Is the Safety Valve Missing from my organ? And, if so, should I be concerned?

[DiapasonDan]

Greetings everyone, I'm new to the forum. See the "biography" in my profile for a bit of background. The short version is, while I grew up dabbling on a Thomas reed organ, and later a Baldwin electric, I mainly focused on piano for many years. I'm relatively new to being bitten by "the organ bug". A few months ago I decided I would buy a digital piano and get back into playing a bit. I thought it would be fun to learn some organ on the digital piano as well, as that is a common alternate sound setting. For various reasons, I ended up with a Briscoe chord organ instead of a DP. I had fun playing around on it, but it was limiting in what I could play, what with only three octaves. So I started looking for something larger. A week ago, with much excitement, I acquired a ca. 1890 Doherty Chapel style organ in excellent condition -- and for less than half the cost of a used digital piano, including the cost of hiring movers. I've been doing a lot of reading about reed organs over the past few months, including reading extensively on these forums.

My question today is regarding the Doherty chapel organ. While I plan to eventually do an extensive restoration on it, for the short term, I hope to clean and tune a few silent reeds and continue to play it, without completely dismantling it, as it is in relatively good condition for its age. I have many questions, but my first question is about the safety valve. When I remove the back of the organ, I do not see a safety valve on the back of the bellows, where it usually appears in photos on other organs. Is the safety valve missing from my organ? And, if so, should I be concerned about playing it without the valve in place? Or is it possibly located somewhere else, hidden from view?

I've attached a few photos. It appears that someone in the past may have cut an access hole in the back of the bellows, possibly to repair the bellows cloth from inside. I'm wondering if they might have removed the safety valve in the process, and not bothered to replace it after the bellows repair. Or am I not looking in all the right places?

Thanks,
Dan
--------------------------
Harmony Chord Briscoe (fan powered reed chord organ)
ca. 1890 Doherty Chapel Organ

[nutmegct]

Dan - congratulations. Doherty has received kudos here on the forum for several years.

It does look like someone opened the back board of the air system, probably to work on the internal valves.

I'd certainly say it *should* have a safety valve - which opens when internal vacuum exceeds the desired limit. However, if the air system cloth and leather is original, there are probably plenty of leaks, so the safety valve would likely never come into play.

What's the condition of the bellows cloth and leather?

With all the dust showing on that small reed box (sub bass?), you'll need to open the organ and do a very deep cleaning of the upper action, as well as check/repair the air system.. A quick test of the air system: Pull one stop knob (diapason, principal, etc.). Then pump the treadles until you the bellows back board is fully closed (pulled inward). Stop pumping, play and hold one key. See how many seconds the sound continues.

How does the organ sound? All the stops and ranks work? Tremolo functioning?

Tom M.

[myorgan]

Congratulations of your find, Dan! The case on that organ has been exceptionally well preserved. The Vox Humana (aka Tremolo) appears to be pristine in your photos, so if it's not functioning, that should be a fairly easy fix. If you've been reading here for some time, you'll already know how to get the missing reeds working and sounding.

As Tom already mentioned, the inside of the organ appears to be quite dusty. Just be careful when removing the dust that some doesn't getting inside the organ-that'll be no end of troubles. You'll be cleaning reeds forever!

Thank you for sharing the photos of your organ, and I look forward to recordings once you have it cleaned up inside.

Michael

[Rodney]

Hi Dan,

Congratulations on that Doherty. It looks like the same one I saw for sale on Kijiji recently. I have always called that one the "Fork Handles" model, also known as the "Four Candles" - I have dry humour. :)

The panel on the rear is as designed in the late 1880s - it is a five panel tongue and groove construction that allows the large wood area of that reservoir board to expand and contract with the humidity. There would be no serviceable parts in that section, as the valves are on the other side in the exhausters (don't try to remove that center panel, it will destroy it)

The spill valve for these models are at the front, between the two exhausters. The only way to access it is either from the bottom, or pull the entire air assembly out of the instrument.

If taking it apart, be aware that there are hidden reed pan screws under the Vox Humana, and the grand organ linkage is a real pain to disengage and connect. Once the reed pan is out the organ is straight forward and fun to work on.

Best of luck,

Rodney

[DiapasonDan]

Thanks for the responses and tips everyone. Haha, "four forks" may become it's nickname. Speaking of which, the four candle holders are missing. If anyone has any leads on candle holders from a similar organ that is being parted out, let me know!

Here is a list of observations, questions and issues with the organ:

1. Cleaning and tuning reeds. Yes, I've found lots of info on this, including not using a vacuum cleaner or compressed air on them, which is the first impulse. Seems fairly straightforward, with proper care and patience. It appears I should be able to access all the reeds without dismantling the entire organ. I see a front panel under the keyboard with four screws. I assume I would remove this to access the front reeds, and the reeds at the rear could be accessed with the back panel removed. Is that realistic? Or do I need to at least remove the sub bass and tremolo fan to access the reeds at the back? I'll take a closer look when I open the back panel again.

2. One key is sticking/rough. Anything I can do about this before opening up the organ? It appears to be coming loose with some playing. Do I risk any critical damage by playing it a lot before opening it up and cleaning out the action? Even with it now returning after playing, it's movement feels rough. What causes the key to stick?

3. Air test: Middle C lasts for a maximum of around 4.5 to 5 seconds after pumping ceases, with only the Diapson Treble stop pulled. How good or bad does that sound in terms of air leakage rate?

4. Visual bellows cloth inspection: from the little I could see of the bellows cloth from behind the organ, with the back panel removed, the cloth appeared intact and in good condition. But I can't see much. The organ has a wood base which covers the bellows from below, so I'm not able to readily view the bellows if the organ were turned on its back, unlike some I've seen online. See attached photos of the bellows.

5. Bass and Treble Dulciana stops not working: If only the Dulciana Bass and Dulciana Treble stops are pulled, there is no sound anywhere on the keyboard. There is no resistance when these are pulled. It feels like a linkage may have busted or come apart. I'll take a look next time I open the back panel.

6. Vox Humana/Tremolo fan: does not spin freely unless using a hand to help it along. When turning it makes a creaky sound. I am wondering if there is felt in the bushings that may be worn out/dried out? That may be causing too much friction for it to spin on its own.

7. Worn stop faces: Some of the stop faces are very worn, though the relief is legible when viewed in certain angles of light. Where can one find replacements? Could the lettering be repainted by an appropriately skilled hand?

8. Hide glue: What strength of hide glue is best to use? For when I get around to that stage.

9. Protecting the wood from drying out: It is very dry here. The organ has a large crack on the bass side (see photo). This may have formed when the organ was moved a few decades ago from a humid climate in Vancouver to the dry air of Calgary by the previous owner. I'm planning to get a hygrometer to monitor the humidity and adjust as needed. Assume a 40 to 50% target is ideal, similar to pianos? Is there any type of coating I should consider adding to protect the wood from drying out in the short term, without extensive refinishing or damaging any existing coatings? I have limited wood finishing experience, but plan to research more before doing anything. I've been reading Casey Pratt's blog to learn more about this.

10. List of Stops
If it's of any help or interest to anyone, here is a list of the stops

1. Diapason Bass [typically 8'?]
2. Principal Bass [typically a 4'?]
3. Sub Bass, for one octave [16'?]
4. Bass Coupler
5. Principal Forte [opens up dampers for more volume, similar to swell knee lever?]
6. Dulciana Bass [8'?] - not working
7. Vox Humana - needs new felt bushings?
8. Dulciana Treble [8'?'] - not working
9. Diapson Forte [typically 8'?]
10. Treble Coupler
11. Vox Celeste [usually 8', tuned a bit lower (or higher?) than the other reeds to create a warm, tremolo sound]
12. Principal Treble [typically 4']
13. Diapson Treble [?']

I uploaded the organ to the ROS database, but it hasn't appeared yet (still in moderation review).

I am in process of learning about the different stops. Feel free to fill in missing info with question marks. I'm working my way through Rodney's Reeding 101 youtube series to better learn how to use the stops.

The organ is currently in a (very small) living room. I have no garage or workshop space. I plan to move to a larger space with a workshop in the next year or two. I had planned to get a larger organ like this after the move, but I couldn't pass this one up. I'd like to avoid opening it up extensively until after the move, if possible, and especially any portion involving work with hide glue. However, if it is unwise to play it much without opening it up, I may ask my family to suffer some organized chaos. I do have space to temporarily store the parts in the basement (with a diligent labeling system, as Rodney has illustrated in the photos on his website, which I have been reading extensively). But that is unlikely to happen for now, I think.

Thanks again. I look forward to your comments.

[DiapasonDan]

P.S. Thanks Rodney for the tip regarding the expansion/contraction joints in the bellows. Very interesting -- and important to know! And thanks for the valuable info regarding the safety valve location, and tips for taking the organ apart. Much appreciated.

[myorgan]

1. Cleaning and tuning reeds. Yes, I've found lots of info on this, including not using a vacuum cleaner or compressed air on them, which is the first impulse. Seems fairly straightforward, with proper care and patience. It appears I should be able to access all the reeds without dismantling the entire organ. I see a front panel under the keyboard with four screws. I assume I would remove this to access the front reeds, and the reeds at the rear could be accessed with the back panel removed. Is that realistic? Or do I need to at least remove the sub bass and tremolo fan to access the reeds at the back? I'll take a closer look when I open the back panel again.

2. One key is sticking/rough. Anything I can do about this before opening up the organ? It appears to be coming loose with some playing. Do I risk any critical damage by playing it a lot before opening it up and cleaning out the action? Even with it now returning after playing, it's movement feels rough. What causes the key to stick?
[snip]
6. Vox Humana/Tremolo fan: does not spin freely unless using a hand to help it along. When turning it makes a creaky sound. I am wondering if there is felt in the bushings that may be worn out/dried out? That may be causing too much friction for it to spin on its own.
[snip again]
9. Protecting the wood from drying out: It is very dry here. The organ has a large crack on the bass side (see photo). This may have formed when the organ was moved a few decades ago from a humid climate in Vancouver to the dry air of Calgary by the previous owner. I'm planning to get a hygrometer to monitor the humidity and adjust as needed. Assume a 40 to 50% target is ideal, similar to pianos? Is there any type of coating I should consider adding to protect the wood from drying out in the short term, without extensive refinishing or damaging any existing coatings? I have limited wood finishing experience, but plan to research more before doing anything. I've been reading Casey Pratt's blog to learn more about this.

#1-Cleaning/Tuning: From the posts I've seen from Casey (SubBase), carefully cleaning each set of reeds properly will generally take care of the tuning as well. Removing the oxidation should bring the reeds back near (if not into) proper tuning.

#2-Sticking/Rough Key: If the organ came from a moist environment, chances are there may be some moisture that has gotten into the felt, causing it to swell over time. Moving the key gently, but firmly from side-to-side can sometimes compress the felt enough to solve the issue, however, a bit of graphite on the wooden pitman (or guide pins) may help as well. Another member recommends a very small amount of lanolin in some cases.

#6-Vox Humana/Tremolo Fan: The same solution for #2 may serve you well here as well-considering the moist environment it came from.

#9-Protecting Wood From Drying Out: If you have a very dry enviornment, sometimes heat pumps and/or propane stoves or other appliances have a byproduct of moisturizing the air enough to keep it in tolerable limits. If you have concrete that freezes in the winter, it will absorb moisture during the frozen months, and give up that moisture when it thaws in the Spring. Generally 40 to 60% is considered a tolerable range. In my area, the humidity can get as low as 15% in the Winter and as high as 85% in the Summer. I don't think it has had any permanent negative effects on any of my pump organs. Your organ has survived over a century so far, so I doubt you'll do it much damage in the next 20-30 years.;-)

Hope this helps.

Michael

[DiapasonDan]

Thanks Michael for the useful tips.

11. Condition of the Exhauster Valves, Bellows Cloth & Safety Valve
Now that I'm learning the anatomy of the organ, I was able to reach up behind the treadles to inspect the condition of the exhauster valves, the front side of the bellows cloth and the safety valve. I attached a few photos.

The exhauster valves appear to be intact, but curling at the edges. You can see the holes behind the leather flap in the photo.

I'm able to feel most of the edge of the bellows cloth where it connects to the front and back panels. The cloth feels intact with no holes. However, a sharp crease is forming where the cloth connects with the front wood panel. Along this crease, a coating on the cloth feels dried, cracked and starting to peel away slightly (a few millimeters). I'm guessing the cloth must have have been redone at least once in its lifetime. I know the organ sat for at least 25 years since it was last played much at all. So perhaps the cloth was last redone some 30 to 50 years ago.

The safety valve springs were loose and not contacting the valve flap at all. One spring fell off when I bumped it. I was able to bend the spring and add some tension to it, so it now at least contacts the valve flap. However, I have no idea what spring tension should be used, so I kept the tension minimal for now. I'll keep researching to see what I can find about the spring tension. Any tips are welcome, but I'm OK to do the work of gathering the info too.

I'm curious to know to what extent the exhauster valves versus the bellows cloth might be contributing the most to any air leakage. But I suppose it doesn't matter in any case, as it all needs to be refurbished, and the organ dismantled to do so. I need that workshop space soon!