Auto body repair & detailing: Fiber glass help, rust holes, rust hole

Question
OK i bought a 1989 toyota celica and i'v been fixing holes with bodu but some are to big so i used some fiber glass to try to fix the biger holes. i got some done .but it was realy hard to do. its realy messy and i was wondering if you could give me some hints.My rust holes are behind the front wheel walls and on the back wheel walls more twords the front...thank you..
ps..im only 16 this stuff is pretty much new to me..but i thinki m doing an ok job..

Answer
If you are using fiberglass cloth and mat,yes it is messy.A better product to use would be a fiberglass reinforced body filler such as dura-glass.Fill the holes with expanding foam trim off the excess and apply a coat of glass filler.Before you foam it lightly hammer the rust hole inward so no rusty metal will be sticking through your coat of filler.Remember the only way to stop rust is to replace all the rusty metal so this is by no means a permanant fix.