Advice on burn marks in cove cutouts??

[Chris Brault]

I started helping a friend of mine a while back with kitchen cabinets. This kitchen has the cove cutouts. It's red oak, and is burned right when the bit entered for just a little ways and exited just a little. He cut them out and told me to take some 40 grit and just work it with my thumb. Is there any easier way you can think of to take care of this? It's hard on the thumb and darn slow. Thanks ahead of time :)

[Jeff Monson]

sounds like a dull cutter or a feed rate issue, burn spots can be hard to get rid of, I usually take another very shallow pass rather than try to hand sand it out.

[Chris Brault]

thanks for the advice jeff, i kinda wondered about that, taking another real shallow pass, it's amazing how hard they are to get out-

[Van Huskey]

I have to echo Jeff if the cutter is sharp I would look at feedrate. IF it is hand fed you tend to be very slow going into the wood and coming out. Jeff is also correct in that a shallow final cut is helpful and you can be quicker with less issues.

[Michael MacDonald]

you might try taking the router bit and running it through the cove with your hand... I have the same problem with some flutes I was cutting, and I haven't tried it yet but that is my intention. I originally tried sandpaper, but it was a losing proposition--even if you get rid of the burn, you probably dull the edges of the cove too much.

[glenn bradley]

+1 on cutter edge and feedrate. Red oak burns easily so any hesitation as the cut is started or ended can be problematic. The burn, as you have learned, is not a surface discoloration, the fibers are burned. The depth can vary and removal is a pain. If I am doing a lot of them, like an under cut for a drawer grip, I set the router about 1/32" shy of the finished depth, make all the cuts and then make them all again with the last 1/32" cut being very low impact, smooth and quick.

If you already have a pile to get the burns out of, file an old hacksaw blade into a sort of customized scraper. I find scraping superior to sanding for burn marks; could be in my head ;-)

[Brent Ring]

I assume that there is no other burning elsewhere, just the coves. IF so, all of the advice above is great, if not, slow the router speed down. I run mine most of the time at its slowest setting. Dont have any burns any more!

[Brian Kincaid]

I find scraping superior to sanding for burn marks; could be in my head ;-)

Scraping is definitely the way to go from my experience dealing with burn marks. Removes the burned fibers instead of grinding them in (sanding). Use a very sharp scraper that matches the profile, or use a curved scraper.

-Brian

[John Harden]

Scraping is definitely the way to go from my experience dealing with burn marks. Removes the burned fibers instead of grinding them in (sanding). Use a very sharp scraper that matches the profile, or use a curved scraper.

-Brian

+1 on this. Sounds like you're not familiar with a scraper. Lot's of good info out there on how to sharpen one. Get yourself a set of scrapers. A curved one will make short work of those burn marks. Just a couple of passes and they'll be long gone.

You'll be amazed at how much wood a properly sharpened scraper will remove. Very precise too in that you can remove wood from exactly the area you want, as well as adjust how much wood you remove by adjusting your angle of attack, pressure, bend in the scraper, etc. Very forgiving and important tool to have in your arsenal.

Final piece of advice is don't use a file to "sharpen" a scraper. That's like using a file to sharpen a plane blade. Use the same tools you sharpen chisels or plane blades with and hone the surface to the same degree. If you use water stones to 9000 grit on your chisels, then do the same with your scraper. You'll be amazed at the results.

Regards,

John

[Rob Young]

Scraping is definitely the way to go from my experience dealing with burn marks. Removes the burned fibers instead of grinding them in (sanding). Use a very sharp scraper that matches the profile, or use a curved scraper.

-Brian

+1 for the scraper. Using a curved scraper you can both adjust the angle of attack and twist the scraper until it fits the cove.

[Rob Young]

+1 on this. Sounds like you're not familiar with a scraper. Lot's of good info out there on how to sharpen one. Get yourself a set of scrapers. A curved one will make short work of those burn marks. Just a couple of passes and they'll be long gone.

You'll be amazed at how much wood a properly sharpened scraper will remove. Very precise too in that you can remove wood from exactly the area you want, as well as adjust how much wood you remove by adjusting your angle of attack, pressure, bend in the scraper, etc. Very forgiving and important tool to have in your arsenal.

Final piece of advice is don't use a file to "sharpen" a scraper. That's like using a file to sharpen a plane blade. Use the same tools you sharpen chisels or plane blades with and hone the surface to the same degree. If you use water stones to 9000 grit on your chisels, then do the same with your scraper. You'll be amazed at the results.

Regards,

John

And if you don't have stones and the other accouterments you can use the Scary Sharp method for scrapers too. Even just following up the mill file (good for quickly squaring the edge but does leave it rough) with some 400 and 600 grit paper stuck down to glass will make a world of difference in the quality of the scraping and the quality of the burr you can turn.

That said, treating the scraper like a plane blade (technically, it is one) and running it up to 8000 grit makes a fantastic shaving. But you can ease yourself into its use by starting out with a mill file for rough shaping and a little bit of 400/600/1500 wet-dry paper stuck to glass.

[Chris Brault]

thanks a million you guys for all of the advice, my thumb is killing me!!!!!! i figured there had to be a better way:)

[John Harden]

And if you don't have stones and the other accouterments you can use the Scary Sharp method for scrapers too. Even just following up the mill file (good for quickly squaring the edge but does leave it rough) with some 400 and 600 grit paper stuck down to glass will make a world of difference in the quality of the scraping and the quality of the burr you can turn.

That said, treating the scraper like a plane blade (technically, it is one) and running it up to 8000 grit makes a fantastic shaving. But you can ease yourself into its use by starting out with a mill file for rough shaping and a little bit of 400/600/1500 wet-dry paper stuck to glass.

+2 My water stone example was just that, an example. I actually prefer using the scary sharp, sandpaper method just as you do. I do use a Tormek for chisels and plane blades, but still follow up with micron paper for a keen edge.

For scrapers, I only use sandpaper. Works amazingly well.