Interior plastic repair at annual

[generalaviationguru]

Our pilot’s seat armrest was completely unusable and cracked all the way around.  Since the interior was removed for SB208 and 20-217 (future post coming on 217 - it was BAD), partner and I went up to work on interior.  
 

I learned from Mooneyspace that we are dealing with ABS plastic.  So, I decided to restore it and used the following practice:
 

1.  Order new ABS plastic sheets from Amazon.  Cut into bite-size pieces.  (I don’t suggest eating!!)

2. Soak plastic pieces in acetone a clean glass jar (don’t plan to ever use this jar again), so the just enough acetone to cover the pieces.  
 

3. Soak will take 3 hours to overnight.  You should have a paste consistency in the jar.  Too watery?— add plastic pieces.  Too stiff? — add acetone. 
 

(remember to remove armrest pad, placards, etc. before continuing)
 

4. Use a cheap paint brush from Walmart to paint on plastic to the ENTIRE backside of the panel.  Once layered on, allow 1-2 hours to dry before next layer.  (You’ll want 3-5 layers for strength and flexibility)

The acetone will partially break down and allow permanent bond  the new and old plastic.  

before
 

5. On the front side, I did several thick layers in the localized areas of stress, mainly around the armrest, for added strength. 

This stuff stinks.   So make sure you have great ventilation and/or a respirator. 
 

6.  Sand and paint per typical procedure AFTER 24 hours cure time.  Don’t be stupid and impatient like me and get bubbles!!

I took the panel to Lowe’s before starting to get paint matched.  

I wish I had a better before picture of the armrest.  It’s hard to see, but it was cracked worse on the outboard size and was cracked almost all the way around.  
 

We are currently planning to pull the rest of the fragile interior panels next annual and refresh and paint the entire interior.  This isn’t an extremely  time consuming project and is WAY cheaper than a new interior.  Just thought I’d share. 

Any ideas to do it better?

 

 

Hampton

[hammdo]

I followed Jaeger's pdf when I did mine.  Flexible materials, patching etc are well documented.

Just something to review -- and the type of paint to use also...

-Don

 

[generalaviationguru]

10 minutes ago, hammdo said:

I followed Jaeger's pdf when I did mine.  Flexible materials, patching etc are well documented.

Just something to review -- and the type of paint to use also...

-Don

 

Great stuff!  Ours was not that severe, so fewer steps and no patches.  But those are fabulous instructions.

[Pinecone]

I would put on a thin layer of the ABS, then press in a single layer of 3/4 ounce fiberglass cloth, then another layer of ABS.  

This will make the panels fiber reinforced and a LOT less prone to cracking and splitting.

[generalaviationguru]

1 hour ago, Pinecone said:

I would put on a thin layer of the ABS, then press in a single layer of 3/4 ounce fiberglass cloth, then another layer of ABS.  

This will make the panels fiber reinforced and a LOT less prone to cracking and splitting.

I’ll keep that in mind for next time!  Thanks 

[PT20J]

I’ve found that two layers of glass cloth works best. ABS dissolved in solvent dries softer than the original ABS sheet material and so it’s best to include some glass cloth for a stronger repair.

I have melted ABS in solvent to make a paste. Legos work well. Both MEK and acetone will work; MEK gives a longer working time. It’s easier to just buy ABS cement at the hardware store which is ABS resin and solvent. 

If I really need to strengthen an area, I glue some sheet ABS to the back of the panel.

SEM Color Coat is a professional automotive plastic paint and holds up well. It adheres better if you spray the panel with SEM Solve first to soften the plastic. Phantom White is the color I used.

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