Please make sure you are posting in the correct place. Server ads go here and modpack bugs go here
The FTB Forum is now read-only, and is here as an archive.
To participate in our community discussions, please join our Discord! https://ftb.team/discord
I would call it a bug (along with behaving like water in all other ways), but I don't think it's something the Buildcraft people have any intention to fix.