jointer knife suggestions

[caveman]

John and I have been turning someone else's live oak "boards" into 3.5" x 1/2" x random length pieces for a customer.  We are doing a lot of jointing and planing.  We have two 8" jointers, one has carbide inserts and the other has four straight knives.  The planer also has carbide inserts. 

I am using the one with straight knives (Titan brand) and it does a good job but live oak is the hardest, densest north American hardwood and with its curly grain dulls them.  I can touch them up on sandpaper glued to glass and reinstall in about 30 minutes, but I like to keep a spare set of knives. 

 Have any of you got an opinion on Xcaliber knives?  They seem a lot less expensive than the Titan knives.  Also, I read (Longtimelurker, I think) that the carbide straight knives will stay almost sharp a lot longer than HSS knives but won't initially be as sharp.  I am interested in opinions on those as well.  

 

 

 

 

 

[Larry]

When jointers and planers are manufactured, the cutting angle is always a compromise.  Something that will work with soft and hardwoods.

Sometimes the cutting angle is changed by grinding a back bevel sometimes called a micro bevel on the backside of the knife.  In my example the red line is the new grind which changes the cutting angle.  As you can see the tip will stay sharper for a longer time.  In my drawing the back bevel size is exaggerated.  It should be kept real small or the knife will hammer (or burnish).  I've made them with just a hone.



I did this a long time ago when I had a big stack of dirty white oak to plane and a few other times on shaper knives.  It worked well, but just guessed at the back angle.

Not smart enough to be much more help.  I used to get help from Charles Schmidt Company as they always had all the answers but I haven't talked to them in years.  If you have a good sharpening service close by it might pay to talk to them also.

[caveman]

Thank you for the illustration and the explanation.  I would have never thought to do that.  Based on the quality of your projects, you have figured out a good deal of things that work for you.