Epoxy ?

Can someone please enlighten me when you talk about epoxy coating your wooden Tears am i to assume you are talking of the following...
I would take that to mean you cover it with what we would call here in the Uk anyway fibreglass resin, which i would imagine would totally water seal and wooden parts if done well.
Or have i missed the point completely ???
Also is there anything that is required to do to the wood prior to "epoxying" it then as in prep..
Pressuming it is fibreglass resin you speak of can it be coloured so as not to show trhe wood below as my VW camper which will be towing it is white it would be nice to have it white to match..
Uk stockists of such materials would also be of great assistance.
One last question being pressuming i go for a wooden construction where the roof meets the side walls or front and back walls the top sheet would obvioulsy go over the side wall Yeh ? and then know matter how good you were there would still be a gap of some sort what do you do with this all be it small gap, in order to keep water out !!!!, my thoughts would be to fill it full of seam sealer as used in motor trade or caravans and fibreglass sheet over the top of it, rubbing down until totally smooth, am i right is there an easier way or am i just plain crazy ????
All assistance appriciated of course, bear with me i'm only learning
I would take that to mean you cover it with what we would call here in the Uk anyway fibreglass resin, which i would imagine would totally water seal and wooden parts if done well.
Or have i missed the point completely ???
Also is there anything that is required to do to the wood prior to "epoxying" it then as in prep..
Pressuming it is fibreglass resin you speak of can it be coloured so as not to show trhe wood below as my VW camper which will be towing it is white it would be nice to have it white to match..
Uk stockists of such materials would also be of great assistance.
One last question being pressuming i go for a wooden construction where the roof meets the side walls or front and back walls the top sheet would obvioulsy go over the side wall Yeh ? and then know matter how good you were there would still be a gap of some sort what do you do with this all be it small gap, in order to keep water out !!!!, my thoughts would be to fill it full of seam sealer as used in motor trade or caravans and fibreglass sheet over the top of it, rubbing down until totally smooth, am i right is there an easier way or am i just plain crazy ????
All assistance appriciated of course, bear with me i'm only learning