That is one of the problems with curved pieces. One one side of the
curve the cutter is cutting into the grain. On the back side of the
curve it's opposite. Several ways to do it. Look at the grain, when you
get to an area where the cutter will lift the grain. Hold the work firm
and take small cuts like your nibbling away the wood. Once the bulk is
gone then make one final pass. You could also do a climb cut but it's
not recommended. The best way is to look at the grain. Then mark your
template where the cutter will lift the grain. Use a flush trim bit on
all the curves with the cutter cutting into the grain. With them done
chuck up a pattern bit with the barring on the bottom flip the work and
finish the cuts. With the work flipped and a pattern bit the cutters
will be cutting into the grain.

..
Jerry wrote:
I'm building an English garden bench out of redwood. To cut the
curved pieces (legs and arms) I do the following:

1. created clean templates of curved pieces out of 1/4" tempered
hardboard,
2. traced the pattern outline on the piece,
3. rough cut to within 1/8" of the outline using a jigsaw (do not own a
BS)
4. attach template using double face tape to top of rough cut piece.
5. Use 2" flush trim bit (top pilot) on router table to trim to
pattern.

The problem I am having is that when I do the flush trimming, it trims
95% of the time OK but occasionally, I get chipout and chunks are taken
out of the piece along the edge I am routing flush to the template.

The lumber is kiln dried clear all heart (CAH) redwood that is
dimensioned lumber (1 1/2" thick). It is beautiful wood (but
expensive), very soft, and seems very dry and splinters easily.

I take the trimming operation very slowly but still get the problem.
The bit is a 1/2" shank, dual flute, 2" flush trim bit Rockler house
brand. I've even tried climb cutting but the operation is very
difficult.

Either it is my technique or just a result of this wood species.
Maybe kiln dried redwood heartwood is just too frail for this type of
operation. The plans called for using a bandsaw to cut to shape --
using the pattern and flush trim bit is my idea.

Any suggestions?