The Flippin Windchest of the 31
Hello All, A bit of advice please. I am having major problems with my windchest again on the 31kl. To cut a long story short it is the same trouble I had a couple of years back. Being a small organ, it has one windchest, the air goes down through the wind chest channels via a pallet mechanism. Now when the chest was made it was glued beautifully to make sure it didn't leak, problem is I am now having any problems inside the thing with channels leaking into each other and some notes having a constant Cipher from the pipes, (nothing to do with dirt on the pallets, I have cleaned them). It appears I have a small crack running across the whole of the chest. Now I cured it for a couple of years by sticking a bottle brush down through each channel and spreading a layer of PVA glue down through. Now it appears the glue has cracked, so back to square 1. So...... has anyone got any solutions for this one? Anything better than PVA that I could spread down through the channels that would last, or is it even worth routering out each channel, sealing the whole thing properly and then putting a new bit of wood on top of the chest for the pipes to sit in (only securing it with screws). Thanks for all the help in advance, it's a horrid one to have to figure out what’s best on your own. James. Oh and another thing with the windchest on mine. There is no where else for the air to escape but through the pipes, which makes the ciphering even worse! Do most organ windchests have some sort of a hole on each channel that is blocked off when the rod is pushed down to play the note, but is open at other times?

Hi James, what is your windchest made from? If it's timber there seems to be movement going on (shrinkage?). Is your trailer insulated? As this could play havoc with the change in temperature. I would plump for putting a sliver of wood in the crack if you're sure its not going to move anymore. (Maybe also checking any screws in its constuction). Regards Robert Washington :org: -25 years in the furniture industry!!!

Something the old builders did to stop cyphering was to carve small 'v' shaped grooves between the chest dividers, this would cause the 'bleed' of air between channels to be diverted out. There's a good example of this method on the Marenghi at Amersham on the chest just behind the bandmaster, you can see the ends of the 'v' grooves! Just an idea! Robert Washington :org:

Everything said by Nick and Robert so far is quite right. May I add my two-penny’s worth? Regarding vee grooves – these are indeed for relief of escaped wind from risers where there are sliders for tuning. This is a standard church organ practice, whereby the top of the windchest itself (called the table) is grooved cross-ways between all the pipe holes. Sliders are mounted between fixed bearers pinned to the table (not glued) to guide the sliders. Upper boards are then fitted on top of the bearers. These also have grooves. The sliders themselves are never grooved. Paper strips are glued to the surface of the bearers to prevent the sliders jamming between the table and the upper boards. There is inevitably some space here allowing wind to escape. The grooves are there to channel this escaped wind to atmosphere instead of causing “running” between notes. This principle is applied to Gavioli and Marenghi organs where there are risers and sliders. The chest itself is not grooved. This brings me to the main chest problem. If the chest is a “bar” type, with solid bars running across the chest separating the notes, the usual practice is to first flood the whole chest with glue (traditionally hot glue, but if made in recent years PVA may be used). The glue is left in the channels for a minute or two to allow it to permeate through any cracks, then tipped out. This is done only a few channels at a time to prevent a general flood of glue onto the floor when tipping out into a paint bucket for use again. It can be a messy job. PVA shrinks a little when drying, so if the cracks are big enough gaps could appear, and this is possibly the main problem here. The trick is to thoroughly -*test*-('") the whole chest for leaks before committing yourself to further assembly. I usually do this by covering all the channels with masking tape, then systematically blowing through one pipe hole for each channel in turn to see if the presure escapes anywhere. If any leaks are revealed the offending channels must be flooded again. This whole procedure is simple enough for a small chest by imagine doing it on one from an 89-key organ, with a hest upwards of 8 feet long! With large cracks on the chest table, the usual practice is to pin and screw these. Here, you drill tiny holes through the cracks into the bars below, taking care to follow the cracks downwards – they might not be vertical, but follow the grain pattern. Then small pegs are glued in, fashioned from dowel. Then, for security, very small screws are placed each side of each peg to prevent the table warping and rising. The pegs serve to stop runnings between channels along the cracks. With the screws fitted slightly below the top surface, the whole chest is then planed with a very thin cut, to make quite sure of it being flat. Once you can find no more leaks, the under surface of the chest is covered with calico, across the bars. This is sealed to prevent leaks – I use PVA mixed with poster paint, to give it body. Then the pallets are fitted. Turning to the question of exhausting the wind from the channels when the pallets close, the usual practice is to drill two (or sometimes four) holes around the pushrod holes. Then small fibre discs are fitted to the pushrods themselves so these holes are covered when the pallets open. There is no need to use leather, as any wind escaping here is minimal. The discs must be glued to the pushrods so they rise with the rods to exhaust the channels when required. However, it’s wise to use small discs of reasonably thick leather between the discs and buttons, to allow some degree of float for good sealing of the discs over all the holes. One old trick if leaks or runnings occur later, is to punch small holes through the calico at strategic points to let excess wind escape, but if your exhaust holes are large enough, this may not be necessary. Sorry for the lengthy explanation here, but it’s an important subject, and needs careful treatment if you’re going to get it right. Regards, John

Point taken Nick & John! Interesting stuff though. Robert Washington :org:

Great stuff, thanks for all your help- I knew I would get some, that's why I posted!! Well with Christmas Bookings starting in 2 weeks, theres gonna be no time to build a new chest, so I have sealed it with PVA again today, which should get it through the festive period, and then I will start a new chest in the spring. At least I know it won't be suffering from a heatwave over the next few weeks!