Repairing plastic stapled to thin wood

[JHZR2]

On my second 1991 MB 350SD, that I got late last year, a few of the window switches were sitting low. I pulled the console and found that the plastic structure that is stapled to the wood, which holds the switches, was coming apart. Almost like the switches were pushed too hard. Lousy repairs were attempted with what looks like gorilla glue.

Looking for recommendations on how to fix this and stabilize the plastic piece. I removed much of the glue, that was causing things to not sit right, and got the plastic to kind of lay right, then used a small punch and got the staples back in. They kind of worked in some spots, not others.

Im hesitant to screw, nail, or staple into this wood. I suspect they did it before finishing it. The original finish is prone to cracking at this age.

Im thinking that some wood cut to a good size. Wood glued to the underside, and then used as a glue or screw base with a few thin strips that are laying perpendicular to the plastic, might hold it relatively tight to the wood.

Any thoughts or suggestions?

 

[wings&wheels]

I just had to laminate a reinforcing plate to some thin veneer and used a thin film of 3M 5200 and pressure to align and compress the finished structure. That should work assuming you do not plan to remove the plastic mounting plate, and keep the adhesive away from where the switches push in. I'd coat as much of the plastic piece as you can and mist the wood w/ some water to drive the cure.

Agree on not penetrating or stressing the wood and you need a strong but slightly flexible bond here.

 

[JHZR2]

I just had to laminate a reinforcing plate to some thin veneer and used a thin film of 3M 5200 and pressure to align and compress the finished structure. That should work assuming you do not plan to remove the plastic mounting plate, and keep the adhesive away from where the switches push in. I'd coat as much of the plastic piece as you can and mist the wood w/ some water to drive the cure.

Agree on not penetrating or stressing the wood and you need a strong but slightly flexible bond here.

Do you mean between the plastic and the wood?

Is 5200 more tenacious?

I was thinking to use thin wood strips connected with glue and/or fasteners, first the blue ones to give more bond surface and depth to fasten to, then the cross strips (red) to hood the plastic tight.

 

[wings&wheels]

Do you mean between the plastic and the wood?

Is 5200 more tenacious?

I was thinking to use thin wood strips connected with glue and/or fasteners, first the blue ones to give more bond surface and depth to fasten to, then the cross strips (red) to hood the plastic tight.

View attachment 143294

'tenacious' is a good word, and an understatement. You should be OK with just the plastic against the wood, but strips as you illustrate would be a good idea assuming you have clearance. Sure you know this, but if not, clean thoroughly and roughen the smooth plastic. Also, 5200 Quick Cure is still a slow cure that can be sped up a bit by moisture.

 

[Cujet]

Plastex. This is the answer you seek. Period, end of story.

The product is a powdered polymer with activator. It is not CA glue and baking powder. Don't be fooled. The repairs made using Plastex are flat out amazing, and will not fail.

It does take a bit of understanding to use the product, it sets up pretty fast (about 5 minutes), but does take about a day to "fully" harden into a rock hard repair.

PLASTEX, PLASTIC REPAIR KITS, FIX CRACKS, REPAIR PLASTIC

Manufacturer of plastic repair kits. Plastex easily glues, fills gaps, repairs stripped threads and can remake tabs or small parts in just minutes.

www.plastex.net

There are various YouTube videos. Showing some innovative and great results.

 

[JHZR2]

Plastex. This is the answer you seek. Period, end of story.

The product is a powdered polymer with activator. It is not CA glue and baking powder. Don't be fooled. The repairs made using Plastex are flat out amazing, and will not fail.

It does take a bit of understanding to use the product, it sets up pretty fast (about 5 minutes), but does take about a day to "fully" harden into a rock hard repair.

PLASTEX, PLASTIC REPAIR KITS, FIX CRACKS, REPAIR PLASTIC

Manufacturer of plastic repair kits. Plastex easily glues, fills gaps, repairs stripped threads and can remake tabs or small parts in just minutes.

www.plastex.net

There are various YouTube videos. Showing some innovative and great results.

To create a cross-piece to hold the existing plastic in place, or to attempt to bond the existing black plastic part to the wood?

I am not opposed to trying an adhesive, though they didn’t originally for a reason.

Plaster looks highly useful so I plan to get some regardless.

 

[Cujet]

To create a cross-piece to hold the existing plastic in place, or to attempt to bond the existing black plastic part to the wood?

I am not opposed to trying an adhesive, though they didn’t originally for a reason.

Plaster looks highly useful so I plan to get some regardless.

It will do both without trouble. not an adhesive, but more of a way to make new plastic, which then adheres to just about thing, with authority.

 

[Astro14]

Ordered some - have a broken center console lid on a Volvo XC90 - for which Volvo wants way, way too much money. Will give it a try.

 

[JTK]

I was thinking to use thin wood strips connected with glue and/or fasteners, first the blue ones to give more bond surface and depth to fasten to, then the cross strips (red) to hood the plastic tight.

If that won't interfere with anything, that sounds like a strong fix. The wood is probably stronger and more stable than the old plastic.

 

[JHZR2]

Ordered some - have a broken center console lid on a Volvo XC90 - for which Volvo wants way, way too much money. Will give it a try.

Do you know the type of plastic? Low surface energy plastics need a special adhesive. The plastex folks have a two part product for that too.

I have a few diys on here for fixing low surface energy plastics. I use a 3m product for that, and a good job uses surface roughing and flame treatment if possible.

 

[JHZR2]

If that won't interfere with anything, that sounds like a strong fix. The wood is probably stronger and more stable than the old plastic.

I’ll need to look later today. The good thing with it is that I can use any material I like and not worry about bond strengths with the OE material. Just the new material to wood…

 

[Astro14]

I think it’s regular ABS plastic. Fairly standard in cars. I’ve had good results in that type of plastic using mechanical repair. E.G. a heated nail as stress reinforcement. The nail melts the plastic, which then cools and hardens back around it.