic.

The ever helpful people at PROTEC paints suggested using their CATALAC system of refinishing before they realised that I was going to use their furniture finishing product in a motor car.

They described their CATALAC product as having almost no ultraviolet resistance as it was formulated for indoor furniture. I responded that if one of my restored woodwork pieces spent 36 days a year in the open i.e. outside a garage I would be surprised. They agreed that a life expectancy of 20 years would be reasonable for that sort of exposure.

The system starts with a clear sanding sealer, which is used in exactly the same way as primer filler on metalwork. It apparently contains filler and about 3 coats are adequate to fill most wood grains. Note that it is very important to strain the filler as I kept getting white spots in my trial wood finish pieces. I thought it was coming out of a dirty spray gun but after much effort in cleaning a spotless gun it turned out to be a paint problem.

After spraying the sanding sealer it should be allowed to dry at least overnight and preferably 24 hours. There is a fair bit of contraction in most fillers and immediate sanding will not allow this contraction to settle into a stable configuration which will sand back and remain a level surface. The problem is known as “sink back” in the motor trade. After the sanding sealer is well and truly dry as previously mentioned it should be blocked down i.e. rubbed back with wet and dry paper supported by a sanding block. The best grade of paper to use is about 360 to 400 wet and dry papers. I have used 280 grade to get a fast cut but then used 400 grade to smooth off the finish.

Note that it can be rubbed wet with water but use it sparingly on Jaguar wood as water may affect the plywood or timber base used under the walnut veneer. Another small word of warning is we have discovered that you really need to rub the sanding sealer right back or very close to the wood. Otherwise there is a slight refractive effect in the finish if too heavy a coat of sanding sealer is applied and not rubbed back properly. It will come through the finished product as a suggestion of “milkiness”.

Once it is all dry the wood can be sprayed with 4 to 6 coats of CATALYC 7500 HG lacquer and a very nice finish results. Trials were carried out with less glossy finishes in this lacquer range which goes from matt to very shiny however we all agreed that the HG [hi-gloss] was the preferred finish.

Probably the best part yet to come is the price of the PROTEC product. A litre of sanding sealer is less than $10.00 and that is more than adequate for one car’s woodwork and it is a similar price for the high gloss 7500 HG lacquer. When I dropped into the PROTEC Geebung branch one Friday afternoon a week ago they were out of stock of 1 litre cans of 7500 HG lacquer but they had plenty of 4 litre cans at $22.00 + GST. I.e. $24.20 retail or just over $6.00 a litre. Since I have other projects on the go where clear lacquer is useful I thought to heck with the expense and lashed out on the 4-litre can