Using A Power Trowel

Toolwh@#e

For years we've been subing out our concrete finishing unless its a small slab and it can be done by hand. I'm starting to lean away from it as finishing cost keep rising and quality keeps deminshing. Any tips and techniques for using a power trowel. I understand the basic princible but I'm not really sure about udjusting the angles on the blades or what blades to use and so on. Any tips and techniques would be appreicated.

WarnerConstInc.

Try a Two footer once with a pan on it, that was a crash course. I guess one of the most important things is timing, then after that the concrete will tell you what it needs. Running a power trowel wasnt to much different from using a floor burnisher or a floor scrubber. Riding power trowels are way cool!

Brock

If you were to compare finishing cost to fuel cost it is about right. If fuel was 18.00 per gallon. We had to bring the finish in-house about 5 years ago due to the rediculous price gouging. Used to be the concrete, carpet, and roofer worked for next to nothing. Now the finisher's have found you can make a buck at it, so we sent all of them packing.

The power trowel is $4500.00. Not worth it it at all unless you are finishing an airplane hanger.

mdshunk

I saw a power trowel launch off a 2nd or 3rd floor deck once. Well, actually I heard and saw it crash. I didn't actually see it flying off the deck. I was looking away at the wrong time, but the crash was spectacular.


That's about all I know about power trowels.

plazaman

i have 1 ride on finisher and 2 power trowels. never really used (bought from equipment surplus auction) i seen videos, but never had the chance to use it. its for sale if anyone is interested.

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Bluemoon

Plazaman,
what size machines( 36" 42" 46") do you have?
what tradename ( Whiteman, Allen, Wacker etc.)
do you have photos?

house bldr

If you have just one trowel you will want combo blades which will both float and finish just not quite as nicely as a blade designated for just one purpose. Start out with the blades as flat as possible without gouging the concrete then tilt them as the concrete gets harder to get the results you need.Tilting to early will cause wavyness and bring sand up causing a rough looking surface.Don't put your trowel on until you can walk on the concrete leaving only slight foot impressions,also keep the rpms low when its green and increase as it gets harder.It just takes practice to know when and how!

themudman

house bldr said it all, well put.

Toolwh@#e

So how "not as good" will the finish be? And what RPM should I run at? So as the concrete hardens I should tilt the blades to take out any waves and flatten the surface?

house bldr

We use combo blades, they do a nice job,just not smooth as glass,if you keep your blades flat and dont tilt to soon there should be no waves to take out other than the trowel marks which will work out with future passes. If you trowel to soon or tilt to soon its hard to get a flat surface back again.It would be best if you could practice with some supervision before tackling a big pour,it could be an expensive lesson!

Joasis

You are asking questions where the only answer is basically this: Experience teaches the techniques.

I generally sub out the larger pours, or at least bring in the concrete crew with mine on anything over 5000 sq/ft. I pay .55 a sq/ft to have it poured and finished...and they do good work. The hang up is that is all they do, so I either wait on them, or we do it.

In my experience, the floating makes the trowel work go hard or easy.....set grade pins on a grid, and screed (we use a vibra-screed) or board...getting the level as close to perfect as you can, then bull float with a fresno style mag board...we use a 5 footer. Float it from all directions if you can, then get off of it and stay off....you can edge the slab, and maybe hand trowel corners or obstacles while waiting....then, starting in the area of the first section of the pour, or the first mud from the truck, check it often....when it feels firm to the finger, not soft, get on it....if you notice you are "moving mud", you are way early.......start with the blades as low as you can without it wanting to dig...if you wait the right amount of time, you will run about half the pitch of combo blades and turn slow....nearly all trowels have a centrifugal clutch, so as soon as you pick up some throttle, the blades are running slow....and that is fast enough. The trowel will want to travel left to right, and you lower the handles (down) and it will then go right to left...if you are early, try to let the trowel run a large circle.....it will leave a better finish in the natural rotation. If the concrete is right to trowel, sweep back and forth, lapping half of every pass, and walking backwards to keep footprints off the finish.....on a larger pour, by the time you get to the end, you will tun the pitch up a little and speed up off idle a little more, and pass it again. If you clip a rock and tear out the surface, then you will need your trusty water bottle with you and work the area to pull some cream and fix it....keeping in mind this will leave a "whiter" area on the floor....if you keep up the passes and pick up the speed, you can "burn" the finish to the point it is like glass......

And, as you trowel, if the machine "rocks" or "jumps" as you are moving, it is telling you that it is cutting into a "hump" or "hill".....if you are on it too early or use a float pan, it will level it without a lot of effort...if you are on it when it is ready to finish, you have to "work" the high spot out....back and forth and in a circle motion...but, if you stay too long, you will make a "valley...which is just as bad.

There are 3 blade and 4 blade machines out there...3 blades will cut a floor up pretty good...and IMO only for experienced guys........a 36 inch is a pretty decent size and forgiving....if you buy a 48, you have to wait a little longer to get on a slab since the machine is heavy...but it can correct level problems easier, since it is heavy, plus, you can add weights to them to aid in trowel pressure. If you plan on doing this for a living, get ready.....good Whiteman trowels can cost $1000 and up used....same for a power screed. I don't own a ride on Allen....but they are not cheap. I always take 2 trowels to a job.....sometimes concrete can flash, and set so quickly you are flooding it with water and troweling like mad....or one will just quit...nothing like pulling the starter rope and it refuses to run and you need to be trowelling....get it?

One floor we poured a few years back was 5000 sq/ft and the finishers had 4 machines at once on it...did I mention it was 90 degrees outside?

Good luck.

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plazaman

I know 1 is a whiteman for sure either a 42 or 46 im leaning towards 46. Im pretty sure the other is a whiteman also, that one looks like a 36".

E-mail me for pics, i have pics of the larger one.

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Toolwh@#e

Thanks a lot for the lesson. I'm excited now to try it. I think you answered all my questions and more. thanks again

Blackhammer

JOASIS said it best.

I run a very similar setup as him. the largest we have poured with 5 guys is 90 yards it was 10' wide by I can't remember how long. We bought a whiteman trowel 36" and I have used it on every job since. I can't remember what I spent but I got a great deal on it. It was a end of model year deal there was only 3 left and I got one with the ez tilt which is very nice. I like the Stow trowels but I think the whiteman are the best of the best.