I hope this is the right place to ask this question. Apologies if it is not.
I am embarking on a new large 00 model with a medium-size 009 section (probably about 6 or 7 metres of 009 track in total). When modelling in HO and 00 in the past I've avoided building in resin as I find it so hard to glue reliably but so many of the available kits in 009 are 3D printed resin that I am going to have to grasp the nettle. Various YouTubers recommend superglue but in the past I've found superglued resin joints very brittle. Is Epoxy the only answer? I'm sure it would work but its a bit of a faff - all that mixing for a tiny joint. Does Gorilla Superglue gel work? I would value any advice on what glue to use for resin kits.
I've used cyanoacrylate (super glue) on resin kits in the past without issue, though I've gotten on better with Paraloid B72 (https://www.google.co.uk/search?q=Paraloid+B72&sca_esv=601029419&source=hp&ei=wtqwZZCPDaiohbIPr5S8aA&iflsig=ANes7DEAAAAAZbDo0inY75eBVJjT6geZ6ssZdg5SBTwE&ved=0ahUKEwiQ-Pev3fWDAxUoVEEAHS8KDw0Q4dUDCA8&uact=5&oq=Paraloid+B72&gs_lp=Egdnd3Mtd2l6IgxQYXJhbG9pZCBCNzIyBRAAGIAEMgUQABiABDIFEAAYgAQyBRAAGIAEMgUQABiABDIFEAAYgAQyBRAAGIAEMgUQABiABDIFEAAYgAQyBRAAGIAESLRMUABY7DpwAHgAkAEAmAGmAaAB4waqAQQxMS4xuAEDyAEA-AEBwgILEAAYgAQYsQMYgwHCAg4QLhiABBixAxjHARjRA8ICDhAuGIAEGIoFGLEDGIMBwgIREC4YgAQYsQMYgwEYxwEY0QPCAggQABiABBixA8ICCxAuGIAEGLEDGIMBwgIOEC4YxwEYsQMY0QMYgATCAgUQLhiABMICDhAAGIAEGIoFGLEDGIMBwgIIEC4YgAQYsQPCAgsQABiABBiKBRiSA8ICDhAAGIAEGLEDGIMBGMkDwgIREC4YgAQYxwEYrwEYmAUYmQXCAgcQABiABBgK&sclient=gws-wiz). That's a somewhat esoteric adhesive, being an archeological conservation adhesive (a Ethyl Methacrylate Copolymer resin dissolved in acetone) that my wife put me onto, but a quick google search suggests one can buy a pre-mixed version (I'd suggest the 10% solution). I've also used Paraloid B67 (https://www.google.co.uk/search?q=Paraloid+B67&sca_esv=601029419&ei=zdqwZaqVJfzYhbIPhbekyAQ&ved=0ahUKEwjqr6-13fWDAxV8bEEAHYUbCUkQ4dUDCBA&uact=5&oq=Paraloid+B67&gs_lp=Egxnd3Mtd2l6LXNlcnAiDFBhcmFsb2lkIEI2NzILEAAYgAQYigUYkQIyBRAAGIAEMgUQABiABDIGEAAYFhgeMgYQABgWGB4yBhAAGBYYHjILEAAYgAQYigUYhgMyCxAAGIAEGIoFGIYDSL0XUK8FWJ4PcAF4AZABAJgBYaABrgKqAQE0uAEDyAEA-AEBwgIKEAAYRxjWBBiwA8ICDRAAGIAEGIoFGEMYsAPCAgoQABiABBiKBRhD4gMEGAAgQYgGAZAGCg&sclient=gws-wiz-serp), which is a similar resin that is dissolved in white spirit, and may be better as white spirit is probably easier to get hold of for thinning / revitalising the adhesive if it dries out in the bottle than acetone.
Both dry (set) quite slowly - minutes as the solvent evaporates against the seconds for superglue - to allow for some adjustment in the joint, and can be undone using the solvent (acetone / white spirit) to dissolve the adhesive in the joint.
I imagine that the Gorilla Superglue Gel is much the same as any of the other superglue formulations (all cyanoacrylate) so should do the job as well as any other.
I wonder if the brittleness problem you are experiencing might be more to do with the material than the adhesive. In my experience resin, and particularly resin 3d prints, can be quite brittle in themselves - as attested by my annoyance at all the work the designer had put in to that fine cab detail that ends up getting snapped off just from handling the model to paint it and I end up replacing with bits of brass wire, etchings and castings!
If your past experience was with cast resin kits then the issue may have been due to residues of mould release agent on the resin surface, as this would play havoc with any adhesive used to join the parts. The way around that is to give things a gentle wash and scrub up with an old toothbrush, but be wary of doing so with 3d prints as some of the resins used can soften in water (especially hot water, or a combination of wet and heat - washing then drying on a radiator for example) so it may be best to consult the manufacturer for guidance on how best to prepare the prints for building / painting.
Hope that helps...
Julien is an acknowledged expert on this sort of thing, however to keep it very simple as an alternative suggestion, my own experience (much more limited than Julien's!) is, for this sort of application as well as white metal kits, is to use De Luxe Materials Roket Gel, code Ad69, cost £8.69 from the manufacturer, which can be obtained in 20mg tubes, has a very long shelf life, sets quickly but not as instant as liquid superglue - around 20 to 30 seconds does it so there is room for manoevre but no need to set up clamps and whatnot. As it is a gel it also has filling qualities that don't exist with liquid superglue.
You mentioned Gorilla gel. I may have been unlucky, but my experience is that it comes in a plastic bottle rather than a tube and is difficult to (a) due to its thickness squeeze it out of the nozzle and (b) very difficult to unblock the nozzle after the first usage.
Mick
I agree with all that is said and can only add that some Shapeways prints use a waxy scaffold material that needs to be removed as with cast resin mould release agent.
Another thing is that some glues are not particularly good gap fillers and a weak or brittle joint can be one with a thick glue layer. Of course there are exceptions and there appear to be resilient glues that provide a buffer. Also, superglue is not very shock resistant so bits that stick out can get knocked off if they don't break.
Something I have not tried, but the Internet AI advertising sometimes thinks I should, is UV curable resin glues. It is maybe naive of me but it would seem to be a good match for 3D printed parts, essentially welding on more of the same perhaps? I don't know how strong or neat a joint they would make, but dentists seem to use something similar so I guess it is strong.
Quote from: GraemeD on January 24, 2024, 12:31<snipped>
Something I have not tried, but the Internet AI advertising sometimes thinks I should, is UV curable resin glues. It is maybe naive of me but it would seem to be a good match for 3D printed parts, essentially welding on more of the same perhaps? I don't know how strong or neat a joint they would make, but dentists seem to use something similar so I guess it is strong.
I've not tried them myself but have heard some good reports as it would allow for the joint to be adjusted before the light is shone onto the joint to cure the adhesive. The only drawback I can see though is that the adhesive needs UV exposure to cure and the curing reaction may not propagate where the light can't get to the joint, and my concern is how well the light would penetrate the joint in a non transparent object, particularly if the joint was deep...
Quote from: JulienW on January 24, 2024, 19:57Quote from: GraemeD on January 24, 2024, 12:31<snipped>
Something I have not tried, but the Internet AI advertising sometimes thinks I should, is UV curable resin glues. It is maybe naive of me but it would seem to be a good match for 3D printed parts, essentially welding on more of the same perhaps? I don't know how strong or neat a joint they would make, but dentists seem to use something similar so I guess it is strong.
I've not tried them myself but have heard some good reports as it would allow for the joint to be adjusted before the light is shone onto the joint to cure the adhesive. The only drawback I can see though is that the adhesive needs UV exposure to cure and the curing reaction may not propagate where the light can't get to the joint, and my concern is how well the light would penetrate the joint in a non transparent object, particularly if the joint was deep...
Dentists use a (blue) light-setting adhesive to fix things (like crowns etc that are opaque) - I believe it works by the light starting a chain reaction in the adhesive layer that propagates into the adhesive film.
Good grief, we seem to be moving on apace from balsa cement vs Croid and Durofix don't we!
I use Loctite super glue precision max in 10g bottles on vertualy everything apart from plastic window glazing, for that I use Humbrol clear-fix.
Quote from: hughn on January 24, 2024, 20:25Dentists use a (blue) light-setting adhesive to fix things (like crowns etc that are opaque) - I believe it works by the light starting a chain reaction in the adhesive layer that propagates into the adhesive film.
Thanks, I never thought to check and instead just went by the general Internet advertising lies. Blue rather than UV makes more sense for shining in someone's mouth or waving a pen about on a hobby bench. I didn't know. The dentist always puts darkened eye protection on me and I generally have my eyes closed too! A bit of digging and it seems as if the LEDs only just squeak into UV aby a few nanometres off the end of the visible with most being a deep blue.
Bluewave (https://dymax.com/resources/news-and-media/blog/uv-led-curing/understanding-the-differences-in-led-uv-and-broad-spectrum-curing-wavelengths#:~:text=LED%20Curing,-LED%20(Light%2DEmitting&text=The%20wavelength%20distribution%20from%20a,the%20selection%20of%20the%20LED.)
It seems the acrylic nail curing LEDs are the same (and safer than fluorescent UV lamps - as well as being faster apparently).
Nail curing (https://www.cncinternational.eu/news/how-safe-are-uv-nail-lamps/#:~:text=The%20emission%20spectrum%20of%20the,in%20some%20cases%20even%20longer.&text=LED%20lamps%20have%20an%20emission,a%20peak%20emission%20at%20385nm.)
Quote from: hughn on January 24, 2024, 20:25Dentists use a (blue) light-setting adhesive to fix things (like crowns etc that are opaque) - I believe it works by the light starting a chain reaction in the adhesive layer that propagates into the adhesive film.
That's the key Hugh. If the curing reaction propagates through the adhesive once initiated by the light then all should be good.
Thanks so much to everyone who responded. I'm not used to such quick and expert responses to my posts on other modelling forums! Fantastic. I'm going to start with Julien's suggestion of paraloid B72. I always have plenty of acetone to hand so that won't be a problem. I'll also bear all the other responses in mind. Thanks again, everyone.