Pianotech

I've come across several of these actions.  The real truth is that WD40 has ruined the action, and turned the wood into mush.  But I have used Protek and other solvents to try to remove the sludge and make the parts work again.  I use compressed air (not from a can) after saturating the felt centers.  Which means a LOT of time, and really not worth the effort, though it does work.  I have not received any callbacks that I remember.  I would not advise doing this job unless there is  some overwhelming reason to proceed like sentimental value or unusual features.  The wood itself is now weakened and likely to break even just by tightening the flange screws.  Back in the day, WD40 probably cured a sluggish action by absorbing the moisture, which is what it's designed to do.  Spray the action, put it back in, collect the check, and book it outta there.  One-time fix.  Or maybe a few times once it gets sluggish again. 

I've come across several of these actions.  The real truth is that WD40 has ruined the action, and turned the wood into mush.  But I have used Protek and other solvents to try to remove the sludge and make the parts work again.  I use compressed air (not from a can) after saturating the felt centers.  Which means a LOT of time, and really not worth the effort, though it does work.  I have not received any callbacks that I remember.  I would not advise doing this job unless there is  some overwhelming reason to proceed like sentimental value or unusual features.  The wood itself is now weakened and likely to break even just by tightening the flange screws.  Back in the day, WD40 probably cured a sluggish action by absorbing the moisture, which is what it's designed to do.  Spray the action, put it back in, collect the check, and book it outta there.  One-time fix.  Or maybe a few times once it gets sluggish again. 

James,

I don't know if this would work but if it was me this is what I would try:

Use automotive starting fluid and soak the bushings and work them back and forth, repeatedly soaking them (the stuff evaporates very fast). On the last soak, use high pressure compressed air to blow it all out.  I would first experiment on one or two parts to see if it works. 

This process removes verdigris from infected Steinway actions (not permanently of course but it does work well in the short term). I suspect it could likewise dissolve and eradicate WD-40. It's worth a try. Use a mask, and do it outside as it's pretty smelly stuff and lingers for a while but will eventually dissipate. 

Peter Grey Piano Doctor 

I've come across several of these actions.  The real truth is that WD40 has ruined the action, and turned the wood into mush.  But I have used Protek and other solvents to try to remove the sludge and make the parts work again.  I use compressed air (not from a can) after saturating the felt centers.  Which means a LOT of time, and really not worth the effort, though it does work.  I have not received any callbacks that I remember.  I would not advise doing this job unless there is  some overwhelming reason to proceed like sentimental value or unusual features.  The wood itself is now weakened and likely to break even just by tightening the flange screws.  Back in the day, WD40 probably cured a sluggish action by absorbing the moisture, which is what it's designed to do.  Spray the action, put it back in, collect the check, and book it outta there.  One-time fix.  Or maybe a few times once it gets sluggish again. 

Auto starting fluid is dangerous to work with and should be used outdoors using hand, eye and breathing protection This means using chemical gloves, proper respirators not just a face mask and safety glasses . a face shield is also good. The fluid is Extremely Flammable and can cause death if abused. KEEP IT AWAY FROM CHILDREN.

As far as I know WD-40 was never intended to be used for, in and around pianos.

I would tell the customer to track down the person that ruined the action and get them to pay for all the damage. It probably was not the first time they used WD 40

James,

I don't know if this would work but if it was me this is what I would try:

Use automotive starting fluid and soak the bushings and work them back and forth, repeatedly soaking them (the stuff evaporates very fast). On the last soak, use high pressure compressed air to blow it all out.  I would first experiment on one or two parts to see if it works. 

This process removes verdigris from infected Steinway actions (not permanently of course but it does work well in the short term). I suspect it could likewise dissolve and eradicate WD-40. It's worth a try. Use a mask, and do it outside as it's pretty smelly stuff and lingers for a while but will eventually dissipate. 

Peter Grey Piano Doctor