Author Topic: Tips on sticking two bits of plastic together  (Read 2266 times)

Gattopardo

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Tips on sticking two bits of plastic together
« on: 09 January, 2022, 10:56:03 pm »
Ok you are a knowledgeable and problem solving bunch.

So I broke a headlamp adjuster on the x type, by fucking about.  These plastic things are brittle and in the UK there are replacements but in France they are thin on the ground and thanks to brexit import costs are high.

So how can I stick/bond the piece of poor plastic and get my headlamp together.

hellymedic

  • Just do it!
Re: Tips on sticking two bits of plastic together
« Reply #1 on: 09 January, 2022, 11:17:32 pm »
Do you know what type of plastic you wish to glue?
Different plastics are VASTLY different.
Poly(ethyl)ene is almost impossible, Polystyrene is easy with Airfix type glue, Shoe Goo might be useful in some places, Evostik and Loctite in others.

More information needed!

Re: Tips on sticking two bits of plastic together
« Reply #2 on: 09 January, 2022, 11:22:13 pm »
Fwiw I repaired a jaguar headlamp, similar problem with self tapping screws + glue.  But yes, let's have a photo please.

Re: Tips on sticking two bits of plastic together
« Reply #3 on: 09 January, 2022, 11:35:09 pm »
Could try "plastic welding". ie use a soldering iron to melt the plastic, and stick it together.
It helps if you can add more plastic on top of the join. This should be the same sort of plastic, so check what it is. Plastic bottles or zip ties could work. Or you can buy plastic welding rods.
Plus can heat up staples and push them in, to give extra reinforcement.

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Tips on sticking two bits of plastic together
« Reply #4 on: 09 January, 2022, 11:40:19 pm »
Do you know what type of plastic you wish to glue?
Different plastics are VASTLY different.
Poly(ethyl)ene is almost impossible, Polystyrene is easy with Airfix type glue, Shoe Goo might be useful in some places, Evostik and Loctite in others.

More information needed!

No idea on what the plastic is, there isn't any marking on the plastic to identify.

Fwiw I repaired a jaguar headlamp, similar problem with self tapping screws + glue.  But yes, let's have a photo please.

Will get photos tomorrow as I'm having phone upload issues.

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Tips on sticking two bits of plastic together
« Reply #5 on: 09 January, 2022, 11:46:20 pm »
Could try "plastic welding". ie use a soldering iron to melt the plastic, and stick it together.
It helps if you can add more plastic on top of the join. This should be the same sort of plastic, so check what it is. Plastic bottles or zip ties could work. Or you can buy plastic welding rods.
Plus can heat up staples and push them in, to give extra reinforcement.

Yeah have repaired motorbike fairings like that and recently repaired a thrown away dyson like that.

But great idea but not sure it will work.

Basil

  • Um....err......oh bugger!
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Re: Tips on sticking two bits of plastic together
« Reply #6 on: 10 January, 2022, 07:57:18 am »
As a youngster, I used to plastic 'weld' by setting light to the end of a bic biro and letting molten plastic drip.
Plastic types will have changed greatly since then.
Admission.  I'm actually not that fussed about cake.

Re: Tips on sticking two bits of plastic together
« Reply #7 on: 10 January, 2022, 08:31:10 am »
Gorilla glue, or Araldite Instant (FCVO Instant)
We are making a New World (Paul Nash, 1918)

Re: Tips on sticking two bits of plastic together
« Reply #8 on: 10 January, 2022, 08:53:40 am »
The answer is likely to move away from the retail brands into pro-brands - this bunch are as good as the pro-Loctite adhesives https://www.bondloc.co.uk/, possibly to this one https://www.bondloc.co.uk/superglues/bondloc-b406-cyanoacrylate-adhesive/ which I have used successfully to make o-rings, that's a common use for hydraulic seal creation for repairs. Do bear in mind they may not handle as easily as the retail compounds (as if they are easy!) and care is required - there are REASONS these are not available retail, mostly the ability to get it wrong. You may also benefit from this https://www.bondloc.co.uk/superglues/bondloc-b770-polyolefin-primer/ if it is a difficult plastic to bond.

Re: Tips on sticking two bits of plastic together
« Reply #9 on: 10 January, 2022, 10:57:26 am »
The plastic brackets that provide locating pegs for the driver's side rubber mat in my car broke. No spares available except by buying a new set of mats!

I drilled some holes and wired the parts together, then applied Araldite at crucial points. Have to take care that the repaired part doesn't foul something to prevent refitting. Not pretty but invisible anyway.

Re: Tips on sticking two bits of plastic together
« Reply #10 on: 10 January, 2022, 11:05:57 am »
I've repaired plastic parts by drilling holes and tying with sewing thread, then soaking the thread with superglue or contact adhesive.

Re: Tips on sticking two bits of plastic together
« Reply #11 on: 10 January, 2022, 11:43:21 am »
Do you know what type of plastic you wish to glue?
Different plastics are VASTLY different.
Poly(ethyl)ene is almost impossible, Polystyrene is easy with Airfix type glue, Shoe Goo might be useful in some places, Evostik and Loctite in others.

More information needed!
My bold
I've successfully glued an 'extension' onto a drinks bottle to increase its capacity as a bottle cage tool container, using the polyolefin primer (and very thin superglue) which Ham refers to above. The drinks bottle is made of low density polyethylene. 14 years later it is still holding strong, despite having been bounced down the road a several of times.

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: Tips on sticking two bits of plastic together
« Reply #12 on: 10 January, 2022, 12:45:15 pm »
Seems to be plenty of x-type headlight adjuster parts on the bay of thieves, UK based eg:

https://www.ebay.co.uk/itm/272673313416?hash=item3f7c989288:g:3H4AAOSwyrlcrE-S

Regards,

Joergen

FifeingEejit

  • Not Small
Re: Tips on sticking two bits of plastic together
« Reply #13 on: 10 January, 2022, 01:40:40 pm »
I've repaired plastic parts by drilling holes and tying with sewing thread, then soaking the thread with superglue or contact adhesive.

Due to a bit of stupidity from faither whne fitting one of my cars headlight units it is held on at one broken bolt hole in a similar manner however with something much more suitably engineeringy

https://en.wikipedia.org/wiki/Cable_tie

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Tips on sticking two bits of plastic together
« Reply #14 on: 11 January, 2022, 01:51:48 pm »
Seems to be plenty of x-type headlight adjuster parts on the bay of thieves, UK based eg:

https://www.ebay.co.uk/itm/272673313416?hash=item3f7c989288:g:3H4AAOSwyrlcrE-S

Not in the UK is the issue, thanks brexit.

Wondering if the bits are moulded or 3d printed.

Gattopardo

  • Lord of the sith
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Re: Tips on sticking two bits of plastic together
« Reply #15 on: 11 January, 2022, 02:47:59 pm »
Here is the bit in the headlight back


Here is the bit that has broken



Am thinking of reinforcing around the "+" with a pin (thin metal thing). Heating the point of the pin, then making a small hole for the metal to locate in to the ball bit in the socket around each inner point.  Then do the same on the base so I can use the pins to hold the broken bit in place.  Then surround with glue.

The answer is likely to move away from the retail brands into pro-brands - this bunch are as good as the pro-Loctite adhesives https://www.bondloc.co.uk/, possibly to this one https://www.bondloc.co.uk/superglues/bondloc-b406-cyanoacrylate-adhesive/ which I have used successfully to make o-rings, that's a common use for hydraulic seal creation for repairs. Do bear in mind they may not handle as easily as the retail compounds (as if they are easy!) and care is required - there are REASONS these are not available retail, mostly the ability to get it wrong. You may also benefit from this https://www.bondloc.co.uk/superglues/bondloc-b770-polyolefin-primer/ if it is a difficult plastic to bond.

Am a fan of bondloc as it was near me and stocked in toolstation. Closest place to me that has glues is a wurth store.

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Tips on sticking two bits of plastic together
« Reply #16 on: 12 January, 2022, 09:55:12 pm »
Hello anymore ideas?  Before I start melting stuff and really fucking things up?

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Tips on sticking two bits of plastic together
« Reply #17 on: 12 January, 2022, 11:42:51 pm »
Tried heating a pin and pushing that in to the plastic so I can cut pins down but that didn't work as planed.
How can I identify the material that the white thing is?
So next plan is either 2 part epoxy or solvent cement.  How can I identify the material?
Seen this for hard plastic - But not for PP or PE https://sader.fr/produits/colle-plastique-rigide
Then this for flexible plastix - No mention of PP and PE https://sader.fr/produits/colle-plastique-souple

So that leaves hot glue or 2 part nail glue.

Or do I find a small drill bit, drill in to the ball and then in the tap the hole and screw in a bolt.

Oh this is fucking annoying.


Re: Tips on sticking two bits of plastic together
« Reply #18 on: 13 January, 2022, 07:44:36 am »
My guess: the white thing is probably nylon as it appears to be vaguely structural.

Gattopardo

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Re: Tips on sticking two bits of plastic together
« Reply #19 on: 13 January, 2022, 07:54:29 pm »
My guess: the white thing is probably nylon as it appears to be vaguely structural.

The issue seems to be that the crucifix (plus shaped) plastic is brittle.  So trying to find something to replace the rod part.  Was thinking of a screw or bolt in place of the rod and I drill a hole down the center and replace with a screw/bolt.  The plastic ball bit at the end will have to stay I think.

Re: Tips on sticking two bits of plastic together
« Reply #20 on: 14 January, 2022, 07:45:04 pm »
Hello anymore ideas?  Before I start melting stuff and really fucking things up?

Would ordering the parts to a UK address and then getting them sent on (as a "gift", for example?) sort the import problem?

I guess that, yes, that is an offer, if plausible...
Back in the saddle :)

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Tips on sticking two bits of plastic together
« Reply #21 on: 14 January, 2022, 11:30:17 pm »
Thank you for the offer.  Should have done that from the outset from new years day.  Have an offer of sending the items but it is expensive to send, probably get hit for tax and then time to get it here. Being without a car here is quite annoying.

Just need to stop fearing failure and get on with it.

EDIT: Also need to separate a pair of rusted bolt and clips on the bumper.  The plastic is quite fragile..

Wonder if hot glue can be used to stick the bits together.

Kim

  • Timelord
    • Fediverse
Re: Tips on sticking two bits of plastic together
« Reply #22 on: 15 January, 2022, 12:26:21 am »
Dunno about your plastic, but there are hot glue formulations optimised for plastics (particularly polypropylene) that do a much better job than the usual crafting stuff.  Long-term durability in a damp environment may be an issue.

jiberjaber

  • ... Fancy Pants \o/ ...
  • ACME S&M^2
Re: Tips on sticking two bits of plastic together
« Reply #23 on: 15 January, 2022, 10:52:17 am »
Seems to be plenty of x-type headlight adjuster parts on the bay of thieves, UK based eg:

https://www.ebay.co.uk/itm/272673313416?hash=item3f7c989288:g:3H4AAOSwyrlcrE-S

Not in the UK is the issue, thanks brexit.

Wondering if the bits are moulded or 3d printed.



Sorry - I've just realised you are in France so it makes sense now! 

From the description, says they are Nylon, but how they are made is unclear.  I can't see a shape on that link that matches the photos you have though anyway - have you tried looking on the usual 3D printing resources? Though that might end up as expensive as an imported part.

From a brief skim through a jag forum it appears those who repaired (using epoxy) just kicked the can down the road as it was an issue with the material going brittle - the recommendation being don't mess around - get a replacement kit and replace both sides.  You've probably come across similar threads detailing how to strip it all down....

https://www.jaguarforums.com/forum/x-type-x400-14/headlight-adjuster-broke-passenger-side-02-xtype-88091/page2/

The issue with 3d printing (mostly) is that it is usually strong in one direction but not the other because of the way it is created, so needs either post treatment (like using acetone with an ABS part to smooth and bond the outer skin) or over engineering in the plane of failure, there are also issues with reliable dimensional accuracy in all 3 planes, but some (IME often a lot of) fettling and/or expensive kit it can be achieved. 

Sounds like, though expensive and a delay, it might be the better repair to buy and fit something.

In the above forum thread there is a drawing (again I don't recognise the part you have in there) but it links to a Polish company Jagcar Poland which may be a lead to source something within the EU.
https://www.jaguarforums.com/forum/attachments/x-type-x400-14/21942d1343756345-headlight-issue-jag_hlight-adjusters.pdf

Potential 3d print part?
https://www.thingiverse.com/thing:3510792

ETA: http://jagcar.pl/


Regards,

Joergen

Gattopardo

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Re: Tips on sticking two bits of plastic together
« Reply #24 on: 18 January, 2022, 04:01:49 am »
Thank you for the reply Jiberjaber,

My initial thoughts, after reading up on the various forums, were to glue the plastic together and then reinforce the outside with a two part epoxy.  But then I over mixed the filler.

Having read up and a cure is to replace the rod.  So the current idea is to drill the back and fit a rod like this:
If I can find a car with a matching ball size.

Or drill through the ball and the base and then thread the bits and replace with an allen bolt.