ABS Sludge

[domin8r]

For a modding project I need some ABS sludge to fill gaps and such.

I have aceton and enough ABS. From what I understand it can take a day for the ABS to dissolve.
If I do this in a jar, will the sludge "keep" until I open it? Or do you really have to pay attention to it and use it immediately once all ABS is dissolved?

[Findecanor]

Put the lid back on quickly and it will last longer. Add a little bit more acetone if you need to.
Glass jars with screw-on metal lids will leak fumes and dry out faster. A jar with a plastic lid that seals shut is best.

I could give you lots more tips. Always mask or cover parts that shouldn't be affected. Always use thin layers. Be aware that you may have to do a lot of sanding also.

[domin8r]

Put the lid back on quickly and it will last longer. Add a little bit more acetone if you need to.
Glass jars with screw-on metal lids will leak fumes and dry out faster. A jar with a plastic lid that seals shut is best.

I could give you lots more tips. Always mask or cover parts that shouldn't be affected. Always use thin layers. Be aware that you may have to do a lot of sanding also.

Great, thanx for the reply! Sounds sensible enough.. appreciate the tips!
Don't mind the sanding, will have to sand the whole thing anyway for it's upcoming paintjob.
If you have more good tips, there are definitely welcome!

What is the best way to apply it by the way? Just smear it on?

[Findecanor]

Yes. A small metal spatula is sometimes best. Then dried ABS can be removed easily.

[domin8r]

Yes. A small metal spatula is sometimes best. Then dried ABS can be removed easily.

Allright, thanx!

Taking pics of the whole modding process so will post pics once it's done. Cheers!

[Vierax]

Yeah that's pretty interesting ! I had this ABS molding idea to make keycaps but I have no time for experimentation.

I'm following this thread with attention.

[Findecanor]

I tried moulding something (not key cap) with ABS sludge once in a silicone mould and it got lots of bubbles inside and against the mould's surface.
Dried ABS sludge when laid thick is often much softer and brittle than solid ABS.

[domin8r]

I tried moulding something (not key cap) with ABS sludge once in a silicone mould and it got lots of bubbles inside and against the mould's surface.
Dried ABS sludge when laid thick is often much softer and brittle than solid ABS.

I believe that for "real" molding they usually but it in a vacuum system, removing all the air/bubbles. Seen them do that on tv.

[domin8r]

Case is sawed nicely.. got a little bit of epoxying still to do and then it's sludge time

[imp]

Heyho,
experimented some days ago with abs and acetone too .
Like Findecanor said, using thin layers will prevent acetone bubbles to build up inside the drying abs. You can see the bubbles in the center of the filled arrow keyhole, after some sanding (wanted to use all the sludge I've got and applied it there in the end).
Inside the filled hole is another piece of the case. Being lazy, I didn't any cleaning on the case - quite surprising the piece that donated the abs chips (the strange looking thing in the upper left corner), combined really great with the case (you can push at it and fear breaking the part, but not ripping of the joint).

abs donor piece and filled hole (with another part of the case below the applied abs)

100_8137.JPG (495.16 KiB) Viewed 4340 times

Dissolving the abs took about 30 minutes and applying the abs with a spoons handle (dipping it after each stroke in acetone allows you to create a smooth surface, since the sludge doesn't stick to the spoon for some time).
The main problem I'm seeing now, is how to remove unwanted material without sanding down some of the original case...

[domin8r]

Well so far, so good. Did my first test with it.

Was surprised how easy it dissolves.. I read here and there that it might take a day to dissolve but it was more 30 minutes. At first I have cut the abs in really small bits but after that wasn't enough I just threw some bigger bits in and those dissolved really easy too.
Had a bit too much aceton so was left with a big layer of dissolved abs with a small layer of aceton on top of it.
The dissolved abs was/is very chewinggum like. Same feel to it and also sticks the same. Applied some with a spatula and was easy to do. Will see how the sanding goes

@imp I think if you sand it with a block that you'll get it flat without damaging the case.

Here is a pic of my first attempt:

[imp]

Here are my results after some work with a file:

re-attached side

100_8174.JPG (490.53 KiB) Viewed 4265 times

case-leg

100_8176.JPG (580.77 KiB) Viewed 4265 times

Cutting the lower part of the case to keep the leg was imho the hardest part.

[domin8r]

Nice, be sure to show how it looks after sanding!

My abs sludging is a bit delayed, have a big gap to fill in my case. First filling it with a glued in piece and then sludging over that I think.