i recently acquired a set of fiberglass fenders very similar to these http://cgi.ebay.com/ebaymotors/Type1...Q5fAccessories but not those exactly. i wanna get some opinions on what would be the best thing to use to fix the imperfections / pores in the fiberglass.

 

body filler or a heavier primer

 

A high build primer is also referred to as "self etching"... Just in case you have trouble finding it.

 

nope, high-build and self-etch are two totally different things.

high build is just that, its sprays on thick where as a self-etch primer is used on bare metal surfaces and over body filler.

to fix the pinholes, i would just sand the whole fender with 600grit sandpaper, spray on about 4 coats, spray on a guide coat and then block sand with 600 to smooth it out

 

and to add to keeble's advice- if you are trying to achieve a very fine finish you may want to use a good finish primer after sanding the high build primer.

Some primers have the ability to be used both ways, less reducer will yield a high build and a little more of the reducer will yield a finish primer, this saves you from having to buy more products