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Roland: Perishing Glue on Key Weights.

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Roland: Perishing Glue on Key Weights.

Postby funkyant » Thu Jun 05, 2008 4:27 am

I have a D70 with the very common perishing glue syndrome.

Basically the epoxy used to glue in the key weights perishes under certain circumstances over time. The result is dripping glue from under the keys and weights falling out, rendering the keys useless.

I've heard of repairing this by pulling the synth apart, removing the weights, and re-gluing them with fresh epoxy.

Has anyone done this? I've tried Googling to no avail.

If I don't get a response, I'm going to just dive in the deep end (I used to repair video projectors for a living, so I kind of have an idea of what I'm in for).

Would love any tips from anyone who's previously attempted it though.
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Re: Roland: Perishing Glue on Key Weights.

Postby funkyant » Fri Jun 06, 2008 2:17 am

Cover me - I'm going in!

If you don't hear back in a few days, send out a search party
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Re: Roland: Perishing Glue on Key Weights.

Postby Yago » Sat Jun 07, 2008 2:02 pm

I'm getting worried , perhaps we better send that search party :P
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Re: Roland: Perishing Glue on Key Weights.

Postby funkyant » Sun Jun 08, 2008 6:18 am

OK.

Firstly, getting into the synth was pretty easy. I've read in other places on the net that they are hard to work on. I'd say this:

If you have a mid level of experience in electronics, then it should be a snap. To remove the entire keyboard assembly you need to remove the bottom cover, Mainboard, Analog I/O board, and the Card Reader assembly, as well as disconnect all the looms and ribbon cables.

Image

Fiddly bits such as the mod-lever, LCD, and power supply can all stay in place.

Surprisingly it is then just four screws to remove the entire keyboard assembly. Below is what is left that you don't touch.

Image

If you need a step-by-step on how to get this far, then I'd say you really should just pay someone else to do it for you.

My one little hint for the experienced, is that the receptacles for the ribbon cables need to be pushed down in order to release them (as opposed to pulled up, which is the norm).

So now I've got the Keyboard assmebly up on the work bench.

Now I can see that the glue is really in bad shape! It has turned into a molten gloopy substance that is slowly dripping into the innards of the synth. Ouch.

Time to dive in further and get the keys off. Now I didn't really take the best pics of this process, so I'll take some better ones when I re-assemble everything and edit this post.

For now what you really need to know is that there is a glued on plastic retaining strip that locks the key mechanisms in place.

Image

I just gently pried it off with a small flat blade screwdriver. Once this is removed you can slide each key forward (about 3mm) to release it. Obviously, white keys need to come out before black keys.

Important: This is like a big jigsaw puzzle. Not all keys are the same. For example different F# keys have different part numbers!!!!!

The key order is as follows, by part number (I'm sure this will save someone's bacon at some stage):

E11
CF21
3-1
G22
3-3
A22
3-4
EB12
CF23
3-2
D12
3-1
EB12
CF23
3-3
G21
3-4
A21
3-1
EB11
CF21
3-3
D12
3-4
EB11
CF24
3-2
G22
3-1
A22
3-3
EB13
CF22
3-4
D12
3-2
EB13
CF22
3-1
G21
3-3
A21
3-4
EB14
CF24
3-2
D12
1-1
EB14
CF24
1-3
G22
1-4
A22
1-2
EB14
CF23
1-1
D12
1-3
EB12
CF22
1-4
G21
1-2
A21
1-1
EB11
CF21
1-3
D12
1-4
EB11
CF24
1-2
G11


OK. Keys are off. Here comes the bad news:

The glue is in dire shape.

Image

And has dripped into much of the unit including the rubber contact membrane:
Image

Both contact boards:
Image

And the Aftertouch strip assembly:
Image

For now, I am halting this repair until I find a way of removing the glue from the parts without damaging them.

I cut of a glue sample with an exacto knife and have tried the following chemicals to break the glue bond - all to no avail:

Chemist grade isopropyl alchohol
Euchalyptus Oil
Contact Cleaner
Butane
Goof-Off (Citrus based remover)

I'm concerned about using acetone, as this can turn plastic to mush.

I've thought about sticking the keys in the freezer, and then cutting it out.

I have sent an Email to Roland asking for any suggestions on how to safely remove the faulty glue.

If anyone has any suggestions at this point, I'd be very grateful.

How the heck do safely remove glue from plastic?
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Re: Roland: Perishing Glue on Key Weights.

Postby Zaxx » Mon Jun 09, 2008 9:55 am

I love the challenge of problems like this - particularly when the problem's someone else's! My first question is whether the already-leaked-out glue has actually damaged or interfered with the operation of any of the things it's dripped onto. If not, just leave those gobs where they are. The only removal technique I might suggest is flicking the stuff off with the tip of a scalpel blade (obtainable from shops that sell stuff for graphic designers), if it works - but if you don't need to do it, don't.

To avoid further glue seepage, time for a bit of lateral thinking. Don't remove it - quarantine it! I notice there's a slight gap between the 'top' (i.e. bottom) of each weight and the lip of the key plastic, and that the weights also seem to be a fairly loose fit. I'd leave the weights in place, but flood the remaining space in the weight cavities with fresh, suitable adhesive - it'll seep down the sides of the weights and give you a layer on the 'top' (bottom - but you'd guessed that), thus sealing both the weights and the dodgy old glue in place. For adhesives, I'd recommend either Power Grab (from DIY stores) - sticks to everything, seems to attack nothing) - this is white (think it's essentially PVA on steroids) and has a sort of creamy consistency, so you could smooth it off along the 'top' (b... - oh, forget it - we both know the keys are upside down at this point) of each weight cavity. For a more subtle adhesive, try Fixogum (rubber solution base, from art/craft shops) - also seems to be non-violent on most materials (test first) - this is clearish and runny, so should flow well - just squirt it in until it fills up flush with the cavity lip. Or maybe use potting compound as used for potting discrete components (if you can still get it).

Does this make some sort of sense?!

(Sorry - just noticed you're in Oz - may be a case of seeking out equivalents for the adhesive brands I recommend - or indeed these same brands may be available where you are.)
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Re: Roland: Perishing Glue on Key Weights.

Postby funkyant » Tue Jun 10, 2008 1:32 am

Hey Zaxx,

Thanks for your reply.

Unfortunately the location of the globs where the glue has dripped causes sticky key action, so I definitely need to clean it up.

We are definitely on the same page though, as I've already sourced a really great pouring resin to 'contain' the offending glue. I am only going to take this approach as a last resort though, as I have 2 concerns regarding this.

The first being, I am not sure what kind of glue was used by Roland in the first place, and have no idea how it would react with the new resin (if at all). I'd hate to do all that work to find that it will fail again over time.

The second, and most important reason, is the delicate balance of the key weight and springs. If I add a gram or 2 of extra adhesive, I am not certain that the feel of the keys will remain true.

I just received a call from Roland Australia whilst writing this post, and they have advised me that they will sell me an entire new keyboard assembly for $250AU (around 90 pounds). This includes a full key set, metal chassis, aftertouch strip, contact boards, and rubber key membranes. It all comes pre assembled, ready to screw in. This is cost price and they'll do it once for every unique keyboard serial number due to the manufacturing fault. Apparently these are newly designed and manufactured replacement parts, addressing all common faults with the D70 - and therefore being far superior to the originals with regards to reliability and strength.

This seems like a pretty good deal to me, so I think I'm just going to order the parts.
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Re: Roland: Perishing Glue on Key Weights.

Postby Zaxx » Tue Jun 10, 2008 11:02 pm

Couldn't resist responding to such an interesting-stroke-annoying problem (probably depends on your mood!). That spares deal does sound like the way to go. I had dealings with their Roland UK counterparts some years back and found their willingness to supply parts to be an absolute joy - they'd often chuck in the relevant circuit diagram/service manual without even being asked, and always at no extra charge.

If you do opt for the glue/resin route after all, I'd just add that Power Grab seems to be highly non-reactive (think it's actually water-based, given that it'll resist anything except lots of water) and oddly weightless - sort of the mass and consistency of thick yogurt.

Keep us posted!
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Re: Roland: Perishing Glue on Key Weights.

Postby funkyant » Wed Jun 11, 2008 7:01 am

It seems that every single D-70 and U-20 suffers from this fault. If yours hasn't yet, then it will.

So in the name of science I am going to try the containment method. I've already ordered the new parts, so I don't see that I have anything to lose (except time).

Hopefully this will benefit somebody out there in the future.

I have discovered that rapidly freezing the substance with butane renders it very brittle. Enough that it instantly peeled off the rubber membrane with ease.

Next is to try to get it off the contact strip.
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Re: Roland: Perishing Glue on Key Weights.

Postby Sonarguitar » Sun Sep 07, 2008 5:48 pm

Hi!

This is my first post to this forum.

First, I want to ask that you NOT discard your original epoxy contaminated keys. If you won't be continuing this project (and chose to buy a replacement keyboard instead), I'd LOVE to have them to continue my experimentations into this Roland "Red Plague" epoxy problem.

Along with the above menntioned U-Series and D-Series keyboards from Roland, you can add the Roland JD-800...all share the same keys, springs, keyboard frame and a few other items. They don't share the same keyboard contact board (the green flexi thing) that underlies the grey rubber bubble contacts.

The differences in the green contact board between models is in how they terminate. So you can't simply take a keyboard bed from a Roland U-20, for example, and toss it into a Roland JD-800...they won't mate up correctly.

SO...if you can spare them (and I'd pay whatever you need for cost and shipping) I'd LOVE whatever keys, weights (connected or disconnected) and springs you have left.

In my next post I'll describe how I attack this problem.

-- Sonarguitar
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Re: Roland: Perishing Glue on Key Weights.

Postby Sonarguitar » Sun Sep 07, 2008 6:31 pm

Okay -- for those in the future atempting a fix, this is the route I've taken. It's time consuming and messy, but it worked.

First, the remaining red Roland epoxy appears to have broken down to the point where serious chemicals that can damage plastic won't be required on the plastic key portions.

I removed all 76 of my keys. First I sorted all the fallen or already separated weights into those plastic trays left over from microwave meals (Stoffer Lasagna in this case, I believe) for future cleaning (they're a mess). Lay them out separately so they don't stick together...they don't adhere to the tray very well, but they stick together like crazy.

Then the second problem was how to remove the weights that HADN'T fallen. The epoxy is in bad shape, but it's still plenty to make removal seem impossible.

So...I turned up the water heater in my home. When it was scalding hot, I ran this hot tap water over the weights still in place. This certainly loosened the epoxy.

Then I carefully used a small flat-blade jewlers screwdriver to work the weights out of the white keys. Many simply started falling out. The black keys took a bit more time and a pair of small needle-nosed pliers to pull out after heating.

So...after all the weights were out and laid out in these trays, I turned my attention to the biggest problem. This is getting the remaining epoxy off the plastec keys.

I found that the areas where the weights were located were, by design, perfect little "troughs" for soaking. So I tried several different commercial cleaners.

NOTE: I didn't soak the entire key! I filled the areas where the weights previously resided with the chemical cleaner.

First I used a household cleaner/degreaser (I used a product called "Fantastic" in this case). It works slowly and you must get in there with a flat blade to remove the residue as it breaks down. I scooped up lots at first and wiped it off onto paper towels. MESSY and still rather STICKY!

It didn't quite do the entire job as clean as I wanted, so I then soaked the "troughs" with a household cleaner CONTAINING BLEACH (I used "Clorox Clean-Up Cleanser WITH BLEACH" in a spray bottle). This really breaks down the remaining epoxy and removes much of it's remaining adhesive properties. It also turns the epoxy to a almost opaque gray color. This is easy to remove with a small flat blade screwdriver and the keys look brand new with no sign the weights ever existed. This takes repeated soakings, so don't expect to get them looking new the first time...I kept at it until they were perfect.

NOW...The weights still had LOTS of this epoxy and the cleaners didn't do a good job...so I tried Acetone because plastics were not involved. It's messy and you need gloves and SERIOUSLY A PAIN IN THE REAR. I only did about a dozen weights this way. Much more trouble that it's worth.

So, I took a second dozen weights down to my local auto garage repair facility where they have a 5-gallon bucket of carborator/parts cleaner (you drop a soaking tray into the bucket).

I left the weights in the bucket over the weekend and by Monday you could easily wipe off the remaining epoxy with a shop towel.

So I continued soaking the rest with similar results. They come out beautifully CLEAN!

Currently, I'm looking at 76 perfect keys lined up and a mayonaise jar full of clean weights ready for reinstall.

I'm just pondering what epoxy I will use for the final step right now.

If anyone else has traveled this road...PLEASE let me know of your experiences!

-- Sonarguitar
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Re: Roland: Perishing Glue on Key Weights.

Postby Wudman » Mon Sep 29, 2008 7:14 pm

Okay, I am official really interested before I decided to retie my D70. It seems the glue really jacks up the black keys and in my case, has caused some intermittent triggering. As much as I like the D70 for the 76 keys and fat sounds, it is a bit tired being pre-general midi, but I have mine apart and am waiting for any more clues on how this project went. I see lots of bombs waiting like reassembling the pesky little springs under each key. More importantly, I would be interested in any alternatives to getting the glue out. Carb cleaner is probably a bit abusive for the keys themselves.
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Re: Roland: Perishing Glue on Key Weights.

Postby funkyant » Tue Oct 14, 2008 6:09 am

Hey Sonarguitar.

I thought this thread was dead and no-one was interested.

I'm glad I checked back.

I also have 2 U-20's so I might give your method a go

Did you find a glue to reset the weights with?
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Re: Roland: Perishing Glue on Key Weights.

Postby where2 » Mon Nov 03, 2008 3:40 am

Sonarguitar wrote:...I'm just pondering what epoxy I will use for the final step right now.

If anyone else has traveled this road...PLEASE let me know of your experiences!

My wife inherited a Roland XP-80 with the dreaded flowing Red Epoxy syndrome. I had it apart some time ago to reset the weights in approximately 6 keys. Since then, over a dozen key weights have fallen out.

Things I learned along the way: The weights will fall out if you apply gentle heat from a hair dryer to the weights that are in the process of falling. You can remove the epoxy from metal parts of the keyboard using heat (hair dryer) and a cotton rag (t-shirt).

When I worked on this project before, I mistakenly thought the key weights were held in with a "hot glue" material that had simply melted in the heat of being transported in a hot automobile trunk in South Florida (95°F outside air temp, inside the trunk it might get to 140°F) However, this has proven not to be the case. As Sonarguitar notes above, the glue material used by Roland is actually an epoxy which is breaking down.

At my local hardware/home center store, I have located a two part epoxy which is formulated for use on plastics. It comes in a side-by-side syringe dispenser that measures the material in a 50/50 ratio. I expect my next effort will utilize this epoxy to reset the key weights in my wife's XP-80. My second choice would be a water soluble all purpose glue, similar to childrens school glue (known as Elmer's Glue in the USA). My third choice would be a low temperature hot glue applied with a glue gun.

Glad to see I'm not the only one curious enough to open the case and get sticky in search for the cure.

Question: If you store the keyboard with the keys upside down, can you keep more weights from falling out and more epoxy from dripping on everything? (aside from the issue of deforming the springs and deforming the chassis because it is not sufficiently supported).
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Re: Roland: Perishing Glue on Key Weights.

Postby bw1000 » Sun Nov 22, 2009 2:18 am

Hi there -

Sorry to bump this up with a couple of questions that are relatively trivial compared to what most here are doing replacing whole key assemblies. I have an XP-80 as well and as you probably guessed, had the same problem with the epoxy.

Roland US actually did most of the repair for me and did a very good job replacing the key assembly. However, they didn't really deal with some of the more cosmetic issues and there is still some goop on the exterior of the unit - mostly the metal area right under the keys as well as a little on the top and a lot on the power cord itself (the keyboard was in a gig bag with the cord on top of the keys when the epoxy started leaking and I hadn't taken it out of the bag for an extended period).

I got out the hair dryer and a dry rag after Goo Gone failed to do anything, but am wary of getting water too close to the unit and also a little unsure of the wisdom of heating the rubber(?) power cord to get the goo off. Do I just need to be patient with the warm air? It seems to take quite a while to get small patches warm enough to melt the epoxy.
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Re: Roland: Perishing Glue on Key Weights.

Postby garden » Wed Dec 02, 2009 7:39 am

My XP-80 have the same problem, call Roland today. they charge me for USD $530-, to get the new keyboard to replace it.

the quality control of Roalnd should be improve more.....
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Re: Roland: Perishing Glue on Key Weights.

Postby funkyant » Wed Dec 02, 2009 5:06 pm

In all fairness, how could Roland possibly have predicted that 15+ years down the track, the key weight epoxy would self destruct?
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Re: Roland: Perishing Glue on Key Weights.

Postby garden » Sat Dec 12, 2009 3:14 pm

I purchase XP-80 in 1997, The first time happen the key weight dorp down in 2000 April.
Since then i no more use my XP-80, and re-pack in the origin box save in the garage.
recently re-open the box, all the key weight drop down.....

I find the way to clean the epoxy as following;
soak in the NaOH(caustic soda)diluted solution for 60-120min.

i got perfect result. The "red epoxy" melt slowly by slowly, then all gone.
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Re: Roland: Perishing Glue on Key Weights.

Postby Chant Master » Sun Jul 11, 2010 8:10 am

Absolutely correct!!! Caustic soda (sodium hydroxide) diluted with h2o will disolve the glue and maintain the plastic keys and lead weights. Thankyou my friends you have saved an ep9 played by a very close friend recently gone. Disolve the resin in sodium hydoxide solution and then rinse with fresh water. The black key weights will naturally fall out - resoak them in solution to clean. Remove white keys from solution and then apply boiling water to weight recess. Pry weights carefully out with fine flat blade screwdriver. Resoak in solution to remove residual resin. Wash with soap water and dry. Thankyou to all contributants to this thread,
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Re: Roland: Perishing Glue on Key Weights.

Postby Quaver » Sun Jul 11, 2010 9:26 am

Interesting thread,I had the labourous job of doing this with my JD800 last year,Wish I had seen this before about the Caustic soda,I used Isopropyl alcohol to remove the Epoxy,and a lot of elbow grease and soaking for sure!!!,thankfully most of the epoxy had stayed intact apart from a few drips here and there on the metal chassis under the keys,the key contacts were ok and I managed to get most of the glue off the keys

I used a small Blob of superglue on each corner of the weight and simply refixed them Inside the keys,since then have not had so much as a single movement in the weights so far so good

It seems that Roland still use this Epoxy(or tree sap,at least its almost as annoying to remove as TS)I noticed its fitted to the keys on my V synth GT as well and also there is a similar type of resin fitted to the Keys on the DSI prophet 08 as well
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Re: Roland: Perishing Glue on Key Weights.

Postby Kiwi1 » Mon Sep 20, 2010 2:30 am

Wow - what a great thread. Thanks everyone.
Question - what dilution of caustic soda worked for you? (ie how much caustic soda to water)
Thanks.
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Re: Roland: Perishing Glue on Key Weights.

Postby wknick » Thu Jan 12, 2012 3:08 am

Caustic Soda (NaOH) it is!!! You guys are the best for posting this info! I was totally bummed cause I thought I got a good deal on a used D70 only to learn it was afflicted with the dreaded melted epoxy on the keys syndrome. Went and got some Caustic Soda from Lowe's and the adhesive was dissolving and coming off within minutes! Excellent info! Can't thank you enough!
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Re: Roland: Perishing Glue on Key Weights.

Postby wknick » Thu Jan 12, 2012 3:13 am

Just be extremely careful with Caustic Soda to anyone that uses this stuff to clean the keys. I also bought some chemical resistant gloves, respirator and eye protection. Very poisonous and harmful. Can cause burns in contact with the skin...!
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Re: Roland: Perishing Glue on Key Weights.

Postby funkyant » Wed Feb 01, 2012 9:02 am

Wow. I seriously cannot believe this thread is still going!

Caustic Soda huh? Who would've thunk it?
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Re: Roland: Perishing Glue on Key Weights.

Postby FA13 » Wed Mar 21, 2012 12:28 pm

Great thread I'm about to pickup a Roland U-20 and a Roland JV-80 for a few bucks that are both advertised as 'most keys not working'. I'm gonna try and fix them just for the fun of it.

When I have them and have taken them apart I will share my experiences.

Bonus tip: if you're looking for free PDF service manuals for a lot of vintage synths look no further: http://www.synfo.nl/pages/servicemanuals.html (not my site, just found it googling for answers )
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Re: Roland: Perishing Glue on Key Weights.

Postby Tartaruga » Mon May 14, 2012 9:32 am

‘Red Epoxy Syndrom ‘ alert…!!!
The weights of my beloved JD-800 start to fall(and local Roland servicing is not trust worthy… :-(
To make things worth,I don’t know if I can trust my DIY abilities …I’m I totally doomed?
Could anyone give the contact adress of ‘Roland’,I would like to talk with them but can’t find the address(Europe,Portugal,whatever…)?
Thanks for your time.
Cheers.
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Re: Roland: Perishing Glue on Key Weights.

Postby Timmo » Thu Dec 27, 2012 11:09 am

My XP80 has the same perishing glue issue. I have taken the steps above and stripped the keyboard down, cleaned all of the keys using a strong solution of caustic soda, (I was a bit dubious of this at first, but it's fine), and I've re-glued the keys using a good quality glue.
My problem is that, apart from losing one of the retaining springs somewhere in the mess of my office, one of the white keys is physically shorter than the rest in length and therefore sits low, I numbered all the keys as I took them off so i know it is back in the original place, I've swapped it with another key the same shape, the new key sits fine, so can anyone tell me if they have experienced the same issue, or how the key was sitting perfectly prior to me taking it apart to clean?
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Re: Roland: Perishing Glue on Key Weights.

Postby keyboardologist » Fri Jun 07, 2013 2:26 pm

Hello,
I'm also trying to fix my beloved D70, I have collected 2 more used same synths (D70) with the glue problem (plus some more) and I have managed to repair in total 2 of these, but all 3 keyboards suffer from perishing glue.
I was considering keeping the best of the 76 (out of 228), just for the one clav, but I have a lot of work to do to fix them. I will try Caustic Soda to one key and see the results. Also, I was thinking about using warm silicone for gluing the weights onto the keys.
I would get back with news...
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Re: Roland: Perishing Glue on Key Weights.

Postby SKY5031 » Sat Jun 08, 2013 5:38 am

The conditions that I have run into that causes the problem with decomposition of the epoxy used by Roland keyboards such as the JV 50 80 90 1000, xp 80 90, U20's and others that have this type of epoxy in part is caused by the case that it is stored in. You wonder how ? The foam
padding used in most cases is what they call a closed cell foam, and the bubbles that you see that make up the foam action is in part a gas action caused while curing the foam into a shape. In time all plastics go though a form a decomposition and in the process give off a gas that in trap in the process of manufacturing. In the case of the Roland keyboards that I've repaired they have been stored for a period of time in closed case and while closed the foam material starts a process of out gasing. The gas that is produced interacts with the curing agent in the epoxy causing the the decomposition and running of the glue all over he keys and frame parts. Is there a fix? Yes and a way to clean this glue up. I've talked to Roland service dept about this problem and the interaction of the materials and sent them the procedure that I use to repair the keyboard rack. It requires time, and dis-assembly of all the keyboard components and then re-gluing with a 5-minute epoxy. I'll add second post with the instructions.
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Re: Roland: Perishing Glue on Key Weights.

Postby SKY5031 » Sat Jun 08, 2013 6:16 am

instructions for epoxy glue removal.use at your own risk.
shopping list:1 deep pan or bucket, 1 small wide paint brush, 1 pair rubber gloves, and the cleaning agent is call "Awesome" purchase thu the dollar store or dollar general, most chain store
carry this brand, !IMPORTANT! use only the yellow colored product for this process.
Remove 1 white key and one black key. for testing. with a small amount of awesome take and dip a
"Q" tip in the solution to test the plastic of the key on back end of the key, this cannot be used cheaper plastic which is not made like the higher end keys .Rub the plastic with
the solution to make sure that the Awesome doesnt attack the plastic and leave a mark where you've rubbed it, judged safe proceed. Most of the better keyboard use glass filled nylon key when they were molded and most cleaning agents will not attack the plastic. Once your sure that there is not a inter action of the cleaner dis assemble the keyboard rack (take pictures of the key assembly so you dont forget where things go, draw pictures, mark cables etc. With all the keys off place in the bucket, pour the awesome in to the bucket and cover all the keys,let sit for five hours. You'll notice after awhile the glue will start to dissolve, weights will fall off to the bottom of the bucket or pry off easy. Once weights are off raise with water and repeat using the gloves and brush as required till all the glue is remove and re soak. Once clean re assemble using a small amount of 5 minute place about a half inch from the tip of the key underside and center, work the weight back and forth the distribute the epoxy to cover the weight and coat the weight well of the key surface. let stand for a hour and re-assemble, epoxy
should cure completely in 24hours. Any questions email me here and I'll try to help you out. sky5031
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Re: Roland: Perishing Glue on Key Weights.

Postby srkendal » Fri Aug 09, 2013 3:37 am

Here is some info I found in another forum, and how I used it:

QUOTE HERE ***********
Sodium hydroxide (NaOH, lye) solution works great to dissolve the red glue without harming the plastic. Here's my technique.

WEAR SAFETY GOGGLES. Even dilute NaOH can permanently damage your eyes.

The sodium hydroxide I like to use is granular NaOH, which I've bought on eBay. If you can get Red Devil lye or some other pelletized NaOH at your hardware store, that will work too, but the granular NaOH dissolves faster.

In a plastic bucket, mix 80 grams NaOH with 2 liters of water until all the NaOH is dissolved. (The bucket will get warm.) Be careful not to splash any of the solution on yourself. If you do, wash it off promptly with a lot of water.

[For you chemistry types, this recipe makes a 1-molar (1 mole/L) solution of sodium hydroxide.]

Immerse the keys in the lye solution. You only need to soak the part with the glue on it, so don't worry if the narrow parts of the keys aren't bathed in the solution.

Leave the keys soaking in the solution for 18-24 hours. After this time, no traces of the red glue should remain, and the weights will simply fall out of the keys into the bucket.

Carefully pour the NaOH solution down the drain. Don't let the weights get poured down the drain too.

Rinse everything with a lot of water. Dry the weights as best you can. It's normal for a bit of rust-colored oxidation to form on the weights.

I like to let the keys soak another 24 hours in a bucket of soapy water. This bath helps eliminate the fishy odor left on the keys by the reaction of the lye solution with the red glue.

When everything is dry and clean, re-glue the weights into the keys. I have had great results using a popsicle stick to apply a dab of 5-minute epoxy to each key. Make sure the weights are properly centered.

The best way to get red glue off the metal chassis is to blast it with freeze spray, then, while the stuff is frozen hard and brittle, chip it off with a single-edged razor blade.

And that's it. Have fun.
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I used a bubbler (a simple type of pump) to keep the lye solution moving and wah the glue out of the keys. I simply took a scrap of 3/4" PVC pipe just long enough that it will sit in the bucket from one corner in the bottom to a point below but near the top of the liquid on the other side. I put a piece of aquarium air tubing though a hole in the side of the pipe near the bottom, and curved it toward the upper end. when air is pumped through the tube into the pipe, the bubbles rise through the pipe and pull the solution along, creating a general circulation in the bucket.

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I wanted to have plenty of solution to soak all the keys, so I mixed up the entire 1 lb container from the hardware store in the same concentration as above: 80 grams NaOH to 2 liters of water is the same concentration as 1 Lb NaOH to 6 quarts of water. Do your homework and read up on the web how to mix the lye and water, and how much heat is generated when mixed. This is a very powerful chemical!
Pay attention to all the safety warnings above, and enjoy your rehabilitated keyboard!
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srkendal
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