Gluing PLA Plastic

[popi1854 1]

A scientifically tested choice. Just another opinion,  but a good one.  

OzS

so...I watched your video and ran out to buy the Loctite Ultra Gel. I put it on a test piece and held it together for 1 minute, then let it sit undisturbed for 5 minutes - total negative bond. Total waste of time and money. Maybe you have a different kind of PLA than what I have?

[drofnas 15]

 

 

A scientifically tested choice. Just another opinion,  but a good one.  

OzS

 

so...I watched your video and ran out to buy the Loctite Ultra Gel. I put it on a test piece and held it together for 1 minute, then let it sit undisturbed for 5 minutes - total negative bond. Total waste of time and money. Maybe you have a different kind of PLA than what I have?

 

I'm curious if you are prepping the surfaces before gluing them together? Do you have an example of what you were trying to glue?

Since I've had great results with CA glue, but I also let it sit overnight, since I assume the manufacturer is lying to me when it says "fully cured in X hours". I pre-sand all surfaces I plan on glueing, usually with 180-220 grit sand paper, and so far I've had 0 issues.

[gr5 2,172]

I pre-sand all surfaces I plan on glueing, usually with 180-220 grit sand paper

Ah! I suspect this is the secret sauce. Sanding creates a rougher surface hence more surface area to stick to.

[killjoy 0]

Plastic Weld is my favorite. Dries in less then 10 seconds and holds on strong. It creates a chemical reaction so your not left with any crease.

[gr5 2,172]

 

@killjoy have you tried this on PLA? Or something else?

[geert_2 557]

For me standard Loctite Cyanoacrylate glue "Super Glue-3" works well.

They also sell a special version of this glue with an activator for plastics: wipe over the plastic with the activator (=a sort of felt pen like a fluo-marker, but colorless), let that dry for one minute, then glue as usual and let it cure. But be fast to bring parts together, because the activator also speeds up the curing.

I found this in the Delhaize supermarket, among the paper, pens, and other school stuff: "Loctite, super glue-3, All plastics".

Of course, grinding may also help, due to the increased contact surface. But do not grind too rough: cyanoacrylate bonds are strongest when the glue layer is as thin as possible (ideally only a few molecules).

[killjoy 0]

@killjoy have you tried this on PLA?  Or something else?

gr5 this works great with PLA and ABS. Been using it for years now,

[rowiac 53]

Aha!  Plastruct Plastic Weld has MEK in it.  That's why it works so good!

Edited September 8, 2016 by Guest

[Labern 774]

Weld-on acrylic glue is awesome. Melts the surface of pla and bonds within seconds so no prep work required. Helps if you rub the parts together while glue is still wet to help dissolve the layer a bit for stronger bond.

I have used other acrylic glues and they work just as well.

[loganpettit 0]

Did you ever complete this project? If so, how did it go?

[kmanstudios 1,120]

I have used good old fashioned Testors modeling glue as well as some of the others mentioned.

It is a welding agent, but can be messy if you are not used to it. Not a fast dry though. No burns or other issues so far. Even worked with Ultimaker nylon

But, types of PLA, environment and other issues can cause any glue to fail. Prep is everything.

Edited April 21, 2017 by Guest

[designsoul 18]

I recommend a 3d printer pen to seal PLA, however I haven't found one that can work with 3.0 mm filament.

You can also heat friction weld PLA with a good multitool.

CA glue doesn't work.

For improving mechanical bonds on larger parts (I do robot parts) you can drill holes and friction fit simple wooden dowels, this is very strong.

[randyinla 14]

I recommend a 3d printer pen to seal PLA, however I haven't found one that can work with 3.0 mm filament.

 

The 3Doodler "Create" & "Pro" work only with 3mm filament

[LePaul 321]

I've used Testor's Model glue in the past...it's so, so stringy tho, so clean up is important.

[kmanstudios 1,120]

I've used Testor's Model glue in the past...it's so, so stringy tho, so clean up is important.

 

I think I am just used to Testors because of all the models I have put together. I like that it bonds the plastics together. ABS really does well with it as it is a styrene much like in model kits. And for some reason, I really cannot get Superglue type of CA to work worth a flip. I know it is me, but I just cannot get it to work.

I am going to be trying something in combination with Testors soon if I can just get one part to print correctly. I have literally burned up a full spool trying to get the heat and such right for no warping.....sigh....And they are long prints just to find an issue. PLA no less!

If it works out, I will be posting with pics soon, but I gotta get this part out right before I release the model. Do not want to release a model that I cannot print.

If I can print it, anybody can.

[ericjforman 0]

HI all, this thread is a bit old but it seems some knowledgeable posts here. I am curious if any of you have recommendations for adhesives for PLA not to itself, but to wood, and specifically for Tough PLA (I'm not sure if the new formulation makes any difference for bonding). I posted a question about it a few weeks ago, but no responses, so I'm widening the net. You can see the full post here, and thanks in advance - 

 

 

[kmanstudios 1,120]

I did not see that post. Sorry. But for TPLA, this is what I have found works best for me. And it will glue anything to the plastic as long as it is dry. But, you have to work really fast.

And, this is specific. Not the clear, or any other, but this cream, plastic welder.'

[cloakfiend 995]

I find pretty much most contact glues should also work. But they have temperature limits.

[ericjforman 0]

Thank you! I'm replying to kman in the original post.

[Adrunodro 0]

I'm using PVC glue too, the one that is used for  piping. It's 2$ and the adhesion is very strong and more flexible than cyano I think. The only problem is that it takes some hours to be ready to use so you need to hold both part in position for some time, which could a pain for small parts

Edited September 25, 2018 by Adrunodro

[cloakfiend 995]

For PLA to PLA, Cynao and accelerant is my saviour. I love accelerant almost as much as acetone!

[Laszlo 0]

I've had great luck with broad surfaces and cloth using Scotch brand "Super 77". It seems to stick to...EVERYTHING!!

 

It starts out instantly crazy-tacky! The tacky lasts quite a while, I've heard the suggestion of applying to both surfaces, waiting 15 minutes for the tacky to start curing, then apply them. But honestly, I've had great success applying with just one side and only 1-3 minutes wait. So there is lots of leeway.

 

It seems to be perfectly soluble with your regular ol' Ronsonol Lighter Fluid, which doesn't seem to affect the PLA at all.

 

Spray sparingly on the surface you want to stick to everything, then use a tiny cotton scrap with some lighter fluid on it to clean up.

 

It doesn't harden to concrete, at least in in the short-term. So cyanoacrylate might be better for stick-real-hard-right-now applications. But I absolutely swear by this stuff! It's awesome.

 

e.g. Scotch Super 77 Multipurpose Adhesive Spray $11 You'll never finish a can! 🙂