You have to scrape off the paint so that the glue can make a positive bond on the mating areas. I either use a thin strip of masking tape to cover the attaching point on the leg and a small dab of blue tak on the mounting hole in the well to keep the paint off.
Ordinarily I also use a hobby knife to scrape away paint from join surfaces. However, if the join area is very small, and difficult to scrape, I use a small drill in a pin vise to drill one or two shallow pits in each surface, making sure it completely penetrates through the paint. This may be easier than scraping, especially on a fragile part, but if you use CA the bond will still be pretty strong.
I too, typically, scrape off the paint on the surfaces that I intend to join; however, I have also used CA and an accelerator to bond areas after painting, specifically, I did this on the landing gear on a 1/32 Bf-109. So far, this has produced a super-strong join.
Yeah, scraping paint away is always your best bet. You’ve got to make sure that the glue makes contact with the plastic and you have a plastic to plastic connection. The glue isn’t really a glue… it actually melts the plastic slightly and allows it to fuse with the plastic it comes into contact with. So if you think of the “glue” as more of a “solvent” it starts to make sense. However, there’s nothing wrong with using superglue or epoxy either. Just remember thou, when using Superglue the fumes will haze clear parts so as long as you don’t use it anywhere near a clear part you should be fine… as for epoxy, it can be rather difficult to work with. Especially if you’re using only a small amount. Its hard to mix a small portion and most epoxies have a rather quick curing time so you have to work fast before it hardens. And when you’re talking small parts, fast is a word you wanna steer clear of. I don’t know how many tiny parts I’ve lost to the carpet monster over the years because I was rushing to get a part done only to find myself on my hands and knees crawling under my workbench with a flashlight trying to find the little part that supported the entire weight of the model! Hours later you find it stuck on your pant leg and smack yourself in the head! Oh the humility! Hope this helps!
Tamiya Extra Thin dissolves paint pretty quickly and sets pretty fast,so in this case you could simply put a little in the hole and simply insert the gear.
I agree… sometimes its even better if you scuff up the surfaces that are being glued together. End up with a much better bond and gives the glue something to bite into to hold onto. Sometimes it doesn’t have to be alot. I know with styrene plastic as long as you got enough of the paint removed to where the two bare plastic surfaces touch (when using regular Testor’s glue) it works pretty well, but if you’re using any other kind of glue (super glue, epoxie, etc) and aren’t sure of the materials you’re using and if they would work well together, it would always be best to scuff the joining surfaces up a bit to allow whatever glue you’re using to be able to grab onto the parts you’re trying to glue together. A piece of sandpaper run across the surface a few times works wonderfully, if you don’t have sandpaper, use the tip of your x-acto knife to the marr it up a bit before applying the glue. You’ll be glad you did.
Now for an old dog like me , I still do what I was taught over 60 years ago .That is Scrape or don’t paint a glue surface .
Every kit I’ve built over the years , says right in the instructions ," scrape paint from areas to be glued ". This is good sound advice that cannot be repeated enough .
Also a good note from " G " , Superglue is fine , But the joint is only as strong as the paint adhesion to the surface of the model or part . T.B.
Great advice and it just reminded be… If you apply Elmer’s glue to all your glue surfaces (edges that will be glued to other parts later) and allow it to dry before you start painting, you can just peel the dried glue off and the surface will be paint free! EASY PIZY! Can even thin it down with a little water (note I say a LITTLE water) and paint it on the glue surfaces to get it more precise. I know alot of those liquid masking products that are available are basically just thinned down Elmer’s glue with a touch of food coloring. Can also be used to mask already painted areas to protect from overspray and will get into all the little nooks and crannys. It just peels off when done so you don’t have to worry about it damaging your model at all!
Has anyone tried that new UV glue that they’ve been advertising on TV lately? The one that you shine the UV light on and it hardens in seconds? Thought about getting some but not sure if I should!
Yes i have tried it and like it very much. Especially on clear parts…no fogging or crazing and it sticks better than anything else i have tried. it also makes windows well and instantly dries . I have not used it anywhere else except for canopies etc.
Hope this helps!