Replies

1. 
   oldusty | Oct 15, 2009 04:46pm | #1

   Usually smaller and more passes will produce better and  burn free results .

      Try one more pass removing like less then a 1/16th.

     Sanding or scraping will remove the burn but avoiding it is easier but will take longer . Try 3 passes or even 4 passes or how ever many it takes .

     Even on a 3hp full size shaper I take multiple passes depending on the profile.

      hope this helps        dusty,boxmaker

2. 
   Dave45 | Oct 15, 2009 04:56pm | #2

   As you make a pass, do you pause while you shift position? Almost all of my burn marks happen when/if I stop moving the router (or workpiece) while I shift my feet or something.

   When using a router, I've developed the habit of moving it slightly off of the cut, shifting my feet (or adjusting my grip), then sort of "sweeping" it back into the cut. Seems to have really helped me.

3. 
   hammer1 | Oct 15, 2009 05:10pm | #3

   Can we assume you are using a variable speed router in a router table? As you probably know, larger size bits often require a reduction in the router speed. It may only be one or two steps down on your router speed. Increasing the feed rate will often increase the visibility of machine marks. It puts more strain on the bit, the router and the work.

   In general, you are often better off to take several incremental cuts, increasing the depth of cut just slightly with each pass. It may take 3 or 4 passes for a smooth cut, depending on the species and profile of the bit. If the last pass is very light, 1/16" or less, you don't often have any burning or marking issues. A skim pass should remove any marks that you have now.

   Going slower and taking less of a cut is usually the cure for marking issues, burns or chattering. Too slow and burning may become a problem. There is a happy medium. Burning should not be an issue unless the bit is very dull or there is something wrong with your set up or technique. You didn't tell us much about that.

   Beat it to fit / Paint it to match