Planer and Jointer Knives angle

Hi, does anyone know what the correct angle should used when sharpening jointer/planer knives. The ones purchased from Carba-Tec seem to be around 50 deg and my sharpening service - Carbide Tool Industries sharpens the blades at 38 deg. They use this angle as the default, but will happily sharpen at any angle desired. I am thinking that the higher the angle the longer the blades will stay sharp and the lower angle will give a smoother surface but not for long. Does anyone think that an angle somewhere in between say 45 deg would be a good compromise?
Regards
Les

Les,

You should copy the angle of the original blades as the manufacturer should have some Idea of what is required.

You may also find that if the slots for the blade don't line up wih a radial of the cutting block that the cutting edge angle is different to the angle ground on the blade.

So different units blades may require different angles.

Just my guess and $0.02 worth

Cheers

Brian, thanks for the reply. After speaking to some other people in the industry, I am led to believe that about 38 deg would be fine unless I am dressing Wandoo or Red Cedar which would require a higher angle.
Regards
Les