A nice tap makes quick work of cleaning a bunged bottle boss. However, there are times when trying to fit a tap handle with tap attached into a tight space just doesn't work. And there are plenty of times as I'm prepping frames and want to clean the paint out of bosses (especially those on the back of the seat tube or on the chainstay bridge) and the tap just ain't going to fit. All I need to do is clean out the paint within the first few millimeters. Screwing a regular bolt into the boss doesn't work because all the threads are engaged and as the bolt encounters paint, it gets jammed up.
Being human and a problem solver, I think "why not make a simple tap out of a bolt." I do this by cutting three grooves length-wise in the bolt and tapering the end as you would find on a tap. Easy. How does it work? Great. So simple and with a ball-end driver, I can get into tight spaces and clean out threads of excess paint super fast. A drop of cutting oil on the DIY tap makes it clean and fast. The cutting oil also prolongs the life of this new home-made too.
Now, this new tool won't, of course, make new threads or clean up damaged threads as the bolt is just not hard enough. But, it will make quick work of pesky paint. It's a very welcome addition to my work bench and if it wears out, I can easily make a new one.
Grooved M5x.8 bolt ready to clean up excess paint.
(What's playing: Uncle Tupelo Sauget Wind)