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Friday, September 2, 2011

Shiny!

A lot of people like to have a really shiny surface on their headphone cups because it can look really sexy! Generally this involves a lot of manual labor. Let the finish sit and harden, scuff off any nibs with wire wool, smooth sand with 500 grit and then work your way up the many grits in a micromesh polishing set. From 1500 to 12000 grits and then use a buffing compound to get that nice shine, finished off with Renaissance wax. Basically lots of rubbing and elbow grease. I normally do my buffing by hand using either Behlens buffing compound or Hut ultrashine and a rag. Today I decided to try a car polishing sponge on my mini orbital sander. I like to use my tiny 12v Proxxon orbital because it's very light, plenty powerful and gives amazing control. Mine is highly modified to use Festool RO90 pads and sanding discs. Anyway, I slapped on the Festool polishing spinge and squirted some Hut compound onto it, wazzed up the speed to maximum and gently buffed away. The Proxxon has a very small orbit of 2mm and a max speed of about 5000 opm. Long story short, very nice results indeed. As good or better than my hand buffing and much more control than a buffing wheel for these smaller items. It's nice when I find something that makes my life a little easier while getting nice results.

Sanding and polishing

Sanding and finishing are generally the nemesis of most woodworkers and not many seem to enjoy the process as it's so easy to mess up. I have so many sanding things here it's mind boggling, and of course none are exactly right for what I want... sods law! I trawl the intertoobs constantly looking for that 'ideal' thing that will cure all my ills, but reality is never as ideal as marketing. One thing that constantly gives me trouble is small radius curves on round surfaces, like my headphone cups. It looks simple enough, sand on the the lathe with some paper, and yes, for the most part that works ok... up to a point. A lot of woods are pretty brittle and have funky grain patterns which can cause all sorts of trouble when shaping with chisels, so a lot of the time I'll stop at a certain point and finish the shaping by sanding.

One of the problems with this approach is that you need some aggressive paper to remove the majority of the wood, this leaves deep scratches that take quite a bit of sanding through to smooth which in turn generates a lot of heat in the wood and can cause micro fissures and warping. Drill sanding pads are generally flat so you're essentially hitting a very small spot on a curved surface, not ideal. Hand sanding is another option as always if you have the time to do it. Getting a perfectly round and even surface this way is difficult and time consuming. If only there was some kind of sanding thing that was both aggressive and shape conforming!

Eureka! There is!

I'd given the 'king Arthur tools' inflatable sanding drums a cursory look before but was skeptical of it's marketing and if it would indeed help my situation. Well, I plunked down the sizable sum to get a drum, some sanding rolls and the pump. Got home and quickly assembles it all and gave it a try. Color me surprised, it actually works way better than I'd expected. One pump is all it needed to hold the sandpaper roll in place while still being very soft and flexible. It conforms to shapes very well and unlike solid sanding drums, doesn't dig in and cause undulations. The thing is a great idea and cuts the sanding/shaping headaches to a minimum. It can be very aggressive and cuts a lot of wood smoothly over curves and can be sanded smoother as you go up in grits. It takes less time sanding and gives very good results. I'm very happy. Its expensive stuff but will make my life a lot less frustrating, so worth it IMO.