Buy a brass barb fitting of the proper size from the hardware store for $5. You don’t even need to tap it, just drill out the hole about 1/32 smaller than the size of the brass fitting. Then screw the fitting, threading it into the plastic. Put some JB weld maritime putty around the end. Idk what size you need but link below is the kinda thing you’re looking for.
Buy a brass barb fitting of the proper size from the hardware store for $5. You don’t even need to tap it, just drill out the hole about 1/32 smaller than the size of the brass fitting. Then screw the fitting, threading it into the plastic. Put some JB weld maritime putty around the end. Idk what size you need but link below is the kinda thing you’re looking for.
https://www.amazon.com/Anderson-Metals-57001-0404-Fitting-Adapter/dp/B002SAO7XQ/ref=asc_df_B002SAO7XQ&mcid=b69668fccd64340dab85d40192819373?tag=bngsmtphsnus-20&linkCode=df0&hvadid=80539344142694&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=m&hvlocint=&hvlocphy=&hvtargid=pla-4584138871873597&psc=1
This but only as a temporary solution. Replace it when you can.