After some (a lot) of procrastination, school work, exams, music concerts, and hiatus later...I've finally picked up the ASHPD again, this time, with a help of a lot of friends. I forgot about this thread for quite some time, so there's a lack of photos as of yet.
I've managed to gotten both of the Portal Gun shells carved out, and after sealing them with Mod Pudge, covered both of them in bondo. God, it's an absolute nightmare to work with. I kept on adding too little hardener the first few times, and after that, I started adding too much hardener, and couldn't work with it before it completely dried up. Took some time to get the balance.
After that, I decided to take a break from the fumes, and went on to working on the main barrel of the Portal Gun. I had already sawed several PVC pipes out, before remembering that I didn't have anything to hold them together with. From what I've seen, most people have been using Apoxie Sculpt. One of the downsides of living here in Singapore is that such things are hard to find, so one of my friends recommended Sculptamold to me as a substitute, which she claimed to work fairly similar.
After testing it out for a bit, the Sculptamold seemed to work quite nicely (In case you are wondering, those orange pieces of plastic are from one of my textbooks.), so I carried on with it.
It takes quite some time to dry, but hey, it works. As you may have noticed, I've messed up woefully on the back of this section, but I think I have a plan to solve it. That's it for now, I've got a lot of spare time during the next few weeks to work on it however, so progress should be quick. Gonna start sanding the life out of the shells and barrel once I find the time. As long as I keep the area well ventilated and keep my respiration mask on that is.