Hohner Pro 36

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  • #7748
    Zoran Terzic
    Participant

    Hi there, I am new to Mworld.
    Primarily a Jazz pianist, I recently discovered my old Pro 36.
    Here is a sample tune with the Pro36 to give you an idea: https://soundcloud.com/zoran-terzi/pampy

    Anyway I run out of air too quickly when playing (compared to say the new Yamaha),
    in other words, I ve got a leaking problem. In my ears the Pro 36 sounds best (even tried the Hammonds etc.), so I try to repair it.

    I ve been messing around with the instrument since, but cannot significantly improve the air leak.
    I assume it s the key pads with their leather surface that are leaking.

    The reason I assume that is that I sealed the first “chamber” i.e. the space above the reeds with tape to make it airtight, and when blowing heavily certain tones are being played without me pressing any key.

    If you have useful tips how to handle leaking, I d appreciate it.
    Does it make sense to send it to Hohner or repair service? (I live in Germany)

    Just to give you an impression, here some pics — I should add that back in the days I had attached a kind of sound enhancement element (wood), this is the black part – it sounds soooo much nicer, and good for stage)



    #7791
    Alan Brinton
    Participant

    Hello Zoran,

    Since nobody has yet responded to your inquiry, I will by saying that the Melodica World expert on the Professional 36 is Melodica-Me. He owns several as well as related models and has worked on them successfully. He definitely knows what he’s doing. Melodica-Me may be tired of repeating what he has said about the kind of issue you’re having and the advice that he has given to some of us. I have a leaky one I started to work on, but I got frustrated and then was able to acquire another that is in good playing condition. However, it is still hard for me to play, as this model takes a lot of air even if not leaky.

    I suggest that you use Search in the Forums to identify past discussion of the Pro 36. Search “Professional.” But you might start with this:

    Hohner Melodica, classic versus new

    My guess is that if Hohner is willing to work on your Pro 36, it will be very expensive.

    I’m sure others as well as myself would be interested in more information on how you modified with wood.

    #7797
    Alan Brinton
    Participant

    A product you might find useful, Zoran, is gasket tape such as the one pictured below. It is very much like gasket material in a lot of melodicas. It’s sticky on one side. That side is exposed by peeling off the shiny strip. There are some such products available through Amazon. You can see the company name on this one, and it can be found on the Internet. This kind of tape can be obtained in different dimensions. 1/8″ thick is best, and then probably 1/4″ or 5/8″. Its easy to cut, cross-wise or lengthwise, and easy to apply.

    #7798
    Melodica-Me
    Participant

    Hello Zoran, your Hohner Pro 36 is very interesting, I would love to hear how it sounds with the wooded piece on it. I own several pro 36 and the all leak a little due to the age of the Melodica. There are several ways to identify leaks in your Melodica. The best way I have found is using a little dishwashing soap and water mix. With the Melodica together start with the air chamber. Go around the chamber with an eye dropper filled with soapy water and wet the joints f the cover to the body and without pressing a key blow into the Melodica and see if you can see any bubble that appear. If so mark those area with a white grease pencil, tape or any way to identify the location of the leak. If your Melodica has a leak I would replace the gasket. I have used the one Alan shows in the past and works good, a little pressure will be needed to close the cover but will make a good seal. I like to use the 1/32 silicone gasket with the sticky back or the neoprene rubber with the sticky back. They all work fine I used to use leather but I find it is a bit harder to get a even fit. Clean the gasket area good, you want to make a good clean contact befor applying the gasket. Next if you still have leaks, the next step is to check the valve pads. In the same way you did the air chamber, wet around the pads completely (do not try to do them all at one time, the soap drys and bubbles are harder to see) place the cover on the Melodica, do not install the screws, just squeeze the cover tight and blow into the Melodica without pressing any keys. Open the chamber and see if you can see any air bubbles. Mark with a grease pencil or a sharpie. Now that you have identified all the locations of your leaks it’s time to remove the pads. With patience you can remove the pads with an exacto knife and tweezers. One you remove the pad the trick is cleaning the valve before you put the gasket pad on. this is where the silicone gasket material with sticky back helps a lot. Pressing the key down adjust the pad with the stick back still on it to see how it fits. Once you happy with the fit remove the backing and place the gasket material in place and release the presure from the key slowly to lower the valve in place. This is not an easy task but With “patience” it is possible. Note: I should have mentioned this step before, make sure that the Melodica is dry and the soapy mixture is completely removed before applying any gasket material. With all the pads replaced and the chamber gasket replaced cover the air chamber and check for leaks. If the back preasure has inproved but you still have some leaks. Repeat the soapy and water treatment to verify you installed the gaskets evenly.if no leaks are visible but you still have leaks you will need to check the wooden body in the chamber for leaks. Start with the corners and and mouth piece area lookin for bubbles. If none are spotted. This means that there may be decade on the wood or soft wood due to moisture building through out the years that was not removed. In this scenario you will have to disassemble the Melodica and check for wood rot or soft wood. I personally if found I would look for another Pro 36 if you find a lot of rot. The repairs and long and not always successful. If little rot is found, dry the Melodica well by setting it out in the sun ( do not leave it over night where moisture can gather. Check for soft spots and remove gently and fill with epoxy Bondo. Do not clunk it on and expect to file it off. Make a smooth finish and replicate the original formation, sand if uneven. Making sure that the Bondo has dried apply a water proof sealer then water proof paint. Let dry completely before re assembly of the Melodica. I do not recommend doing the last repair,unless you have worked with the epoxy, sealers and paints before. I learned the hard way, taking lots of pictures during the process will help you when you reassemble the Melodica, plus you can share here and help others. Let me know if this helps you, and please let me know if you have any questions.
    Thank you
    Melodica-Me
    Monsters of Melodica

    #7800
    Alan Brinton
    Participant

    Great post, MM. I meant to add that this gasket tape (at least the one I have) has some stretch to it, so that any joints in the gasket can be tightly pushed together so that, with luck, no other kind of sealant is required. I just replaced the gasket in an (1970s?) Italian Pianetta in this way. I decided to try first applying the tape on top of the remaining old gasket material, after just brushing off the loose, crumbly stuff. That worked just fine.

    #7810
    Zoran Terzic
    Participant

    Hey, thanks to all replies,.. I didn t think someone would reply eventually, so I had sent it in in the meantime,
    the repair man exchanged the sealing, adjusted the reeds etc. now I m a shocking 250€ short and still to go.

    @ MM > I do have a question :
    the repair guy suggests to cut open the back cover in order to be able to approach the pads and “arms” of the keys, in order to adjust the closing mechanism (without changing the pads), I assume he is trying to adjust the arms so they press the pads more firmly on the hole —
    does this make sense?
    that would be 90 more;

    That s his page BTW, he sells olds instruments now and then, a good overview:
    http://www.akkordeon-maurer.de/documents/d/Accordina_Clavietta_Pianica_Claviola_Melodica_Vibrandoneon_Eolina.htm#Melodicas

    the wooden construction makes for a louder and warmer sound, I post something once I m done — Z

    #7811
    Melodica-Me
    Participant

    Hello Zoran, is it Martin Maurer who is working on your Pro 36? Are you sure this is what he is saying, or can it be a problem in the translation. In order to take out the keys, you have to remove the end cap closes to the high notes (if you un-screw the brass screws on the side you will a flat point and a sharp point remove the side where it is flat). Once you do, you will see the pin (piano wire). You will need a pair of vise grip pliers to gently pull out the round pin (the pin can be tight, so take your time) at the back of the keys, it is the length of the Melodica. Only remove the first two keys so you can see how it is done (tip, at the the closes point to the Melodica gently rotate the pin to looses while pulling it out). Be careful not to bend the long pin as you will need to reinstall it once you are done. After the pin is in the right position you can remove a key (you will see the key drop a little at the rear of the key) this means that the pin has cleared the back of the key and you can now remove the key by simply lifting the key from the front tip of the key allowing it to clear the stops. Now simply push the key to the rear and you will now have access to the key to work on it outside of the Melodica. Once you have made your repairs and have installed all the pads, replace the pin by pushing it in from the closes to the Melodica with the vise grip pliers (rotating while pushing in) and not at the far end as you can bend the pin and you will then have to replace it. Once all is back to normal you will need to silicone the end cap (inside th Melodica) so no air can leak. I will take some pictures and post in the next couple of days to help in my How To discription.

    I revised the post to clarify the steps. I hope this helps you.
    Melodica-Me
    Monsters of Melodica

    #7813
    Melodica-Me
    Participant

    Hello Zoran, I attached a link showing pictures on how to remove the keys so you can work on the pads. unfortunately they are not in order but I titled them so you can referance them to the privous post. I put these pictures in an old link showing the removal and replacement of the main gasket using a material similar to the one Alan posted. Remember the most important part of the pin/rod removal is not to bend it. When you replace the rod you do not want to have any kinks on it, you may have to file any burrs that may have occurred while you where removing it with the vise grips pliers.
    Please let me know if you have any questions.
    Melodica-Me
    Monsters of Melodica

    http://s355.photobucket.com/user/BigPwr/library/Hohner%20Pro%2036%20Gasket?sort=3&page=1

    #7815
    Zoran Terzic
    Participant

    Hi MM,
    thanks for the photo instruction. It is very helpful – however, my instrument is still at martin maurer’s, and he is unable to extract the metal pin (somebody must have oiled/waxed it once and now it is more or less glued inside.), he is afraid something will get damaged if he applies too much force etc.
    So, I cannot take this thing out to check keys separately.
    I have a question:
    Since I cannot take out the keys separately to improve the air sealing, is there any fluid, fat, or the like, that I could put on the valve pads that would make them seal the air off better (instead of replacing them, I mean)? Or any material that I could attach to them without replacing them…?I assume the original valve pad material is leather?
    (At this point no idea can be too silly if even experts cannot solve a problem.) best regards Z

    #7816
    Melodica-Me
    Participant

    Hello Zoran, the pin is not easy to remove, especially if you do not do it as I mentioned in my previous post. The pin must be rotated and pulled at the same time. The use of WD-40 lubricant, sprayed at each point of exposure of the pin. This means in between the keys and body and left to penetrate over night. You can’t use regular pliers, you need to use vise grips. I have removed several of these and they have all been tight. As for adding anything to the pads I am not sure of this as this would not be a permanent repair so why bother (my opinion) I am a little OCD lol. I replaced some pads in the past by leaving the key in place but you need to make sure you remove all the glue from the key before you install the other pad or it will not sit evenly. Question, is Martin sure the pads are leaking?.
    Melodica-Me

    #7818
    Zoran Terzic
    Participant

    yes, he replaced all the rubber seals, still leaking;
    it s getting too costly for me to go further,

    #7819
    Zoran Terzic
    Participant

    instead of removing the pads can I stick other pads on each of them? should be viable—

    #7820
    Melodica-Me
    Participant

    I am not sure if they will stick as the pads have little ribs (see close up of pads in the pictures I posted) you can also cut the rod in the middle and pull from each end and then replace the rod (you can use a piano wire) what is Martin saying can be done that will cost a lot. If you want to request Martin to send it to me I can try to remove it for you. I will not charge you to do this just pay for the rod and the postage back to you, with the understanding that there is a chance that it may break. I can then place with temporray rod in it and send it back to you to change the pads. Let me know.
    Thanks
    Melodica-Me

    #7828
    Zoran Terzic
    Participant

    Thanks for the offer, but I need to see the instrument myself first after repair to known what has been done on it in relation to what I paid. best regards Z

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