[penguinpages]

I built a set of four speakers.   When I built the boxes with Hiddensity MDF I did my normal damp rag wipe down to make sure dust / things clean before I did peel and stick of no-res

After about three months I noticed on the one tower a weird flopping noise during some lower frequency ranges.  I ruled out seal issues around speaker etc..  and ended up taking speakers out and found two peices of no-res delaminated and flopping around.   I did a clean with damp cloth.. even used a bit of alcohol to remove any oil .    re-applied  but came back again.  So I used some 100% Silicon to re-adhere.

Now my Servo Sub on the one side a few months later started making a weird "flap" noise on certain note.  Pull speaker out and two peices of no-res flopping around.

Questions
1) Are others having issues with long term adherance of the no-res to MDF?  Maybe their is a prep step I missed of box..... or maybe one should be added. 
2) How / what is best recomemnded path to repair this.  Silicon is option that (knock on wood) seems to have fixed tower issue.. but before I re-seal this servo sub, would like to get other ideas. I am considering using short nails / brad nails...(mechanical) in addition to silicon. 

Are others seeing this issue with No-REs?

I also tried to capture image of the back of the No-Res pads... noting the different adhesion patterning. The Lighter/highlighed sections is less sticky and to me , would denote that it "left" its sticky side on the MDF side.  AKA:  Those locations reflect bonding sufficient to have created a delamination of the glue to the wood higher then the plastic backing substrate.  This is good IMAO.  But question is .. why is it not uniform.  This would seem to indicate very un-even application (user error) ..  possible... but not my first goat rodeo and I try to do things well, and avoiding miss/ poor application of peel and stick was something I tried to avoid by cleaning, pressing.. wiggling.. rolling in one direction etc.. as I applied.  With this stiff of a material, my guess is.. I did not do so well, and so the glue kind of needs to be a bit more "strong", but .. lets see if others can add experience to broaden base.

Thanks in advance for updates / ideas and corrections.

[Peter J]

First off, I've been using NoRez for some years and as far as I know never had failures like you describe. Here's some food for thought.

The adhesive used NoRez and many other self-adhesive things is called PSA, Pressure Sensitive Adhesive. For best adhesion it requires significant pressure to fully adhere. It's my understanding that the bond strength actually has a window of increasing tenacity when applied correctly. It's also import that the pressure be evenly applied to as much of the surface as possible.

The adhesive qualities will certainly be diminished in a second go-round. Contamination, exposure to atmosphere etc. will play a part. First time is a charm in this case.

Water is not something I'd introduce into the cleaning procedure. It's slow to evaporate and if not fully dry will come back to haunt later by interfering with the adhesive bond. Alcohol would be a better bet. A tack rag or any other fast evaporating solvent could also work.

Lastly, and be forewarned that this is a pet peeve, there is no such thing as silicon adhesive. Silicon is an element found on the periodic table. What you and many others are describing is silicone caulk or adhesive is not the same thing. While silicone caulk has adhesive qualities and is way overused in my opinion, this would be way down my list of choices for re-adhering NoRez. Contact glue, used as specified, would be a better bet. One of the things that makes NoRez work is intimate adhesion to substrate with as close to 100% contact as practical.

This kind of adhesive is applied in a thin film sheet. I suspect your last photos shows places where film is has been pulled loose from the damping layer itself.

[HT1278]

Agree with Peter about not using water.

If the cabinets are made out of MDF, I would not apply water, water if not dried quickly can/will damage MDF.

Would the glue sand off, from what I have found need to use abrasion if you can not remove the glue easily.  If sandpaper does not work well, what about steel wool, with a piece of wood between your hand and the steel wool, basically use the steel wool like sandpaper?

Perhaps the glue left behind from the no rez install on the inside of the cabinets would allow for the new glue to adhere to it?

     You could try a small piece, to see. 

Not sure if it would "activate" it?

When installing next time, perhaps something like this would work well.

     https://www.amazon.com/Deadening-Application-Abatement-Wallpaper-Deadener/dp/B07GVGTX2V/ref=asc_df_B07GVGTX2V/?tag=hyprod-20&linkCode=df0&hvadid=242009426076&hvpos=&hvnetw=g&hvrand=7617601447082651468&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9030236&hvtargid=pla-526183979459&psc=1

Auto Car Audio Sound Deadening Application Rolling Wheel Roller,Heat Abatement Mat Wallpaper PU Deadener Application Seam Roller

[HT1278]

My experience with No Rez is that it sticks so good, I can not remove it when I need to.  It sticks insanely well.  I put some No Rez in a place where I wanted to put a crossover board and I had to tear off all of the foam, since the backing would not come off from the MDF.  It was glued solid, seems basically permanent.  Did not break out a chisel but it did not budge at all, I had wished it would have come off.

[WGH]

Not sure if it would "activate" it?

3M Hi-Strength 90 Spray Adhesive will fix everything
https://www.3m.com/3M/en_US/p/d/b40069424/

[S Clark]

Many years ago, when the company AV 123 was going bankrupt, I bought a pair of cabinets from them for my LS9 speakers.  When it came time to apply the No Rez, it wouldn't stick.  They had applied some sort of spray to the inside of the cabinet that interfered with the adhesion.  My solution was several tubes of Liquid Nails.  That's probably 10 years ago, and it's still holding.

[jimbones]

mine never sticks well either so I dont use it anymore

[S Clark]

mine never sticks well either so I dont use it anymore

This is certainly not my experience. 

[Tyson]

I used NoRez in several speakers and never had any issues.

[yakbob]

I second the use of 3M spray adhesive, 90 or Super 77. However, that stuff is bad for anything with a pulse, so wear a respirator. Alternatively, Weldwood contact cement ( green can not red can) should do the trick and will be easier to work with inside the cabinets.

[penguinpages]

Thanks all for responses.

If a customer asked / showed me the pictures.. my response would be:
####
<In my head>  "You did it wrong.. lack of pressure... dirt on surface.. user error"

<To the customer>  "Clean surface. damp rag to collect dust and other surface dirt.  If any oil  believed to contaminate surface, then damp with alcohol.   When applying ..  peel and stick within a few min.  Apply more even pressure.. start at one end and lay it down in rolling pattern to ensure no bubbling.   If you can use roller .. those help increase pressure .. start one end and push to edges.  As noted.. most peel and sticks today are the opposite issue.. once its on.. ya.. get a scraper and you will be digging into the wood to pull it up."
###

Bad thing is.. I am that customer  

Just to clarify.. damp.. does not mean sufficient water to even note discoloration or see any moisture on surface, but to break electrostatic surface adhesion of dust.   

I will us spray glue to re-attach.   That was input I needed, as well as sometimes the community catches these cases and others have issue that everyone assumes is themselves.

Thanks

[penguinpages]

Just to make closing post.   Spray stick was perfect.   To avoid de-soldering of speaker from box... I just wrapped it in some plastic bags.. (just to keep any off-gasing from glue to have any effect on cone or spider), and sprayed the backs of the two No-res pads..  stuck.. pressed..  then tried to yank off.. 

They were rock solid.

Thanks for advise.