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

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I know these things happen, Pete … But it would be helpful to your readers if you could separate your ‘reply’ from the text that you are quoting.

As for whether the content of John’s posts is acceptable … Neil has already determined.

MichaeG.

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Edit: I’ve just seen your edit, Pete 

Edited By Michael Gilligan on 24/01/2022 10:01:52

It got worse when I tried to edit, never had it before but I could not get my my reply below the vertical lines??

There was a red boarder present, I did finally get my reply below the vertical lines but it still didn't work out. Don't know what was happening?

As we used to say "the boss is not always right, but he is always the boss", lol

Sorry for barging the thread .

I do feel the moans about commercial content are more due to peoples attitude towards John and his attituted to others.

There is one other and possibly a second active thread that are commercial. In the case of the one I know for sure the poster often asks for assistance and not once have I seen complaints about it being related to their business. So do members have double standards and only complain when it suits them?

Fascinating to read how knowledgeable you all are on adhesives! I'm the technical director of an adhesive company. Unfortunately not for adhesives along these lines.

Natural Rubber is very hard to bond. Typically done with cyanoacrylate (which is why everyone keeps suggesting it) and not a lot else.

I believe you are going to need a primer. If you coat the natural rubber with a thin layer of cyanoacrylate and let it dry your question then becomes how do I bond cyanoacrylate to ABS, then the answer is use a two part epoxy and clamp it hard (use the loctite plastic bonder). Use an ultra thin superglue and that should give you a really neat coating. if you can coat the rubber before cutting to shape you would get a great coating. you wouldn't need to apply much of the epoxy, thinner the layer of the adhesive the better, you just want good coverage.

Any tape (and we supply the adhesive on tapes) will creep fail over time, whilst the unika tape is very strong, there is no real weight (stress) being applied on a worktop edge.

If you are actually planning on these two pieces of ABS being bent back and forth then you need something that dries hard.

Sanding / scratching the surface of the rubber / ABS will help greatly.

Just a heads up that there is a lot of marketing going on with adhesives. For example superglue for metal, is the same thing just a different tube as superglue for plastic and the same trick is played for "epoxy resin for X". You sell more when you make it very clear what it can be used for. That said... there are different types of epoxies, the curing system used can make a difference (this is clearly stated on the tube).

Thank you for your input Andrew

With CA as a primer, even the smallest amount of the stuff seems to cause severe curling of a soft NLR, but I shall experiment further.

> Any tape (and we supply the adhesive on tapes) will creep fail over time
Do you mean "double-sided adhesive tape" or "transfer tape"... or both?

Truth to tell, I have literally just thrown the loctite plastic bonder out because even when properly mixed and fully set, it was so soft. It wasn't even fingernail proof!

My testing is now leaning towards using silicone rubber rather then NRL, because I am now being told that I should be able to get a "much" more decent bond to silicone than with NRL, if using a silicone based adhesive (+primer).

J

PS. By way of trying to not ignore anyone, re the moaning about anyone "commercial" being allowed to participate in this forum, to recap, it is NOT against the rules of this forum for commercial organisations to participate. What is not allowed if for them to promote their own products.

Edited By John Smith 47 on 24/01/2022 13:18:00

Jason, I think it has more to do with the nature of the question and following helpful advice the abrasive responses from the OP. The start point is always high precision but with limited machinery and budget the OP resorts to basic hand tools and methods suggested by forum members and poo-pooed earlier by the OP. He then wishes to measure a hand filed radius with precision, what is being measured and where on the component? To produce consistently accurate radii by hand is a skill few if any posses.

One thing which is clear is that if the OP had purchased the Unimat 3 with all the accessories for sale at reasonable cost and suggested by members of the forum and myself then a lot of the tasks laboriously undertaken could be completed with far greater accuracy and speed. The precision element stressed as of critical importance when originally posted.

I also feel the OP try's to stifle criticism by suggesting members use the ignore button, I have been tempted but find the posts very amusing.

The for profit element is of no concern to me.

Robert Butler

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Edited By Robert Butler on 24/01/2022 23:03:07

Edited By Robert Butler on 24/01/2022 23:03:31

Tempting though it always is to descend into a war of words, I have shall ignore the all personal attack. I have learned to develop a thick skin, when people are being unreasonable... and fighting back with similar personal criticisms & comparable attacks back ever EVER helps.

But please try get your facts correct...

> He then wishes to measure a hand filed radius with precision,
Wrong. I have never wanted to measure with precision the radiuses that I have only hand filed. This is factually incorrect. What I have been measuring is the consistency of radiuses/radii on edges may or may not have involve a hand-file to do the grunt-work, but that have always then been either finished either with a deburring wheel or made with a precision diamond hone (possibly using with a modified honing guide), or both.

But nope, never just with a hand file.

Whilst we're here Robert, although:
a) my workspace is exceedingly tight and
b) although I had no immediate requirement for a lathe of any size and
c) although I also have basically no idea how to use a lathe and
d) although I don't really have the time to spend learning how to use one and
e) although it has a circular pillar (which is not ideal) and
d) although the Unimat 3 being an exceedingly old, and second hand product, so being a novice I would be extremely likely to buy a dud with shot bearings or some such problem...
...and probably not even know!
...However the point here, is that I have - many months ago in fact - already thanked you for the suggestion and have also - many months ago - eaten the humble pie of conceding that I should have bought that darned thing!

That said, the Unimat 3 would not help me ABS plastic to NRL rubber, so I'm technically we committing the crime of being in the incorrect thread.

Hey-ho.

But I am gratified to hear you are enjoying these threads... Me too

And I have learned a LOT about tools. And I am deeply grateful for that. Sadly my technical knowledge is so limited (or so I keep being told!), and the expertise around here is so high (mostly!) that there isn't much I can offer in the way of knowledge back.

J


PS At some point I may just use a new email address and start again. And hopefully people will go back to answering the questions I pose, let me make my own mistakes and stop trying to join do join dots about what my various private/IP protected projects involve.

Back to this thread's question...

UPDATE

I have been doing quite a lot of testing of materials. I now have found a less watery and slightly less aggressive type of CA/Superglue called Powerflex made by Loctite, which goes no more like a gel which would definitely help reduce spillage...

Unfortunately, although the bond to rubber latex (NRL) is good/sometimes excellent - even a thin layer of the Powerflex causes swelling/warping of the latex, which then unavoidably seem to cause lumps & bumps in the outer surface of the RNL. See upper half of this photo:

In the lower half of the photo is my only real success so far, which is Elastosil E41 + NP2 primer, which combine to product a REMARKABLY good bond onto 1mm thick Silicone Rubber. In fact you may not really need to primer.

And crucially it forms it's bond in a very 'civilised' manner giving you time to wipe off excess (using IPA) and has a reasonable repositioning time - which can seriously help when model making.

Adhesive/glue FAILS include:
- Repair Extreme
- Dowsil 732
- Loctite Plastic Bonder
- BSI Epoxy 15min
- Collall All-purpose
- Zap Z-poxy
- B7000
- E6000
- Professional Welder
... } all of which TOTALLY failed the fingernail test (not even close!) when bonding each of NRL rubber and Silicone Rubber. That said, some of the glues claim to keep getting stronger for 48 hours so I may be being slightly premature...

Interestingly, almost all of them bond wonderfully well to my ABS plastic despite it's high-gloss finish. Ironically the one notable failure was Plastic Bonder!

I am delighted with Elastosil E41. My sight problem is that an extremely despite a soft shore hardness (of 40° my silicone rubber is nothing like as elastic a natural rubber latex. Latex can be stretched to a length of about x2, whereas the latex can easily do x3.

J

You might want to check that closing line, John … and correct it accordingly.

” Latex can be stretched to a length of about x2, whereas the latex can easily do x3. ”

MichaelG.

Good spot, but now too late to edit... 
The first stretch was of course the silicone rubber.

At a quick re-test of my rubber sheets, I am getting Silicone rubber x2.5, and NRL about twice that at x5.

To be fair, it's not 100% clear where the elastic limit lies. Not least because it depends on how long you hold the stretch. That said, the exact degree of elasticity is less important than the model falling to pieces due to shear forces overwhelming inadequate adhesives.

J

Edited By John Smith 47 on 26/01/2022 09:32:33

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Despite the fact that we all know that adhesive tapes will peel …

Did you ever try using the “heavy-duty, double-sided, carpet-fitting for the use-of” tape which I originally suggested ?

Its mechanical properties must be pretty close to your requirements, although it permits no time for adjustment.

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MichaelG.

No, I confess I haven't tried any more adhesive tapes - neither double-sided or transfer tapes - because I have been unable to identify anything that sets hard. Do you have any specific suggestions/recommendations?

Also I am extremely keen to have something that permits a little adjustment time. Although I have bought a water sprayer for the purpose, if I can find something that claims to set rather than just use tack.

J

No, sorry … The tape I have ‘in stock’ is probably thirty years old, and is just a remnant.

There is no identifying ‘branding’ on the reel

It’s 50mm wide and the tape itself is ‘flesh pink’ [the colour commonly used for prosthetic devices]

I can only suggest that you enquire of a friendly local carpet fitter.

MichaelG.

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As already stated, though : it is instant stick [no time for adjustment]

Edited By Michael Gilligan on 26/01/2022 13:54:06

Have any of you come across "Poly Kits" from Tech-Bond

**LINK**
(https://tbbonding.com)

They claim to be able to bond basically any plastic to any plastic including PP, PP and even PTFE...!

Too good to be true?

J

Btw, I have been in touch with the manufacturers. And they are still talking a big game about what they can bond that nobody else can bond. I think I have found some a 'good enough' solution using the E41, which does allow a bit of repositioning time, which the tech-bond stuff doesn't readily offer (not without tweaking their protocols that is).

They are US-based and when I asked them about UK distributors they said that there aren't any. But he then asked me if I knew of anyone who might be interested?

So... anyone here interested?

It does SOUND like amazing technology...