underfloor bolts captive nut turning

[Berti]

im repairing the rear corners of my bailey orion under the floor and need to remove 4 bolts 3 of them are turning but the captive nuts are turning as well.
ive got one out and its 100mm.
i can cut the heads off and then fit in a new piece of ply but could i use long screws to replace the bolts to re secure the floor?

 

[Mr Plodd]

Ask yourself why bolts were used in the first place. Here's a clue, the plywood floor survaces are about 3mm thick, thats not very much for a screw to fix into is it?

Stick with bolts (and big washers)