OT: ABS plastic repair for electronics enclosure

JB Weld.

--
Tim Wescott 
Control system and signal processing consulting 
www.wescottdesign.com

"plastic weld 5 minute" stuff appears to work. Or acrylic solvent cement. But grinding up some ABS plastic, mixing it into a little acetone to get the desired consistency, and applying works too. Just be aware that the acetone will affect the surface of any ABS it touches. I've not tried direct application of acetone to the surfaces.

(Heat up the ABS surface to about 230C with a heat gun? I haven't tried that and don't think it would be workable for most cases.)

I built a 3D printer that uses ABS (and PLA) plastic. Very interesting. Will be building another, soon -- much, much larger this time, though. I think I'll use Johnson pocket door 2000 series aluminum rails and rollers -- they appear perfect for the 2-axis lower portion, anyway. Getting all this dead flat over a large area and/or calibrating what variations remain is going to be fun. Worth a try. (The first layer or two picks up some of the variation, luckily.)

Jon

JB weld.

"Jon Kirwan"

"plastic weld 5 minute" stuff appears to work. Or acrylic solvent cement. But grinding up some ABS plastic, mixing it into a little acetone to get the desired consistency, and applying works too. Just be aware that the acetone will affect the surface of any ABS it touches. I've not tried direct application of acetone to the surfaces.

** Just be aware that you need pure acetone - " nail polish remover " contains oils and colourings as well.

... Phil

Drill & countersink some screws from the back-side into the pillars.

Machine surface where broken pillar bases are & replace with new hex brass pillars & csk screws through case.

Some of the plumbing cements will bond to ABS.

A few years ago I needed a feature on an ABS pipe fitting that simply wasn't available. So I ground up some ABS pipe, mixed the shavings into ABS cement from the hardware store, the shavings dissolved in it, and then I modeled it up. Worked.

Be careful, I believe the fumes are not healthy.

--
Regards, Joerg 

http://www.analogconsultants.com/

That's probably where I would have ended up after the JB Weld failed.

Or get new cases.

--
My liberal friends think I'm a conservative kook. 
My conservative friends think I'm a liberal kook. 
Why am I not happy that they have found common ground? 

Tim Wescott, Communications, Control, Circuits & Software 
http://www.wescottdesign.com

Make sure it is indeed ABS:

Is there anything that J-B Weld WON?T bond to?

J-B Weld will not adhere or bond well to:

Any flexible rubber surface Leather Vinyl Canvas Polypropylene plastic Polyethylene plastic

--
Les Cargill

Not sure if JB Weld is ABS cement. If it is: I modeled a few features onto ABS using ABS cement and ABS pipe shavings dissolved in the cement. A day later I gave it a test, to see how stable that it. Took the big mean-looking pliers, grabbed the new feature, torqued, torqued some more, leaned into it ... *POP* ... the pipe fitting broke somewhere else and some of my muscles hurt.

--
Regards, Joerg 

http://www.analogconsultants.com/

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JB Weld is a two part epoxy that has some filler added (iron?) to make it thick. It's been around forever. I recall this hardware store display, from my childhood, that had all sorts of things stuck together... (the gold ball is what I remember most.) I've used it to fix all sorts things. Including a small crack in the engine block of my tractor. It takes high temperatures well.

George H.

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^ oops ..............golf ball.

Then it's not ABS cement. What I mean is the stuff that literally dissolves ABS and lets one part "flow" into the other. If done right those joints are as difficult to break as the ABS itself.

--
Regards, Joerg 

http://www.analogconsultants.com/

That happens all the time with laptop cases. I use: for the purpose. Getting good adhesion requires some MEK to soften the plastic parts before gluing. You might try that with the superglue again. I like to apply pressure with glue clamps until the glue has set. Since it appears that your plastic has "stretched", making an air tight fit impossible, methinks the solvent and pressure tricks will be required.

Also, do it right the first time. Once you've slopped glue all over the plastic, it's rather difficult to scrape off the old glue and to get get a good fit the 2nd time.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

ABS is relatively easy to fix well, since ABS plumbing glue is a stock hardware item (in a less well stocked store, "all purpose" plastic pipe glue that includes ABS is usually available if a dedicated ABS glue is not.) As Jeorg mentioned, you can grind up ABS and add it to the glue to fill gaps.

This will usually hold up far better in the long term than gluing something to ABS - a plastic solvent glue approach results in a joint that is more-or-less welded, while a more generic glue will simply be adhered to the surface (which is often iffy with a plastic surface.) Physical or thermal shock is more prone to separating an adhered joint at the glue line.

Depending on exactly what the problem is, another approach that can be quite useful and has the benefit of speed is hot glue.

--
Cats, coffee, chocolate...vices to live by 
Please don't feed the trolls. Killfile and ignore them so they will go away.

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it will in acetone, not so sure about turpentine

-Lasse

Goop.

Greg

Not sure if that will work but ABS plastics may dissolve in turpentine.

Years ago I got shown a trick by an old navy radio tech and what he did was collect the same type of plastic, break it up into something like a small jar, like a baby food jar for example, then add turpentine to it and put the cover on. The plastic will dissolve given enough time and then you can apply via a wooden tongue suppresser or what ever.

If you take your existing posts that are broken off and dip them in a thin pool of turpentine, you may be able to soften and force a weld bond. Also put a drop on the other side to soften that too. You'll need to support it while the turp evaporates.

P.S.

This is how you make liquid tape, too! Just through in a roll of electrical tape or a piece of PVC from some source..

Jamie

There is a whole line of 'Goop'. Why not use the proper chemicals and be done with it?