Many years ago, when access to trials parts was very poor and people were running 19" or 25" rims, most of them ended like that. My mate had a shelf full of rims with sidewalls which just exploded under tyre pressure. I had it happen too, even remember welding a rim because I couldn't get a 19" anywhere. Needless to say it exploded as soon as I got reasonable pressure into the tyre. To put it short, it's not going to last, but when it bursts, it's going to be funny. So keep riding it.