Fax: 01444 414813
Email: info@airstream.co.uk
by Peter Brett - December 2006
For more information call Christine
01444 440188
01444 440188
Why Flap?
Rhodius has named the new grinding wheel “Fusion” because it combines the features and benefits of a grinding wheel and a flap wheel. Now I quite like flapwheels and have used them a lot for removing rust and pits from things as diverse as sash cramps, an anvil and a long steel RSJ. But flapwheels tend to wear out very quickly and they can have other little unwanted quirks which limits the applications for which they can be used.
On the other hand, grinding wheels can be a lot more difficult to use well, especially in unskilled hands and in a controlled fashion, so I was intrigued to see how the Fusion would combine the merits of both.
On close examination, the Fusion grinding wheel is just a little bit thicker than your average wheel at just under 7mm thick. This allows for some considerable grinding life, a flatter grinding angle and the capability to dress the edges to a profile of your choice. Take careful note, because these things are important later!
In order to test the Fusion grinding wheels I acquired a lump of discarded steel fabrication with messy welds and angles and quite a bit of rust too to see whether I could directly test the Fusion’s claims.
When I first started grinding a weld I have to admit that I couldn’t immediately see the advantages of the Fusion grinding wheel. It felt much like an ordinary grinding wheel in use and seemed to give more or less the same results. However, as I worked on a bit more, I began to notice that the Fusion works more smoothly and repays a bit of careful use. If you gently apply pressure and use a smooth oscillating motion you are rewarded with a smooth finish, certainly smoother than I would have expected from the 40 grit wheel that I was using.
When I tried a flapwheel in this same situation I really could see what Rhodius is on about. The flapwheel is simply hard work and takes a great deal longer even to get an acceptable finish. Also, the weld line is still very visible because the flapwheel, being flexible, simply lifts over the weld line while giving it a passing polish.
Of course, the usual sequence of events would have been to use a grinding wheel first, followed by the flapwheel to give a good finish. With the Fusion, it is perfectly possible to skip the flapwheel stage for many jobs. I had also been able to use almost all of the grinding area on the Fusion disc because the angle of attack can be a very low five degrees to the work.
What was also quite noticeable on the Fusion wheel was that it had hardly worn very much at all. With previous grinding wheels I have used, after fifteen minutes of serious grinding, the disc would be more or less due to be replaced. Even the sparks produced by the grinding process with the Fusion are very well spaced and neat.
One of the other features of the Fusion is that the edge of it can be dressed to a suitable profile in order to safely grind welds that are in internal sharp angles. This is in order to get the (right) profile the welding should get. I did manage a fairly competent round edge and then set to on one of the internal angles of my discarded steel frame. For me, visibility was the key to good work here, because it is all too easy to grind away bits that can’t be easily seen. What helps the Fusion disc, as opposed to a flapwheel, is that you can direct the edge of the disc exactly to the grinding point and work directly on it. With a flapwheel, there are sometimes unintended consequences as it flexes away from the grinding point and grinds away at something else nearby. As before, a gentle pressure with controlled oscillating movement gives the best results. However, this is one area that I shall leave to the experts because I wouldn’t like to show my efforts to anyone!
The range of Fusion discs is wide with 15 options available in various grits (40, 60 and 80) and three diameters (115mm, 125mm and 180mm) and having only had the 6.5mm thick discs to try, it was clear to me that they would actually be too wide to use in some applications like grinding tight internal angles.
However Rhodius has thought of this and 4mm thick discs are available in the 115mm and 125mm diameter discs. The largest disc size available is 180mm by 7mm thick.
Having recently been forced to read the grinding wheel safety regulations again in my capacity as person in charge of the Design Technology facility, I was once again struck by how we mostly take the safe operation of grinding tools pretty much for granted. Actually, a piece of bonded abrasive flying round at 80 metres per second can be quite dangerous should it shatter. It was therefore with some interest that I read that Rhodius is a founder member of the oSa (Organization for the Safety of Abrasives) Formed in 2000,this organization is committed to meeting all relevant safety standards and developing safety standards even further. This is a very important role, bearing in mind the way in which some of these technologies develop so quickly.
All products with the oSa badge meet the highest possible safety standards and therefore users can be guaranteed that they will be safe when used correctly.
Retailers should be able to confidently recommend the Fusion, not only because it does a very good job, but because it is safe to use as well. Some other cheap abrasives may not be able to make those claims.
Airstream Communications