I bought some half inch plastic leters to make a sign on the roof of a building similar to the way some old newspapers had signe on their guildings’ roofs. The letters aren’t polystyrene but I don’t know what they are. I plan to put them on some Evergreen Styrene strips then mount them. Any idea what type of cement might work best in this kind of application?
I note that Locktite makes a combo etchant & CA pack. I also see that Plasttuct(?) has three different types of liquid cement for plastics but I don’t have any experience with them.
I’m looking for suggestions; thank you in advance.
You could try Aileen’s Tacky Glue. It is a simple adhesive that does not really bond, but it holds very well. It won’t hold a lot of weight, but for something light like letters or figures it’s terrific. I use it for my little people because it will hold them securely but with a bit of a nudge they come off with no damage, no lost little feet.
Ed has already provided links to the pertinent areas of the Plastruct website, but here is the Description that Plastruct provides for each of those two adhesives:
I’ve tried all but the Tacky Glue with NO real success. I bought the Locktite product and it didn’t work either. I guess Tacky Glue is next but I can’t believe that somewhere out there, there isn’t a glue specific to this plastic.
Glues with MEK (Methyl Ethyl Keytone) aren’t going to do the job. They are meant for polystyrene really. While they work with other plastics, it doesn’t work as well. And to be honest I’m moving away from MEK as joints brittle with time. (Breaks easier when handled.)
CA will bond just about anything. But if you are worried, just go over the bonding surface once or twice with 60 grit sand paper and then wash it off. It’s possible your plastic letters are covered in some sort of release agent to make them easy to remove from the mold. Letting them soak in soapy water may help.
I like Wilhold, which is very similar to the canopy glue mentioned earlier. Dries absolutely clear on plastic and the joint can be broken almost all of the time (in case of mistakes, etc.) without breaking the plastic.
OKAY, good news! I purchased and tried the Locktite special cement for plastics and it worked pretty well. There are two parts; one appears to be some kind of etchant and the other is more like a traditional CA. The etchant is applied with a tip that looks like a Magic Marker, you wait a minute or so then use the liquid cement. The letters have been in place for about an hour. I picked at them a little and they are stil where I put them.
I’m told that this also works with delrin plastic but I’ve not tried that yet.
Since I have plenty of extra letters, I may add a few to a blank piece of plastic then test the bond. But for now, the Locktite product seems to work pretty well.
