Cement mixer cleanout

[metricmonkeywrench]

I found a deal on a used but in decent shaped cement mixer (its an old Sears) online and picked it up today. Been wanting one for a while but really didn't want to pay full price for something that will just sit most of the time, even from the cheap tool outlets.

The downside is that one of the previous owners let a good amount of concrete set up in the lower 3rd of the drum. Short of renting either a demo hammer or jackhammer is there some magic method to clean out a drum or am in in for a long bout with a masonry drill, hammer, chisel and sweat?

265919

[DGV]

keep it wet and use a brass or lead hammer hitting the outside while machine is running. Be careful , the heavier the better. 4lbs min. plan on a few hours of work.

[Atonic]

Calcium chloride, I think. Not sure what it would do to the drum.

[Winger Ed.]

Beat on it where the 'rock' is with a big hammer to get a vibration going like ringing a bell. A lot should fall off.

Or, if there isn't too much in there, use it like it is.

[country gent]

You might try dry tumbling some rocks or short chunks of steel in it will be loud but may slowly break up the concrete. One place for info would be the concrete yards that deliver by the truck and ask what they use.

If its a third full you may have to break it up some just to get it out and be able to handle it.

[Bazoo]

Freezing water in it might offer some cracking and releasing.

[bikerbeans]

C4. :bigsmyl2:

BB

[Gtrubicon]

I have been a licensed tile contractor for more than 20 years, I have several mixers of different types. the way we clean our mortar mixers is to put a 5 gallon bucket of clean 3/4 gravel, crushed not round river rock, a gallon of muriatic acid and 5 gallons of water and fire up the mixer, the acid dissolves the cement. When done spray the mixer with water to neutralize the acid. We use a cheap air hammer to break up the big build up prior, don’t beat the outside of the drum with a hammer, it will dimple the drum, it gives the cement a great place to bond to, makes your next clean out more difficult.

[Pressman]

From someone who had to clean out a 6 yard mixer, the only thing that works 100% is a jackhammer.

Beating the outside runs the chance of damaging the drum.

[15meter]

I think myth busters did an episode on this, if I remember correctly, they had to resort to high explosives.

Wasn't much left of the mixer but it was a pretty impressive display of instantaneous disassembly of a cement mixer.

[wildwilly501]

I know a guy who got a drum off a truck for scrap that was half full.He burnt it out said it worked I don't know how long it took. I don't think it falls out but does weaken it a lot.Doing a search shows some danger of doing it says it can explode

[NyFirefighter357]

https://youtu.be/Gxm_qpKh7Jw

[JonB_in_Glencoe]

Note to self: Do not buy a cement mixer for cheap, that is partially full of cured cement, thinking I can clean it out easily.

[15meter]

https://youtu.be/Gxm_qpKh7Jw

But it worked! No more concrete in the mixer:drinks:

[FLINTNFIRE]

I used ospho to clean one , the acid attacks the concrete , Gtrubicon posted above try that first .

[Plate plinker]

I have been a licensed tile contractor for more than 20 years, I have several mixers of different types. the way we clean our mortar mixers is to put a 5 gallon bucket of clean 3/4 gravel, crushed not round river rock, a gallon of muriatic acid and 5 gallons of water and fire up the mixer, the acid dissolves the cement. When done spray the mixer with water to neutralize the acid. We use a cheap air hammer to break up the big build up prior, don’t beat the outside of the drum with a hammer, it will dimple the drum, it gives the cement a great place to bond to, makes your next clean out more difficult.

This works well.

[NyFirefighter357]

But it worked! No more concrete in the mixer:drinks:

I love watching that video, I remember watching it when it first aired. It's great to post to questions about removing cement.

https://youtu.be/Gxm_qpKh7Jw

[bedbugbilly]

IMHO banging on the outside of the drum is never a good idea as it is too easy to get carried away and you will end up with a dimpled drum. Try what the pros above suggest . . . just be careful with the muriatic acid - use goggles and rubber gloves and when you are done and have your drum clean, make sure it and your mixer are well cleaned . . if not, the muriatic acid will rust it and any other metal around it.

My Dad started myself and my brother out at a very young age - we had a stationary mixer and later one that went on the back of the 8N Ford that rally worked slick. We mixed a lot of cement for projects on the farm and he had us shoveling to help and to learn how to do it. The one thing he drilled, hammered and pounded into us was to CLEAN the mixer up completely when the job was done. Never ceased to amaze me when we were at farm auctions and others and there would be ce,emt mixers and you'd look into them and they weren't cleaned properly and like the one you bought. Sweat and provably a few swear words along the way but you'll get it cleaned out and you'll certainly appreciate that you have it when you need it. Good luck!

This reminds me of an incident back in the late 80s. We had a contract for trimming out a number of houses in a subdivision that was being built. Behind the house we were working not they had dug a basement and were ready to pour the footers. We were taking a mid-morning break for a coffee and as we took it, we watched a Reds-mix truck carefully make its way backing up to where it could get the chute in a good place to dump for the footers. It was in the fall - typical rainy wet Michigan weather for the week before. The cement contractors were up on high ground and directing the truck back - thank God nobody was in the basement yet because when they got the truck where they wanted it and the driver got out, in less than 30 seconds the wall of the dug basement gave way and all of them jumped bak.
We couldn't believe what we were watching but that large Redi-mix truck slowly slid back as the wall of the dug basement collapsed and slid right down into the basement - with a full load of cement on board. Thankfully no one was hurt but they ended up having to bring in a large crane in order to get the truck out and I have often wondered just how they ever got that full mixer of cement cleaned out - if they ever did. They weren't able to get a crane there until the next day so that load sat well over 24 hours.

[Mal Paso]

Have you seen the Beirut Explosion Videos? 27,000 Tons of Ammonium Nitrate.

[brass410]

I have been a licensed tile contractor for more than 20 years, I have several mixers of different types. the way we clean our mortar mixers is to put a 5 gallon bucket of clean 3/4 gravel, crushed not round river rock, a gallon of muriatic acid and 5 gallons of water and fire up the mixer, the acid dissolves the cement. When done spray the mixer with water to neutralize the acid. We use a cheap air hammer to break up the big build up prior, don’t beat the outside of the drum with a hammer, it will dimple the drum, it gives the cement a great place to bond to, makes your next clean out more difficult.

this works. also if you take hammer drill and judiciously bore into the thicker areas carefully (as to not damage the steel tub) this will speed the process up

[Dusty Bannister]

I was told years ago by a manager of a redi-mix company that if you can get a few bags of sugar in the cement mix and roll the barrel, it will prevent the concrete from setting up as it should. In the case of the truck in the basement, that probably was not an option.

[cat-mechanic]

IMHO banging on the outside of the drum is never a good idea as it is too easy to get carried away and you will end up with a dimpled drum. Try what the pros above suggest . . . just be careful with the muriatic acid - use goggles and rubber gloves and when you are done and have your drum clean, make sure it and your mixer are well cleaned . . if not, the muriatic acid will rust it and any other metal around it.

My Dad started myself and my brother out at a very young age - we had a stationary mixer and later one that went on the back of the 8N Ford that rally worked slick. We mixed a lot of cement for projects on the farm and he had us shoveling to help and to learn how to do it. The one thing he drilled, hammered and pounded into us was to CLEAN the mixer up completely when the job was done. Never ceased to amaze me when we were at farm auctions and others and there would be ce,emt mixers and you'd look into them and they weren't cleaned properly and like the one you bought. Sweat and provably a few swear words along the way but you'll get it cleaned out and you'll certainly appreciate that you have it when you need it. Good luck!

This reminds me of an incident back in the late 80s. We had a contract for trimming out a number of houses in a subdivision that was being built. Behind the house we were working not they had dug a basement and were ready to pour the footers. We were taking a mid-morning break for a coffee and as we took it, we watched a Reds-mix truck carefully make its way backing up to where it could get the chute in a good place to dump for the footers. It was in the fall - typical rainy wet Michigan weather for the week before. The cement contractors were up on high ground and directing the truck back - thank God nobody was in the basement yet because when they got the truck where they wanted it and the driver got out, in less than 30 seconds the wall of the dug basement gave way and all of them jumped bak.
We couldn't believe what we were watching but that large Redi-mix truck slowly slid back as the wall of the dug basement collapsed and slid right down into the basement - with a full load of cement on board. Thankfully no one was hurt but they ended up having to bring in a large crane in order to get the truck out and I have often wondered just how they ever got that full mixer of cement cleaned out - if they ever did. They weren't able to get a crane there until the next day so that load sat well over 24 hours.

Nowadays, once they have a broke down truck, they just accept the loss. At least the larger companies do.

Once they get the truck running again, or towed out of the basement, ;-) Then they will already have a new drum on order or some of the larger companies have one in stock. Then swap out the drum and a couple of rollers. Then the truck is ready to go. The old drums get set at the scrap pile and they will sit for years.

[cat-mechanic]

I was told years ago by a manager of a redi-mix company that if you can get a few bags of sugar in the cement mix and roll the barrel, it will prevent the concrete from setting up as it should. In the case of the truck in the basement, that probably was not an option.

I've heard this as well. But in 30 years of being around heavy equipment, construction companies and mixer trucks, I have never seen any sugar anywhere.

[metricmonkeywrench]

Well, worrying about dimpling the drum is long past on this one. I do have a couple of rust holes along the neck seams and the motor plate that will need some attention before the first use but overall it’s looking pretty good so far.

I picked up an air chisel from the local big box hardware store and was able to break up about half of the contents before the air chisel quit, kinda disappointing. The website reviews warn of this type infant mortality on this brand.

[Tatanka]

I've heard this as well. But in 30 years of being around heavy equipment, construction companies and mixer trucks, I have never seen any sugar anywhere.

Not to mention the obvious-- concrete is not an accident, and is not mixed by the driver. All the ratios and all the additives are ordered through a contract that is quite specific, according to specifications called out by an engineer or an architect in the design documents, and measured as carefully as any baker measures ingredients for a cake. The results on large projects are then tested to make sure they meet those specifications. There are commercial retardants that slow how fast concrete sets; no one would use something as unpredictable as sugar.

Nobody would allow some idiot to throw a bag or three of sugar into a truck of concrete.

Where sugar is used is on the surface of various exposed aggregate finishes. It's used in various forms, I've seen pop, sugar water and molasses, but that has nothing to do with concrete in a drum.

[cat-mechanic]

Not to mention the obvious-- concrete is not an accident, and is not mixed by the driver. All the ratios and all the additives are ordered through a contract that is quite specific, according to specifications called out by an engineer or an architect in the design documents, and measured as carefully as any baker measures ingredients for a cake. The results on large projects are then tested to make sure they meet those specifications. There are commercial retardants that slow how fast concrete sets; no one would use something as unpredictable as sugar.

Nobody would allow some idiot to throw a bag or three of sugar into a truck of concrete.

Where sugar is used is on the surface of various exposed aggregate finishes. It's used in various forms, I've seen pop, sugar water and molasses, but that has nothing to do with concrete in a drum.

And the last part of that equation, the only time you would want to do it, if it truly worked, is with the drum spinning in order to distribute it throughout the mix. But if the drum still spins, it can unloaded. If the drum has stopped spinning, throwing some bags of sugar on top of the wet cement isn't going to keep it from setting up.

[Dusty Bannister]

Agreed, that is why I also said "roll the drum". The idea is to mess up the chemistry so the concrete will not set correctly and it can be cleaned out easier. NO ONE would want bags of sugar around a construction site. Please take the comment in context. The truck was not going to deliver the product, so maybe they could save the expense of a new drum or barrel by preventing a hard cure of the product.

[rockrat]

Where I used to live, on the road out of town there was a cement truck drum just sitting by the road. Was there for decades. Heard the cement truck went off the road with a full load and it was a few days before they could get it out of the ditch. Guess company just unhooked the drum and rolled it off the truck however they do it and left.

[Plate plinker]

Well, worrying about dimpling the drum is long past on this one. I do have a couple of rust holes along the neck seams and the motor plate that will need some attention before the first use but overall it’s looking pretty good so far.

I picked up an air chisel from the local big box hardware store and was able to break up about half of the contents before the air chisel quit, kinda disappointing. The website reviews warn of this type infant mortality on this brand.

Just hit it with the acid. Dump a quart of acid in with a gallon or two of water and let it run for awhile. When it quits off gassing rinse it out and whack at it with your favorite tool. Repeat and rinse as desired.

[slim1836]

I would at least try a rubber mallet, the vibrations may break to bond to the drum.

Slim

[Ozark mike]

Heat is yore friend heat the metal with a acet torch steel expands at a diffrent rate than limestone

[white eagle]

I found a deal on a used but in decent shaped cement mixer (its an old Sears) online and picked it up today. Been wanting one for a while but really didn't want to pay full price for something that will just sit most of the time, even from the cheap tool outlets.

The downside is that one of the previous owners let a good amount of concrete set up in the lower 3rd of the drum. Short of renting either a demo hammer or jackhammer is there some magic method to clean out a drum or am in in for a long bout with a masonry drill, hammer, chisel and sweat?

265919

like has been said lots of work to remove but it can be done
shame I have the exact same mixer works like a charm
best of luck

[metricmonkeywrench]

Success... air chisel #2 finished off the job and got the drum is fairly clean. At least to an acceptable level for me. I figure there was at least a bag+ in there. At least I can now move it a lot easier

265998

[skeettx]

Wonderful
GREAT effort :)

[jsizemore]

Looks like the needed ingredient was persistence.

[BD]

Keen Crete is the homeowners version of what we use at work. I think we pay about that same price for 5 gallons commercially. Put it in the mixer with a couple of shovels of 3/4" crushed rock and run it a few hours, then let it sit and run it again. It will get clean enough to use. "perfectly clean" is not a realistic concept in the world of concrete.https://www.homedepot.com/p/1-Gal-Multipurpose-Concrete-Remover-and-Dissolver-Bottle-32110/206586454

[metricmonkeywrench]

Gtrubicon and BD Thanks for the tips on the 2 acid baths, that should finish off the cleaning once I address the few rust spots on the upper portion of the drum to keep the water and cleaner in and keep from making a mess.

I also should fashion some sort of belt guard. I haven’t had time to see what the original looked like

Overall I am pleased with the purchase and the wife’s plans will ensure we get our money out of it.

[Mal Paso]

If you store it outside with the barrel opening down, put a cover over the bearings on the back of the yoke to keep rain out. Or store it opening up with a cover. Those bearings are a pain to replace.

[15meter]

Have you seen the Beirut Explosion Videos? 27,000 Tons of Ammonium Nitrate.

Didn't check but 27,000 tons sounds a tad high, used to put urea on wheat @ 200 lbs. an acre, 27000*2000/200 = 270000 acres, that's a BIG pile of fertilizer.

But I've been wrong before, just ask any of my sisters. 65 years and 1 day of being wrong.

And still counting.

[Mal Paso]

Didn't check but 27,000 tons sounds a tad high, used to put urea on wheat @ 200 lbs. an acre, 27000*2000/200 = 270000 acres, that's a BIG pile of fertilizer.

But I've been wrong before, just ask any of my sisters. 65 years and 1 day of being wrong.

And still counting.

You are correct, I got the figure from the news, it was actually 2,750 Tons. Equal to 1,200 Tons of TNT. Estimated 10 to 15 Billion in damage.

[Minerat]

Nobody would allow some idiot to throw a bag or three of sugar into a truck of concrete

Well if it means that or losing a $40,000 drum on a large ready-mix truck the owner of the $500,000 truck might be that idiot.

[Winger Ed.]

Well if it means that or losing a $40,000 drum on a large ready-mix truck the owner of the $500,000 truck might be that idiot.


A friend of a friend had a buddy that got a job driving a concrete truck one summer.
They told him about the sugar thing, and kept it in the batch plant shack.
But he never put any in his truck.

One day, he ran out of fuel on his way back to dump about 1/4 of a drum that was left over in the pit they had, and the concrete set up.
When he got in, he told the boss what happened and asked, "I guess I'm fired, right"?

The boss told him 'Oh no, it happens, no big deal, we even keep the hammers and long chisels to deal with it'.

After spending the rest of the day busting it all out and tossing it through the little scuttle hole, he finally came in and put away the tools.
Then the boss said, "Now you're fired".

[DDriller]

We used cement on drilling rigs to keep surface equipment from being screwed up with cement. It was dumped in the cement when we got the cement returning from cementing casing. Still messy but easier than hammers, picks, and chisels.