
Foam Dumbbell (part 4)
Where everything that could go wrong, did go wrong.
You can check out the foam dumbbell video if you haven’t seen it yet — then read how the basic shapes were made and then put together. Here’s where we left it in Part 3:

The first thing I wanted to do was add caps on the “inside” faces of the weights, near the bar. There was a problem though in that this was already assembled, and I had already added the + shape.
The solution I came up with was to add hot glue. This worked very well for the fake thick weld lines, so I’d hoped I could do the same here and then just push it into shape before it cools:

Uhm… so, that didn’t work. I just turned it into a mess instead. The hot glue cooled too quickly after placing it. There just wasn’t the time to change the shape. Aaand… now I was stuck with it.
I obviously wasn’t happy with this, so I started looking into ways that I could further fill up all those gaps and hopefully turn it into a prettier cap instead of a blobby mess of hot glue. That’s where I ran into two-component polyesther filler (the commonly known Bondo brand is one of these).
I’d never used any of those things before, so to help me get a well defined ‘cap’, I decided to mask off the areas over the foam to make a bit of a circle, and masked off the rod that I’d already primed and painted metallic gray so that I’d get a sharp line. I then mixed a small amount of filler and applied it. I let it dry for a little while, then removed the masking tape, and… uhhh, uh-oh….

Not only was the result barely any better than the hot glue by itself, but an entire chunk of primer and paint pulled off as I removed the masking tape. That wasn’t supposed to happen… So now not only did I not have no cap — I had a terrible cap, and the paint had started chipping off the bar. Wonderful.
I eventually decided to add a whole bunch of layers of gesso on top what should be the cap, and then I sanded it all down into as reasonable a cone shape as I could. The result wasn’t great, but it was much better
I was also going to have to redo the central rod… prime it agian, paint it again. For the best possible result, I was going to have to remove the existing primer and paint. Unsurprisingly, it came off with no trouble at all by just sticking a piece of masking tape onto it, and taking it back off… sigh:

I stripped off all the remaining paint, and then masked off the rod and prepared the rest of the foam. Then I took it outside and primed it. At least after priming, it looked more cohesive:
After the first layer had dried, I’d applied another layer in black primer:

By this point I was starting to cheer up a little. Black was going to be the target color for those weights, so the black primer really gave me the feeling that I was making progress again. In fact, I liked the black well enough that I decided that I might as well keep the black primer layer as the finished layer. It helps that the result was as matte as it was going to get, which is what I was going for.
The next step to make it feel more real was to add a logo or two. I used to work out a lot before my health issues got worse and the joint issues required that I stop, and the gym I used to visit had bullshitty sporty logos on all their equipment, often in poor English.
Obviously I had to do something similar here. 😛
Here’s what I came up with first, and I cut this out of adhesive-backed vinyl on my vinyl cutter:

I also came up with a weight for the dumbbell, having decided on 30kg/66lbs. I had this cut out of adhesive vinyl as well, then applied both of them on the side of the dumbbell. Note that they’re both stencils, which means that they’re intended to be painted over, and then removed:

Pretty cool!
Since some of those letters were pretty close to the edge of the vinyl, and I was going to have to paint these in by hand, I added some additional masking tape to help prevent any small accidents, then started painting it in with a cheap white paint I had lying around:

I got a bit of a sinking feeling as I realized the black was starting to come through the white paint incredibly easily. I’d hoped to paint everything on in one or two layers, but the white simply refused to block… I ended up spending two days painting about 10 layers of white on before it was as white as you see on the picture above. And then I didn’t have any time left to remove the stencil and mask until the day after that, so this took three days in total.
It was only later that I learned there are two types of white paint. The cheap one, commonly found in cheap paints found in discount stores, is zinc white. Zinc white is not opaque. This is why I had so much trouble getting my logo to go white, especially with that black primer underneath. The white I should have used was titanium white. Titanium white is more expensive, so it’s usually only found in the better paints and paints from good brands. Of course, I didn’t know it at the time I’d been trying to get this to go white, which was incredibly frustrating…
Then, to make matters worse, here’s what happened when I removed the stencils and masking tape:

. . .
At this point I just wanted to cry. The masking tape and adhesive-backed vinyl completely pulled the primer off the foam. The sides were completely ruined. I work slowly, so for me, I’d wasted half a week and ruined my prop to boot.
Fantastic. 🙁
There was no way to cleanly recover from it. There was only one thing that I could think of that would let me keep all the work I’d put into this prop so far and not throw it out. I’d initially wanted to make the foam dumbbell sharp, crisp, clean, neat-and-new looking…. but I could, instead, make it a bit rusty, used and damaged.
It’s not what I really wanted… but it’s the only thing I could do.
I’ll write about the recovery from the list of failures in the next post in this series. Keep your eyes on our website and social media so you don’t miss any future posts!