Filling Saw Cuts Before Grind and Polish?

[philbilly20]

Going to have my floor ground and polished in the next month. Wanted to fill the expansion saw cuts before it was ground and polished it so it would blend in and be perfectly smooth.

Was wondering what everyone was using for this situation? TIA

 

[lynnbilodeau]

i just sealed all my saw cuts last Sat. I used NP-1 by MasterSeal. I followed this guy's advice, except that I initially tooled dry, then went back and finessed it wet.

I was pleased with the results. But.... and this is a big but, I don't know that you want to seal the saw cuts before it is ground. I have no idea how much they will take off when grinding. If you grind down below some of the new sealant, I can see it getting torn up pretty good.

If you are going to use a flexible sealant, I would think you would need to grind and polish before applying the caulk.

 

[Rusted Nut]

You can grind and polish, and then fill with a liquid caulk, but you will see the caulk joints. Other way is too fill cracks with highway bridge cement based patching compound. Use a real high strength product, like 9000 psi ( avg concrete is 2500 - 4000 psi). Trowel it in really well, hard pack it. Use the mix on the dry side. Let it cure at least 3 days. You will need at least a 1/2” deep joint for this. Make sure joint cut is clean. Then grind and polish. You will still have some lines, but much less than with a caulk type product.

 

[Shea]

Going to have my floor ground and polished in the next month. Wanted to fill the expansion saw cuts before it was ground and polished it so it would blend in and be perfectly smooth.

Was wondering what everyone was using for this situation? TIA

You need to use a polyurea joint filler such as Metzger McGuire Edge-Pro 80. The joint is filled and trimmed before the polishing process begins. It's available in a variety of colors to try and match the concrete or stand out in contrast. You can see it here. Once the concrete is polished, you can close your eyes and run your hand over it and not be able to tell it's there.

 

[loganb]

Nothing super useful to add, but had to add another similar avatar to the OP's

 

[benjy]

EMAW!

 

[benwah]

You need to use a polyurea joint filler such as Metzger McGuire Edge-Pro 80. The joint is filled and trimmed before the polishing process begins. It's available in a variety of colors to try and match the concrete or stand out in contrast. You can see it here. Once the concrete is polished, you can close your eyes and run your hand over it and not be able to tell it's there.

This is the correct answer.

I love the Edge Pro 80 because it has moisture tolerance unlike the RS 88 and it is a bit softer which lets it stretch and move a bit more, over time.

I would suggest using this product BEFORE your metal bonds, very first step. Clean your joints, then abrade them with a nylox wheel on a drill. Be sure to overfill the joint. I do it in 2 passes, hit the joint with one pass to “seal” any cracks, then a second pass that overfills the joint. This is a fast cure polyurea so it skims over in about 45 seconds and is cured in about 45 mins, depending on temp of course.

Then using a sharp floor scraper, scrape flush. Doing this before hand will keep your joints intact throughout the polishing process. If you run your metal bonds first, you will break out all of the 90° edges of your joints leaving you with a not so glamorous filled-joint afterwards.

Using a polyurethane sealant is not recommended.