Picking the correct grinder

[loosegroove]

I am planning on renting a grinder tomorrow for my Wolverine garage floor project, but the rental yard has two types of grinders.

They have the following two:

1) A Dual disc Grinder with Diamond serts (stones)
2) A walk behind 7" Turbo Grinder with a diamond wheel.

The rental yard claims to rent the 7” Turbo much more often for garage floors and it’s 1/3 the price. Will there be a real difference between the two machines?

thanks

 

[mat_GTI-R]

I did my single car garage with a dual disc Edco grinder in 3.5 hours ..... a 7" grinder would have taken atleast twice the time!!!

 

[nip_tuck123]

What was the working width on your edco grinder? I'm renting one next weekend from sunbelt rentals and the guy told me I could do my 3 car garage in one day with his dual disc grinder that has a 22"-24" working width...sounds like it's gona be a long day.

 

[Cabby89]

It took me a couple hours to do a 230 sq ft garage (1 car) using a 7" angle grinder with diamond wheel.

If I remember from talking to my local rental shop about grinding equipment. There is a difference between single diamond cup grinder and one with stones. Usually the stones is for taking off more material. If your floor is fairly good you should have no problem with the smaller turbo grinder and diamond wheel.

 

[Jeremy W]

get a dual disc, the extra $$ will be worth it in time and labor savings.. I got the small edco single disc and ground for about 16 hours on my 30x30 floor. it had some nasty sealer on it and it took forever to grind the **** off.

 

[loosegroove]

Thanks for the help guys!

I have the dual disk ("24") Edco reserved for tomorrow morning. Hopefully I can complete the grinding of my 450 sq ft garage in one day.

 

[Jaguar Fan]

Thanks for the help guys!

I have the dual disk ("24") Edco reserved for tomorrow morning. Hopefully I can complete the grinding of my 450 sq ft garage in one day.

Take some pics & post them of the process! Before & after & during.

thanks & good luck

 

[nip_tuck123]

Any feedback on the grinding process? I'm picking up an edco dual disc grinder friday morning to prep my 3 car garage.

 

[AlphaGarage]

I haven't used one of the turbo models, but I asked a coating contractor about these and told me they're pretty effective. They have smaller grinding area, but they operate at a much higher RPM. If you have high spots you need to grind down, or the floor is uneven all around, it may fill the bill.

On a very smooth floor the lqrger ones move at a good clip, but if the floor has high and low spots the process can slow down - a lot. The grinding inserts aren't that effective at grinding down concrete, so you you can spend a lot of time in one area just getting down into the valleys.

These are smaller, so they can get into those low spots, and if you do have a high spot these can cut them down much quicker.

Again, don't have first hand experience, just what was relayed to me.

 

[BOSS Garage]

You didn't say if the 7" rental unit is gas or 220v electric, but we're talking 1740-3150 RPM's. The dual disc EDCO runs 190-562 RPM's, which is significantly slower (and cumbersome). The great thing about the 7" TG is that you can get right up to the edge of the wall with the notched dust shroud. I have a 10" TG and trust me it's plenty fast with a diamond disc. I ground a 440 S.F. garage a few weeks ago in less than 2 hours. I'd recommend having a helper manage the vacuum hoses and electrical cords. Good luck.

 

[loosegroove]

I ended up getting the dual disc Edco. I don't know if it was the better choice because it took me almost 8 hours for 450 sq ft. Even after the grinding (with an extra 50# weight) the floor was still very smooth and I still had to acid etch with muriatic acid.

 

[Gino45]

I figured that my floor had some sealer on it since the color was darker than my neighbor's, so I rented a sanding disc machine. They are usually used for sanding wood floors, but i got the coarse sanding disc (20 grit) and tried it. Well, it only sanded the high spots, so i went back to the rental shop. I then rented the same machine, but with sanding stone blocs instead of the sanding disc. Better than before, but once again it didn't take off all of the sealer. Back to the rental place for a third time. This time I rented a hand grinder with a diamond cutting wheel (7"). If you don't mind working on your knees for a few hours, this machine really cut through the sealer with no problem. The grinder even had a hookup for a vacuum, so i figured it wouldn't cause a dust storm. Boy was I wrong. . It took me 4hrs to grind the floor and 8hrs to clean up the dust. The grinder cost $70CDN. If I had to do it again, I would skip the sanding disc machines and rent the grinder and then spend an hour putting a tarp over all my shelves before commencing grinding.