Glue for 3D printed models

[Nutntooit]

I use Isopropal Alcohol works well for me.

Thanks for the tip I ran out of bsi so I gave isopropyl alcohol a try it it works just as good for a hole lot cheaper.
David

 

[JITSU_UK!]

I'm sure I read somewhere Acetone can be used as a bonding agent for PLA etc. I haven't tried it yet but will tonight!

I didn't know the Revell Plastic Adhesive worked but as I do model in plastic too it's handy to know.

 

[HobbitFertang]

Acetone is quite nasty stuff

 

[JITSU_UK!]

So I tried Acetone, Isopropyl, Revell modellers adhesive, Pipe weld and Plastic cement and all failed to stick pieces of PLA+ together. Some may have worked if they had been clamped together but that's not always an option, especially with small pieces so it looks like it's still Superglue for now.

 

[GAP]

So I tried Acetone, Isopropyl, Revell modellers adhesive, Pipe weld and Plastic cement and all failed to stick pieces of PLA+ together. Some may have worked if they had been clamped together but that's not always an option, especially with small pieces so it looks like it's still Superglue for now.

I use super glue gel and when it is place spray isopropal alcohol to get it to set fast it sometimes goes white is a brittle; a sprinkling of baking soda is better to speed up the process.
Lightly moistening both surfaces prior to gluing actually helps the adhesion as super glue is apparently water activated, the surfaces should be just damp not wringing wet.

Technical bit from google about baking soda ON;
Baking soda (sodium bicarbonate) speeds up super glue by acting as both a highly reactive alkaline catalyst that forces instant curing and a structural micro-filler that creates a rock-hard composite material. [1, 2]
Unlike water or isopropyl alcohol, which merely trigger the surface of the liquid, baking soda interacts with super glue on a deep physical and chemical level to create a massive chain reaction throughout the entire volume of the adhesive. [1, 2]

1. The Chemical Catalyst (The Alkaline Trigger)
Super glue contains built-in acidic stabilizers to keep the liquid monomers from linking up inside the tube. As established, it takes a weak base to neutralize these acids and start the curing process. [1, 2]

• Highly Basic: Baking soda is naturally alkaline (basic).
• Instant Neutralisation: When the liquid cyanoacrylate touches the baking soda powder, the alkaline molecules violently and instantly neutralize the acidic stabilizers. [1]
• Explosive Polymerisation: With the stabilizers completely wiped out, the cyanoacrylate monomers don't just link up—they polymerize almost explosively, turning from a liquid to a solid plastic in less than a second. [1]

2. The Physical Filler (Creating a Composite)
When you use a liquid like water or alcohol, the super glue simply turns into a standard, thin layer of acrylic plastic. Baking soda completely changes the physical makeup of the bond. [1]

• Micro-particles: Each tiny grain of baking soda acts as an anchor point.
• The Composite Effect: The liquid glue flows into the spaces between the baking soda grains, wrapping around them and locking them into place.
• The Result: Instead of just hardened glue, you get a plastic-matrix composite (similar to how fiberglass is made of resin and glass fibers, or concrete is made of cement and gravel). This compound is significantly harder, thicker, and more rigid than super glue alone. [1, 2, 3]

Why the Baking Soda Method is Unique
Because baking soda acts as a bulk filler, it solves the biggest limitation of super glue: the inability to gap-fill. Super glue normally requires perfectly flush surfaces to work. If you try to fill a crack or a missing chunk of material with regular super glue, the inside will stay liquid forever. By adding baking soda, you can fill large holes, rebuild broken plastic tabs, or create thick, structural fillets over joints. [1, 2, 3, 4]

How to Apply It
There are two primary ways to use this combination, depending on what you are fixing:

• The Layering Method (For Gap Filling): Fill a crack or hole with baking soda powder, blow away the excess so it is flush, and then drop thin super glue directly onto the powder. It will instantly wick through the powder and turn to solid plastic. You can repeat this layer-by-layer to build up a large area. [1, 2, 3, 4]
• The Top-Dress Method (For Joint Reinforcement): Apply your super glue to the joint, press the pieces together, and immediately sprinkle a pinch of baking soda over the exposed glue seeping out of the seam to lock it in place instantly.

The Warning: Severe Heat
Because baking soda forces the entire volume of glue to react simultaneously, the exothermic (heat-generating) reaction is magnified significantly. The mixture will get extremely hot to the touch instantly, and it will give off strong, irritating acrid vapors. Always work in a well-ventilated area and avoid touching the mixture until it has completely cooled down.
Technical stuff OFF

these are what I use

https://www.bunnings.com.au/gorilla-20g-super-glue-gel_p0381626

https://www.bunnings.com.au/loctite-3g-super-glue-power-gel-control-adhesive_p1560413

I have heard of baking soda but never used it so will go and give it a try evidently it works well on PETG which I use.