Say hello to our grace and savior: Alex-Flex.

Alex-flex is a “high performance spackling paste” that is meant to be used for “repairing holes and cracks in drywall, plaster, wood, and stone” but we used it to cover the body and head of our robot.

Now, Alex Flex is both my best friend and worst enemy.

It’s my best friend because it allowed us to smooth down our robot and have a base in order to properly paint our robot and not have the paint get soaked up into our insulation foam but it can be a PAIN to work with.

So the Pros:

  • easily buildable
  • works well with primer, paint and spray paint
  • can give you the smooth finish you want but also allows design
  • takes a while to dry so you can manipulate it for around 5-10 minutes after you put it on
  • can use water to slightly smooth it out
  • inexpensive ( 16 oz container costs around $7 at Home Depot)
  • sands easily

The cons:

  • curing time as whole is greatly affected by thickness, the more you have on it can take overnight to dry (as we found out by how much we put on our body)
  • spreading is hard when you don’t have the right tools
  • when you are spreading it with your spreader, it will dry pretty quickly on it so if you want a smooth finish you have to constantly clean your spreading tool or else the dry specks will get into your wet spackle and it will quickly ruin your smooth finish
  • it will flake if you are not enclosing what you are spackling on all sides perfectly
  • can easily dent if you’re not careful

Since we wanted a perfectly smooth finish, we used alotttttttt of spackle, that we applied with putty knives (we didn’t realize it until we did some cutting of our robot’s body that we had used around half an inch of spackle in some places almost, good thing it was cheap to buy.) You can use your gloved hands to spread it but it wont apply very smooth easily.

Like mentioned earlier, our body and head is composed out of insulation foam that we glued together that we just directly applied the spackle to. Sanding of our body without the spackle was roughly around 3 hours, and with it applied was another 2. We spent HOURS sanding the spackle and I’m pretty sure more spackle ended up on my clothes, shoes, and floor (and nose before I realized I should definitely put on a mask), but the good thing is was that it was very easy to sand.

The good news is that we were able to get the finish we wanted especially when we primed him, then painted him, the bad news is he took a couple tumbles leading to some dents in the spackle that we weren’t able to sand out, our mistake.

Overall: Alex-flex is a godsend, you just have to be patient when working with it.