Monday, August 1, 2011

Home-Made Vibrator

So somehow I got sucked into building a deck for my boss even though I have vowed to take a break after completing the 14' x 20' shed I built for some other people I know. Anyways, I was preparing the tools and going through the process in my mind wondering how I'm going to consolidate the concrete and make it air bubble free since the deck needs twelve 8" concrete posts, 4'-6" into the ground and hitting it on the side with a hammer (which I normally do to get the air bubbles out and the surface nice and smooth), since it will be several feet in the ground I won't be able to do it, so I got an idea that I could try to build my own concrete vibrator.

From Wikipedia:
Concrete vibrators consolidate freshly poured concrete so that trapped air and excess water are released and the concrete settles firmly in place in the form work. Improper consolidation of concrete can cause product defects, compromise the concrete strength, and produce surface blemishes such as bug holes and honeycombing. An internal concrete vibrator is a steel cylinder about the size of the handle of a baseball bat, with a hose or electrical cord attached to one end. The vibrator head is immersed in the wet concrete

It was about 9PM when I headed out to the shop trying to find some materials to build the vibrator when I walked past our old, dead tread mill in the garage. Looking at the roller the belt runs on I thought I might be able to make it work.

The roller is about an inch and a quarter diameter, with a half-inch stainless steel core held in place by two bearings, one on each side. Pretty basic set-up. I managed to take the center core steel rod out, grind it flat and weld a 3/8" by 3/8" square solid steel rod to it. Then I took the grinder and ground off some more materials of the center rod opposite the square steel rod to make the rod off-weight.

Once it was welded, I placed it back into the aluminum roller, attached it to a 25ft. plumbing snake and enclosed the whole thing in some ABS pipe and water hose.

The original roller


Another close-up

With the square steel rod welded to the center core

A close-up of the opposite side that was ground off to make it more off-balance

Cut off one end of the rod that was sticking out

Steel nipple as an adapter to connect center rod with plumbing snake

Steel nipple on the end of the roller

Finished DIY concrete vibrator

This is where the drill will attach

Actual concrete vibrator head


Alan keys
Cordless drill
Snap-ring pliers
Ear muffs
Screw driver

Old treadmill roller (free)
16" of 3/8" by 3/8" square steel rod (free)
4" by 3/4" pipe nipple (free)
25' plumbing snake ($14.95)
20" of 1.5" ABS pipe (free)
ABS cap ($2.49)
ABS reducer ($2.59)
ABS connector ($0.67)
Water hose adapter ($0.54)
Water hose clamp (free)
20 feet of 3/4" water hose (free)


2.5 hrs


I'll update the blog once I've finished pouring the posts.