Another garage floor coating newbie

[JediScott]

All,
I've been working at this garage floor coating thing for just over a week now. Been taking my time because I don't want to jump the gun and coat before the surface prep is done. One thing I've learned from reading lots is the 3 most crucial things are surface prep, surface prep and surface prep.
I have a 2 car garage with a 4 ft bump out on one side and some extension to the rear where there is no house behind. I am doing one half at a time as there is no way for me to get all that stuff outside at once. I'm amazed I got all my stuff packed into the smaller half of my garage as it is.
I looked at a few epoxy systems and decided to go with a tinted Quikrete Epoxy system (2 part water based) from Lowe's

Here's what I've done so far:
- Compressed air to knock down dust and cobwebs from walls (unfinished outer wall)
- Cleaned floor first with sweeping then with pressure washer. Made sure all debris and dirt was cleaned out of control joints.
- Used Bond-Lok to clean and etch floor.
Here I wasn't happy with the results as it did not lift the oil spots as well as I'd of hoped. The etching it provided also wasn't as good as I'd of liked. So.....
- Bought Simply Green HD to clean floor well (1 to 3 parts) with direct use on heavy oil spots and this seemed to work MUCH better.
- Bought Sika etching solution (Phosphoric / Nitric Acid) and this gave a nicer profile to the concrete. Still not 80 grit but definitely 120-150 grit. I pressure washed this out several times and with water and litmus paper the concrete appears to be about a 6-7 pH without any extra neutralization.

Now I come to my dilemma:
- I have some dark areas of the concrete near my control joints which I'm concerned are water coming up in my control joints. Its been a very wet last week here in SW Ohio. The slab tests for moisture (2x2 plastic) yield no moisture, but I'm concerned about the joints.
I have Sikaflex SL with 1/2 backer rod to put in the joints as I had a vision on filling in the seams and getting a floor finish free of seams. I tested a small joint toward the back of the garage and was not pleased with my technique thus far.

Questions:
1. Other experiences in how to get a flush seam with the top of the concrete (how to do it, is it wise, should I leave a small recess in the seam?)
2. Opinion on how to address the moisture (Is it moisture, will the filled seams take care of it)
3. Experience with Epoxy over a Polyurethane seam filler (Sikaflex SL). Does it bond well, Should I etch AGAIN after filling the seams?
4. Advice when doing a garage in two stages (how to minimize line between stages, strength issues I could face, should I only stop at a seam?)
5. Any other watchouts or words of wisdom?

Lots of questions I realize but I'm new to this and have picked up EVERYTHING I know from reading and listen to others discussions and now I need some advice for my specific situation.

Thanks in advance,
Scott

 

[nate379]

For the filler, I masking taped both sides of the crack and they ran a putty knife over it to get it level.

So it in 2 coats. Fill it about 3/4 of the way and they the next day all the way. Worked better for me on the section I did that.

Can't be moisture in the slab. I just set my oxy/acy torch down low with a rosebud and heated the joints to cook out any wetness... this was after letting it air dry for a couple days.

Use a 3/4" roller. I tried with a 3/8" at first and it didn't work out as well. Put it down thick and sorta sloppy and go back over it. If you take your time it will dry so no more wet edge.

 

[tcianci]

I have been told not to get too excited about the residual oil spots, the cleaning of the surface buys you time to coat it...allow me to explain. When you clean the concrete, it is much akin to cleaning a spot out of a rug, only to see it return again after a short while. While the spot is indeed clean, in the case of the concrete or the rug, not every trace of the soiling material has been removed so over a period of time the remaining material will "wick" back up to the surface you have cleaned. This makes it look like the spot has returned when in fact, the surface was clean enough for the epoxy to bond to although there is residual junk still showing. This was explained to me by a commercial epoxy sales rep and installation crew supervisor. Because the epoxy penetrates the concrete to a degree as long as the initial surface is clean, the epoxy will bond and the offending material is sealed under the surface. I would be interested to hear what you other epoxy sales guys think of this guys eplanation. I went with it, and outside of the fact that I have beat the daylights out of my epoxy floor from projects and such, I have not experienced any adhesion or other problems with my floor which had about 20 years of **** on it before I cleaned it and coated it 9 years ago.

 

[JediScott]

Good thought on the masking tape. I will definitely try that with some of the blue painters tape we have in ample supply in the house for our painting jobs. My wife is painting walls and I'm painting floors

Going to fill some joints tonight... thanks.

 

[hansen1]

What filler are you using? I want to fill the saw cuts on my freshly poured floor. I don't plan on painting the floor but want to keep junk out of the joints. I was thinking I could find something that would fill to the top of the joint and be fairly durable and not shrink or work itself out of the crack.

 

[nate379]

Stuff I bought at Lowe's. If you look under my thread on the epoxy there is a picture of the tube. SL80 self leveling It's around $6 a tube.

 

[JediScott]

I used the Sikaflex SL. So far looks like it worked pretty well. They sell it at the big box stores with the concrete supplies, not with the caulk.