robdebie

Did you leave the lids off for the outgassing? If so, the resin absorbed moisture, and foamed because of that moisture during the cure. I try to limit my resin's exposure to air / moisture as much as possible, but with every opening you let in fresh air with new moisture. When I reach the bottom of the bottles, they have had maximum exposure, and the mixed resin will foam, if not put in a vacuum. Fresh casting resin should not have any of these problems though. Rob

Best Balsa has a great decal set: https://www.bestbalsakits.com/tamiya/tamiya-detail.asp?kitnumber=3239 Rob

I use the 7-minute Smooth-Cast 305 (with some black dye), and I'm happy with its material properties after curing. I cast some fragile parts, like the jet nozzles right from center and the bomb fins in the center, and never had failures. On the other side, since the cure is slow, the resin doesn't heat up, and a hot cure of a fast resin might give better material properties. The drawback of a hot cure is that you'll have more shrinkage. Rob

I'm looking for the DVD-ROM 'Scale Auto Enthusiast - The First 35 Years'. In return I can do custom decals, or parts casting, or 3D part design and printing, or maybe something else. More on decals and casting can be seen on my website: https://robdebie.home.xs4all.nl/models/customdecals.htm https://robdebie.home.xs4all.nl/models/casting.htm There are eleven pages about 3D CAD and printing projects on the main modeling page: https://robdebie.home.xs4all.nl/models.htm I joined this forum in 2016., and made 379 posts so far. Rob de Bie Delft, The Netherlands

Building on Peteski's comments, maybe you can scrape the resin parts, to release the original smell. Rob

That's an amazing story - I had never heard of resin shrinking after being cast. I do know that polyester can shrink a bit after curing, in boats etc the 'fiber print through' will often develop over a week of so. But I'm guessing these car bodies are polyurethane as usual, and I've never ever read accounts or warnings of shrinkage after curing. Maybe your account of the two body halves contains a clue: it sounds like the paint caused the shrinkage. But even that I've never heard of. It's probably no help to you, but here's what I wrote about shrinkage on my webpage about vacuum casting (https://robdebie.home.xs4all.nl/models/casting.htm😞 - - - - - - Shrinkage A few words on the subject of shrinkage. Shrinkage can occur both in the mould and in the casting: regarding the mould: one of the reasons for choosing addition cure (platinum catalyst) silicone rubber over condensation cure (tin salt catalyst) silicone rubber is that the former has close to zero shrinkage. The latter shrinks during cure, and (amazingly) continues to shrink during its life. Therefore my choice is simple: I use addition cure silicone rubber, and the mould will not show shrinkage. regarding the castings: polyurethane resin itself shrinks very little during the curing reaction. However, there's a big 'but': when the resin heats up during the cure, because the cure is exothermic, it expands, pushing out some resin from the mould cavity. When it cools down after the cure reaction, the natural thermal shrinkage occurs, making the part smaller than the mould. The resin's potlife mostly determines the shrinkage: a fast cure means it gets hot, and a slow cure means it will hardly heat up. Fast curing resins can get so hot that they form steam bubbles in the centers of the castings! I use a 7 minute potlife resin (SmoothCast 305), and I never felt a temperature increase in the small parts that I produce. Therefore the resin hardly shrinks. SmoothOn lists less than 0.1%. I tested the above theory by measuring my largest casting, the ALE-2 chaff pod. The master is 87.5 mm long, and of the five castings that I measured, four were 87.7 mm, and one 87.9 mm. I blame the length increase on temperature differences of the days I cast the mould, and the days I made the castings. Silicone rubber has a large coefficient of thermal expansion: I found values ranging from 200 to 300E-6/°C. Compare that to polystyrene 70E-6/°C and aluminum 21-23E-6/°C. That means a 10 °C difference makes a 0.25% larger silicone rubber mould, and that equals the size increase from 87.5 to 87.7 mm of my ALE-2 pod. - - - - - - Rob

In my experience, epoxy putties don't stick well during application, so that might create the impression that it won't work. But once cured they are attached solidly. Rob

Yep.. It helps a lot to freeze the film every few second (use space bar), and study what you see. Each frame is quite sharp. Rob

Here's a third video: https://www.youtube.com/watch?v=MlSOAy21qmA Rob

One more vote for epoxy clay, like Milliput, Tamiya epoxy, or Apoxy Sculpt - I use the latter. No shrinkage, no solvents that make the plastic swell, good hardness after cure, nice to sand. If required, you can use water to smoothen the putty. The drawback is the mixing required, but for me the advanteges outweigh that completely. I do the mixing by squashing the two compenent under a modeling knife, and repeating that a number of times. I try to limit skin contact as much as possible. Here are some recent examples of work with ApoxySculpt. Rob

Here's another video of the same collection, showing lots of different areas of the collection room: https://www.youtube.com/watch?v=bVN-5upkwXk The filming is shaky, but it's again worthwile. Rob

Sorry, I hadn't seen that this video was already mentioned in the thread '40 year model car and airplane collection.' But it's nice to see that I wasn't the only one blown away 🙂 Rob

Maybe 50% slot cars, but also lots of scale models, plus original box art artwork, wow.. https://www.youtube.com/watch?v=kfwuz0NA64k Lots of shop displays that I'd never seen before. A fantastic collection! Rob

Like Peteski, I glue nearly everything with CA. Transparent parts are the exception, I use epoxy for that. But I never use plastic glue. I am the exception in our club though. Rob

You on the other hand have a very good eye for shapes, something that is rare in my experience. I've studied 'seeing shapes' among modelers, and I think only 10% sees shapes and shape errors. Just to be sure: I wasn't talking about different wall thicknesses, I only observed the outer contour of the cab-to-hood lip. Rob