Eliminating Burn Marks when Routing Flutes

Tips on router techniques to prevent burning at the end of flutes, and on tools and methods for removing burn marks when they do happen. December 28, 2005

When dealing with hard rock maple I always get a burn mark on the starting end when making fluted columns. I have been as careful as possible but always seem to get some burn marks. Does anyone out there have a good solution for sanding these off without disfiguring the end of the flute? I have tried everything I can think of. Hand sanding does not apply enough to get the burn to disappear. I’m looking for a new trick. Maybe a variable speed router?

Forum Responses
(Cabinetmaking Forum)
From contributor J:
I would suggest trying a Dremel tool. Before our CNC router, we had the same problems with burns. Hand sanding disfigures the rout. Dremel has a round end tool that worked pretty well. We were able to keep the shape. We had to sand a little afterwards.

From contributor F:
I have a palm gouge that I use for carving (very sharp). One swipe across the grain and there are no more burn marks. It’s fast and there is no sanding needed.

From contributor T:
This works for me: Cut your flutes in two passes. The first pass removes most of the stock. Between the first and second pass, moisten the end of the flute with some water. Dampening the wood like this will go a long ways to minimize burn marks. It will raise the grain a bit, but this is easy to sand off when it dries. Stop blocks at both ends of the cut help minimize the hesitation that allows for heat build up. Sharp tooling is also handy.

From contributor C:
I do just like Contributor T. Plunge your cut in the middle of the piece and work your way back at intervals graduating to the desired depth of cut.

From contributor M:
We use a PTP for our flutes as long as 9 feet. They sure come out beautiful. Before the PTP, we used a router table with stops and the burnout was minimal.

From the original questioner:
I am not a newbie woodworker, but have found over time that everyone finds little tricks or gadgets that help with those little pesky problems. In case anyone is wondering, being the sucker that I am for buying new tools I went and got a Dremel tool at our local Lowes. It is a great little and very powerful little mini router on a wand. I got the 10.5 lithium cordless which had as much power as the larger plug in. I can now see a lot of uses for this thing. I will try the second pass using the water idea above – it sounds very interesting and I never even considered this. Also I will be purchasing a couple carving tools just in case.

I am using stops at both ends. The burn happens when I drop it down even if I am quick about it sometimes the burn is worse then other times. I am using a really shallow cut as to avoid using two passes, but I will have to try this along with the water.

From contributor G:
I wonder if slowing down the router bit and the feed speed would help? Still do the ends as quick as possible, but slow down through the straight section to preserve the quality of cut.

From contributor F:
An English furniture maker taught me that a scraper is the best tool to remove burns with. If you can get your hands on an old triangular scraper with a handle and then grind one of its three corners to the same radius as your flute, it will scrape out a burned flute end fast.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor D:
I had the same problem in cherry. The burned are the worst when you start your plunge. The best thing to do is to start cutting the flute a couple inches away from where you planed to end the flute. It will still burn, but almost all of the burn marks will be cut away when you make your full pass. If you plunge your router at the one end of your flute, then you have to sand off the burns and yes, it does distort it no matter if you use a scraper/sandpaper/gouge/etc. When you get to the ends of your flute move quickly and as soon as it hits the stop block release the plunge and move it before it gets hot. It shouldn't have any burns at all when you are done, especially if you cut in two passes.