Plastics Glue / Welding: Whats Your Experience?

Community
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Have you ever worked with any solvents or welding compounds that contained NitroMethane? Have you ever used Undo 6020? Have you also used other super glue removers on super glue, and how would you say they compare? What is your experience with surfacing and welding plastics with solvents, like Xtanar, Acetone or Alcohol?

Honestly I am not even sure if I have been working with NitroMethane or some other compound left over. But I would like to know what the community thinks. If NitroMethane is in fact not the effective solvent compound, then what is, and what other products might have the same stuff?

Story:

I stumbled upon a chemical sold as Super Glue remover, sold by CyberBond. Undo 6020. This particular container has literal drops left in it. It was marketed to remove a blend of cyanoacrylate marketed as Apollo. [My employer had been looking to see if it would bond HPDE. No one can convince my coworkers that NOTHING bonds HDPE. Though I have found that Re-position-able adhesive sprays work wonders, even as a base coat, but they MUST be the reposition able (cannot dry, cannot get hard).] The remover has little to no odor, maybe a little musty. One might think the stuff had long since deactivated. But a few drops on any super glue creates a jelly that can be removed easily in seconds. Let the glue sit and it will harden again.

Thinking about it’s behavior on super glue, I wondered if it would behave the same on other materials. Like a scratched Multimeter lens. And it did, similar to having exposed it to Alcohol or good off, but without the white residue. Several drops were enough to soften the entire surface. After several days it was completely hard again.

Wondering what effect it might have on non acrylic compounds I moistened the ends of some broken mounting points inside a old retractable ruler. I will guess the material was ABS. The ends softened and welded back together. I left then to sit over night and by morning they were solid, like new solid. Even the really powerful stuff like Xtanar wasn’t that good, assuming because it breaks down too much.

I looked to see if I could learn anything about the stuff. Apparently its regarded to be extremely flammable. It’s supposed to contain a compound called NitroMethane, also marketed as RC racing fuel? A new 2oz bottle cost more than 30, but a whole Litter of Actual Nitro Methane from a hobby shop costs less than 30. So the prices do not math up even remotely. Also given its age, and that the bottle has never expanded or gassed out, I suspect the NitroMethane left town a long time ago. Meaning I have no idea what the actual effective compound really is.

Background:

I have used many kinds of glue and adhesives. Most were over the counter. JB weld, Super Glue, Elmer’s, Silicone, etc. I have also done potting with several epoxy compounds from several chemical companies.

By far the most potent stuff I ever used Xtanar and another similar I think Xtanar replaced were these small clear liquids that contained some solvent combos that melted pretty much anything, had a strong smell, cold on skin and burned like crazy when washed. It surfaced and welded pretty much everything. Drawbacks were it evaporated crazy fast outside the bottle, and took days to fully cure any exposed plastic.

I also know Alcohol, Goof off, Paint thinner, and Acetone also make good plastics welders. Depending on the combo this creates a residue that must be removed and can take several days to cure

Most of the time these days I will opt to actually weld the plastic with hot air and soldering pen, even add more plastic if available match. Re-drill holes if needed. This in general gives me the best control. Though a wash in solvent can aid in getting a good gloss shine if desired.

This is a market ready solvent that uses NitroMethane
https://www.hisco.com/Catalog/Chemicals-Cleaning-Supplies/Chemicals/Cleaning-Solvents/135542-30769#asr

This is one of the Chemicals that I think I recall being listed on the bottle of Xtanar. A little splatter is harmless, but spill this on yourself and its a nasty chemical burn. Dont use water to clean up.

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I have little knowledge about glues but I have successfully used acetone slurry to glue ABS
details here : How To Make ABS Juice, Glue, and Slurry | MatterHackers

A glue that I particularly love is B7000. Made and sold cheap in China it is very powerful and not brittle. It glues everything on everything but not Polystyrene. (It glues EPP).
https://fr.aliexpress.com/item/1005003653423730.html?spm=a2g0o.productlist.main.1.1b5f3ab29ma9Al&algo_pvid=ee959260-6ac0-4ac7-a6f6-79a483b52bc5&aem_p4p_detail=2024022109334316214134163780680000608471&algo_exp_id=ee959260-6ac0-4ac7-a6f6-79a483b52bc5-0&pdp_npi=4%40dis!EUR!2.85!2.28!!!21.65!17.32!%402136675517085368234103280ed588!12000031131454468!sea!FR!704525008!&curPageLogUid=OOrqGySwLZ7s&utparam-url=scene%3Asearch|query_from%3A&search_p4p_id=2024022109334316214134163780680000608471_1

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Usually I just look up what:

suggests and source and use that.

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I’ve also stir-welded ABS by chucking short sections of ABS filament in my dremel and running it along a crack. I did that successfully for a freezer basket, but then months later chickened out and also covered it with a good thick layer of ABS slurry for more strength. It seems to be doing well.

Thank you for introducing me to the fact that nitromethane is a good superglue solvent. With that information, I discovered that yes, lots of people buy the fuel specifically for dissolving superglue. I am interested in getting away from the smell of acetone, and this is a way.

I see that a lot of RC fuel is 15% nitromethane, but you can buy 99.9% nitromethane. $60/qt delivered here; shipping is expensive because hazardous material transport I guess, and the closest I find it is an hour and a half drive away from where I live. Is what you are finding pure nitromethane, or is it an alcohol/nitromethane mix? Maybe it doesn’t matter?

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It’s that so far despite my experience with many plastics and solvents, my exposure to UNDO 6020 and NitroMethane is very limited. And given it’s age, there is an uncertainty as to just what is in the bottle. If nitro methane can evaporate, then what is left? I hoped those with more experience with the chemicals might chime in.

My worry is that fresh genuine NitroMethane might be more dangerous than Xtanar. Meanwhile the old Undo6020 is very stable and seems to be as nonreactive as water.

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Sometimes glue is the only acceptable method for part assembly . . . such as bonding a plastic slip joint plumbing fitting.
Although, for some projects a strong double sided tape can be a useful alternative.
3M brand UHB (Ultra High Bond) is an amazing product and can be used to assemble lots of plastic materials.

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Its been a few weeks, I know. Work has been hectic. Gears are shifting, and should be able to start ordering a few materials to test.

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Could not easily locate. Google is saturated with references to 3M VHB tape. No solvents or glue.

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Sorry
VHB tape is correct not UHB

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:+1: for that!
The laser module in my laser engraver is stuck to the z-slider with double-sided carpet tape (a good brand)… this is a stopgap measure I never needed to ‘fix’.

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Big Clive (of YouTube fame) recently posted this:

Surprisingly positieve demo and tear down of a tool to heat and embed metal staples in plastic.

Looks useful, I can think of a load of times I could have used one, even just as reinforcement for a glue repair.

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Not bad but in these cases I generally just weld it directly with a hot soldering iron and then file smooth. Had to do that with a Magnifier that included a UV lamp and the the whole thing seems to be made of PLA so the weight of the glass lens is gradually breaking the plastic. I took the time to poke through the plastic all the way around every single crack and now it’s steady again. Though it looks like a Frankenstein project with the scars outlined in a darker shade, given the whole thing is egg shell white, or beige.

Still I suppose there could be times when a device like this would be very helpful as it embeds a disposable wire.

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Splurged on a fresh bottle of UNDO 6020.

I have 29 various rolls of thermo plastic.
Of those PETG+, ABS, Opaque PETG, HD PETG and a no name blend of TPU called natural eflexable all reacted. ABS and ASA having the strongest reaction. The eflex did not bond but did soften slightly.

I also tested Transparent PETG, TPE, Nylon, PLA, and TGH. These did not react at all. Oddly the PETG reaction was not expected and that some PETG reacted and others did not is a prime example of why a maker should NEVER ever assume that two spools of the same material are the same unless they are the same color, same batch and same MFG.

Not sure the material the soda bottle caps are, the bottles are PETE, and I suspect the caps are HDPE. No effect on either one. Pretty sure the material of the storage bottle is also HDPE, as are many chemical resistant containers unless they are PP.

Without question this solvent will dissolve and weld Acrylic. However note in large quantities, if Acrylic is not dried extremely slow, it may warp, and blister. This makes it suitable for very limited surfacing use and fixing cracks. But not for deliberate reworking of acrylic surfaces.

I will enter this data on my chart of materials. Maybe this post is good enough reason to create another chart that only refers to solvents and glues that work well with thermoplastics.

I have to date repaired a tape measurer body that looked like it had been run over by a truck. The internal screw posts were broken off. They welded clean and solid. I fixed the crushed body. It now support the tightly coiled tape without question. After and over night cure the device is fully usable again as normal. Also fixed a calipers that had the small plastic hook holding the metal adjustment wheel broken off twice. The last time it was fixed with super glue. This time I removed the glue and welded it. Good as new.

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I found this video interesting : https://www.youtube.com/watch?v=Oqh01j7ZG_s&t=2s

As a result I got some DMSO - it’s not the best, but it sounded adequate for bonding TPU sheet. However it didn’t work for me. I may experiment more. I bought Loctite too and it does stick fairly strongly but it’s a glue, not a solvent. The two chemicals he preferred appeared to need too much care in use for the production process I had in mind. DMSO isn’t great but DMF and THF are pretty bad. The Loctite 406 might work on HDPE.

I use Acetone for ABS (also plumbers pipe solvent which I think is an Acetone/ABS slurry) and Methylene Chloride which is available easily in the UK as Plastic Weld Cement 12x 57ml - Model Making Solvent.

I can’t find Undo6020 in UK suppliers but will try nitromethane.

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To the best I know the only chemical that will work on HDPE might be some insane substance that can dissolve a car with the driver inside. Probably nothing we want to mess with. I have seen references to an ultra sonic welder but dont have access to anything like that. Heat for sure is the one way to weld HDPE. I generally use a soldering iron, apply chips, and weld the crack closed before using a file to clean it up.

The down side of TPU is that saying TPU is a bit like saying Autistic. It’s an extremely broad category with more sub types than we can shake a stick at. I plead with the public and industry to please be more descriptive about the composition, where possible.

Thanks to your reply now looking up DMSO, DMF, THF, MC.

Undo6020 is hard to get any place so it’s not a surprise.
I looked for a moment and also don’t see any suppliers over sea.

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I have been working on this for a moment. This document is Solvents, Thermoplastics, and Resins.
-Wishing I could get more vendors and MFG on board. Guessing that wont happen. Every one likes to create their own thing and none want to create some thing that lets any one compare everything. So I will keep building at my own pace, but I am happy to have help if any are up to the task. The more data we can pack in the more useful it will become. Also, google can do nifty things like auto export to HTML, EXCEL or PDF as needed, which can be insanely useful.

Sheet is private as in I am currently the only editor.
Access is PUBLIC Any one should be able to access it.
If you want to contribute make sure you have a valid google account, I will consider adding editors so we can add more resins, filaments and solvents.

I would love to get some big guys like filaments.ca, MaterHackers, or Atomic Filaments on board. Maybe some chemical companies like BASF too. If you happen to have connections, please refer them!

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Found out that Methylene Chloride, or MC is actually Dichloromethane, and that stuff is exactly as nasty as I thought it is. There are materials it has no reaction to like HDPE and others that it easily effects.