Not sure exactly what you mean by U shaped.
One point of concern is to determine the direction thet the grain meets
the surface being planed. It will always esentially hit the surface at
some angle. You want to make sure you feed the board so the angle of
the grain is pointing back out of the end of the planer that you are
feeding it in from. So the angle is aligned with the direction the
blades are hitting the surface (if that makes sense). This would mean
one end first for one side and the other end first for the other side
(usually).
If the grain has a lot of figure (ie wavy, irregular, changing
direction) it may just not work well in a planer. You can try wetting
the surface, which will help a little on figured grain.
I haven't worked with Birch too much but I've seen it used in my shop
(a lot recently) and they don't seem to be having those problems. One
guy mentioned some fuzziness when he edge trimmed some stuff but sharp
bits seemed to fix that.
"my"wrote in message
> I'm seeing tearout using a planer on birch. a closer look at the grain
> of the board I'm planing shows the grain in a u shape. I'm guessing
> that
> this was my first lesson in proper board selection. am I missing
> something?
>
> (I already tried replacing and adjusting the knives...no joy).
Plane it in the opposite direction, take off less per pass, moisten the wood
beforehand with a damp cloth or a spray bottle. May not help, but you will
have then tried most everything there is ... other than becoming a neander.
--
www.e-woodshop.net
Last update: 8/07/05
"Swingman" <[email protected]> wrote in
news:[email protected]:
>
> "my"wrote in message
>> I'm seeing tearout using a planer on birch. a closer look at the
>> grain of the board I'm planing shows the grain in a u shape. I'm
>> guessing that
>> this was my first lesson in proper board selection. am I missing
>> something?
>>
>> (I already tried replacing and adjusting the knives...no joy).
>
> Plane it in the opposite direction, take off less per pass, moisten
> the wood beforehand with a damp cloth or a spray bottle. May not help,
> but you will have then tried most everything there is ... other than
> becoming a neander.
>
>
And even if you become a neander, you will have to plane it in the correct
direction, take small amounts per pass, moisten the wood on occaision, and
sometimes scrape. ;-0
Relax. It's wood. Sometimes, it just does that.
Patriarch
my wrote:
> I'm seeing tearout using a planer on birch. a closer look at the grain
> of the board I'm planing shows the grain in a u shape. I'm guessing
> that
> this was my first lesson in proper board selection. am I missing
> something?
>
> (I already tried replacing and adjusting the knives...no joy).
>
1. try running it through in the other direction.
2. take SMALL cuts
3. dampen the board.
4. if all else fails, buy a drum sander :)
Dave