I have a brick patio that needs mortar repair. What is the best method

I have not worked with brick, but I recently did a firepit project with flagstone that was super easy with concrete/sand mix. (check my profile). I put it in dry, smoothed over with a dry paintbrush, and then dribbled water onto the rock. This technique might work for replacing your damaged mortar. You'll have to dig some broken mortar out and try it. For $7 it's worth a shot. I hope to fill in come cracks on my tired driveway this summer.

Part of me wonders if moisture is your enemy here, along with winter temps. Good luck : )

I had the same idea Jim has. Try power washing the brick to get all the old mortar out then sweep sand (and concrete if you wish) in the cracks with a broom, then sprinkle down after crevices are all filled.

Our patio is laid in sand and has sand between the bricks. Here is a walk laid the same way and also our driveway which was professionally done. All laid in sand.

The best thing to do is remove the old mortar with a grinder. You can find an angle grinder for cheap. It's as simple as just running the grinder over the mortar. After the mortar is out, you can re-mortar and it'll 'be' brand new. You can chisel out the broken bricks and replace too. New mortar color will never match old mortar at first, but will over time. The silka mortar fix is a poly sealant and applied using a gun. You should stay away from quick fixes. Also choose the correct mortar when you replace it. Look for N-mortar. You can use jointing sand, but replace the broken bricks in the edge with mortar. Good luck, it's not as difficult as it sounds.