How do I explain to someone that we need to sharpen our blades instead of buying new ones? I used to sharpen them once a week and I was only mowing 20 yards. We mow between 40 and 50 yards a week. I personally think we should sharpen our blades at least once a week, but I was told that its better to buy new blades because sharpening makes them weak... Put on a new set of blades 3 weeks ago and I can notice they aren't cutting as good and the mulching capability is suffering, thus they need sharpening. We mow bermuda and st. augustine. Sometimes pretty high grass. The math makes sense to me. $12 a blade x 2 mowers x 10 sets a year is $240 in blades! We could cut that down to a quarter of the cost by sharpening. Any advice on how to make my claim with the reasoning why?