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Thread: Removal of Burn Marks - How???

  1. #1
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    Removal of Burn Marks - How???

    I just routed hand holds the (3) cutting boards (cherry) & ended up with burn marks from using a 1/4" roundover bit. Sanding with coarse to fine grit is taking forever. Is there a better/quicker way to remove the burn marks? I will be using Butcher Block mineral oil on these boards, so the burn marks will show if I don't remove them. Re-routing will most likely renew the burn marks or affect the size of the hand holds(???).

    Could there possible be a "solution" of some sort, that would work, yet not adversely affect wood?

    I have a deadline of this weekend to finish the boards, so would appreciate your comments.

  2. #2
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    I imagine that you will have to re-rout them but with a new (sharp) high quality bit and keep the router moving...
    =Howard

  3. #3
    Rounded scraper will work

  4. #4
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    I've seen woodturners squirt a puff of Great Stuff foam on the end of a dowel and spray-glue some sandpaper to it for inside sanding of hollow forms. Might work for this scenario as well if you trim the foam ball well. I'm assuming the grooves are probably 3/4", so I would cut about a 1 1/2" circle and make several radius cuts so the outside edges will overlap when wrapped over the foam. Work slowly and it might do the trick.

  5. #5
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    If your using a bearing guided bit, remove a small amount of material where the bearing rides and re-rout with the slowest rpm and move the router faster.
    The significant problems we encounter cannot be solved at the same level of thinking we were at when we created them.

    The penalty for inaccuracy is more work

  6. #6
    Cherry burns like crazy if you go the least bit to slow or have dull bits. I have used the router bit as a scraper afterwards to remove the burn marks and it works great. Practice it on a scrap to get the hang of it. My bit was a carbide tipped bit. Is yours?

    Red
    RED

  7. #7
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    I've had some success at cutting in two passes. One to remove material, and a second skim pass to just shave off the burn marks... Maybe removing a 64th of an inch or so.

    Give that a shot. Sanding it off takes forever.

  8. #8
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    As mentioned cherry (and others) can be burn prone. A sharp bit and a good Feed rate is critical. You could practice your feed rate on a piece of scrap. For removal after-the-fact I find a VS Dremel with something like a sanding star useful.

  9. #9
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    Thanks for the comments. I'm finding out how susceptable cherry is to burning.

    Although the router bit is carbide I did clean it up first to remove any old deposits on the blades. It''s a bearing guided bit, plus I did try to keep the chip thickness up with a faster feed rate to draw off the heat. My router is an old Crafstman (courtesy gift of a member here - remember Glenn?) & I can't regulate the speed.

    I have since managed to clear up the (2) handholds on the first board using a dowel with emery from 150-320 grit. Took about almost an hour. I was hoping for some kind of "solution fix", but it's not to be. Two more boards to go (4 handholds) & I think I'm going to have to live with that.

  10. #10
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    A lot of good suggestions. The best router bit for round over that I have found is the Freud Quadra Cut bits. They cut very clean and less prone to burning.

  11. #11
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    Rasp and files should work pretty good.
    Don

  12. #12
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    Quote Originally Posted by Peter Aeschliman View Post
    I've had some success at cutting in two passes. One to remove material, and a second skim pass to just shave off the burn marks... Maybe removing a 64th of an inch or so.

    Give that a shot. Sanding it off takes forever.
    And run the final cut in the backwards direction - a climb cut.

    A 1/4" roundover doesn't have much cutting surface in play, and you are only skimming the surface, you won't have any problems running a climb cut - which is something you wouldn't want to normally do.
    When I started woodworking, I didn't know squat. I have progressed in 30 years - now I do know squat.

  13. #13
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    The best way to get rid of burn marks is not to create them. Slow down your rpms and speed up your feed rate. Cheap carbide and nearly all high speed steel bits will leave burn marks. Dull bits will do the same. Unless I stop for several seconds I don't get burn marks with my Freud 1/4" round over bit, even on cherry or maple.

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