What is the strongest way to bond styrene onto ABS?

[John Smith 47Participant @johnsmith47]

Hello

What is the strongest way to bond styrene onto ABS?

I have access to:
– EMA Plastic Weld
– MEK-pak by Slaters
– Mr Cement S
– Tamiya Extra Thin

I also have access to these epoxy glues:
– Super Glue corp's Plastic Fusion (but it never seems to set really hard)
– Devcon – "Plastic Welder"
– UniBond "Repair Plastic"

And Cyano Acrylate glue:
– Loctite "Super Glue – Precision

With thanks

J

[John Smith 47Participant @johnsmith47]

[Michael GilliganParticipant @michaelgilligan61133]

John,

That's a rather tricky question; given that ABS is a styrene

… The answer will most likely depend upon the other styrene that you are using.

Please come back with more detail.

MichaelG.

.

P.S. … If you are working on a small scale, AND both materials are hard styrenes [i.e. not, for example, 'expanded polystyrene'] then this is an excellent solvent adhesive. … 'though, of course, it has no gap-filling ability.

Edit: … That was first on your list 

Edited By Michael Gilligan on 09/11/2015 08:29:43

Edited By Michael Gilligan on 09/11/2015 08:33:20

[Involute CurveParticipant @involutecurve]

Copydex works well with styrene, I used to use it when making aircraft model wings.

HTH

Shaun

[Gordon WParticipant @gordonw]

I used Gorrilla Glue , the slightly foaming stuff, To stick a plastic sole on my new shoes. I don't know what plastic but felt like styrene. This glue seems to stick to anything , don't yet know how long it lasts but so far, over a year, is ok. Any joints must be clamped.

[J HancockParticipant @jhancock95746]

I would advise you to research the ' 3M adhesives and sealants' website if you have a really serious application.

After ten years ,I am still trying to pull apart the trial piece of double sided tape for aluminium foil/foil , without

success, or failure , depending which way you regard it !

[FatgadgiParticipant @fatgadgi]

Hi John

There are special solvent type adhesives that bond styrene based plastics (and Michael is right, ABS is a styrene). These work by melting the parent material, so they are probably the best bond you will get.

Never tried it, but styrene modelling cement may work.

I have seen DIY glues made with Acetone and the parent ABS melted into it for one off jobs – could be worth a try ?

Cheers – Will

[Michael GilliganParticipant @michaelgilligan61133]

Given the question posed in John's other post … I think we will find that the unidentified 'styrene' is a hard material, in quite small sizes.

… I may, of course, be completely wrong !!

However: If I am correct, then the big question will be:

"How close-fitting are the joints?"

MichaelG.

[MuzzerParticipant @muzzer]

Lego bricks and solvent weld waste (plumbing) pipes are made of ABS. The cheapest way to weld them is to go to a plumber's supplier, Screwfix or B&Q and get a tub of solvent weld cement. Costs peanuts and is designed for the job. I expect that's what the Lego designers use to glue their models together.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Muzzer on 09/11/2015 13:34:24:

Lego bricks and solvent weld waste (plumbing) pipes are made of ABS. The cheapest way to weld them is to go to a plumber's supplier, Screwfix or B&Q and get a tub of solvent weld cement. Costs peanuts and is designed for the job. I expect that's what the Lego designers use to glue their models together.

.

Quite true, Muzzer …. But if John is working at small scale, these 'filled" solvent cements may be a bit gloopy, and something that flows by capilliary-action more suitable.

It all depends what he is actually doing: Hopefully he will be back to tell us.

MichaelG.

[Jeff DaymanParticipant @jeffdayman43397]

Tamiya plastic model kits (the hard plastic parts) are made of ABS. Tamiya cements intended for assembling their plastic model kits will work very well for bonding ABS to ABS or ABS to styrene. They have liquid cement and gel type cement in tubes. In my experience Tamiya products are VERY high quality.

For larger jobs with larger joint clearances the ABS cement for ABS plumbing drains will work fine, with good strong joints, but as others have said it is thick and goopy and as such is not the best for fine work. JD

[John Smith 47Participant @johnsmith47]

Sorry for delay – just spotted these replies (it wasnt completely obvious that they existed!)

I am working at small scale c.10cm model. Needing to be accurate to 0.25 to 0.5mm. I am using white plasticard/HIPS solid stryrene. The ABS I need to join it so is something like this:
"White Smooth ABS Sheet A6 A5 A4 A3 Acrylonitrile Butadiene Styrene Sheet" either 1mm or 2mm **LINK**  which I am layering up using solvent to become about 10mm.

So far I have used "Tamiya Extra Thin" to do the cementing and then left it over night to dry.

I need a STRONG bond, with minimal flex, as it will take quite a lot of force through a torsion spring.

I was hoping to just melt the two plastics (ABS / HIPS-styrene) together using a solvent like Tamiya Extra Thin or EMA's plastic weld. One thing that I have discovered is that you do need to leave the plastic quite a long time to evaporate – at least 2 days – before they reach full strength.

I guess I could possibly reinforce the critical parts by drilling out and inserting some small pins which I could then bond into place using er… superglue (cyano acriylate) possibly more solvent??. Or better yet possibly some ultra-fine screws (say 1 to 2mm in diameter) although where would I get them… ??

Thanks :^)

P.S. On a separate note I now need to bond/attach stryene to what appears to be PE polyethylene, which sounds very much harder. I might start a separate thread for that. (Having done some more research first!)

 

Edited By John Smith 47 on 09/11/2015 14:44:19

Edited By John Smith 47 on 09/11/2015 14:44:34

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John Smith 47 on 09/11/2015 14:43:44:

I am working at small scale c.10cm model. Needing to be accurate to 0.25 to 0.5mm. I am using white plasticard/HIPS solid stryrene. The ABS I need to join it so is something like this:
"White Smooth ABS Sheet A6 A5 A4 A3 Acrylonitrile Butadiene Styrene Sheet" either 1mm or 2mm **LINK** which I am layering up using solvent to become about 10mm.

.

This is getting much more interesting/challenging, John

The contact areas you are bonding will probably dictate the best approach.

… any chance of a rough sketch ?

MichaelG.

[Jeff DaymanParticipant @jeffdayman43397]

You CAN NOT bond anything to polyethylene or polypropylene with cements. Research "low surface energy plastics bonding" for more info. Polyethylene is NOT harder than ABS or styrene, it is much softer.

Depending on force, I would not recommend loading ABS or polystyrene parts with a heavy torsion spring. It will likely creep and fail after some period of time. If you need to laminate 10 mm of ABS to get the required strength, it sounds like machined aluminum or injection moulded glass-filled nylon or acetal would be better material candidates for the job. JD

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Jeff Dayman on 09/11/2015 15:14:32:

… Polyethylene is NOT harder than ABS or styrene, it is much softer.

.

Jeff,

I'm pretty sure that John meant "harder" as in "more difficult"

MichaelG.

.

P.S. … This, from Loctite might be worth trying.

Edited By Michael Gilligan on 09/11/2015 16:15:45

[John Smith 47Participant @johnsmith47]

Posted by Michael Gilligan on 09/11/2015 16:10:08:

Posted by Jeff Dayman on 09/11/2015 15:14:32:

… Polyethylene is NOT harder than ABS or styrene, it is much softer.

.

Jeff,

I'm pretty sure that John meant "harder" as in "more difficult"

MichaelG.

.

Michael is corrrect

[John Smith 47Participant @johnsmith47]

Regarding cyanoacrylate – yes that "LOCTITE PLASTICS BONDING SYSTEM" might be worth a try.

One thing I don't really undersand about CA glue is that apparently it is the water/moisture in the air that it is reacting to yes? So how does it get to set so quickly but only when you press 2 surfaces together? And what happens if you need to fill a larger gap. Does it *ever* set? And when happens if I I want to bond a long thing pin say into a hole will it set at the bottom of the hole? Does the water vapour from the air somehow get all the way to the bottom of the hole? Or is there enough vapour on the surface of pretty well everything in order for it to set? Either way how come it does stay liquid for so long?

[Jeff DaymanParticipant @jeffdayman43397]

CA glue on ABS and Polystyrene will not result in as strong a bond as solvent cements intended for ABS and PS. The reason is that CA glue is not a solvent but depends on surface energy and mechanical roughness to obtain a bond between materials. For example it works really well on broken ceramics and woods because there is plenty of rough topography at a microscopic level for it to grip on.

I have used Loctite's plastic bonding glues extensively in industry. In my opinion they are no better than any other good quality CA glue in my experience. However their Black Max product is slightly better than other CA for softer resins to be bonded due to the addition of rubber particles in the resin. This makes it more ductile but not stronger.

The solvent bond glues melt both surfaces and fuse them together. Very strong, but it does take time for the solvents to dissipate and for the melted surfaces to re-solidify.

As to air drying of CA with applied pressure – the way CA sets is that moisture in the air catalyzes the resin and starts the long molecule monomer chains cross-linking (polymerisation) to cure the resin into a rigid acrylic polymer. (CA is essentially a type of acrylic resin). If there is a thin film of resin, caused by applied pressure, and sufficient moisture at the exposed part of the joint, the reaction starts at the surface and travels chain-reaction style down the joint. The less the volume of resin, the faster and more complete the cure. If the resin is thick or deep down a hole, the reaction can take a long time to complete and may not finish for a very long time if the hole is very deep. I have taken glued things apart and found liquid CA in deep holes a week after CA was applied.

For this type of joint you can usually achieve full cure with an accelerator spray catalyst. One brand is Zip Kicker. This will more fully catalyze the resin and is used to speed build time by fast-setting the resin. Bear in mind that all CA cures are exothermic, that is they give off heat as the resin is cross-linking. With accelerator spray this can result in VERY large amounts of heat being released – I have seen glued wood start smoking, and have burned my fingers holding joints while using accelerator spray. Use of pliers or clips to hold things being glued with CA and accelerator is recommended.

Accelerator sprays contains some very nasty chemicals (State of California USA has identified it as a suspected carcinogen) and so I would recommend using them as little as possible and always with good ventilation. Good ventilation or outdoor use is recommended for CA glues and solvent glues in general, not good stuff to breathe in at all.

Dollar store/ pound shop CA glue varies greatly in quality. I have used some for household repairs and it worked fine, other stuff never cured, some cured the instant it hit the air, and cured the whole tube! If the joints are important I would recommend getting good quality CA at a hobby shop or industrial supply. JD

Edited By Jeff Dayman on 09/11/2015 22:06:57

[John Smith 47Participant @johnsmith47]

Interesting but extremely mysterious how CA works. I mean if it's really the water that it likes, how come just breathing on it doesn't make it start to solidify faster? Also if it likes water, surely we should be a mist of water down any hole first. But I just bonded a pin into some HIPS very robustly. And what exactly is it about forcing things tight together that seems to work so well. Also I still don't quite get why en mass it refuses to set (for a v long time). All v mysterious.

Out if interest do you think there will be much to choose between Deluxe Materials and Loctite?
http://www.model-engineer.co.uk/forums/postings.asp?th=112066

Thanx

J

Edited By John Smith 47 on 09/11/2015 23:32:46

[Jeff DaymanParticipant @jeffdayman43397]

As mentioned before there is NO cement or glue I have found or read about that will make a reliable solid bond between any plastic and polyethylene or polypropylene, and I've been at this sort of thing in industry a very long time. The surface energy is just too low. Solvent glues and epoxy glues are also ineffective on PP/PE.

Some firms I worked at tried have tried expensive commercial corona discharge treatment on PE and PP parts to try and change surface energy for gluing but the bonds were only a little better than untreated surfaces. Same for primers/inhibitors. As one polymer chemist I worked with used to say "unless there's fusion, there will be con-fusion" in reference to fastening by gluing or heat-fusing thermoplastics.

There are several mechanical ways to join things to PE. Research 'heatstaking' for a good one easily done in home shops with some pins formed on one part, fitted through holes on the other, after assy the ends of the pins are melted and compressed (like rivets in ironwork construction.) Screws with nuts or screws self tapping, if the right type and if holes are designed correctly to suit screws used, will also work fine. Snap fits work well if properly designed.

Pop rivets with backup washers under the rivets, both sides, are also very good for joining things to PE/PP. JD

[Martin KyteParticipant @martinkyte99762]

Having no idea of the actual componant configurations as you haven't given a drawing yet, this may be off target but could you not go for a double sided adhesive tape. If you have a reasonable surface area and the the joint is not subjected to a peel stress it may suit.

regards Martin

[John Smith 47Participant @johnsmith47]

Re D/S tape
I need a lot more strength than ordinary double-sided tape will give.
For the sake of simplicity imagine two rods of 5x5mm cross-section, one of HIPS the other one of Polyethylene (PE). And I need to bond/connect them together robustly.

Re 'heatstaking'
After a quick search I'm somewhat bemused. It sounds like an industrial process involving push-fits. I need something that can be done in a home workshop. Can you provide any explanatory links is this is something that I might be able to do at home using a small butane torch or similar?

Btw, I dont know if this is what you are talking about, but in the apparent absence of any decent glues (the above mentioned Deluxe Materials & Loctite Activator/CA glue not withstanding) it occurs to me that what is needed is something like layer of strong higher melting point material (e.g. steel?) with small say 1mm spikes (or possibly microscop?) spikes (or hooks?) sticking out that one simply melts into place on the PE and which then bonds physically rather than chemically. Does such a technology exist for use in the home workshop?

[Jeff DaymanParticipant @jeffdayman43397]

I have no idea what you are trying to make, but it sounds like you are overcomplicating it if you need special technology that does not exist yet.

I've designed literally thousands of plastic parts and assemblies over the years in industry, some of which companies have made millions of, and never needed technologies like you are talking about. Chances are there is a simple way to redesign things and choose materials that do the job at reasonable cost without a lot of high tech or nonexistant methods.

As I explained before heatstaking can be done in the home shop with a soldering iron. A pin on one part passes through a hole in the other, the pin projecting past the surface of the hole part. A soldering iron is used to melt the head of the pin, forming it like a rivet. JD

[John Smith 47Participant @johnsmith47]

Jeff – to get clear when you talk of "soldering iron" are you referring to a normal soldering iron for use with electrical solder (which I have) or a special version designed for use with plastics (which I do not have)?

[Jeff DaymanParticipant @jeffdayman43397]

normal iron at lowest heat setting JD

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