Questions about styrene vs abs

[G3750]

All:

This is probably a stupid question, but I would like to know: how easy is it to glue abs plastic vs styrene? My understanding is that styrene parts are much easier to glue together than equivalent parts in ABS.

I'm about to order some Plastruct parts. Some of these structural shapes are available in both styrene and ABS. As rest of the structure will be in styrene, I'm wondering if I should avoid ABS if possible.

Also any thoughts on the relative merits of Plastruct Weldene, Plastruct Plastic Weld, or Ambroid Proweld for this purpose?

Thanks,

George

[Rufus T. Firefly]

how easy is it to glue abs plastic vs styrene?

If you are using the specified Plastruct solvent adhesive for this purpose, should be no problems

If not, then using MEK is what you can use for ABS-ABS or ABS-Styrene

My understanding is that styrene parts are much easier to glue together than equivalent parts in ABS.

Styrene-Styrene is generally easier, but with the correct solvent based adhesive to weld the plastics together, it's not a problem. Methylene Chloride (Tenax) will work fine for Styrene-Styrene

Just make sure that whatever you do, do not trap either solvent in a manner to prevent its evaporation or exit. It will find a way out otherwise.[/quote]

[G3750]

how easy is it to glue abs plastic vs styrene?

If you are using the specified Plastruct solvent adhesive for this purpose, should be no problems

If not, then using MEK is what you can use for ABS-ABS or ABS-Styrene

My understanding is that styrene parts are much easier to glue together than equivalent parts in ABS.

Styrene-Styrene is generally easier, but with the correct solvent based adhesive to weld the plastics together, it's not a problem. Methylene Chloride (Tenax) will work fine for Styrene-Styrene

Just make sure that whatever you do, do not trap either solvent in a manner to prevent its evaporation or exit. It will find a way out otherwise.

[/quote]


Thanks Rufus!

George

[chuck]

ABS doesn't do well with stuff like Texex/dichloromethane. It will weld with Acetone. Acetone will also weld Polystyrene but it's too "hot" for most PS plastics. It also evaporates as you are watching it. By the time you get enough Acetone to actually melt the PS it tends to melt it completely.

Your best bet to attach ABS to PS is crazy glue.

BTW, there are other solvents that will melt both of these plastics but they are much more toxic/hazardous. Even if you get both to melt there is no guarantee that they will actually "weld". You just may wind up with puddles of goo in close proximity to each other.

[Rufus T. Firefly]

Acetone actually boils at a higher temp than methylene chloride (Tenax) and is quite flammable as well. The density of methylene chloride tends to limit inhalation as well. It works well for styrene.

ABS is a PITA, but MEK does work well with it. Several issues back in OST I reviewed a gondola kit that was an ABS kit - spectacularly detailed kit but needed MEK to assemble it. Hate the smell of MEK and it's quite flammable, and a bit of an inhalation hazard.

Trick to applying solvents for stuff is to use a moderate sized brush that you can either toss or dedicate purely to this purpose; just dip and brush on just enough to get the plastics to "weld". Stop there and gently evaporate the solvent by exhaling on it.

If you were nearby, George, I'd give you a bit of both to test and "play" with a bit.

CA is a maybe with ABS depending on what formulation of ABS it is; CA does not work for many plastics - some of the Grandt Line detail parts that are not styrene simply will not be bound to anything with CA.

[chuck]

Ruling pen works well (assuming you can find one) for applying these water like solvents. You won't need to worry about it melting or having to toss it afterwards.

MEK is pretty nasty. It does smell bad and it is very volatile as well as very flammable. Minimum immediate health effect is headaches and it gets very bad, very fast from that point on. A well ventilated space would be "outdoors".

[webenda]

Do you need more answers, George?

2 part epoxy.

Reference: http://www.permabond.com/materials_bond ... -bond-abs/
http://www.permabond.com/2015/07/22/bon ... lonitrile/

Why do I like epoxy? I am too clumsy for thin solvents that weld plastics together. Epoxy just sits there, does not destroy my model by running like water down the sides of the car or structure when welding by capillary action. No need to rush, epoxy does not evaporate before you can get the parts together nor does it bond before you can get the parts aligned. Epoxy does not need a perfect joint either, small gaps get bridged with epoxy.

[chuck]

I've used 5 minute expoxy's when it was more appropriate for the project. One cautionary note, some epoxies generate heat when they cure and some need some heat to cure (later is only an issue when the ambient temps are actually below 50-60 degrees). The exothermic stuff can melt or soften things if the objects involved are small, really should not be used on plastic to plastic if there is no way for heat to be released.

Non flammable contact cement. Expensive but the solvents involved are less likely to melt plastic. Good for applying facing materials

LockTite PowerGrab. Construction adhesive, can be found in smaller packaging, aka toothpaste tube size. Has about 35-45 second working time.

3M F77 Sprayment May not be suitable for think plastic as the solvent is pretty aggressive. Can be applied to opposite surface and used as a contact cement. Nice for applying "facing" materials, aka broad surfaces with a lot of contact.

Most urethane based adhesives. These tend to be extremely sticky and will bond to almost anything (a few "slippery" plastics are the main exception). Work time varies but cleanup is usually an issue. You can toss the applicator and you really, really, really need to make sure it doesn't go anyplace you don't want it to because it's probably not coming up unless you act immediately.

[G3750]

ABS doesn't do well with stuff like Texex/dichloromethane. It will weld with Acetone. Acetone will also weld Polystyrene but it's too "hot" for most PS plastics. It also evaporates as you are watching it. By the time you get enough Acetone to actually melt the PS it tends to melt it completely.

Your best bet to attach ABS to PS is crazy glue.

BTW, there are other solvents that will melt both of these plastics but they are much more toxic/hazardous. Even if you get both to melt there is no guarantee that they will actually "weld". You just may wind up with puddles of goo in close proximity to each other.

I re-evaluated the strength requirements of the model. Each roof truss will be 28" long; I'm thinking ABS for it for the sake of rigidity and strength.

I must confess that I've never had any success with Crazy Glue. It's too fast and no matter how much care I exercise, all I end up gluing together is my fingers. I've really come to hate the stuff.

I've had a lot of success with E-6000. It's slow enough to allow me to get things positioned correctly and it seems to hold.

George

[G3750]

Do you need more answers, George?

2 part epoxy.

Reference: http://www.permabond.com/materials_bond ... -bond-abs/
http://www.permabond.com/2015/07/22/bon ... lonitrile/

Why do I like epoxy? I am too clumsy for thin solvents that weld plastics together. Epoxy just sits there, does not destroy my model by running like water down the sides of the car or structure when welding by capillary action. No need to rush, epoxy does not evaporate before you can get the parts together nor does it bond before you can get the parts aligned. Epoxy does not need a perfect joint either, small gaps get bridged with epoxy.

Thanks Wayne! Very informative.

George

[G3750]

I've used 5 minute expoxy's when it was more appropriate for the project. One cautionary note, some epoxies generate heat when they cure and some need some heat to cure (later is only an issue when the ambient temps are actually below 50-60 degrees). The exothermic stuff can melt or soften things if the objects involved are small, really should not be used on plastic to plastic if there is no way for heat to be released.

Non flammable contact cement. Expensive but the solvents involved are less likely to melt plastic. Good for applying facing materials

LockTite PowerGrab. Construction adhesive, can be found in smaller packaging, aka toothpaste tube size. Has about 35-45 second working time.

3M F77 Sprayment May not be suitable for think plastic as the solvent is pretty aggressive. Can be applied to opposite surface and used as a contact cement. Nice for applying "facing" materials, aka broad surfaces with a lot of contact.

Most urethane based adhesives. These tend to be extremely sticky and will bond to almost anything (a few "slippery" plastics are the main exception). Work time varies but cleanup is usually an issue. You can toss the applicator and you really, really, really need to make sure it doesn't go anyplace you don't want it to because it's probably not coming up unless you act immediately.

Very useful information as well, Chuck. Thanks!

[G3750]

Ruling pen works well (assuming you can find one) for applying these water like solvents. You won't need to worry about it melting or having to toss it afterwards.

MEK is pretty nasty. It does smell bad and it is very volatile as well as very flammable. Minimum immediate health effect is headaches and it gets very bad, very fast from that point on. A well ventilated space would be "outdoors".

Chuck, what is a "ruling pen"?

George

[Roy]

George, please tell us about the E-6000.

When I've worked with high-impact styrene, abs and other thermoplastics, acetone seems to evaporate too quickly. I can't recommend it. MEK works much better, but you need to provide lots of ventilation. Try not to breathe it at all, if possible.

[Roy]

Is it possible to get the epoxy manufacturers use to build jetliners?

[chuck]

Ruling pen is a draftsman tool. Handle with a pen nib that's adjustable width at the point. On phone so I can't pull up a picture.