 The Bassoon BBoard
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Author: joem5636
Date: 2011-10-05 20:20
I am a good amateur bassoonist but have offered to try to get a local school's bassoon playing half-way decently and have little experience with, especially, intonation repairs. The instrument seems fairly "tight" but two notes in particular have serious intonation problems:
Low-G plays about 50 cents flat. I tried some tape on the top and (alternately) bottom sides of the F hole but that did not seem to help. I have had someone push the various keys on the butt while playing the G to see if some key is leaking but without success. I can lip this note up about 20 cents but it then switches to the middle G (which does play well).
The forked Eb is very sharp. I have cleaned all the tone holes and the bore. I have not tried tape on the inside of the D hole yet (and can never remember whether it should be on the top or bottom to correct which direction. I assume top makes it sharper?).
I have a call in to my own repair person, but hate to mooch too much.
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Author: Ian White
Date: 2011-10-08 08:47
Low G - first thing is to check the opening of the F pad & E pads which should be about 4.5 mm. The opening of the bass joint keys also affects the tuning of other notes all over the instrument; again the C key should be about 4.5mm - so often these are set far too high which, counter-intuitively, lowers the pitch of G. Try playing the low G & slowly close the low D, C & B & see what effect this has. Have these as low as possible without affect the tuning & tone of other notes. A thicker cork under the end of the low B touchpiece nearest the pad key will close these down to suit.
Forked Eb - check that the Eb vent pad on the wing joint is sealing well (Key #17p on the chart in the resources section of the Fox web site). Also is the ring key of the boot joint (High G vent #25) closing tightly? Problems in these places can cause all sorts of tuning oddities.
Also do you use just LH 1 & 3 for this note? If so try adding the Bb key (L thumb) which is needed on most instruments to stabilise the Eb, despite what some fingering charts show.
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Author: joem5636
Date: 2011-10-11 12:41
The suggestions were helpful. I am not sure what all helped reduce the problems (it was a Linton), but it now plays at least. One technique that seemed to help quite a bit was to paint around the tone holes with nail polish to build-up the seat (Linton had pretty flat seats mostly) and smooth the wood (most were very rough what with wood grain and the varnish Linton had applied).
The Eb seat was a mess as suggested. I scraped off the old varnish that was cracked and repainted that area with the nail polish (BTW, I used Hard as Nails as the clerk claimed it was the best -- it does seem to have worked pretty well with good build-up and hardness albeit it dries somewhat slowly for the same reasons).
I found some of the small tone holes somewhat clogged -- there are some tiny ones on the low G hole!
The Bb key's holes were also not sealing well. Again, building up the holes with nail polish and a little bending of the key helped.
The low G was still unstable but at least sounded in-tune when playing up/down scales and ignoring the meter. At least the low notes were sounding far better.
Many thanks for the suggestions. Holden McAleer also gave me some suggestions (mostly similar).
Best,
Joe
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