A simple thing I've seen done in other DIY workshops is to hang some peel-ply as a curtain material as it it quite strong and durable yet still lets light through.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

If you have compressor you can buy pneumatic sander,  and they they have efficient dust removing system, and you can wet sand using it. Abrasive paper for pneumatic sanders have holes to remove dust.

~~~Everytime I hear sound of demoulding part I have eargasm~~~

I have tried attaching a vacuum cleaner to my power sander and while it reduces the dust somewhat I still seem to get dust everywhere, unless perhaps I could buy a different power sander which is more effective?  I cannot wet sand with a power sander and hand sanding what I need to do would be very slow.  Perhaps it is possible to buy a waterproof power sander?  Although that may just chuck water all over the place which will then evaporate leaving nasty fiberglass dust.

I mean that you can attach vacuum cleaner to your sanding block, or you can wet sand. 

~~~Everytime I hear sound of demoulding part I have eargasm~~~

perhaps you have a smaller workshop but vacuuming a 40m^2 room with 2 workbenches, quite a few shelves, all the contents of said shelves, ladders etc on the ceiling (yes, the dust gets up there too...), tool chest, pillar drill, welder etc, various bicycles etc etc would take quite some time and not something I'd want to do on a regular basis.

Hi, I think that using vacuum cleaner is easier.... think about it sure you can construct tent. 

~~~Everytime I hear sound of demoulding part I have eargasm~~~

I've generally done sanding of fibreglass outside because it's messy however the current weather makes working outside inpractical so I'd like to do it in the workshop.  The problem is when I sand in the workshop the dust goes everywhere and gets all over everything.  While I ware a respirator while I am actually sanding, I don't use one all the time I am in the workshop so I could be kicking up dust which has settled on things and then breathing it in and I know it ain't good for me.  So I was thinking if it would be possible to construct somekind of tent in the workshop to contain the sanding dust.  Either a ready made tent or a self made one.  I was wondering if clear plastic sheeting or maybe tyvek roof membrane would be good matirials to use if I was to make my own tent.  Has anyone ever tried making anything like this?

Thanks, lee