One Easy Step to Stress Reduction
A while back during some conversation about whitening toys with H2O2, someone mentioned that stress marks could be fixed really easily. All it takes is a little while under a hair dryer. I've performed a few tests to get a better understanding of the pros & cons of this. Anyone who has had success or failure using the hair dryer trick, feel free to post here.
Test #1 - Roller Force
I tried this out a couple of weeks ago on a G1 Micromaster Roller Force who had a decent sized stress mark on the front of his car mode. Put the hair dryer on the highest setting and pointed it as best as I could at the general area of the stress mark (which, given that a Micromaster is way smaller than the mouth of a hair dryer, was pretty much the entire figure).
Badda-bing badda-boom! It couldn't have worked better. The photos are way out of focus with my crappy iPhone camera, but I can no longer see where the stress mark was to the naked eye. Success!
I haven't tried this with any other figures yet, and you'd want to be careful not to melt some types of plastic I would assume, and who knows how it will affect stickers, but it seems like a very useful trick
UPDATE:
Test #2 - Devastator:
A couple of stress marks inside Devastator's forearm. These were more than just stress marks, as the plastic is bent and weakened at this area.
The stress mark was hugely reduced, although it is still visible in person. This plastic seemed to take a lot longer and it was a good few minutes under the heat. I was also able to bend the plastic back into shape a bit better when it was hot, seems more solid now.
BUT: when I went to attach the arm back onto Devy some time later, the hole was now too small for the peg (actually it kinda fit on, but it took mighty effort and was too tight to rotate). So I had to scrape out a little plastic from inside the hole. I probably could have just reheated it then reattached it, but it was late and I didn't want to wake up my GF with the noise of the hairdryer . Over all this was no big deal and still a success.
Test #3 - Classics Hot Rod (2006).
You can see this guy has a massive stress mark, and another smaller one. It's been like this since I got him. The two pins don't seem to have been aligned right, so theres actually some cracked plastic (not visible in the pic) and he doesn't align perfectly in alt mode.
This took quite a bit of time (4 -5 mins bu not constant) and was tricky to get at. You can see afterwards the stress marks are 95% gone (they are still slightly visible). However, I think his plastic is not quite as robust as G1 plastic, as there is some very minor melting visible near to where the stress mark was (some of the edges are a little more rounded off than they should be and the area is a little glossier). Not really an issue at all, as you don't notice it unless you're practically looking at him with a magnifying glass. Also, like Devastator, I think some parts have slightly expanded/shifted as it is now quite tricky to slide out his right shoulder from the hood. But it still works so overall this is still an improvement.
Test #4 - Powerglide
This guy had not one, not two, but three stress marks. The one on his right wing also looked much worse than it does in the photo.
Beautiful result! The one on the wing went very quickly (30 seconds or so) and is no longer visible at all The one on the tail I had under heat for maybe 4 minutes or so, and it still never entirely went away, it is much improved though. The one on the right engine thing took maybe a minute and went away entirely.
I took this as an opportunity to find out what the heat would do to the rub symbols. I attempted to shield the symbol with my finger as much as I could, but that one stress mark is about 1mm away from it, so for that it was definitely getting blasted with heat. As you can see in the centre pic, the rub symbol still works fine, but the edge near the stress mark (left side of the centre pic) is now darker than the rest. A better result than I was expecting.
Overall: Works great, but try not to expose any joints to too much heat. The plastic in modern figures may not be as durable as G1 figures. Use at your own risk.