Highlander Posted August 28, 2011 Report Share Posted August 28, 2011 I have two new projects in a medium I have only tried once before -- resin. One is an aircraft and the other is a figure. I will need to fill some tiny air pockets, sand off some injection lines, and smooth out some surface on both. Any tips on these areas? My prior resin attempt was a mess -- trying to fill air pockets and then sanding the imperfect results over and over. Specifically: What's the best way to fill a small air pocket? What kind of files and sandpaper are recommended for removing injection borders and for cleaning up mold marks? What approach is recommended for smoothing of less than perfectly smooth resin surfaces prior to putting on a base coat of paint? Help appreciated. Link to comment Share on other sites More sharing options...
JohnRatzenberger Posted August 29, 2011 Report Share Posted August 29, 2011 Other than the dust concern, I handle resin like styrene -- that is, I use the same tools to do the same jobs except I saw more than slice/chop. Hasegawa Tri-Tool set and the CMK saws are handy to have for fine cutting. Many times a sharp #11 blade used as a scraper is better than sandpaper. I usually work more carefully until I understand the quality of the resin -- sand slowly & gently to avoid taking too much. I fill air holes with CA. If they are really big, I use Tamiya Basic Putty, then CA. Link to comment Share on other sites More sharing options...
Ron Bell Posted August 29, 2011 Report Share Posted August 29, 2011 To fill pin holes, I've used two methods. One is just a dab of white glue. Let it dry, then go over it with a moist Q-tip to smooth it out. This only works well on small pin holes. For larger hole/gaps, I use Squadron Green Stuff diluted with Testors liquid cement. Get it to a soupy consistency, then smush it into place. Wait til it dries and smooth as normal. This doesn't work well for large gaps as the diluting leads to more shrinking. Finally, for larger areas or edges, I dilute the Green Stuff with Superglue. Work fast! When it dries, its harder than normal Green Stuff and the Superglue helps adhesion to the resin. Link to comment Share on other sites More sharing options...
ghodges Posted August 29, 2011 Report Share Posted August 29, 2011 The tips above are great starting places! I'll add that you can thin superglue with baby powder or talc to make a paste to use for filling pinholes. It sands and fills better than regular superglue. One word of caution when working on pin holes or a "pitted" resin surface. If this is prevalent or common over the entire kit (typical of older resin kits that were not vacuum cast), be VERY careful about doing heavy sanding. You may fill the ones on the surface and then sand THROUGH those and expose more that are embedded below the surface! Sand gently, and only enough to fill and smooth the ones you see on the surface. By the way, if you need to fill or repair a partially modeld item (such as a knob with a hole in it, or perhaps a broken prop tip), you can add super glue to the part (holding it downward so that gravity pulls it to the end of the part being repaired), hit it with accelerator to make it dry instantly, and keep adding glue (and spraying it with accelerator) until you build up enough to sand the repair to shape. Other than that, the guys are spot-on when they say you generally just treat the resin like it was styrene! Best of luck! GIL Link to comment Share on other sites More sharing options...
VonL Posted August 30, 2011 Report Share Posted August 30, 2011 (edited) A couple techniques I've used are: - Drill into a significant bubble/hole to insert a piece of stretched sprue/rod with superglue, snip at the surface, then seal & finish as described above. - Restore missing bits using the gravity glob method as above, using 5-minute epoxy, vs. superglue, and file to shape. That GREEN STUFF & SUPERGLUE combo sounds intriguing. Gotta try that! The main issue on which I'm still unclear would be an effective, reliable method for cleaning the mold separation crud off the resin before applying paint. Past that point, RUSTOLEUM makes a 'plastic primer' that seems to work well on resin and on soft plastic. Edited August 30, 2011 by VonL Link to comment Share on other sites More sharing options...
dsteingass Posted August 31, 2011 Report Share Posted August 31, 2011 (edited) Squadron Green putty can be thinned with acetone nail polish remover too. I use the green putty straight from the tube, then dip q-tips in acetone and smooth over the putty. As for cleaning the mold-release agent off the resin so paint and glue will stick to it.....lemon dishwashing liquid!! or the orange stuff would probably work too, just fill the sink like doing dishes, scrub, rinse and dry Edited August 31, 2011 by dsteingass Link to comment Share on other sites More sharing options...
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