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Greetings,

While sanding a maple top (electric), I noticed some dark marks where the quarter round was located.
I think the marks may have been made by the quarter round router bit as it passed.
The marks are located mainly on the end grain, and don't sand away.
The marks are not usually visible until a solvent such as naptha is applied.

Any ideas on the removal of these marks before finishing?

Regards,

Steve

I would think some coarser sandpaper and some more elbow grease.

Got any pictures?

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Horton, MI

Kirt,

Thanks for your comments. Attached is a photo ( somewhat poor though ).

I went the route you suggested. But, I stopped when the quarter round was no longer round.

I guess the " burn " is deeper that I expected.

Steve

You could sand the top down about 1/32” through a drum sander and then re-rout the edge.
Are you using Carbide or high speed steel bits?
My preference is high speed steel over the carbide bits. They hold a sharper edge and tend to burn less but they just don’t last anywhere near as long as carbide. I use the carbide bits for general work and save the HSS bits for the critical work. Toss them when they dull.

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Rich S

"The inconvenience of poor quality will linger long after the thrill of a bargain has been forgotten"

Hello Kirt and Rich,

Thanks for your help. You've given me some ideas to work with

Steve

Yeah, looks like you'll need to either feed that puppy a lot faster or use a bit with a bearing instead of a shank guide. End grain tends to burn worse.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Have you tried raising the grain then re sanding?

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How long is that in luthyears?

Bob,

I used a Freud round-over bit with bearing, although it has been used a fair amount.
The speed is not controllable on my "antique" Craftsman router. (Might be time to get a new tool ;o).

Brett,

I didn't try your suggestion. I'll give it a try.

Thanks for your help,

Steve

Or a Harbor Freight Router Speed Controller. On Sale now: HERE

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Always, always check the bearing turns smoothly before using, and like Bob said, adjust the feed rate. Not the speed the bit spins at, the speed you move the router over the workpiece. Better to do a few relatively brisk passes, lowering slightly each time, than hogging off everything in one go, having the motor bog down (it shouldn't slow at all), and/or leaving it in place for too long. If it burns with a bearing, the bearing's not moving smoothly enough; ideally it should remain stationary on the workpiece while the bit spins inside it.

Mattia,

I think that may be the way to go. I did the round over in one pass. Next time, I will make gradual cuts.

Thanks for the comment(s).

Steve