This instructable converts an old string trimmer I got from a yard sale into a tire scrubber or high speed brush for any hard to reach area. As you can see from the video this thing redefines "elbow grease".
The cost was $10 for the trimmer at a yard sale, the tire brush $4.50 and the T nut I found at my local hardware store for less than a buck.... all in for around $15.
This trimmer actually has a high and a low speed switch. I found it helpful to slow it down even further by "pumping" the "on/off" switch.
Step 1: Demo and Prep
The old string trimmer is a Ryobi Model 123r which had become unusable due to worn parts.
In order to modify we needed to take the old trimmer components off. This involved unscrewing the center nut and discarding the string hopper. Save the center nut for sizing the new nut. You can take it to the hardware and try it on a variety of bolts until the right one is found. Most hardware stores have these testers (but don't buy these):
For the brush I used one that I've had a few years. I knew we would need to take off the handle to make a flat surface to mate with the trimmer. I placed the brush in a vice and used a sawzall with a longish blade on it but you could use just about any hand saw to effect the same result.
The brush we used is a Carrand Model #92014. Here is a link to one:
Step 2: Final Assembly
This final bit is what makes it work well. The "Tee Nut " is a self grabbing nut used in furniture construction but the prefect way to attach the brush. We drilled a hole in the center of the brush, stuck the nut thru and tightened it down. Make sure you take extra care to get the hole for the t nut centered otherwise you will get excess vibration.
If not available at your hardware store the T nut can be found here:
Ours was a size M8 but yours may vary.