Please help: I need to stick etched brass coach sides to adapted polystyrene coach sides and I believe the accepted glue to use is a contact adhesive. I recall an article in a model railway magazine some years ago in which the author used Thixofix to stick Plasticard to brass sides. He wrote that it was successful but on a tin of Thixofix it says not to use Thixofix on plastic probably because the solvent could melt the plastic: does that mean it's best to use Evo-stik? What other glues may be suitable for a job like this? Araldite or even superglue?
The trouble with Evostik along with all other impact adhesives is that they are petroleum based, and remain active for some *considerable* time after use.
I recall some years ago fitting some fairly thick plastic cobble stone sheeting to a wooden former and it was only after about 18 months that they they began to warp.
Use a water-based, acrylic-latex contact cement. Brush/smear a little one both surfaces, wait 5 to 10 minutes, then carefully align and press. If you need a little time to align the sides, don't let the glue dry, but it will take a lot longer to set.
I don't use solvent based contact cements at all anymore.
Some years ago I overlaid Comet etched brass sides onto the clear plastic sides of the Southern Pride basic kits. I used Thixofix and haven't had any problems with the glue attacking the plastic or with subsequent warping. I think you just have to use the glue sparingly, and don't put the two items together too soon. If the glue is still "glossy" and not almost touch dry when the parts are put together the plastic is more likely to suffer attack. Positioning has to be right first time as the glue will grab instantly.
Lepage. The package I have calls it "pres-tite green contact cement", and it's #7 in their line of adhesives. It's in a 30ml tube, bubble packed onto a cardboard backing with all kinds of info printed on it. I don't know if Lepage market their glues in the UK. No matter: what you want is similar stuff. Ask at a DIY, but NB that the stuff for gluing hardboard etc to walls is _not_ what you want; it's too thick.
For light duty, acrylic medium (used by artists) can work as a contact cement. Silicone sealants can also be used as contact cements, again for light duty. You can even use PVA, by letting it dry on both surfaces first, the spreading a thin layer on one of the dried surfaces. It will grab almost instantly. That's a trick that works with most glues, I can't remember who taught me that, probably a shop teacher many years ago. The most important thing about any glue is that it works for the materials to be joined. No glue is universal. ACC (cyanoacrylate) glues come close. For your purposes, ACC might be better than contact cement, but NB that the fumes are toxic, and it can instantly bond skin to skin. Contact cements do not work very well with metal.
One problem with any contact cement is the thickness of the glue layer, for model work you want it as thin as possible. That's why I like the Lepage stuff. It's very thin, about the consistency of cream.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.