Monday 9 July 2018
Mark Baker tests the complete sanding system from Kirjes
Inflatable drum sanding units are not new but the Kirjes Sanding System seems to be the one that most people are familiar with, although they are not necessarily aware of what it does and how it useful it can be. Many claim it has helped improve their sanding no end, and I thought it would be worth trying it out.
The basic principle is for the system to utilise drums or domed inflatable units of various sizes that can be pumped to produce a firm or soft sanding surface to cope with flat or curved work. You can buy a Kirjes sanding kit as a stand-alone item and it comprises one round and one drum-type inflatable sander with a mix of abrasive sleeves for both, and one pump. The drums can be fitted into the end of any electric drill.
Alternatively, you can also purchase a flexible shaft unit which fits in something like the large rotary units from Foredom and Dremel, or a drill/pillar drill to allow the user more flexibility and ease of use.
By far the most popular option is the Kirjes Sanding System comprising a double-ended motor with a Jacobs-style chuck at each end, a flexible drive, one of each of the four drum sanders available (one of which is a dome) and a selection of sanding sleeves for the drums. This is the unit I am looking at here along with a dust extraction attachment – an optional extra – which fits to a vacuum cleaner or portable extraction unit.
The flexible handpiece is connected to the double-ended motor system via a key-operated chuck. The fitting of the extraction unit is simply a case of laying the flexible shaft handpiece in the moulded extraction section and screwing it together.
The next step is to select it an inflatable drum or dome depending on the job and fit the grit grade over it, pumping up the unit until the pressure is as you require. I find a pressure that has a reasonable amount of give is the most useful for me. One pump is all that I usually require, but each project is different. To release the pressure simply undo the nut at the bottom or the hex-head machine screw at the top, and squeeze. This allows the pressure to escape ready for replacing the abrasive sleeve or adjusting pressure.
The motor unit is solidly build and robust. The drums are well engineered and precise, and the flexible shaft seems to be well constructed and worked well in use.
Having connected the extraction unit to a vacuum extractor, I needed to repair a hollow form which had been damaged and required a soft(ish) pressure on the drum. The flexible shaft is easy to work with and is not too stiff. The speed of the motor unit is quite low, which affords the user a great deal of control over the whole sanding process, and prevents burning with the abrasive too. Also, a coarse grit allows you to power through waste timber very quickly. I set the sleeve on the drum to over-hang the end a little and it then acts as a soft edge to the abrasive, allowing me to gently edge up to the carved lip detail on the piece I was working on.
I worked with all the grit grades and the finish left from the abrasive was excellent. I actually found the sanding process a lot easier than using a mandrel, which I could have only used for part of the restoration job anyway before resorting to hand or delta sanding. The process was quick and simple. I have used the system on other carved work too and really have only scratched the surface of the potential for this product. The system is easy to use, as so are each of the components/optional extras. Having the option of working with the flexible drive and drums either with the Kirjes motor or attached to a corded, cordless or pillar drill provides flexibility of use as well as price. I think these products are well constructed and considered. They can be used in many more situations than I have used them for and I am sure that people will find their own benefits in using them.