Can't Get Rid Of Router Lines

[brianlidgard]

Hi, question…  Can't get these router lines out of this long parota slab, sanded it with orbital 60 80 120 220 and all looked good... then sealed it ([b]Brushed on polycrylic satin 2 coats), lines came back.  Stripped it down again and repeated the same sanding process 60 and up to 220 again, looked good, didn't see any lines from any angle of lighting, didn't feel any lines......, sealed it (sprayed on polycrylic 2 coats), lines showed up again.  Never seen this happen before.  Help!?[/b]

[barryvabeach]

Brian,  I often get router lines when making multiple passes, the slightest tllt of the router is all it takes.  My suggestions is a card scraper. lee valley  Sandpaper will smooth ridges, but generally won't make them disappear.  Once you get used to sharpening a card scraper, you will find it is much quicker than sanding, and your use of sandpaper will go way down - just a quick pass or two after the card scraper.

[jteneyck]

I get those, too, when flattening slabs.  My approach is sanding but I start with 36 grit and go across the grain, then at 45 deg one way, then 45 the other, and finally with the grain.  Repeat with 60, 80, 100, and 150 grit.  The key for me is starting with 36 grit.  I know that sounds heavy handed, but the slabs end up flat. I do large table tops the same way.

John

Looking at your photos again, it looks like you have some divots in the wood, not just those router marks. I hard pad on your ROS would help prevent that, along with good technique. Also, the larger your sander the better. I use a 6".

[brianlidgard]

I get those, too, when flattening slabs.  My approach is sanding but I start with 36 grit and go across the grain, then at 45 deg one way, then 45 the other, and finally with the grain.  Repeat with 60, 80, 100, and 150 grit.  The key for me is starting with 36 grit.  I know that sounds heavy handed, but the slabs end up flat.  I do large table tops the same way. 

John

Looking at your photos again, it looks like you have some divots in the wood, not just those router marks.  I hard pad on your ROS would help prevent that, along with good technique.  Also, the larger your sander the better.  I use a 6".

Thanks for the info.

[Cabinet Monkey]

What kind of bit were you using ?