Grinder help

[pnut]

Local rental place had a few choices.

1) 17" single head edco. Lots of head choices but the best one they recommended was a copper disc with tungsten carbide teeth sticking out all at least 1/2" from the next one. Looked aggressive. They also had a diamond head but they were smooth and looked more like polishers. this was not a carbide grinding disc that is diff.

2) 2 head edco. Very heavy. The heads were square blocks which mounted to the discs each block with 3 diamond cutters running the width of the block. They thought this was way overkill and more akin to significant material removal.

What is the better choice? I am thinking the 17" single. Concrete is in west Michigan. Very smooth trowel. It is about 60 days old. Planning to do the work tomorrow.

 

[Garage Flooring]

Local rental place had a few choices.

1) 17" single head edco. Lots of head choices but the best one they recommended was a copper disc with tungsten carbide teeth sticking out all at least 1/2" from the next one. Looked aggressive. They also had a diamond head but they were smooth and looked more like polishers. this was not a carbide grinding disc that is diff.

2) 2 head edco. Very heavy. The heads were square blocks which mounted to the discs each block with 3 diamond cutters running the width of the block. They thought this was way overkill and more akin to significant material removal.

What is the better choice? I am thinking the 17" single. Concrete is in west Michigan. Very smooth trowel. It is about 60 days old. Planning to do the work tomorrow.

I am sure I will get outvoted on this, but, if you are asking the question, I would go with the single head. I put it that way because there are some very experienced users who like the dual heads....

 

[dcs Inc]

It's all about the tooling. Ask them if the one you choose doesn't work, can you exchange it for the other without any penalties. They should be OK with that. Which rental company is it. If it's a major outfit and they don't accept those terms, let me know and I will put my 2 cents up their ****. I spend a lot of money with several of them.

 

[pnut]

It's all about the tooling. Ask them if the one you choose doesn't work, can you exchange it for the other without any penalties. They should be OK with that. Which rental company is it. If it's a major outfit and they don't accept those terms, let me know and I will put my 2 cents up their ****. I spend a lot of money with several of them.

Yes they said they can and will do that. It is Taylor rental in Holland, MI. Nice people I have rented there before and they are quite knowledgable.

 

[pnut]

I am sure I will get outvoted on this, but, if you are asking the question, I would go with the single head. I put it that way because there are some very experienced users who like the dual heads....

The two headed looked very heavy, very hard to manipulate, and too large to work effectively in my small garage. Guess we will see tomorrow.

 

[pnut]

Also if anyone has photos of the grinder heads they do or do not recommend that would help. I've read a ton of posts about strips this, diamond that, deserts, but have no idea what any of them look like.

 

[oilslick]

Why are you grinding it? Is this a concrete polish job or prep for epoxy?

 

[pnut]

Why are you grinding it? Is this a concrete polish job or prep for epoxy?

Epoxy prep. Water and even oil beads. It has lot of surface tension.

 

[LegacyIndustrial]

Single head and skip the carbide, go for the diamonds.

 

[pnut]

Single head and skip the carbide, go for the diamonds.

I don't think they, nor anyone else in town have that, but will check again today before I go get it at the end of the day.

 

[miken123]

Called my local Home Depo today in ann arbor and they had the floor buffer with the diamabrush head. Maybe the one nearest you has it too? (To be fair my local one said their diamabrush head was broken so they wouldn't have it for a while -- but those are details in this case ).

From what I gather the floor buffer with diamabrush is the best way to go for a DIY'er.

Pretty cheap too he said it would be somewhere around $120 for a full day's rental!



Here's a question that you might ask next so I'll ask it anyway:
Once you've ground your floor with a big machine.. what do you do with the edges / corners that you couldn't get to with the machine?? (I don't know the answer to this question!)

 

[dcs Inc]

The diamabrushes wont take a beating. Wont level high spots. They do a good job on profiling. Hit a bolt or a high edge and you can screw them up. (Take you for a ride too).

As far as edging. A 4" grinder with a cup wheel on it works well.

 

[DustynF]

I am hoping to get some useful info as well. I decided polished concrete route but I am confused what to go with. I called sunbelt rentals and they have a 10 hp grinder with diamond teeth that you switch out to create different abrasiveness. He couldn't tell me if it would match a 400 or 800 grit. He started talking about sanders and then I was really confused what I should go with. This is what I was looking at: http://www.sunbeltrentals.com/equipment/equipment.aspx?itemid=0320070&catid=s340


I do have high spots as well as some smooth concrete. I would like the end result to be smooth surface with a semi gloss appearance.

 

[pnut]

Here is my follow up:

I went over the whole floor twice slowly, took about 1.75 hours for a 2.5 car garage. I used a single head floor polisher type machine. The "head" or "plate" was a tungsten carbide teeth widely spaced apart.

It worked Decently. Certainly it removed alot of material based upon the amount of grinding leftovers I had to clean up.

I decided to do acid afterward just to be sure, and I couldn't get all the dust up no matter how much I vacuumed. So I was thinking to rinse anyway may as well use some acid. I had a problem with uneven application from my sprayer, and didn't probably apply enough (2 gallons of mix to the whole floor, at 2 parts water, to 1 part muratic acid).

Overall I think it is ready. The skin is broken, and water soaks in VERY fast. I actually had a hard time keeping it wet during the acid. I would like to ideally see the pores more open. I may do another acid wash tonight, but I need to be careful since I am applying Friday and need it to be really very dry.

 

[miken123]

I've read here on the forum (haven't done it myself yet) that when you acid etch the concrete floor it tends to leave residue in the pores of the concrete that needs to be rinsed off with a powerwasher to get it out.

I don't know if this is totally true but maybe you want a final powerwash to get it cleaned out. Just what I heard!

 

[LegacyIndustrial]

Prime that floor pnut. If it ***** water that fast your coating will do the same , potentially leaving flat spots.

 

[pnut]

Prime that floor pnut. If it ***** water that fast your coating will do the same , potentially leaving flat spots.

Thanks. Just finished primer coat. Soaked in like a sponge. Color coat tomorrow clear sunday Bubbles though. Probably due to quick weather change unexpected. That's another story....