Hot-riveted plastic clips - how to uninstall and reinstall

[Ilya]

I have some plastic front panels that are mounted to the main aluminum body via plastic pins that are melted and formed into a “mushroom” shaped blob at the opposite side of the aluminum panel.

I wonder if there’s any way to restore these pins and remove the plastic front panel. The plastic panel needs to be reinstalled once the work on the underside aluminum body is finished.

Currently, I heat the pins with a gun and carefully pull the panel so that the pins are reformed back by the hole in the aluminum backing. But this process is very finicky and has a high risk of melting some parts of the plastic panel.

Any other methods? I’d rather not drill plastic and install screws (which is obviously the easiest way to deal with this).

 

[ruffrecords]

I am sorry I cannot help with your problem but I am curious about different ways of constructing front panels. Separating the mounting of controls function from the front panel legend function is a common approach but it can be expensive. Using low cost plastic legend panels is one way to reduce this. Any chance you could post some pics of the items concerned so I can see how it is done?

Cheers

Ian

 

[Ilya]

Here's how the front panels look like:

This is the back side:

The black dots are those melted plastic pins that I'm talking about.

 

[zamproject]

Probably this is not the kind of plastic you can melt more than one time, you probably won't have that many choices...

Any other methods? I’d rather not drill plastic and install screws (which is obviously the easiest way to deal with this).

You don't need to instal screws, if you want to keep aesthetic.
Cut the -mushroom- head flush, and keep the feet (mechanical alignment)
Then there is various industrial double-sided adhesive that will be as strong keeping the panel as the actual hot rivet.

 

[Ilya]

I though about adhesives. The downside is - the panel is not flat and touches the backing aluminum plate only at the edges. These edges are not very thick (maybe 1.5mm, 2mm max), and may not provide enough space to hold the plastic firmly.

 

[zamproject]

What is the space between the flat plastic surface and alu plate ? There is adhesiv with many thickness in substrate, or you can use a thin plate as spacer ?

 

[Ilya]

I guess there's something like 1-2mm room between the plastic and aluminum. Don't have the panel at hand to measure.
I had another idea of gluing M3 screws to the back side of the plastic panel. They may actually hold everything in place just because of friction.

 

[zamproject]

The head screw will probably by to high ? or use countersunk head ? if you redrill a little the alu panel to let say 4mm (for M3 head) you'll gain some depth.
I'll be more concerned by the glued junction screwhead/plastic plate, especially when you bolt the other side to the alu panel, rotating force is rapidly high and may break the glue or plastic panel ?

And a plastic rivet glued to the back of the plastic panel ? this is longitudinal force, less stress on the glue.
Or something like this ?
https://fr.farnell.com/multicomp-pr...ING-Catch-All-Test-14-Apr-23&gross_price=true

 

[Ilya]

This is a great idea, thanks!
As for screws, I was hoping that friction will do it. Screwing them will probably ruin the panel or tear off the screw.

 

[zamproject]

I was hoping that friction will do it

don't really get what you mean by that ? little off axis so the thread grip the alu panel ?

Another option is PVC screw and bolt, you can easily reduce the head with a file for proper height which also scratch the surface for better glue grip, then as material is soft the bolt tightening should absorb some part of the rotating force, with enough holding before anything break ?

I'm sure you'll find the best practical way to do this.

Cheers
Zam

 

[Tubetec]

https://avt-connecting.com/products...l/rivets-mounting-buttons/plastic-snap-rivetsThis first kind listed on that page I think are the type used , you sometimes see them in electronics construction ,to mount pcbs/panels etc .
Once these are fitted a quick touch of the soldering iron melts the pin at the back and seals it .




By the way Ilya ,
you never told us what the machine your working on is , is it a synth or a mixer ?

 

[zamproject]

I call what you show a push-lock rivet, that's not what I see on this Polivoks (yes it's a synth !)
It's molded/injected plastic panel with pin fitted, not a pass through rivet, once in place its heated (like your technic)

 

[Tubetec]

Those pin types I showed dont need melting to holdfast , in the correct diameter mounting hole there stable and can be easily released if needed .

There a usefull method for mounting smaller pcb subassemblies , if you look around there available in a variety of panel depths , heights ,

 

[zamproject]

Yes I know them, all back panels cover of my console use this kind of rivet.
But if you look at the OP pictures, the plastic cover panels are not drilled nor holded by a pass-through element, but self maintained with (heated) pins.

But maybe you mean using only the holding part of those rivet (and not the lock button) glued to the cover panel ?

 

[abbey road d enfer]

you never told us what the machine your working on is , is it a synth or a mixer ?

The name "Polyvox" and the word "syntezator" give a clear explanation.




PS: I don't speak or read russian, I just cheat with google.

 

[Ilya]

don't really get what you mean by that ? little off axis so the thread grip the alu panel ?

I mean that the screws can be made large enough so that they will stay in place just by friction. My initial though was to apply heatshrink to the screws.

This first kind listed on that page I think are the type used , you sometimes see them in electronics construction ,to mount pcbs/panels etc .

These are nice, but will require to enlarge the existing holes, which I'm not willing to do. Besides, installing and removing these clips requires quite a bit of force and can damage plastic panels.

you never told us what the machine your working on is , is it a synth or a mixer ?

As pointed by abbey this is indeed Polivoks synth. I'm doing quite a bit of restoration, upgrade and MIDI retrofit work on these synths and those plastic panels are a pain to work with.

To sum everything, I think that gluing metal or plastic screws to the underside of the plastic panels is the best option.
Thanks for your input, gents!

 

[abbey road d enfer]

I see you don't want to enlarge the holes, but still I mention this to you.
https://fr.rs-online.com/web/p/ecrous-a-sertir/0827619

 

[Ilya]

These are handy, but I can't see how I can use them in my current situation.
Besides, they require a press to install, which I don't have.

 

[abbey road d enfer]

These are handy, but I can't see how I can use them in my current situation.

I don't see enough details in the pictures, so you're probably right.

Besides, they require a press to install, which I don't have.

They can be pressed with a hammer or glued. The larger footprint gives more adhesion area than a standard hex nut.