Repairing ABS plastic - dash trim, door panels, etc etc

[OldGray]

The best way I have found to repair cracks or even holes in ABS is to use melted ABS.  If you take some old ABS plastic and break it up into tiny pieces and melt it in Acetone, it makes a slurry that can be used to glue or rebuild damaged ABS plastic.

Below are pics of my 1979's dash trim and door panels.  The Door panels had cracks in them and there were some screw holes that were busted out.  My Dash trim had two corners snapped off at the screw hole.  Here are pics of the repairs. 

I hope you find this information helpful.

The ABS pellets melting in Acetone:





The Dash trim:
before




Here are the molds I made for the corners




Here are the panels with the plastic added to the corners




Here they are filed down to shape them, and new holes drilled.  Of course you could probably make them look better than I did, but these work fine for me.






Here are some cracks and holes I fixed on my old Door panels.
The top ridge of the panel had split completely off and I reattached it.


This is a screw hole that was broken out - it has been refilled and this is before drilling it out.


After re-drilling a repaired hole


Here is the door panel repainted and installed.  Again, these are not perfect, but they work for me.  Someone with more talent at carving might make them look better than I did, but hey, THEY WORK!

[AZ87V10]

Nice! That turned out looking good enough! And if you want perfect, then buy a new panel! Lol! Where did you get the ABS pellets? Was that just old broken up parts, or can they be obtained new somewhere?

[OldGray]

I found this method of repair a few years ago.  At that time I just used to find an old junk piece of ABS and break it up as small as possible.  But with larger chunks, it takes hours to fully melt.

I found a guy who sells ABS pellets on Ebay for this very purpose and they work very well and melt much quicker.

The ABS slurry will melt into and bond with the old ABS for a permanent bond, unlike most glues people try.  I have even repaired golf-ball sized holes before. 

The corners I built up were thick so it took a good two days for them to cure.

[K20Detroit]

I have heard of this technique in the past, though i have always done plastic welding for these repairs.
The guns are either direct contact, or heat gun style. I prefer direct contact style.
Different tips are available to shape the plastic.
As long as you have access to an outlet, it's great.

[OldGray]

I'd love to try plastic welding!  Though I am not sure you could "add" corners onto trim that way - I think it would be tough.  And filling a very large hole in a panel might be a tough one too, unless you could heat-melt a small batch of it and pour it.

The reason I use the acetone method is because I already had the junk lying around to do it... and I am a tightwad...   

[K20Detroit]

The nice thing about plastic welding is, you can shape things with or without the welder, then add them with it.
IE for the corner, it would be simple to cut with a dremel, or even a hack saw if you were in a bind.
For large patches, I find large pieces of ABS scraps to use for that. The largest I remember doing is a 4" x 4" patch

[OldGray]

K20 -

Can you post pics of the repairs you are describing?  I'd be really interested in seeing that.  I am always looking to learn a new repair technique.

[IdahoMan]

Very cool.

Now if there is a putty (like water-weld), quick drying, that you could use like a photoshop "stamp" tool to capture and apply texturing to the melted ABS that would be cool too.

[OldGray]

I'll bet you could make a mold out of plaster or something.  Certainly has endless possibilities for the tightwad, like me!

[80Chevy4x4]

What kind of ratio did you do between the pellets and acetone?

[big_al273]

what's a good mixing container? with a lid.

[OldGray]

The ratio is about 1-1.  Better to make it thick and then thin it as needed.

I use an old glass jar with lid for mixing it.