1200 Grit

[Ross Lowry]

I am working with some wood called Kauri and it says to sand to a 1200 grit for best results.
I had went from 120 to 220 to 500 to 600 then to 1200.
The 1200 is a Harbor freight brand and is leaving the wood looking black in spots.
Is this due to cheap sandpaper or maybe the wood isn't smooth enough yet?
If it is due to cheap sandpaper then what brand would you suggest?
Thanks again!

[Anthony Anderson]

Are you using a wet/dry sandpaper? If so, sometimes the black/grey grit will transfer to the workpiece. Try using some 6" DA paper that is 1200 or 1500 grit. Bill

[Steve Schoene]

Your results have given you reason to distrust the Harbor Freight brand. 3-M and Mirkla are quality brands, plus Klingaspor has a good rep for on-line materials. Sandpaper isn't a place to economize, especially with very expensive wood.

[Ross Lowry]

Thanks for your inputs.
Yes I was using wet/sand paper.
What is 6" DA paper?

[Ross Lowry]

Ok another question.
I am finishing with a polyurethane and it says to sand with 220 in between coats, but since I am using 1200 for the wood I am afraid of scratching the actual wood with the 220 after the first coat.
Can I use fine steel wool or even 1200 grit inbetween coats or will there be an adhersion problem?
Thanks

[Steve Schoene]

If you are using varnish over the wood, there is no point in sanding beyond 220 in the beginning. The sanding to 1200 is for an oil finish at best, wax alone, or even no finish, just polishing the wood taking advantage of the natural gum that kauri has.

Using 220 grits between coats is rather coarse, with 320 being the most common, and 400 the finest one should use. Varnish, and particularly polyurethane, needs the "tooth" for adhesion.

Personally I would never use a polyurethane varnish over such pricy wood. Polyurethane is not as clear and will be much more challenging to rub out to an even sheen. My first thoughts would run to shellac, which can be French polished or rubbed to a very high gloss yet very thin transparent finish. Kauri is a fairly soft wood, so I wouldn't be using it for applications that really needed the abrasion resistance of polyurethane varnish. (No varnish will stop a soft wood from being dented or scraped.)