I see in a lot of WIPs that people pre paint parts and glue these paired parts together. I do the same. Problem is I thought you had to use ca or something other than plastic cement because that stuff can’t be used over paint. But ca isn’t all that great under pressure. I end up breaking stuff glued with ca and prefer a stronger bond. What do you guys do about this?
Definitely, avoid painting parts before glueing, and use a solvent type substance like Tamiya Thin Cement. It melts the plastic and fuses it together. It will not work through paint, and will probably dissolve some types of paint resulting in an ugly mess.
I try to assemble as much as I can before painting, but some parts or subassemblies are easier to paint beforehand, especially if a lot of intricate masking would be required.
One of the rules of thumb I try to think about is that if the parts were painted separately on the real thing, then you should try do the same thing on the model.
If you must assemble painted parts, then you should scrape the paint away from the joint surface before gluing in order to get a good bond (rather than scraping away paint I sometimes will mask off the joint surface prior to painting). I like to use a gel-type CA to keep the adhesive where you want it to go. I also keep a tube of Testors Plastc Cement handy on my bench that I use on occasions when liquid cement would be too messy.
Mark
I paint before assembly, but when it is time to join parts all you need to do is remove the paint from the areas that you are going to join. when i paint before hand i try to make it close to what the primer color would be or a white/light grey to act like a primer.
I almost always find a bur or something I forgot to clean up when I paint the parts this is why I paint first also the plus side is they are still on the sprues for easier handling. And I save the detailed painting for later, as I have on several occasions of building something and then go wait I want to use that vehicle, tank, figure in another diorama etc…
You can try white glue (like Elmer’s or Aleene’s, thinned). It will hold just about as well as CA on painted parts, and if the part comes off, you can clean up the area with water and re-attach.
I try to mask off the attachment points with either white glue or Micro-mask or even masking tape before I paint if it is possible to get at them.
John
The problem with gluing painted parts is that no matter what kind of glue you use, the bond then is only as strong as the bond of the paint to the plastic- never among the strongest. A good agressive primer helps, but it is still better to scrape or drill through the paint so you are bonding plastic to plastic.
The one exception is small PE pieces. They are so light that they have no inertia, so do not need a really strong bond. They will stand a good jar. However, if you bump them they will break off. So many of us leave PE as last step wherever possible.
Hi !
What I do is simple actually . Where most parts mount on a painted surface , I take a number 11- X -ACTO blade and using the tip (which has the very sharp tip broken off ) and carefully scrape the paint away . It has worked all these years ,so I keep doing this . Tanker-builder P.S. When removing the tip of the blade , don’t remove more than aboit a 32nd of an inch from the tip and then file the end with a whetstone to a slightly rounded profile .
Shawker,
I agree, I too will paint, especially the small parts while they are still on the sprue(s) making it easier to hold them while painting them. Plus if one has an X-Acto (or other company) third hand with alligator clips (with or without magnifying glass) one use the alligator clips to hold the part by a piece of the sprure instead of by the part itself. Thus avoiding doing any damage to the part itself.
Then as others have said one can use either an X-Acto knife blade, or Testors sanding film, or an emoryboard/sanding stick to remove the paint from the surface(s) to be glued.
experience taught me to mask all axle and wheel attachements on warwheels before priming and painting. sometimes just a little layer of paint makes the part too thick to attach. i also mask off obvious sub assembly attachemnt pints. usually the exposed area can be touched up without being obvious. sometimes i attach unpainted parts with ca instead of plastic glue if i think i am going to have to undo it.
I do something very similar. I use a pinvise with about a #65 drill. Exact size isn’t important. I just drill a little holes through the paint into the plastic in the footprint area on both pieces. typically drill about three holes in the footprint area for very small parts. Holds quite well, as it allows plastic to plastic bond.