A couple of months back I happened across an enco 10" grinder on craigslist about the time I was about to start prepping my month old concrete floor for coating.
In that time I have tried:
1) the disc that came with the grinder (green - which I later determined to be a 'hard bond' disc). I spent HOURS grinding and was only able to do about a hundred square feet before I gave up and looked for a better disc, thinking that was the issue.
2) I bought a 'Medium bond' disc, as at the time I couldn't find a soft bond disc. It worked slightly better than the green disc, but ultimately it was extremely slow as well.
3) Finally tracked down a 'soft bond' disc for hard concrete ( I have 4000psi that I kept flooded for a week during the cure and it is rock hard). It seemed to work quite a bit better when I tried it out - lots more dust (so it must be grinding more material) but it is still PAINFULLY slow. Today I marked off an approximately 6x6 foot section and spent TWO AND A HALF HOURS on it with the soft bond disc and the results are in the picture. Some of it seems to cut easy, but there are a LOT of shiny parts left. I assumed at first these are low spots that the disc isn't hitting, but in some places I can see swirl marks from the disc where it has scratched them. I can spend 10 minutes going back and forth trying to get some of these shiny spots out with no luck.
Is this concrete just too hard to grind?
Do they make a more aggressive disc that I can use - or one specifically for concrete that seems harder than a diamond?
Is there something I'm missing with configuring this machine? I know it's not the best but I figured it would be better/faster than using a handheld on my hands and knees (I am seriously questioning this now).
The disc seems to be flat/level - I have added additional weight in the form of some steel scraps and chain I put on the machine over the existing weight. It is at the point now where much more weight will stall it out.
I've tried various 'techniques' with no success (different directions/speeds/etc.).
What are my options at this point? - I have a lot left to go and am about to go and buy a pallet of muriatic acid and flood this damn place at this point and hope for the best. I had hoped to have my floor finished by Thanksgiving but at this rate it won't be ready by NEXT Thanksgiving.
I know the answer will be "get an industrial machine" - I am looking for someone that might have one of these locally - anyone know of someone in western washington/south sound that does this type of thing? Was trying to keep costs down (plan was to grind with enco and resell to recoup much of my investment).
Should I try a 'diamabrush' type deal? Grind by hand (Not an inviting option with the square footage I have to do)?
Give up, coat the small section I have and just live with the rest being untreated concrete?
Are these enco machines this worthless? I don't see anything wrong with it and the disc seems to be flat/flush on the floor and from other posts it seems like people have had success with it. Maybe it's just the idiot running the machine (me)? Doesn't seem much I can change/adjust on it either - it is what it is.
I read somewhere that the enco should be able to do 200 square feet an hour(!). Either way I'm still glad I bought this thing, as I probably would have spent more than it cost renting the same thing for days on end for more $$ and the same results.
In that time I have tried:
1) the disc that came with the grinder (green - which I later determined to be a 'hard bond' disc). I spent HOURS grinding and was only able to do about a hundred square feet before I gave up and looked for a better disc, thinking that was the issue.
2) I bought a 'Medium bond' disc, as at the time I couldn't find a soft bond disc. It worked slightly better than the green disc, but ultimately it was extremely slow as well.
3) Finally tracked down a 'soft bond' disc for hard concrete ( I have 4000psi that I kept flooded for a week during the cure and it is rock hard). It seemed to work quite a bit better when I tried it out - lots more dust (so it must be grinding more material) but it is still PAINFULLY slow. Today I marked off an approximately 6x6 foot section and spent TWO AND A HALF HOURS on it with the soft bond disc and the results are in the picture. Some of it seems to cut easy, but there are a LOT of shiny parts left. I assumed at first these are low spots that the disc isn't hitting, but in some places I can see swirl marks from the disc where it has scratched them. I can spend 10 minutes going back and forth trying to get some of these shiny spots out with no luck.
Is this concrete just too hard to grind?
Do they make a more aggressive disc that I can use - or one specifically for concrete that seems harder than a diamond?
Is there something I'm missing with configuring this machine? I know it's not the best but I figured it would be better/faster than using a handheld on my hands and knees (I am seriously questioning this now).
The disc seems to be flat/level - I have added additional weight in the form of some steel scraps and chain I put on the machine over the existing weight. It is at the point now where much more weight will stall it out.
I've tried various 'techniques' with no success (different directions/speeds/etc.).
What are my options at this point? - I have a lot left to go and am about to go and buy a pallet of muriatic acid and flood this damn place at this point and hope for the best. I had hoped to have my floor finished by Thanksgiving but at this rate it won't be ready by NEXT Thanksgiving.
I know the answer will be "get an industrial machine" - I am looking for someone that might have one of these locally - anyone know of someone in western washington/south sound that does this type of thing? Was trying to keep costs down (plan was to grind with enco and resell to recoup much of my investment).
Should I try a 'diamabrush' type deal? Grind by hand (Not an inviting option with the square footage I have to do)?
Give up, coat the small section I have and just live with the rest being untreated concrete?
Are these enco machines this worthless? I don't see anything wrong with it and the disc seems to be flat/flush on the floor and from other posts it seems like people have had success with it. Maybe it's just the idiot running the machine (me)? Doesn't seem much I can change/adjust on it either - it is what it is.
I read somewhere that the enco should be able to do 200 square feet an hour(!). Either way I'm still glad I bought this thing, as I probably would have spent more than it cost renting the same thing for days on end for more $$ and the same results.
