Well, I wouldn’t call it blind trust. I posted it so that others who may know can also vet it.
I occasionally use glue, but not enough to pursue this topic all the way through to justified true belief. It’s cheaper for me to occasionally buy the rip-off loctite solution and call it a day, because freshness also counts. On the other hand, if you’re a heavy glue user, you have more reason than I do. This is just my small contribution to the collective effort, for whatever it’s worth.
Really? I did not know that. I’m going to have to try that out.
Yep. Sure would. Sure would.
It looks like heptane is used as a carrier.
If you want to glue PLA together and have it stay together you want to use a solvent called methylene chloride. This is found in most paint strippers. This solvent will allow the two components of PLA to bond together, and is way stronger than the bond that glues will give you.
The biggest issue that you will have is that it is paint stripper, and it is bought in large amounts (minimum I could get was a litre, so you will have a lifetime supply of it.
If pla cannot be bonded together then our models would fall apart, we just need to find a way to use a heat bond.
@BillByrd did you ever find your perfect PLA glue?
I’m reading this thread intently because I’d live to find the perfect solution.
My first thought was plastic model cement. I built a ton of models growing up but after trying it I assumed that the FDA nerfed it, but that may not be the case.
I concurred that plastic model cars and buildings must be made out of injection modeled (some other) plastic.
I also see that a lot of the solutions mentioned here would be considered toxic, and most of my High School glue sniffing friends (yes I just dated myself), would have loved them.
And I almost coughed my coffee across the room hearing your grenade story, because I too mixed up baking soda but I used vinegar. It explodes way better but you better get rid of it fast.
That said never, never mix liquid nitrogen and water. I have an associate that is missing muscles in his hand.
Sorry, back to glues. Have you seen this study?
I’d be interested if anyone else found the perfect answer.
I’m using plain super glue but I usually add pins and holes if I want a part to fit snugly.
What is the active ingredient? Perhaps it is more widely available outside of germany as the generic than as the brand name.
This was a very old thread revived btw…
The chemical in pla prevents most glues from sticking. Same logic as to why they sell glue in a plastic bottle - certain glue just doesn’t stick to certain things.
For pla the surface MUST be scuffed and the glue must be pure Cyanoacrylate.
The end.
You can stop your glue searching.
Both are press to hold 10 seconds and you are done. hold 30 sec if you F’d up and put too much glue. (All skin is considered lost if this touches it fyi. Don’t let it…touch any skin you value because it will rip off…)
I’ve used this 1st link (cyafixed) for over a decade now 0 problems all the monster hunter swords I just posted were glued with this. This is my workshop superglue for 99% of most things.
The second link cameo I recently got for testing and it’s also working very very well with much bigger bottles and applicators for the price. I am still testing this :
Mini edit : just battery tested this on multiple scrap pieces to see. Very liquid, don’t need a lot, scuff first no problems across all filaments from silk to petg. I don’t have abs to try but should be ok.
I like this brand as well now even though it’s new because of the massive 2 bottle vs price.
Can confirm a 2nd brand that works here.
Part of what you said reminded me of an old joke. Joe said “I’m going to invent an acid that will dissolve anything on earth.” Then Jim said "Whatcha gonna keep it in?
I started this thread back when. You seem to be saying that CA is the way to go as long as it’s pure CA. I’ve always assumed that every label gets their CA out of the same barrel so to speak. And if that were true, they’d all be pure CA or none of them would be.
So my question to you is How do you know which ones are pure CA and which ones aren’t? And if some of them aren’t, what’s in them that makes them less than pure CA?
If you are insisting on using CA try this one:
Otherwise just use what everyone else uses:
Done, solved, thread closed.
Lol Bill here.
Trash in this one, not pure, doesn’t hold sh*t in the printed world. Baby mucus bonds pla more 
The above in my original I posted (both) are pure, there is only 1 ingredient on the label. Cyanoacrylate.
Mugg - I agree on the cra in the link above, but your 2nd link is for contact cement basically lol. That will bond anything so kinda cheating haha but ya, if you want stinky but works yes…any contact cement will bond most prints.
Just go no additive CA. That’s what we basically discovered as why not all working - some are additive.
Edit: added small test comments to my above post.
Hadn’t though of baby mucus. I was a respiratory therapist and sucked out a lot of mucus, baby and otherwise. I have a new great granddaughter. I may try that first. 
Thanks for the tip. I’ll be looking at labels.
if they ever have it in stock and shipping wasn’t overpriced
I recently had to perform a dodgy fix at work to bridge the time for the plumber to arrive.
The beauty of long weekends I guess.
Anyway,…
With not really many stores open I had to use some petty cash and a paint supply shop.
They suggested I shall use a sealant from T-Rex and so I did…
What a nightmare!!!
Looks like clear silicone but the stuff literally sticks to everything, especially things you don’t want it on, like your hands LOL
Turns out reading the instructions would have helped as it said to use oil, not water to smooth out things if required.
I only had to stop a cracked drain pipe from leaking that day but could not resist to try the remaining stuff on some printed plastics.
A printed bolt with a light smear of the stuff on it means you won’t move the nut once set, you break the plastic.
Tried a simple soap holder on a spare tile and let it cure for 2 days - I broke the dish but not the glue.
PETG on PLA ? Why not, the sealant does not care and just bonds strongly.
On smooth PETG (like the side printed on a hole plate) the bond is not ultimate and does come off the PETG with enough BRUTE force.
It is not the easiest to work with as you have to forget all you learned about working with silicone caulk first but I have to say it seems to be one of the few products where the advertisement is actually factual.
It even bonds to wet stuff and under water - might be nice for a long trip on rocky shores with that tinny …
Here are the obvious downsides I noticed >
Price - the stuff costs far more than other solutions. I paid $16AU for it and that was on special.
Handling - unless you release the pressure it will ooze out badly so don’t put it on something you don’t want to mess up. Put some old newspaper under…
Cleaning - near impossible as it sticks to everything like mad.
Use tape to cover areas and where that does not work sacrifice some old cloth or scrubbing sponge.
A slight smear of oil, any oil, will prevent the stuff from bonding- use this where required 
Smoothing out only really works with oil or if happen to have a teflon scraper.
It would be interesting to know how well it works with a typical PLA joint as that’s what most of us use most of the time. To get my approval it would mean two different colors of PLA joined together and when ripped apart both pieces would bear remnants of the opposite color. I hope that makes sense.
I will print some bars or such and glue them with the remains I have at work next week.
But from my tests I am quite sure the bond strength of this T-Rex stuff will be at least on par with the printed PLA.
So what is your desire here?
No! not that desire Bill…
I mean in terms of layer arrangement…
I guess some equal cubes glued together will suffice here?
Will have to check though if I still have some plain PLA somewhere.
Currently using matte and translucent and I know on the matte PLA the bond is really strong thanks to the ‘rough’ surface.
I struggle a bit with your requirements for approval though as during my test it was the part that failed not the glued area - so no remnants as the joint was not affected.
Not sure if I can make it fail at the joint but will try…
Yes, I’ve not been clear as to what I call a satisfactory bond. In the fifties when I was growing up and sniffing hadn’t yet become a thing, I would buy plastic models and put them together with the glue available at the time for such models. Once you glued the wing to an airplane, you weren’t getting it back off without breaking it. I guess that’s what I would like to see. But-- that’s really a ‘weld’ instead of a simple adhesion and it probably ain’t gonna happen in my lifetime.
Have you tried this?
No I haven’t. I’ll probably give it a try. Testors has been around forever. Thanks.
