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    Dreaded Foam -- What years?

    Howdy friends, I'm looking to buy another Hammond (either an A-100 or a C3), and while researching these models, I've read threads that mention foam and it's cancerous effect on resistance wires. Someone mentioned mid-sixties as when Hammond started using this foam. My question is, what years did they use this foam? Is 1963 a "safe" year? What years should I avoid? Thanks!
    sigpic
    1956 Hammond C-3
    Circa 1965 Leslie 145
    1963 Hammond D-152
    1963 Hammond C-3
    1959 Hammond HR-40 Tone Cabinet
    Motion Sound Pro 3
    Motion Sound Low Pro
    1958 Hammond M-3
    C.Bechstein D282 9'3" Concert Grand
    1977 Wurlitzer 200A

    #2
    Originally posted by Doctor Robert View Post
    Howdy friends, I'm looking to buy another Hammond (either an A-100 or a C3), and while researching these models, I've read threads that mention foam and it's cancerous effect on resistance wires. Someone mentioned mid-sixties as when Hammond started using this foam. My question is, what years did they use this foam? Is 1963 a "safe" year? What years should I avoid? Thanks!
    My May 65 UK A100 has it. Still... Haven't dared to take the covers off to see how it's doing...

    Comment


      #3
      They started using the foam in 1964. Check for the rivets in the manual cover to be sure. Rivet = felt. Empty hole = foam. I have a 1964 A105 that had one of each.

      Jim
      Click image for larger version

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        #4
        Originally posted by Jaim View Post
        They started using the foam in 1964. Check for the rivets in the manual cover to be sure. Rivet = felt. Empty hole = foam. I have a 1964 A105 that had one of each.

        Jim
        [ATTACH=CONFIG]31468[/ATTACH]
        Any idea when they stopped doing that, or was that something they stuck with until the model was discontinued?
        sigpic
        1956 Hammond C-3
        Circa 1965 Leslie 145
        1963 Hammond D-152
        1963 Hammond C-3
        1959 Hammond HR-40 Tone Cabinet
        Motion Sound Pro 3
        Motion Sound Low Pro
        1958 Hammond M-3
        C.Bechstein D282 9'3" Concert Grand
        1977 Wurlitzer 200A

        Comment


          #5
          Originally posted by Doctor Robert View Post
          Any idea when they stopped doing that, or was that something they stuck with until the model was discontinued?
          The foam strip stayed until the end of production.
          Current organs: AV, BC, A-100
          Current Leslies: 22H, 142, 147, 760
          Organs in the past: L-100 (several), M-100 (x2), T-100, E-100, CV
          Other keyboards: Roland FP-4, Yamaha DX7, Yamaha TX81Z, Yamaha Motif ES Rack, Korg Krome, Novation Mininova

          Comment


            #6
            Originally posted by enor View Post
            The foam strip stayed until the end of production.
            Ah, so is it advisable to avoid any models made in 1964 or later? Or do pre-'64 models have their own issues? And with ones that have foam, how often is this a problem? Is it just a matter of time?
            sigpic
            1956 Hammond C-3
            Circa 1965 Leslie 145
            1963 Hammond D-152
            1963 Hammond C-3
            1959 Hammond HR-40 Tone Cabinet
            Motion Sound Pro 3
            Motion Sound Low Pro
            1958 Hammond M-3
            C.Bechstein D282 9'3" Concert Grand
            1977 Wurlitzer 200A

            Comment


              #7
              C2 1953, as old as I am and 760 rebuilt, Custom M3 1955, custom HX3, Hohner OAB, Ventilator, Service for friends on A100, B3, BV, M100 and some Leslies

              Comment


                #8
                It is also due to plasticizer migration So You might also be OK if the foam is placed far enough from the resistance wiring.
                Hi Wes

                The early versions of Polyurethane foam will degrade in any climate but I am jumping ahead a lot here so please allow me to back up and explain

                The vary nature of the foam itself starts to degrade the day it is created. This degradation is not related to only one of the climate features like UV light , heat, moisture, humidity, directly In other words it is not just because of these factors that the foam is degrading. Most people would like to point at one of these sources as THE cause and say hey that is the reason...Not so .
                Most comments I have seen so far, are a combination of dis information bits. The reality is that Age in a perfect environment is the killer of this type of foam. It is design by the polymers used, to break down. Polyester and Urethane are mixed along with blowing agents to make a product which foams. This foam when cured is then cut, sliced and diced into rolls of product that we see. It is an open cell which means if you were to drop water say on this foam ..it would find its way to the base layer. That's how they get a cushion type of product that can compress when they put the cover back on and it is soft enough to not crush the resistance wiring when it does this. It is also designed as a dust stop...well more like a dust collector. That's the function of open cell - it can be compressed and then expand when the pressure is off.... The longevity of this early type product is 15 years at the best. IT is no wonder we are have issues with the stuff today - most of us have machines created in the early 60's . Things like UV light, Heat, Moisture, Humidity, are all major contributors to how fast the foam is degrading. The more exposure of any of these the faster the timeline. Think we can rule out UV exposure . WE cannot rule out heat from the tubes and operation of the equipment is likely a large contributor The localized regional temperature is also important but maybe more from the impact it has on the adhesive substrate and coatings of adhesive in the double sided tape used. Mine has a carrier for the double coated tape - so I know it was applied after the foam was created to make the product we see in the organ. Although I am not certain of the chemical make up of the adhesive it is likely based on age of the product a rubber based adhesive and because of this, subject to the elements, like age as is the foam, so it is going to dry out with age. The foam as it ages will get brittle and not hold its compression ability ( cant spring back ) and as it dries out, will also granulate - see my pictures above.

                SOME have experience a very gooey mess. When they go to remove the foam This is due to some external chemical interaction that is effecting the foam. One of the biggest causes not discussed yet is the interaction between the foam in place and the plastic PVC resistance wire comb. If you look at my pics above # 3 to # 6 closely you will see that the Poly and Urethane foam is coating the ends of the PVC comb where the wires are.... Pvc is manufactured with Plasticizers - This Plasticizer material is what allows PVC to be extruded/and formed along with heat into so many different functional parts. If you feel this plastic it is what gives it a slippery greasy feeling and the same stuff that allows forming. Plasticizer never dries and it is what is attacking the Foam. Plasticizer migrate - they move The plasticizer is turning the foam to the gooey gunk. It can also be accelerated with the heat it experiences from the tubes in the organ and cold moisture rich climates They all contribute. But the PVC plasticiser is the the main culprit to the gooey mess. Once it starts to migrate and causes a chemical reaction with the poly based foam it will continue and speed the reaction hasten on by the other environmental conditions present
                The fact the resistance wires are so close to the chemical reaction is really unfortunate because they get caught in the reaction and can add to it as well as cause degradation.

                Bottom line is this The foam regardless of where you are....warm climates, cold climates wet or dry. THE Foam is degrading because it has lived past its useful life of 15 years. This has likely been hastened by the heat from the tubes in the system and you might find that the upper manual is worse that the lower manual. At this point we are just talking about the foam drying out and becoming brittle, Dropping off the double coated adhesive tape into the bottom . IF it is touching the resistance Wire comb....It is going to get gooey as it degrades especially around the resistance wires. This is the gooey mess that is likely to eat or corrode the resistance wires sitting next to the ends of the resistance wire comb.

                Should you take it out? Yes I sure would! If you don't have an issue right now with lost notes ....the foam has already dried out and it is crumbling. Some may have already gone gooey at the ends of the resistance combs - you just don't have any resistance wires stuck in the gooey mess - deteriorating.

                All this info shared with you comes from my 15 years as MARKETING Manager with the largest foam tape manufacture in North America and supplier of single coated foam products world wide both open cell and closed cell . Did this US company sell to Hammond....my guess is they did and for this application too but I don't know for sure.

                PGR
                Practise the theory...realize the practical
                Hammonds L100 /A100 /B3 Leslie 147 and 122 Yamaha E352 Key board driven in OVATIONS 15" 40 watt power

                Comment


                • Admin
                  Admin commented
                  Editing a comment
                  Great overview of the problem. Thanks!

                #9
                Very informative. Thank you!
                sigpic
                1956 Hammond C-3
                Circa 1965 Leslie 145
                1963 Hammond D-152
                1963 Hammond C-3
                1959 Hammond HR-40 Tone Cabinet
                Motion Sound Pro 3
                Motion Sound Low Pro
                1958 Hammond M-3
                C.Bechstein D282 9'3" Concert Grand
                1977 Wurlitzer 200A

                Comment


                  #10
                  Originally posted by Doctor Robert View Post
                  Ah, so is it advisable to avoid any models made in 1964 or later? Or do pre-'64 models have their own issues? And with ones that have foam, how often is this a problem? Is it just a matter of time?
                  Generally speaking about Hammonds:
                  The earlier model, the better the build quality; with the definite degradation starting in '68-'69.
                  Current organs: AV, BC, A-100
                  Current Leslies: 22H, 142, 147, 760
                  Organs in the past: L-100 (several), M-100 (x2), T-100, E-100, CV
                  Other keyboards: Roland FP-4, Yamaha DX7, Yamaha TX81Z, Yamaha Motif ES Rack, Korg Krome, Novation Mininova

                  Comment


                    #11
                    The worst thing about the foam business is not the actual removal, even though that is clearly tricky on some organs. It's actually having the Hammond out of action for some time, I think that's really what's putting me off having a look inside the keyboards. But then, one could say, better a month now than having a Hammond go into senile decline... Mine was built around the time, May 65, I was taking my university finals. Will it be me or the organ who goes first!.

                    Comment


                      #12
                      Putting an exact date of manufacture on any Hammond is, at best, an approximation.

                      These days, keyboard swaps are pretty common, so there is no absolute guarantee that either of the keyboards is original. I have seen organs with one keyboard having foam, and the other had felt.

                      The only way that you can determine if a keyboard has foam is to look at the back for the telltale rivets.

                      Click image for larger version

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                      Bob
                      In theory, there is no difference between theory and reality.
                      In reality, there is.
                      '54 C-2 & Pair of 122 Leslies
                      H-324/Series 10 TC
                      '35 Model A (Serial# 41) with a 21H
                      Look at some of my rescues:
                      https://www.flickr.com/photos/58226398@N03/albums

                      Comment


                        #13
                        Some of the points about my note on foam degradation in Hammonds is that if the foam was placed far enough away from the key combs holding the resistance wires then the foam over the long yeas of use would just dry up with heat and age. It at any time it falls on the key combs - especially before it ages but also after it ages the PVC plasticizer will creep into the foam and this is when you get the gooey mess attacking the resistance wire coating and all the trouble with the foam
                        Practise the theory...realize the practical
                        Hammonds L100 /A100 /B3 Leslie 147 and 122 Yamaha E352 Key board driven in OVATIONS 15" 40 watt power

                        Comment


                          #14
                          Originally posted by Bobmann View Post
                          Putting an exact date of manufacture on any Hammond is, at best, an approximation.

                          These days, keyboard swaps are pretty common, so there is no absolute guarantee that either of the keyboards is original. I have seen organs with one keyboard having foam, and the other had felt.

                          The only way that you can determine if a keyboard has foam is to look at the back for the telltale rivets.

                          [ATTACH=CONFIG]31659[/ATTACH] [ATTACH=CONFIG]31660[/ATTACH] [ATTACH=CONFIG]31661[/ATTACH]

                          Bob
                          Mine has no rivets and I'm pretty happy with the date of May 65, though of course the keyboards will have been manufactured earlier, because the organ has the original UK QC label hanging off the wiring harness, QC'd by 'Grace' 5/5/65:
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                          The date also fitted with the various amp electrolytics which I have replaced.

                          Comment


                            #15
                            Originally posted by alpine View Post
                            Mine has no rivets and I'm pretty happy with the date of May 65, though of course the keyboards will have been manufactured earlier, because the organ has the original UK QC label hanging off the wiring harness, QC'd by 'Grace' 5/5/65:

                            The date also fitted with the various amp electrolytics which I have replaced.
                            1965 ... no rivets, it's likely to be a foamer then... I hope you land lucky.

                            Am about to pull the manuals out in another 1966 C-3 and am just hoping that the damage isn't too great. It seems to be a bit of a lottery when you (very carefully) pull the back cover on the contact bins.... hmmmm
                            1966 C-3 / 925
                            1965 M102 / 145
                            1967 M111A / 330

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