[Lupus]

I hate purpleheart!!!!!!!!!!!! Never again! How do you get these $&@# burn marks out!

 

[kelsky]

Are they from sawing or sanding? I've not had an issue when I've worked with it in the past. It definitely is harder than most woods and susceptible to marks like this. Nice looking board by the way.

 

[Steve Neul]

Well it's woodworking. It's suppose to be fun so lighten up. When you sand don't bare down so hard and move around a lot. If you were using a belt sander with your innitial sanding it would go a little better. The orbital sander you are using is just building up heat. Also if when you change grits with your sandpaper if you would wipe the wood down with a damp cloth and let it dry, it would raise the grain and make your sanding more effective.

 

[cabinetman]

Keep an eye on the sanding disk. If you get a build up, it can burnish and scratch the wood instead of abrading it. I wouldn't use a belt sander on wood projects that have grain in varying directions. I would stick with a ROS.

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[Lupus]

Thanks guys, I burned it with the table saw. I've been using a card scraper but I can't get a good burr on it so it doesn't last long and I've hit it with I believe it's 60 grit with the ros. Also I've used about 6 razor blades to shave off some but it seem like iris very deep and won't lighten up at all. Ill try the wetting it trick also. Sorry for the anger earlier I've just been working on this in my spare time and it isn't fun at the moment as I feel I'm getting nowhere!

 

[MarkE]

A very finely set smoothing plane would probably work.

 

[Steve Neul]

Thanks guys, I burned it with the table saw. I've been using a card scraper but I can't get a good burr on it so it doesn't last long and I've hit it with I believe it's 60 grit with the ros. Also I've used about 6 razor blades to shave off some but it seem like iris very deep and won't lighten up at all. Ill try the wetting it trick also. Sorry for the anger earlier I've just been working on this in my spare time and it isn't fun at the moment as I feel I'm getting nowhere!

I thought I could see saw marks on it. If you are having that much trouble with the 60 grit paper you might pick up some 40x discs and go over it first with that until you get the saw marks off. Then go back to 60 grit discs and continue until you work your way to 180 grit or finer. Think of it as polishing. You use the 40 grit to work out the saw marks and 60 grit to work out the swirls the 40 grit makes and so on.

 

[Rick Mosher]

If you have a decent size cabinet shop near you, take it to them and have them run it through their wide belt sander. They will usually charge a resonable hourly fee and it will be perfectly flat.

 

[Dave Paine]

Purpleheart can burn when cut, like many other species. Sharp and clean blade helps to minimize.

The burn marks can be sanded out. Since this is end grain, I would sand first, but perhaps no need to remove entirely. Once you apply whatever finish you intend on putting on the board, that end grain will become as dark as the burn marks.

 

[Lupus]

I think I'm just going to try and keep at it with the card scraper. Maybe this project will be the one I how to sharpen one. Thanks for the help guys!

 

[Dave Paine]

I think I'm just going to try and keep at it with the card scraper. Maybe this project will be the one I how to sharpen one.

Card scrapers are not sharpened per se. They need a new burr applied by a burnishing tool.

Flatten the edge by a file or sanding, then burnish the edge to deform the metal slightly. It is the burr which scraps the wood.

You can purchase a burnishing tool, but essentially any round, smooth and hard steel will work. Some folks use the shank of a round Philips screwdriver, some folks use the non-fluted end of a drill bit.