Upgrade: Reinforcements - Coming to the Chest Plate's Rescue

So after a year or so of trooping, my chest plate started getting cracks in the underarm area and the neck. Part of the issues is that, like many troopers, I keep a lot of electronics on the underside of my chest plate, fastened with H&L tape.

More on this setup in the next blog post, but as you can see,

it's more than just my Pyle Pro these days.

This puts weight onto the chestplate. Further, if I end up fidgeting with the volume gain on my Pyle Pro, or making sure a wire didn't pop out (not an issue with my new, current set up above), I'd have to get a hand underneath the plate, creating pressure on the edge return and causing cracks and lines.

So I would grind them out, fill them in with ABS paste, sand and polish them, and put reinforcement behind it with ABS paste and scrap ABS.  But after every few troops, I'd get a new crack right after the reinforcement scrap ended, or worse, in between two reinforcement scraps. It eventually turned into a meme.

"Lines! Divisions! Every day more lines!"

Well, more than just lines, Saw... full-blown cracks through the material and past my reinforcements.

Reinforcing these stressed edges was definitely something I needed to do. At first, I tried applying a bead of ABS paste near the edge return, but this didn't really strengthen the armor, and I kept getting more cracks.

KMan suggested an old trick from the FISD forums:

This method works fine for a crack here and there. However, after the many times I've already needed to repair cracks in the chest plate, I didn't want to piecemeal it anymore for every new crack. Instead, I went with the nuclear option: fiberglass mat reinforcement with epoxy resin along the whole length of the arm edge returns end the neck.

I started by buying some fiberglass mat and epoxy from Home Depot, along with a couple of foam brushes to help with application. With fiberglass, you have to take extra precautions, as it will get into your skin and irritate you, or get into your lungs and cause health issues, so when working with this stuff (before it's glazed in place with epoxy or other resins), I wore long clothing, latex gloves, and a dust mask to protect myself.

The first step was cutting some strips to length. I used a long and short strip for each side edge return to work around the curve, and  a short but wide piece for the neck. I didn't worry about matching the curves at this point since I would be trimming and sanding later.

After the stips were measured, I sanded the target areas with some 100 grit paper to make for a better bind. Then, I mixed and applied epoxy to this areas, and set the fiberglass strips on top. The hard part in this step was to get the strips into the crevices along the edge returns. I did end up with some air bubbles, but I take care of those in the next step.

I prefer quick set epoxy because it sets up faster and is less likely to run, but I still let it cure for a full evening before I continued my work.

The next night I proceeded to the next step: trimming and glazing. Now that the mat was glued in place, it was time to trim the mat as much as possible to fit the curve, and then add more epoxy to the top and edges of the mat to keep everything in place. In addition, I used a hobby knife to cut into any air pockets (from a somewhat hasty mesh installation) so I could fill them with epoxy and then clamp them back shut. Again, I took precautions when trimming the fiberglass. I trimmed the curves and also excess material inside the plate near the overlap at the arm edges, and around the H&L tape. Once all the trimming was done I mixed more epoxy and generously covered the top of the fiberglass strips, including the remaining edges. This step used the rest of the remaining epoxy.

Again, I let it rest overnight before proceeding to the final step: sanding and polishing.

With the edges now rigid, cutting off and sanding ane remaining frays was trivial. Again taking precautions against the fiberglass, I carefully trimmed with a hobby knife and sanded the edges clean against the edge returns. I also made sure to sand down any remaining edges on the inside of the armor to keep from getting myself or my undersuit torn or scratched. I mostly used hand sanding but also broke out the Dremel at low speed to help with some inside work, especially near the H&L tape. Any remaining rough edges where glossed over with a little E6000.

What better way to test my work than two back-to-back troops, the latter being a parade in 90+ heat?

The armor was OK!

I should have drank more water :P

In both troops, I had to slip a hand under my chest plate to fiddle with the Pyle Pro volume, to get good voice volume while avoiding feedback. But I didn't get one new crack in either case. Now, the remaining cracks I do have in my chest plate are minor cosmetic inconveniences that I can take more care in correcting and polishing up, rather than major structural issues that I have to patch immediately before the next troop. And with as busy as May has been this year, that's quite a relief.

On my next blog post I'll talk about the TK Talkie v3, an upgraded version of the TK Talkie v2 that allows one to make adjustments on the fly - through a phone app. until then...