Interior plastic repair recommendations?

[lanejacobs84]

Does anyone have an idea on the best way to repair our cracked interior plastic where the curtain rod Molly screw has pulled out and fractured the plastic? 

Maybe some type of “splint”?

Thank you!

1979 J

 

[hammdo]

I did some work on mine, maybe this will give some ideas..,,

 

[EricJ]

It's ABS plastic, which is very easy to repair.   You can weld it with a soldering iron, or use a slurry of ABS pieces and acetone to glue/fuse it, and reinforcing pieces can be made with ABS sheet and heated to form into shape.   Other glues/adhesives/methods also work, and there's a ton of stuff online about various techniques.

[N201MKTurbo]

When the plastic becomes brittle, there is no fixing it. You could add a thin fiberglass backing.

[anthonydesmet]

Completely repairable.  I’ve repaired as EricJ stated. I have also bought Bruce Jeager’s interior repair kit which comes with a few ways to patch up things.  Looking at yours I would use some 3M Aluminum strips as backing, take a piece of abs plastic (you can get online or in Bruce’s kit and attach to the tape then fill in cracks with ABS PVC glue (the blue label), sand and paint.  Whine you start with that repair you will want to repair and repaint all your panels…..I did.  It was actually fun and you get to put some personality into it…..

[Brian2034]

Simple process to repair plastic interior panels with epoxy resin and fibreglass cloth.

I’ll post a couple pictures of a recent repair I just did on one of our aircraft. The before door image shows a piece missing and if you look closely you will see the plastic panel is actually cracked in a couple of places and the only thing holding the panel together is the door frame. 
The other interior trim piece was broken into three parts and the centre had a missing section that was long gone.

I use EPOXY resin and fibreglass cloth usually 7781 from spruce but you can go to your local fibreglass shop a purchase a light weight glass cloth.

Usually I hot glue the pieces back together and sometimes if the parts are really damaged I glue them to a board or the bench top with hot glue to hold them in place. Hot Glue the parts on the exterior side (the exposed side you see in the aircraft). For the missing areas use what ever you require to make the shape of the missing area. I use foil tape as my first alternative because you can rub a little mould release wax on the tape and the epoxy won’t stick to it. I’ve used cardboard, tape, plastic from containers, aluminum foil, believe it or not one of my best products for complicated shapes is PlayDo. What ever it takes to hold the shape required.  Also I use epoxy resin over other resins because  it adheres to the plastic better than vinyls or polyester. When the part cures you can touch up the front side with a little body filler or epoxy resin and q-cell mixture. Than off to the local auto store to pick up a spray can of whatever paint that matches the finish required.

[Brian2034]

Couple of parts I pulled a mold from and made new parts but you can see on the broken parts where I used foil tape, tongue depressors,  hot glue , body filler but it gives and idea of what can be accomplished.

[1980Mooney]

On 3/19/2025 at 11:03 AM, lanejacobs84 said:

Does anyone have an idea on the best way to repair our cracked interior plastic where the curtain rod Molly screw has pulled out and fractured the plastic? 

Maybe some type of “splint”?

Thank you!

1979 J

 

 

1. If you look at the screws on your other curtain rods, you will see that they are threaded into an aluminum threaded grommet that was bonded into the Royalite (ABS)
2. Obviously the fastener for your rod has been broken/pulled out previously.  You call that fastener a "Molly bolt" but it almost looks like someone did a "shade tree" repair with a plastic drywall fastener.
3. If you are going to build up the broken corner per the guidance above you need to make a decision
   1. Either bond a threaded grommet back into the corner like the original
   2. Or maybe just remove the curtains completely and rebuild the corner back smoothly

[Pinecone]

I would not use hot glue for anything except holding some parts in position while making a proper repair.

ABS is so easy to work with.  You can buy ABS paste/putty or make your own.  Just dissolve some ABS in MEK (paint section at hardware or box store). 

To reinforce, I would use 3/4 ounce fiber glass cloth.  Apply with MEK with a small amount of ABS dissolved in it.  Then once that dries, add another application of MEK with more ABS dissolved in it.

[PT20J]

4 hours ago, Pinecone said:

I would not use hot glue for anything except holding some parts in position while making a proper repair.

ABS is so easy to work with.  You can buy ABS paste/putty or make your own.  Just dissolve some ABS in MEK (paint section at hardware or box store). 

To reinforce, I would use 3/4 ounce fiber glass cloth.  Apply with MEK with a small amount of ABS dissolved in it.  Then once that dries, add another application of MEK with more ABS dissolved in it.

That's what I do. I use two or three layers of cloth. It also works well for reinforcing around screw holes where cracks start to form.

[Ragsf15e]

1 minute ago, PT20J said:

That's what I do. I use two or three layers of cloth. It also works well for reinforcing around screw holes where cracks start to form.

And you’re wetting the fiberglass cloth with the abs glue mixed with abs bits or the abs putty or the mek with abs mixed in?  I was thinking the abs glue or putty would be easier than mixing epoxy to laminate over the fiberglass cloth.  There’s so many different ways people do this.  I’m definitely going to start with a few simple (and hidden) pieces in the baggage.

If you need to cover a hole (such as removing the ashtray) how do you texture the visible surface?

[PT20J]

35 minutes ago, Ragsf15e said:

And you’re wetting the fiberglass cloth with the abs glue mixed with abs bits or the abs putty or the mek with abs mixed in?  I was thinking the abs glue or putty would be easier than mixing epoxy to laminate over the fiberglass cloth.  There’s so many different ways people do this.  I’m definitely going to start with a few simple (and hidden) pieces in the baggage.

If you need to cover a hole (such as removing the ashtray) how do you texture the visible surface?

I created a slurry with MEK and white LEGOs, but I've also just used black ABS pipe cement from the hardware store. I put down a thin coat of cement, then press in a piece of glass cloth, then add some more cement, then more cloth and finally more cement. Usually two layers is enough unless it is an area of high stress. You don't want a big puddle of glue -- just enough to saturate the cloth. Acid brushes work well for applying the cement.

I had to do some extensive repairs on my glare shield and that is the only part I had to sand down and texture. I used a SEM product called Texture Coating. You can get a variety of textures. I just sprayed it lightly which provided a light sandpaper-like texture. You can spray it on heavily and even use a putty knife to knock it down to provide other textures.

[Ragsf15e]

1 hour ago, PT20J said:

I created a slurry with MEK and white LEGOs, but I've also just used black ABS pipe cement from the hardware store. I put down a thin coat of cement, then press in a piece of glass cloth, then add some more cement, then more cloth and finally more cement. Usually two layers is enough unless it is an area of high stress. You don't want a big puddle of glue -- just enough to saturate the cloth. Acid brushes work well for applying the cement.

I had to do some extensive repairs on my glare shield and that is the only part I had to sand down and texture. I used a SEM product called Texture Coating. You can get a variety of textures. I just sprayed it lightly which provided a light sandpaper-like texture. You can spray it on heavily and even use a putty knife to knock it down to provide other textures.

Excellent, thank you!

My son isn’t going to like his legos disappearing, but he’ll be happy if they help fly him to Disneyland!