Anyone have any concrete grinding tips?

[matthew1]

Certainly no progress yesterday.

[matthew1]

Progress yesterday with my new ventilator mask. Don't laugh at the headphone cord this tool is loud. I have foam earplugs in also.

[matthew1]

Progress overall is very slow. You guys were right, a hammer drill would almost certainly be faster. I'm going to wait a few weeks, then pick one up.

[Sveedy]

Honestly, you could have simply made a form and poured part of a bag of premix ( $ 2 per bag ) in it for a fraction of the price and energy that your going through. Build a little tube form - maybe 1 hour at most because you have to drive to get it. It's made of cardboard and comes ( HD or Lowe's ) in different diameters. Pour in the mud, go have a beer ( or two ) while it dries. Then cut it off with a razor knife. You could press any bowl into the wet mud, or just scoop some out before it sets up. Either way would be so much easier and less hazardous.
Grinders, respirators,and now a hammer drill ? How are you going to firmly hold on to that cylinder while using a hammer drill ? And what if it cracks at that point ? Could happen and then what ? This is nuts ! My son bashes me with this all the time : " Dad, work smarter, not harder ".
Not that I really have a opinion on this.

( P.S. Please don't ban me )

[matthew1]

No banning! That's for spammers.

Part of the allure is this project is recycling something, and it has a pretty cool patina (is that the right word for this thing?) - being a core with rocks and all showing on the sides. "There's a story behind it" type of thing.

But hey, I didn't know much about any of this before and now I do... including the casting and premix you mentioned. I'll get to that one day also . That really does sound fun and creative.

As for the hammer drill, this core weighs 40-50 pounds easy. It's heavy. And if it cracks -- drumroll please -- I have two more just like it

[matthew1]

I could let it be as it is and it'd make a nice (if "modern art", not for everyone but surely for me) bird bath. I was thinking about that... that I'd drill a horizontal line in near the top to make a nice discrete path for a child line that I could punch into a yard watering drip line to replenish water for the birds 4x per week.

Or, I could forget the hole and find a copper line to feed the water. That would look super. I'm nuts.

[Sveedy]

Thank You for not banning me. Yet.
I like the copper line path. You could start building up with that.

I get the " story " part of it. Guilty of that as well.

Many many years ago I formed all the stanchions for the light poles in a parking lot using forms like what I'm describing. I pulled the form tubes off as soon as the concrete was firm enough, but not yet completely set. Sprayed them down with water to expose all of the gravel and give them a weathered texture. For what your doing, the cheap post hole mix has little pea gravel in it which could look cool.
If you go with the hammer drill, then make it a smaller one; not a big boy type that needs two hands to operate. Probably no bigger than a 3/8" bit.
Good Luck ! ( have you ever considered basket weaving ? )

[volvolugnut]

No banning! That's for spammers.

Part of the allure is this project is recycling something, and it has a pretty cool patina (is that the right word for this thing?) - being a core with rocks and all showing on the sides. "There's a story behind it" type of thing.

But hey, I didn't know much about any of this before and now I do... including the casting and premix you mentioned. I'll get to that one day also . That really does sound fun and creative.

As for the hammer drill, this core weighs 40-50 pounds easy. It's heavy. And if it cracks -- drumroll please -- I have two more just like it

Thanks for making the updates with photos. I enjoy watching other peoples projects. I also like to watch others work.

volvolugnuty

[matthew1]

If any group appreciates projects, it's this group. Us MVS regulars are DIY types by definition, to the core (no pun intended). Hell, I started this site because I appreciate DIY so much. If truth be told, I wish I'd started 20 DIY sites back in 2001. Although I'd be hard-pressed to name 20 DIY subjects I'm interested in.

Concrete update:

I found a hammer drill to borrow

It's an old red Mikita with no 2nd handle, aka looks like a normal drill, just as Sveedy suggested. Not that I wanted that type, but that's what my mom's husband had when I was at their house and remembered to ask. That guy has a ton of tools and is always always busy doing something or other around their house. They bought that place new 10 years ago, and not a day has gone by without him puttering around working on it.

Maybe he's just good at staying unnagged by my mom, which is smart. Can't be nagged if you can't be found, right?

[matthew1]

I'm 50, and things in this world continue to surprise me. In this case, it's the sheer amount of energy required to remove just a 2-inch deep (at center), concave amount of regular old concrete. I'm sure a mechanical engineer could quickly come up with a joules calculation, but that wouldn't have swayed me. I think the best characterization would just be "40-50 minutes of pushing and twisting combined with a diamond-tipped disc on this grinder running WOT."

It's really amazing. It wouldn't have stopped me from starting it... I guess I'm shocked at how dense and unforgiving old concrete is.