Patsy,

1) What kind of saw-blade are you using ?

If you have only one jigsaw blade included in your saw kit, chances are you realise it is of the coarse grade. You shouldn't use this.
You should go and buy a Fine grade blade, that's to say in the wood-cutting series.

2) In which position is the metal sole of you saw ?
It should be taken to the Fore posish.
You should unscrew the sole, take it to the fore position and screw it in its new place, so that the small side of the keyhole-shaped opening (through which the blade moves inside the sole) comes foreward so as to frame the blade.
So it will hold the panel in place, preventing chips from being ripped off the wood piece.

3) Is your panel firmly clamped so that it won't vibrate ?
I pick small ply panels and use at least four or six cee-clamps.
You may put a heavy object on the middle of the panel if you don't have more clamps. Clamps are cheap, and the more you have, the better.

I've just been working at this today, using my jigsaw for the first time, on pine plywood (the worst outdoor quality, perhaps the equivalent of Luan), and there is NO ripping at all.
Absolutely neat.
So you can be optimistic about okoumé !

Eric

: OK, how do you cut Okoume without ripping the crap out of the surface?
: I got out my brand new cheap Black and Decker one speed jig saw last night,
: put in a new blade, and cut about an inch off one end of a sheet of
: plywood to get a water stain off. First thing I noticed is how hard it is
: to cut in a straight line as it vibrates a lot. The top surface looked
: fine, although it did rip out a small piece of the veneer in one spot. The
: bottom, however, looked bad. About an eighth of an inch of shattered
: veneer all along the cut.
: Not a problem if I'm going to scarf it there, but a definite problem if I'm
: not.

: I changed from a wood cutting blade to a metal cutting blade, thinking the
: smaller teeth would rip less. It cut a straighter line, but the tearing
: was actually worse on the bottom as well as on the top.

: I'm thinking it has to do with the vibration. I was cutting an inch off with
: the board just hanging over the edge of the table. This was a very
: discouraging start, I must say, but I'm confident you all will give me
: lifesaving advice.

: Thanks,

: Patsy