What do you guys think of this high-gloss finish on a warehouse floor?

Getting that deep clarity really depends on how much time you spent on your 50 and 100 metal bonds. If you rushed the initial transition from metals to ceramics or hybrids, you’ll get a high gloss but the reflection won't have that "mile deep" look. The lithium densifier helps for sure, but it can’t fix a scratch pattern that wasn't fully refined early on. ussually, if the reflection looks a bit fuzzy despite the shine, it’s because the **cross-hatching** at the lower grits wasn’t thorough enough to remove every single trace of the previous stage. Matching the edges to the main field is the bane of every polisher's existence. The problem is usually the difference in **head pressure** and RPM between a big planetary machine and a hand grinder. I’ve found that using the same brand of diamonds for both the field and the edges helps a bit, but you really have to over-grind the edges at the lower stages to compensate for the lack of weight. If the field is at a 400 resin, your edges shold probably be worked a bit longer at that same grit to ensure the scratch depth is identical. For those control joints, if you're seeing any dip or concave profile, it usually means the joint filler was shaved too early or the machine was running too hot over the gap. To keep them flush, I like to wait untill the filler is fully cured—sometimes 24 hours depending on the polyurea—before hitting it with a razor or a flush-cut blade. It prevents the machine from plucking the material out and leaving that shadow line that ruins the seamless look. If you’re still seeing streaking after the final pass, it might be the application method of your sealer or guard. Using a high-speed burnisher with a heat-activated pad usually blends those streaks out and pops the shine even more. And just make sure the floor is bone dry before the burnisher touches it, or you'll just be moving ghosting marks around.

I'm still trying to wrap my head around the cross-hatching. How do you guys actualy see those tiny scratches from the 50 grit when you're in the middle of a big floor? I feel like I'm just guessing when to switch to the next stage. Also, is a hand grinder always going to look diferent than the big planetary machine? I tried a small slab recently and the edges turned out way darker than the center. I didn't realize the weight of the machine changed the color that much.

You need a high-lumen LED light bar right on the floor to catch those low-grit scratches. If you're just looking down from a standing position, you'll miss half of them.

As for the dark edges, you’re likely burning the concrete with that hand grinder. Those small units spin way faster than a big planetary, and it's easy to glaze the surface if you aren't moving fast enugh. Try backing off the pressure and keeping a steady, overlapping sweep. If the edges are getting dark, you’re basicly cooking the resin into the pores.

I’ve found that the 'pencil trick' is a lifesaver for those low-grit stages. Just scribble some lines across the floor before you start your next pass. If the lines are gone, you know you’ve hit the whole surface evenly. It’s way more reliable than just squinting with a flashlight. Also, watch your vacuum suction on those edges. If you're letting dust build up under a hand grinder, it acts like a lubricant and stops the diamonds from cutting. Keeping it clean as you go is the only way to get the aggregate to pop the same as the middle of the floor.

I've noticed that even with the pencil trick, if you don't mop between grits, you're asking for trouble. Residual grit from a 30 or 60 metal bond hiding in a tiny pit can ruin a 400 resin pass in seconds. I've started using a squeegee to check the slurry clarity during the wet stages; if it's still milky, I haven't cleaned enugh. For the dry stages, I'm obsessive about a double-pass with the vacuum. It realy helps keep that 'mile deep' look from getting clouded by micro-scratches you can't see until the sealer hits.