Ok, this board has some true experts, so here's my question. How do you paint yellow onto the black Delrin handrails of the Atlas cabooses? I have 3 cabooses to do and so far my efforts have been less then stellar. Thanks Joe
Try using a silver Sharpie as a primer -- it gives the paint something to 'stick' to. It also makes the paint stick better when the handrails flex.
I had the same problem with TTX yellow (only on bare metal instead of handrails) until I decided to take the extra step and primer first. It worked. Should be the same with the handrails. Brian
painting a yellow color over black delrin plastic presents two problems. First is that you are trying to paint a light color over a dark one. Second is that the delrin is too slippery and doesn't give the paint anything to stick to. Here's the solution I have heard but not tried. First, soak the part in vinegar for several minutes. Second, paint it with automotive grey primer This will do two things it will give a neutral color to paint your final color and it will give some "tooth" for your final color to hold onto. Then paint your final color..
The best thing to do would be to talk to the manufacturers and have them change the type of Delrin used in their manufacturing: Product designers can now achieve the “unplastic” appearance of painted or metal-plated parts in components delivering the unmatched performance and mouldability of DuPont™ Delrin® acetal resin. http://www.newmaterials.com/news/1135.asp Imagine, plastic you can metal-plate! :teeth:
Joe, I use Pactra Racing Finish Acryl paint over the silver sharpie with good results. I got tired of finding yellow and white handrail flakes all over the layout because it had chipped off. Bob
I use Tamiya Color for Polycarbonate thinned with Tamiya X-20A Acrylic Thinner. As Ploycarb paint is flexible, I don't have any flaking issues :teeth:
i recently did some tests with sandblasting the handrails prior to painting. unfortunately i had no time to extend my testing. here's what i intend to do : sandblast several handrail sets use primer and modellflex paint no primer and modellflex paint use primer and floquil paint no primer and floquil paint use primer and tamiya polycarbonate paint no primer and tamiya polocarbonate paint guess you get the point. i will then build a handrail-flex-until-paint-chips-off machine to simulate rough handling.
You could also try an adhesion promoter (e.g. Dupli-Color). This prepares slippery surfaces (fiberglass on auto bodies) for painting. It's available at many auto parts supply stores. I've used it, but I have no long term experience with handling anything I've used it on. In other words, so far, so good.
All, THANK YOU THANK YOU THANK YOU!!!! I tried Dave N's method of a silver sharpie over the black and it worthed BEAUTIFULLY. I will post a pic of the model when I complete the decal job. I knew this board would have the answer! Thanks again to ALL who offered ideas. Dave N, many thanks! Joe
there was an article in MODEL RAILROADER about this a few years ago, and they also recomended that paint. They said that TAMIYA also makes a paint that works.
There are three issues here: Getting yellow/white to cover over black. Getting any paint to stick to delrin. Getting any paint to be able to flex and not crack. Light colored primers/undercoats help the coverage issue. They are probably thinner than multiple coats of the yellow/white. Sandro mentioned sandblasting to give the surface some tooth. (There is no practical etching solution (like vinegar)) There are some adhesion promoters as another poster mentioned. I've not tried it, but Loctite makes a primer/conditioner to allow superglueing slippery plastics. The problem with multiple coats makes the paint layer thicker and therefore less bendable. The Tamiya paints for polycarbonate RC car bodies is one approach since it is meant to flex. You can also get an automotive paint flex additive meant to use on polyurethane "bumpers" (remember them?). My take: either sandblast or scrape with a blade to slightly thin (and roughen), use a surface conditioner, undercoat with a primer or silver, paint the yellow with a flexible paint. Bob in IDaho (or... don't mishandle <grin>)
