Will I have trouble with this splotchy floor?

[Ruddy]

Using an epoxy coating. The garage floor is about 3 yrs old, but the first year was during construction where they had a Wood-Mizer in there. I always thought the brown splotches were just dirt I could wash out, but today I tried to clean a couple of spots for the first time, using some borax. These are photos of the "clean" spots and the brown is still in there.
Is just power washing it and an acid rinse going to be enough?

 

[Ruddy]

hmm, the picture link inserter did not seem to work.

http://pics.ww.com/v/ruddy/junk/HPIM4415.jpg
http://pics.ww.com/v/ruddy/junk/HPIM4416.jpg

 

[BoutTime64]

I had some permanant spots from oil or somthing like it. I power washed, and scrubbed and used the acid etcher, but it still remained.I used the quikcrete brand and it went over it with out comming up. I did have some problems with an area that was rather rough and i dont think i got it down good enough in the crevaces, cause its comming up a bit, that and its exposed to standing water quite a bit in that area. Check out a thread i had regarding epoxy floor job, it has some pics.

good luck.

 

[TheBanker]

Maybe do the water test. Put water on it and see if it beads up. Smooth the water around with your hand. If it doesn't bead, you may be okay.