Ron here with a little conversion quickie. Are you sick of gaunts/warriors/carnifex/crones/(insert pretty much any plastic tyranid model) with unwaveringly straight tails? Do you wish they had a little more variety, or a more unique/dynamic pose? Are you running 3 crones like me because the internet told you to? Well good news - it's easy to bend these tails, and doesn't take a lot of time.
So the only thing you need besides the model is a heat gun, which is fairly inexpensive (mine was ~$22 USD). I recommend one with multiple settings - specifically one with a "low" setting (750 degrees F) like the one I have: Wagner HT1000. Heat guns are generally safe (as safe as something named "heat gun" can be), but proper safety considerations should be followed (see the end of this article for more warnings).
While bending plastic is fairly simple - I do recommend starting with something like a gaunt so you can get the feel for it, and not weep bitterly should your prized model turn in to a puddle on your desk (hyperbole, it would take some deliberate melting to really jack up a model). Start with the lowest setting your gun has. Here is my gaunt test model:
Start where the plastic is the thickest (higher up on the tail) and work your way down the plastic with the heat gun. Thicker areas will need more heating time to bend smoothly. Don't stay for too long in any one area - you want to move the gun smoothly back and forth, and keep it 3 inches or so from the plastic. Ideally you shouldn't be staying in one spot, the gun should be constantly moving. Rotate the model so the heat gets applied evenly to top/bottom/sides. You should let the heat gun do the bending work as much as possible as pushing the tail too hard manually can lead to an unnatural crease where the plastic isn't warm enough to bend fluidly. (You can see an example of this creasing about a quarter of an inch from the base of the tail in the above photo.) The tail will naturally curl in the opposite direction of where you apply the heat, but may need some coercing from a smooth tool (I use the handle of a paint brush).
Next I moved on to a Tyranid warrior. This is the perfect conversion for that shiny new warrior box with the same old straight and long tails. It adds some variety, is easy to do, and can really give you some unique nids.
With my confidence up - I put the $80 crone to the test. As you can see this method works on any thickness of plastic with some evenly applied heat and patience (still no more than a few minutes). One thing to note on the crone is that I used plastic glue to build the model and there are seam lines along where I bent the tail - these seams become more pronounced with heat applied and bending (expansion and separation). These are easy to fill with putty/liquid green stuff.
WARNING: This heat gun method works with plastic models built with plastic glue, but should not be used on models built with super glue! Heat on super glue can compromise the join, give off fumes, and generally jack up your model (so I've read).
Plastic has a melting point well below 750 degrees, so keep the gun moving, and if you see the plastic start to bubble/deform (lose shape)/discolor, remove the heat immediately. You want the plastic to be soft, not liquefied.
Keep the gun away from details as much as possible since it is easy for the heat to deform these. This method works on smooth sections of plastic only. Also, be smart, heat guns can be dangerous and you are dealing with 750+ degrees F. Don't use it on your hands, don't touch hot plastic with your bare hands, keep it away from flammable objects, and please ask an adult for help if you are under 18. Any vapors given off from heated plastic should be considered caustic, and proper ventilation is recommended.
I hope you enjoyed this article. I'd love to read/respond to any comments/questions you have. Until next time - keep battling that grey tide!