Yeah very cool. Can you elaborate on the moulding process? It would appear that you used some sort of plaster of paris to make a mold of your chest.
From there, you then jump to where there’s the liner added to the inside of the fabric/plaster mold.
Is that a liquid that hardened?
I use the OMP rib protector because I used to race Calspeed rental karts and the seat needed to be so far back I hunched a little. My spine would always bruise up, so I wanted the spine pad to go up to my mid back. It is nice and snug in my 206 seat.
Nice job on the custom rib protector up the thread
Thank you all for the nice comments 
Heres how I did it
I put a old T shirt on, had my friend wrap my middle torso with wrapping plastic. Its important to somewhat hold your breath and try to keep lungs full. Dont wrap tighly
First mold was made using casting plaster wrap, 50mm wide. Buy wrap that is continuous. Just wet the wrap with water, have a friend walk around you and apply the wrap. You have to assist and hold/guide the first layer or two but it gets easier as thickness increases. Wrap bigger area than the final rib protector will take. All the molds should cover bigger area than is needed - that way theres support to make a solid laminate right to the edges of the final product. Again dont wrap tight and make some effort to keep good posture, dont slouch. Make the casting 10mm or so thick. Now if you sit or stand - that affects the shape. I decided to sit upright in a bar stool and read Kart Pulse
After the casting felt somewhat dry - I cut it open from the front and lowered it into the ground. Then I taped the cut shut, eyeballed that the casting stands true as it was cast and put it out of harms way to dry
After couple of days, it was dry enough. I smoothed most of the bumbs from the inside with coarse sandpaper wrapped around plastic bottle, rubber hose etc. I filled some voids with glasfiber bodyfiller . After the rough smoothing I painted inside and outside with gelgoat, then topcoat. I did this gelcoat + topcoat + sanding to the inside few times until the finish was good enough. The coatings also give the mold some rigidity. Dont be surprised if your ribgage isnt perfectly symmetrical. Humans are made without tape measure or water level
After coatings were dry and sanded smooth, I waxed the inside with mold release and applied polyvinyl alcohol
Second mold was laminated inside the first mold. I applied few layers of glassfiber twill until I had about 1.5-2mm wall thickness. I used polyester resin as it hardens quick
Before cutting the first plaster mold open to reveal the glasfiber mold I glued some wood sticks inside the glassmold so it would stay in shape
Then did some eyeballing how the glassmold fits to the seat. I added some bodyfiller to the sides to make room for padding. After the shape looked good, painted the glassmold with gelcoat, then topcoat and sanded/polished to a nice finish. Then wax + polyvinyl alcohol
Glued steel pipe to the wood supports, this pipe would fit inside a bigger tube that was attached to a vice. I could then rotate the mold while laminating
I used polyester resin as it dries fast and I dont get any skin symptons like when using epoxies. Epoxies are nasty stuff for skin. I laminated kevlar few layers and few layers of carbon on top. Laminate thickness at the back/front 1.5mm, sides 3mm. Back and front should be flexible - no need for thick laminate there. Ribcage gives under g forces and if the laminate is very stiff on all sides - it will press your lugns
Bought some 8mm thick foam rubber that has adhesive on its backside. Made the foam pieces bigger than the laminate - to give a nice soft edge. Sanded the foam pieces with power tools - final touch with oscillating sander smoothes out the marks. Applied electrical tape to the adhesive and folded the tape over. It stays on because of this fold. Electrical tape kind of tries to dig into the foam
Something I observed - prior this I made one mold while sitting in the kart. My thinking was that then the ribcage, body everything would be in driving position - So the fit would be perfect right ? I started the mold by cutting a piece of 1mm carboard, long and high enough that it would cover my ribcage. Cut some slits to it so it would conform but stay somewhat rigid. Put on a thick shirt, had my ribcage wrapped with wrapping plastic, then fiberglass twill soaked in polyester resin and on top of this again plastic wrap so the laminate didnt droop. Put a plastic bin bag to my kart seat and sat in to it. The laminate heats up - thats why the thicker shirt. It also emits nasty odor while hardening so mask is necessity. The reason why this didnt work - the mold becomes exact replica of the seat. All the bones,skin, muscles ( fat ) push the laminate right into the seat. The sides come straight. A exact replica of the seat. So in theory as the ribgage is rounded, the vest should also be round. Flat surface would concentrate pressure to one point on the ribgage. Roundshape that matches your ribcage distributes the load over all ribs. So ditched this mold and made the plaster one
Now question for all you kart racers who competed back in the day - when padded seats were available. Did padded seat cause rib injuries? What are your experiences in using them? Why did they go out of style? I havent used a padded seat so I have 0 experience. In perfect world I would like to drive without a rib vest and have been wondering would it be possible with a padded seat
I’ve been wondering same about padded seats. They seem to have gone out of style.
For sure modern rib protection is superior to the padded seats I’ve had. But on the other hand, the padded seats were adequate at the time given my more, eh, light stature back then.
Could be amplified by the prevalence of softer tire compounds these days. The hard compounds seemed to be more common at club and regional events in the past. Nowadays “medium” compounds seem to be the norm… demanding more of the rib cage.
I thought the padded seats died out as folks started using seats as a tuning element. I recall seeing them on rental type karts when I started but haven’t seen any in race karts.
When I raced 250’s in the UK we didn’t have padded seats but we would buy a seat a little bit too big and glue our own firm padding on to it.
Was the seating position upright as in sprintkarts or was the seat more horizontal like in superkarts? Were your ribs fine with just the padded seat? Did your ribs get sore - did you feel the seat supports struts etc at the sides? Was the padding laid so that it formed straight side? Or was the padding following ribcage shape - there was no empty space in the back corners of the seat ?
In general - I guess if the seat would be firm enough at the sides - at mounting locations - the seat wouldnt give in and form a pressure point. The side would stay straight while cornering. It would give large area of firm support. Now ad padding to a seat like this and maybe it would do a good job? In my NEK seat the sides have reinforcing rib so they are quite stiff in that direction. Only the mounting points give. Maybe its enough that the seat flexes mostly from the middle + bottom but sides are stiff (ish ).
In F1 as the drivers lay horizontal - theres a lot support for the body. Specially when the seat is exact fit to the body. I guess they dont wear any kind of rib protector? The seat just fits like a glove
Have you seen how they make custom fit seats using the big bags of plastic pellets and a reactive chemical that causes it to foam up? It conforms to body shape. I can’t see an obvious way to make this work for karts since we can’t have an oversized seat.
Yeah Superkart semi laydown seats. Those seats were very rigid and they kind of wrapped over you kind of had to twist yourself to get in as the edges were narrower then the rib cage. They worked really well if you took the time to contour the padding correctly. I just got back into karting (Rotax max) and had never heard of rib protectors before 
I am using one now however and I have the Ribtect which seems to work very well. I like what you did that’s awesome 
Whats your experience with Stilo Carbon Curva?
I am thinking to buy one but I cant find any review, feedback or a test.