Im having the same issue Ive tried so many iterations of mod load order and water settings, Cant seem to stop it happening.
Im just waiting for it to happen to kanajashi on his current youtube series but he seems to be okso far.

I've been experiencing the same issue as well.
I place down a bunch of small grid blocks that are connected to a rotor, but as soon as I start to weld them up, something (maybe the block itself) explodes and flies up into the air and it crashes into the ground nearby or it hits the water and skips along the surface for a few km's.

It was funny as first...not so much now.

I've been having the same problem. Hopefully, this gets resolved soon, or what's causing the problem is highlighted.

Can confirm its doing it for me as well, the instant a block is welded when attached to a piston head the head spazzes out acting like it would if you built it in a spot occupied by another block. Phantom forces then take over and turn everything around it into a crater. Not the first time this has happened either and was the main reason I stopped using the mod last year when every time my boat or rover would touch the water it turned into a crater as well, (Update: Just dropped a small and large grid block onto the ground under water and it made a crater the second I welded it up. so good lick fixing your boats now.)

Mine also had a weird affect where they would float off randomly at times as if they were possessed

Yeah, haven't been able to figure out why it's happening yet

Originally posted by Jakaria:

Yeah, haven't been able to figure out why it's happening yet

I can send you the file to the world I have and see if you can reproduce it unless you already can and just cant figure out why it does it.