# Why isn't mixing DIY concrete in bags/plastic more popular?



## Skoorb (Oct 6, 2009)

Myself and a buddy mixed 20 bags of concrete in a single go some years back using a trick I saw on youtube: thick plastic sheeting cut in a large square, concrete placed on it, hole in center for water, each person grabs two corners, and you roll it around. A bag can be mixed in under a minute without any tools.

I'm working on a deck now and I mentioned this to a professional contractor who said he always just mixes with a trowel. So I gave that a shot to see if I was missing something. It's terrible: not only does it take way longer to mix, but it's way messier; scraping the edges, bottom of it, muscling the trowel through all the aggregate. It's crap! In lieu of plastic sheeting this time I just poured my concrete into heavy duty contractor bags, put the water in, 45 seconds of rolling it around on the lawn and it's completely, consistently mixed everywhere throughout. Bonus is now all the concrete is in a bag and can even be carried over to a hole. I found the contractor bags were good for 1-3 60 lb concrete bags before they got a small hole in them


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## Bondo (Dec 8, 2007)

Ayuh,.... I bought a wheelbarrow style mixer with an electric motor,....

That, 'n built a wood debaggin' table to bust up the bags, 'n push the premix into the turnin' barrel,....

2 of Us have mixed 2 pallets of 80lb. bags in a day, No problem,....


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## Skoorb (Oct 6, 2009)

Bondo said:


> Ayuh,.... I bought a wheelbarrow style mixer with an electric motor,....
> 
> That, 'n built a wood debaggin' table to bust up the bags, 'n push the premix into the turnin' barrel,....
> 
> 2 of Us have mixed 2 pallets of 80lb. bags in a day, No problem,....


Yeah, the concrete mixer is definitely better than the bags, but a concrete truck beats the mixer


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## Bondo (Dec 8, 2007)

Skoorb said:


> Yeah, the concrete mixer is definitely better than the bags, but a concrete truck beats the mixer


Ayuh,.... No Doubt,....

Shot 'bout 14 yd.s through a 4" pvc pipe system I set up last December,....

Truck got close enough to shoot into a funnel I built outa a big propane tank, 'n it flowed nicely through the 16' of pipe,...

House is down under/ in front of a 10' concrete retainin' wall,....
Truck access is above, 'n behind,...

Gonna be shootin' in another 5yd.s or so to top out the radiant floor, then tile,....

The 1st 14yd.s was ballast fill,...
Inside the new foundation walls We poured with the wheelbarrow mixer,...


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## Skoorb (Oct 6, 2009)

*Senior*, you PMed me but I cannot PM back due to not having enough posts, sorry!!

Wanted to say the bags I am using are Contracts Choice 3 mil bags. These are very expensive bags at $.50/piece at lowes or amazon, but there's nothing worse than breaking garbage bags. Didn't originally buy them to do mixing actually 

6 mil plastic sheeting, available at any home improvement store, is way stronger and less likely to tear, but you need to be more careful preventing the stuff running out the side (it's easy with a little caution, though--mountain of concrete then hole for water then grab corners and lift up to avoid it spilling out the sides). Here was the vid I saw years back. It really works although this guy's mix is a bit dry. When I did bags I just add water all at once.


Bondo said:


> Ayuh,.... No Doubt,....
> 
> Shot 'bout 14 yd.s through a 4" pvc pipe system I set up last December,....
> 
> ...


Are you ever worried about the motor on the mixer dying mid-pour, leaving you in the lurch unable to finish the pour in one go?


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## Bondo (Dec 8, 2007)

> Are you ever worried about the motor on the mixer dying mid-pour, leaving you in the lurch unable to finish the pour in one go?


Ayuh,.... I suppose that will be a Bad day, But,....

My job is fixin' things, 'n operations that Break,....
I'm pretty Handy, at makin' lemonade outa lemons,....
I'll adapt,....


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## Skoorb (Oct 6, 2009)

Bondo said:


> Ayuh,.... I suppose that will be a Bad day, But,....
> 
> My job is fixin' things, 'n operations that Break,....
> I'm pretty Handy, at makin' lemonade outa lemons,....
> I'll adapt,....


I assume you could detach the motor and just turn it by hand to finish a job if you had to :biggrin2:

I get stressed working with concrete because the stuff hardens and you gotta do it all at once!


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## Bondo (Dec 8, 2007)

Skoorb said:


> I assume you could detach the motor and just turn it by hand to finish a job if you had to :biggrin2:
> 
> I get stressed working with concrete because the stuff hardens and you gotta do it all at once!


Ayuh,.... It's only a 1 bag mixer,....

At worst, I'd need to build an acceptable cold joint, 'n quit for the day,....
At Best, I'd run into town, 'n steal a gas mixer from one of the companies I'm affiliated with, or rent one,...

I work with asphalt 6 months a year,....
It usually hardens a 'ell of alot quicker than concrete,....


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## Yodaman (Mar 9, 2015)

The best $100 I ever spent was for a used cement mixer. Even so, any job requiring more than a couple yards and and I'm calling custom mix.
But when mixing I usually buy sand and stone by the yard and 94 lb bags of portland.


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## Yodaman (Mar 9, 2015)

You can buy a actual concrete mixing tarp. This one is under $10 on Amazon.

I have seen the technique used on a TOH episode awhile back, but have never given it much consideration. 

I am going to set a single gate post today. Think I try a using heavy contractor bag. Normally I would mix very small lots like this in a pail,
a heavy duty right angle drill and a mixing paddle.


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