Wally wrote:
I find myself using the multitool a lot on jobs, more and more often.
It does a great job on cutting drywall, wood base, all sorts of things
that occasionally have nails in them. The blades are pretty expensive
and this last job I dulled a couple of them.

I started out placing an order for more blades and it occurred to me
to try sharpening one of them. The Harbor Freight dished half moon
blades I filed with a triangle needle file, took maybe 5 minutes. The
Versatool bimetal blades (nice blades, by the way) were too hard for a
standard file, so I used a Harbor Freight diamond triangle needle
file. A stroke or two on each tooth and a couple minutes and it was
good as new.

The blades have a slight amount of set to the teeth and I didn't worry
about it or filing from both sides, I just clamped them in a vise
between two scraps of wood and had at it. They work good as new.

I figure I saved more than $50 in a half hour.

Here's another way: Use a Dremel rotary tool to cut notches in the blade,
1/16" deep, 1/16" between.

You're done.

And I can't detect ANY set to the teeth.