Varnishing secrets article in FWW #168

[snowman]

I have read David Sorg's article in the latest Fine Woodworking. I have a couple of questions that people may know the answer to, about differences in products available in the US compared to here.

First of all I assume that when he talks about varnish, he means polyurethane?

He describes a process of sanding the final coat to 2000 grit sandpaper, then rubbing out the finish using pumice followed by rottenstone. I know that U-beaut sell tripoli powder. How does that compare/relate to pumice and rottenstone? Would you sand to a higher grit before using tripoli powder?

Also are the grades of sandpaper grit the same between the US and here? I'm curious as to why they always refer to grits 180, 220 and 320 in the FWW magazine - 240 grit is readily available here while I have never seen a 220. I'm sure that it would make no difference but it made me curious as to whether their 320 is the same as ours.

[ubeaut]

G'day Snowy - The grits are the same, 220 is available here but most shops skip a few grades to keep it a bit more managable, otherwise if they had 220, 240, 260 280, etc it would become a bit hard to keep track of and the poor old purchaser wouldn't have a clue what to buy.

The varnish they talk about could be good old fashioned oil based varnish or it may be poly, however rubbing out poly is a lot harder than rubbing out varnish because the poly is basically a plastic and isn't very cooperative when attacked with abrasives.

We do much the same finish here using varnish (lacquer, shellac or poly) sand with 1200 grit or higher then use EEE-Ultra Shine. Personally I reckon the pumice is a bit harsh for this application.

Rottenstone is similar to Tripoli but slightly softer. The Ultra Shine basically starts cutting at around 800 - 1000 grit and as it is being worked it breaks down to give a finer and finer cut until it is working at equivelent of around 4000 grit or even higher, when it is basically polishing the surface of the finish.

Hope this is of some help.

Cheers - Neil