I am currently rebuilding an old steel bike with some modern parts and am searching for a OSPW because it looks quite cool. However a "real" one from CeramicSpeed seems way to expensive for just looking cool. So I checked AliExpress for some cool looking ones and obviously found some. After some research I found out that the main Problem with them is, that the inner bearings are non sealed bearings meaning they get dirty extremely quickly and therefore are not a good upgrade because they probably break before the standard one and cost me more watts than its worth changing them (source for the open bearings is this video here from Trace Velo)
To fix my Problem I was thinking of either adding seals or just saving the ceramic balls and transplanting it into a steal ball bearing housing with seals. Henceforth my Question is firstly: Is this even possible? I am aware that you can rebuild and therefore change parts when you are using cup and cone bearings however I never heard from anyone that they done it with cartridge bearings.Secondly is this feasible and doable without specialist tools and experience?
Thanks for your help
Edit: Weiwen Ng's Answer pretty much sumed it up already. Getting replacement Seals would be quite impossible especially because one of the bearings had nylon races and both had no groves cut out to hold any seals. My other idea of reusing the ceramic balls was proven impossible as well because they where running out of true (probably because the balls aren't really round). I therefore pretty much went with Weiwens idea and just bought new 689 ball bearings with proper seals (I luckily had a small shop specialized in sealing bearings that had cheap bearings available) and pressed them in. That all worked quite nicely and therefore I am now the "proud" owner of an OSPW with fully sealed ceramic bearings for round about 15€. I'll give another feedback when I need to replace the bearings on how long this hack worked out. For now I can just thank everyone who gave his answers/comments to help me with this idea.