I would like to hear from those that have had blades sharpened as to this question.
We all know a sharp edge is the intersection of two straight faces to make that edge.
Now when i look at the teeth of a table saw blade and see the small pieces of carbide welded on to form those teeth, my question is when they sharpen said teeth do they only grind the single face that is the front side of that tooth?
Or do they do all sides ie two outer sides, top and front face?
Reason i am asking is if a tooth has a chip then the face that corresponds with that chip surely needs to be ground too.
Also how do any of the faces get to meet and hence form a sharp edge if only one face is ground on the tooth.
The thing that has me going is that these blades are advertised as 6x sharpening etc . Implying that you can get numerous resharpenings done of the blade.
But i am thinking that in the case of something like the thin kerf diablo freud blades, available here for $39 for a pretty good all round blade i dont see that its worth getting the blades resharpened if the returned result is going to be less than what the original was in the first place.
A $100 plus woodworker full kerf etc i can understand but even then whats it like if only one face is "touched up" ?
Then another observation i was making from reviewing a bunch of blades at the store was we often have comments made by various folk about how they like this or that blade and dont get this or that problem eg tearout or cutting ability etc.
But no one seems to have commented on just how much carbide is used in those teeth.
My point is, when i look at some of the real cheap blades around, if one takes a moment to put the glasses on and compare the more expensive with the cheap blades one will see the magnitude of the problem i am referring to. The cheap have what i would term a "token chip" of carbide as a tooth.
Even taking this and comparing it side by side with a diablo from freud probably the lowest on the freud totem pole, one can see the substantial difference in the amount of carbide.
Now subsequent to learning to take a good look at the carbide on a router bit ( and do this for yourself sometime, compare a Lee Valley router bit and some other private label) one can see the huge difference in thickness. When one considers that this bit of steel heats up rapidly when its working, then if its a small chip its going to battle to dissipate and distribute the heat away as it works.
My question then is whats the real value of these blades if one were to lay out the coin to sharpen them given that a already relatively small chunk of carbide is being made even smaller.
Its in these subtleties that i feel the manufacturers fail to educate the market to raise the value of the product such that the price does not become the lone arbiter of blade quality.
My thanks go again to Carol the router lady for her book, if i recall correctly i got this insight of course related to router bits from her book. But its transferable know how.
To me this is particularly relevant to hobby woodworking where cost is always considered and for the most part the majority of hobbyists probably have contractor saws not 3HP and 5Hp table saws.
In my mind therefore a good compromise on cost is to use a reasonable quality thin kerf blade to make it easier for those smaller motors to push through hardwoods and then forget about re sharpening them and rather go for a new blade.
Would love to hear thoughts and opinions on this point but also more intricate detail of the sharpening process used if anyone has knowledge of it.