How can I bond ABS (plastic) to NRL (rubber)?

[John Smith 47Participant @johnsmith47]

Hello

I need to glue/bond ABS plastic (Acrylonitrile Butadiene Styrene) onto NRL (Natural Rubber Latex). Any suggestions?

Note: The idea glue/adhesive should permit a few minutes of working time (e.g. 5 minutes) to allow for slight re-positioning and it would then bond as hard as possible, as soon as possible after that.

The bond would not need to flex. The bond must not in any way creep – e.g. due to gentle sustained forces – after it has set.

J

PS I have been trying "Bostik 218M Latex Adhesive" but it doesn't bond particularly well onto the ABS.

Edited By John Smith 47 on 14/01/2022 14:59:30

[John Smith 47Participant @johnsmith47]

[Dave SParticipant @daves59043]

Are you covering the abs with a layer of rubber, joining abs to rubber to something else?

Geometry of the joint may make a difference to recommendations.

Do you need the glue to be thin as possible, or is a thick glue line acceptable?

Often rubber bits on plastic are 2 shot moulded – the plastic is molded the loaded into another mold and the rubber injected. The surface design of the plastic substrate and the heat assist in a bond.

More info will help a better answer, but in the absence of it (cos it’s bound to be secret and “not relevant&rdquo I would look at a SikaFlex. Not going to set in 5mins tho. If quick set is actually required then an impact modified cyanoacrylate is where I’d start.

[Michael GilliganParticipant @michaelgilligan61133]

Double-sided tape [as used by carpet-fitters] might do the job neatly.

… but, of course, it has zero working-time, so you would need to get positioning ‘right first time’

MichaelG.

[Ady1Participant @ady1]

pinkgrip

Everything I've done with it has kept going and going

Changed the angle of my bandsaw blade a year ago by using it on rubber/aluminium and here we are a year later with no issues so far

Edited By Ady1 on 14/01/2022 18:23:15

[JasonBModerator @jasonb]

If it was not for the slow setting requirement then Loctite 380 "blackmax" would do nicely

[Engine Doctor ( Phil )Participant @enginedoctorphil]

Use a slow setting Cyanocryalate (cyano or super Glue) for a permanent no creep bond . Generally the thicker superglues are slower.

[John Smith 47Participant @johnsmith47]

Posted by Dave S on 14/01/2022 17:52:14:

Are you covering the abs with a layer of rubber, joining abs to rubber to something else?

Geometry of the joint may make a difference to recommendations.

Do you need the glue to be thin as possible, or is a thick glue line acceptable?

Often rubber bits on plastic are 2 shot moulded – the plastic is molded the loaded into another mold and the rubber injected. The surface design of the plastic substrate and the heat assist in a bond.

More info will help a better answer, but in the absence of it (cos it’s bound to be secret and “not relevant&rdquo I would look at a SikaFlex. Not going to set in 5mins tho. If quick set is actually required then an impact modified cyanoacrylate is where I’d start.

> Are you covering the abs with a layer of rubber, joining abs to rubber to something else?
I am using strip of rubber to create a hinge between two plates of ABS.

> Do you need the glue to be thin as possible, or is a thick glue line acceptable?
It doesn't need to be super-thin. I suppose up to 0.2mm thickness would just about be okay.

> Often rubber bits on plastic are 2 shot moulded
Yes, absolutely. This is a model for exactly that.

Since asking the question I have been experimenting further, with various glues. I am finding them all extremely hard to apply evenly and the result quickly gets exceedingly bumpy and messy.

But in my experience, what has been an absolute game-changer, for producing really smart results, is if one can use some sort of glue-tranferring tape, so long as it's thin enough.

e.g. This stuff "3M 9088-200 High Performance Double Coated Tape"

**LINK**
https://www.3m.co.uk/3M/en_GB/p/d/b40070391/

It certainly is amazingly tacky! (i.e. sticky) The results can be seriously smart, and with care it is slightly (but not very) repositionable, in that with patience you can generally peel it back off a solid surface.

However I suspect that it doesn't ever form a solid bond. And so when the hinge is under long-term, sustained pressure, particularly if the item is accidentally left in direct sunlight, I suspect that it may fail… despite what the specs claim!

J

[John Smith 47Participant @johnsmith47]

Posted by Ady1 on 14/01/2022 18:09:53:

pinkgrip

Everything I've done with it has kept going and going

Changed the angle of my bandsaw blade a year ago by using it on rubber/aluminium and here we are a year later with no issues so far

Edited By Ady1 on 14/01/2022 18:23:15

Have you tried Pinkgrip with rubber?

I couldn't see any mention of rubber…
https://www.everbuild.co.uk/products/adhesives/grab-adhesives/pinkgrip/

[Robert Atkinson 2Participant @robertatkinson2]

+ 1 for 3M VHB tape suggested by John. If you need fiddle time wet one of the surfaces with water.

Second choice would be a toughened acrylic adhesive such as Loctite Multibond 330. Permabond also make these. They are a clear glue (like UHU) but it needs an activator brushed on one surface. In this case ativator goes on the ABS

Robert G8RPI.

[John Smith 47Participant @johnsmith47]

Posted by Philip Fearn on 14/01/2022 19:58:09:

Use a slow setting Cyanocryalate (cyano or super Glue) for a permanent no creep bond . Generally the thicker superglues are slower.

I did try a couple of different types of Superglue. One had extremely strong instant grab and was an instant disaster. The other was slightly less aggressive, but there was very little repositioning and the rubber quickly swelled like crazy causing it to curl. Also CA seems to denature the rubber, and any spillage on the front surface will leave a nasty reflective marking.

If all else fails, I could probably get it to work… but to be honest I've always rather hated CA, because:
– the fumes rather sting the eyes,
– it requires a good fit (i.e. not good at filling in any gaps) and
– it's such a nightmare to clean up any spillage – particularly if it gets on the your skin!

[John Smith 47Participant @johnsmith47]

Posted by Robert Atkinson 2 on 14/01/2022 21:24:18:

+ 1 for 3M VHB tape suggested by John. If you need fiddle time wet one of the surfaces with water.

Interesting suggestion. For precision work, would you literally paint water on with a paintbrush? Or try to use a fine spray/mist? Either way does the bond end up being just as strong as normal?

J

[Robert Atkinson 2Participant @robertatkinson2]

Spray / mist is best. A tiny amount, literaly a drop in a liter of washing up liquid can help with wetting. Final bond is just as good as dry but takes longer. pressing on join forces the water out.
It's similar to how car "wraps" are applied

Edited By Robert Atkinson 2 on 15/01/2022 15:16:31

[John Smith 47Participant @johnsmith47]

Posted by Robert Atkinson 2 on 15/01/2022 15:15:15:

Spray / mist is best. A tiny amount, literaly a drop in a liter of washing up liquid can help with wetting. Final bond is just as good as dry but takes longer. pressing on join forces the water out.
It's similar to how car "wraps" are applied

Edited By Robert Atkinson 2 on 15/01/2022 15:16:31

Extremely interesting. I now just need to find a sprayer somewhere!

Out of interest, do you happen to know whether the bond itself ever properly sets/hardens over time? Or whether it just stays super-sticky…

J

[Frances IoMParticipant @francesiom58905]

ask a friend for an empty perfume bottle – they usually produce a fine mist.

[Robert Atkinson 2Participant @robertatkinson2]

3M VHB stays flexable long term. It' used for things like sticking th aluminium sides of commercial vehicles on.

[Gerhard NovakParticipant @gerhardnovak66893]

I would be careful with long term bond strength. If one of the materials contains a softener (I suppose the NR compound would, I am not sure about the tape itself) you could get softener migration which could either make the material brittle or slimy sticky in the contact area. Best thing is to try, it may be fine for a long time.

I don't think UV is a problem for the 3M material, there are many additives on the market which prevent accelerated ageing by UV rays.

[John Smith 47Participant @johnsmith47]

OK, 3M's VHB is a failure.
I am using the Natural Rubber Latex (NRL) as a hinge and the peeling forces are too great for it.

RECAP
– I don't want to use Superglue (/CyanoAcrylate) type glues as they are too aggressive and any surplus instantly messes up the surface of the NRL.

I would love to find a new "general purpose" adhesive that:
– Sets properly (must at least be "fingernail proof" )
– Once set it remains highly bendable & flexible
– Can bond well to rubber and most plastics (e.g. PS/ABS… maybe Nylon too??)
– Can bonds "most things to most things" (including woods and metals)
– Allows at least few minutes of repositioning time (no instantaneous grab)
– Isn't too aggressive (e.g. doesn't immediately denature rubber)

And as a bonus, if possible it:
– Doesn't need to be mixed
– Is clear

e.g. Have any of you folks tried:

A. Unibond Repair Extreme (now Henkel)

B. Dowsil 732 ("Multi-Purpose Silicone Sealant" )

C. Elastosil E41 from Wacker ("Moisture Curing Silicone Rubber" )

D. Loctite Plastic Bonder (2 part epoxy, designed for plastics)

Or do you have any other suggestions/personal favourite "general purpose" glues that might work?

Many thanks

J

Edited By John Smith 47 on 20/01/2022 22:58:15

[Dave SParticipant @daves59043]

When hunting a Unicorn it is usually best to start with the Unicorn breeders

Henkel, Sika both have very helpful technical teams

[Gerhard NovakParticipant @gerhardnovak66893]

If you want a really good bond from a tape try a worktop edge one, like UNIKA worktop tape. available for 6£ from screwfix. Bond is incedible strong, tape is quite thin.

What I said a few posts up is still valid – you don't know about the long term performance.

[Robert Atkinson 2Participant @robertatkinson2]

Rubber to ABS with high dynamic peel forces is a severe challenge for any adhesive.
Peel was not mentioned in your original post.
Sikaflex might do it given long enought to cure.

I wish you luck but won't be placing any bets……

Robert G8RPI.

[Neil LickfoldParticipant @neillickfold44316]

Can you use another material instead of the ABS? ABS is terrible stuff to try and glue to, especially when a peel strength is required.

[Steve Skelton 1Participant @steveskelton1]

"I am using strip of rubber to create a hinge between two plates of ABS."

Why not redesign it using polypropylene so that you use one piece of material – PP make perfect natural hinge material? May be easy to 3D print it? Would be a much more elegant solution.

https://www.protolabs.com/resources/blog/living-hinge-basics-for-injection-molding/

[HowiParticipant @howi]

Simple Evostick contact adhesive will do the job wiuthout anything fancy.

[John Smith 47Participant @johnsmith47]

Posted by Dave S on 21/01/2022 08:22:37:

When hunting a Unicorn it is usually best to start with the Unicorn breeders

Henkel, Sika both have very helpful technical teams

Good suggestion. However long story short, I have basically drawn a blank from both of them. :^(

3M have been super-slow to reply but are also now chewing on the problem. 

UPDATE:
I have now bought and done careful test on all 4 of the above adhesives that I listed above. For the hell of it, I even also tested Zap 30min Epoxy and Collall general purpose glue.

Sadly all of the glues were complete FAILS.  i.e. None of them were able to resist even pretty weak peeling forces and they have basically failed to bond well enough.

Clearly the designs of my prototypes will need to be improved so as to avoid peeling vulnerability, but for now it's too late as the prototypes have been 3D printed in high res and are well advanced.

I have now spent multiple hours on this exact question (googling/emailing/phoning…) but I am broadly none the wiser, except I have a strong sense that a primer is required(!). Also I am told that silicone sealants are likely to work best with silicone rubber, even though silicone rubber is generally hard to bond to.

I was offered some Wacker G718 primer to go with my Elastosil E41 sample, however at c. £300/bottle and no way to get a smaller sample, I'm afraid I didn't go for that.

More or less out of desperation I have order some Sikaflex EBT+, but I remain unsure what primer it really needs to bond to plastics like ABS. Also out of desperation, I have also ordered some Dowsil 1200 OS Primer to go with my Dowsil 732 silicone sealant, even though there was little evidence that it worked on plastics.

If all else fails I could try superglue again, but it's it instantly screws up the NRL rubber's finish. And so small accidents would be irrecoverable as unlike most glues they are not be able to be cleaned up (e.g. using Isopropanol)…

Hey-ho.

Edited By John Smith 47 on 21/01/2022 19:07:05

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