{"id":41,"date":"2009-05-07T23:18:13","date_gmt":"2009-05-07T13:48:13","guid":{"rendered":"http:\/\/makeamarimba.com\/5octavemarimba\/?p=41"},"modified":"2009-05-13T01:06:10","modified_gmt":"2009-05-12T15:36:10","slug":"tuning-and-sanding-the-bars-for-the-5-octave-marimba","status":"publish","type":"post","link":"https:\/\/makeamarimba.com\/5octavemarimba\/?p=41","title":{"rendered":"Tuning and Sanding the Bars for the 5 Octave Marimba"},"content":{"rendered":"<p>Welcome back marimba building enthusiasts! The last installment of this blog saw me at the point where the bars had all been cut and sanded in a basic way \u2013 basically to the correct dimensions. The next steps involve doing the basic tuning \u2013 then doing the finish sanding\/polishing \u2013 then some tricky bits involving finding nodal points and providing a good average layout (more on that process later) \u2013 then finally the drilling and fine tuning.<\/p>\n<p>\nBy far the bulk of the actual work is the basic tuning and sanding and let me tell you it creates a LOT of sawdust! Because of this you really need to do it in a workshop or even better \u2013 outside! Well I\u2019ve been a bit hampered by rainy weather over the last couple of weeks, so work has been sporadic, but these two tasks are now ALMOST done.<\/p>\n<p>\n<center><img decoding=\"async\" src=\"images\\marimba_bars_tuned.jpg\" width=300 height=253 border=0 title=\"some marimba bars roughly tuned and sanded\" alt=\"some marimba bars roughly tuned and sanded\"><\/center><br \/>\n<br clear=\"all\"><\/p>\n<p>\nLet\u2019s have a look at some of the steps. Above is a photo of some bars that have gone through the basic tune and sand process. This involves routing or sanding the arch under the marimba bar in the appropriate places to get the fundamental tone and any harmonics you want to also tune to the correct harmonic relationships with each other and also all down to about one semitone above the final pitch.<\/p>\n<p>\nBelow is a photo of my laptop all covered in gladwrap plastic to protect it from the sawdust. I\u2019m using the fantastic Peterson Strobosoft II deluxe software which makes tuning even the higher and short lived harmonics much easier than pretty much anything else I\u2019ve ever used.<\/p>\n<p>\n<center><img decoding=\"async\" src=\"images\\tuner_software.jpg\" width=300 height=443 border=0 title=\"tuning marimba bars with a software stroboscope\" alt=\"tuning marimba bars with a software stroboscope\"><\/center><br \/>\n<br clear=\"all\"><\/p>\n<p>\nAt this point there is minimal chance of knocking the bar about anymore, so I use 80 grit sandpaper on the orbital sander to go over all the bar surfaces and smooth them out, making sure there are no leftover scratches from the coarse sandpaper. This will lower the bar pitch a little but that\u2019s ok as we started with a whole semitone to spare. After this, it\u2019s back to the sanding disc and the bar is tuned down to the point where it actually reads the correct note \u2013 but only just! \u2013 In other words about 40 cents (40% of a semitone) sharp.<\/p>\n<p>\nThe next stage is the fine sanding and finishing of the bar faces (particularly the main top face). This can be easy and fast, or very time consuming, depending on the level of finish you want to obtain. I\u2019m personally going for a highly polished finish, there have been many hours of work. The idea is to use sandpaper on a sanding block and sand the bar by hand using gradually finer and finer sandpapers. I start with 120 grit paper and work my way up in about five steps to 1200 grit paper. The photo below shows six bars that have been through the fine sanding process.The bars on their edge to the right of the photo have not yet been hand sanded.<\/p>\n<p>\n<center><img decoding=\"async\" src=\"images\\marimba_bars_sanded.jpg\" width=226 height=318 border=0 title=\"marimba bars after fine sanding process to 1200 grit paper\" alt=\"marimba bars after fine sanding process to 1200 grit paper\"><\/center><br \/>\n<br clear=\"all\"><\/p>\n<p>\nNext comes the polishing of the marimba bars. For this I use Marveer furniture timber polish. You can use any non-silicone based polish. It\u2019s essentially just a light oil. Moisture will tend to raisethe grain of the timber a little, so to counter this as well as a final abraisive stage, I actually use a fine steel wool to apply the liquid. I bit of \u201celbow grease\u201d is required \u2013 each bar gets rubbed firmly for a few minutes with the steel wool till the polish has soaked in thoroughly all over. Then a soft cotton cloth is used to wipe off the residue then apply a little more polish which cleans any excessive fine wood particles away \u2013 then dry the bar. This photo below shows the lowest few bars all polished \u2013 note the dark red colour has been brought out of the timber.<\/p>\n<p>\n<center><img decoding=\"async\" src=\"images\\marimba_bars_polished.jpg\" width=300 height=196 border=0 title=\"the low marimba bars after the polishing process\" alt=\"the low marimba bars after the polishing process\"><\/center><br \/>\n<br clear=\"all\"><\/p>\n<p>\nAs I get all the bars to this finished point, I\u2019m laying them out in sequence on top of my 4+1\/6 octave marimba in the studio. You can see from this photo that I\u2019m almost done with this process, with just the top two octaves (with much smaller bars) to go. The extra bars at the low end have just been stacked up. This keeps me motivated as it\u2019s exciting to see what these bars will look like when in position on an instrument. I\u2019m really loving the colour of this particular batch of timber \u2013 particularly the middle bars which have some colour variation and patterns on some bars \u2013 a bit like a Jersey cow!<\/p>\n<p>\n<center><img decoding=\"async\" src=\"images\\marimba_bars_layed_out.jpg\" width=450 height=110 border=0 title=\"marimba barsfor the 5 octave marimba layed out in position\" alt=\"marimba barsfor the 5 octave marimba layed out in position\"><\/center><br \/>\n<br clear=\"all\"><\/p>\n<p>\nKeep reading here for updates all! Next will come the node finding and finding of suitable frame measurements. When the instrument is done you will be able to get the comprehensive building guide from <a href=\"http:\/\/www.makeamarimba.com\" target=\"_blank\">www.makeamarimba.com<\/a><\/p>\n<p>\nJim McCarthy  <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Welcome back marimba building enthusiasts! The last installment of this blog saw me at the point where the bars had all been cut and sanded in a basic way \u2013 basically to the correct dimensions. The next steps involve doing the basic tuning \u2013 then doing the finish sanding\/polishing \u2013 then some tricky bits involving [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-41","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=\/wp\/v2\/posts\/41","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=41"}],"version-history":[{"count":12,"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=\/wp\/v2\/posts\/41\/revisions"}],"predecessor-version":[{"id":60,"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=\/wp\/v2\/posts\/41\/revisions\/60"}],"wp:attachment":[{"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=41"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/makeamarimba.com\/5octavemarimba\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}