I am working on the new ICM Twin Beech in 1:48. Most of the transparencies are fine, with nice large flanges. However, the cockpit side windows are not flanged- they are butt joints along the edges, with thin fuselage sides, so glue bond is critical! So I have been trying to use epoxy. But my first attempt was very weak, and the window bond failed.
I thought maybe my epoxy had goon bad, so I bought some new stuff. I then made two test pieces, gluing two pieces of styrene together. First piece was with spare sprue pieces from kit, second was with two pieces of styrene from my styrene stock. I let them set for several hours, far longer than instructions said for complete bond.
Both test pieces failed easily! I am at a loss now on how to proceed. And I am wondering why epoxy doesn’t work now, when it used to!
I use a 5 minute two part epoxy for any bond that isn’t styrene to styrene (i.e. photo etch, resin) and rarely use cyanoacrylate. I do my very best to make sure equal amounts of each are added, of course, and mix for at least one minute (I set my wrist watch near where I’m mixing and time myself). Generally, I get a tough bond with a small amount of flex, which I prefer to a rock hard and brittle bond. The three thoughts I have are to do with your ratios, the thoroughness of your mix, and mostly whether you’ve passed that time where the epoxy starts to gel. I personally find if I’ve not applied it wet, when it has begun to gel, my bond does not take. I’m sure you’ve thought of all of these points, but sometimes it’s the basics that get missed or forgotten.
Not all “epoxies” are the same. Not only are cure times different, but the epoxies themselves are of different formulas. Some are designed for specific uses, metals, glass, plastics. Loctite Plastic Bonder has worked well for me on plastics that didn’t work at all with CA or 5 min epoxy. Loctite also has a plastic bonding system that appears to be a CA, but claims to bond all plastics including polyethylene and polypropylene. I’ve not tried that.
I still haven’t figured it out yet, but for moving along, I am thinking of trying CA. I have had bad luck with many of the fixes for preventing white frosting of the transparent material. But I have the windows already masked (and the masking even sealed). I am wondering if the masking will protect the window from the fogging. I think I’ll set up a little test.
I have tried both GG and the Revell stuff and find them not strong enough. If a window falls into fuselage after joining, it is pretty much a disaster. And the closing of the fuselage, of course, is done at a fairly early stage, with all the finishing yet to do. I often had windows pop in during sanding of primer or color coats.
Same as Revell or Testors transparency glues. My test came out fine. For some reason there was no frosting, even on unmasked area. Now I can prime and paint interior
