Well, I decided today to try and use a fiberglass repair kit to patch a hole in my floor. Oh Boy what a mess! I didn't realize the patching material just kind of turns to a glompy mess after dipping it in the solution. Is there a better way to use fiberglass? Is there a patching material that doesn't turm into such a mess after putting it in the stuff? Is body filler a better way to go for minor holes like this? I was thinking the fiberglass would hold up better tham bondo but now I'm not so sure. Yes, I realize metal would be the best way to go but I plan to sell the car in about a month anyway. It's not too badly rusted, I found a hole in the rear driver side floor, cleaned it up, painted it heavy with rust encapsulator and attempted this really messy fiber patch. I tried to patch the hole from underneath too, pretty much a disaster. Glompped fibergalss all over. Mechanicals are fun, this kind of work is just annoying.

Look at the POR 15 products.

http://www.por15.com/

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car

Years ago, a friend and I covered the extrerior of a boat with fibreglass and we first spread the polyurethane liquid over portions of the hull and then pressed the dry fabric into that. Then we spread more of the polyurethane into that surface. It looked really good when we were done.

I don't know if that is still a method of application but it was very easy. Our polyurethane was thick enough that it would have been difficult, but not impossible to soak the fabric before application.

Maybe this method would work for you.

You did not say what size hole you were dealing with... this can affect the patch advise...
Por15 products are great... and they have expanded to include some things designed for floor repair.
If you look at the Eastwood Co. site you will get lots of ideas from the tools which they offer.
Generally it is best to find one brand of fix it stuff and stick with it from one end of the job to the other... that way you do not take a chance on one item being incompatible with another and you having to take both off... talk about a mess ....
Many times if you are going to use Fiberglass it is best to rough up the surface and be sure all the rust is off,, including any and all dust from wire brushing etc.. and all traces of silicone and wax... ie, treat the area the same way you would prep for a paint job... I use Klix88 silicone and wax remover and power dry with compressed air.
If you have an actual hole it is nice to place a piece of metal on the area and pop rivet it in. This supports the fiberglass and the resin so it is not leaving the work area.
The resin gets sticky fast.. so one of those rollers with grooves in it helps smooth out the cloth ( if that is what you are useing) and runs the air bubbles out to the edge...
Put disposable gloves on. Be sure you are in a well vented area.. you CAN get sick from the fumes...
Many times it is best to do this in steps... with some sanding in between , especially underneath where you may have things which look like stalagtites...
After you are finished and have let it cure as long as possible.. you may want to put some wax on it... some fiberglass will be weeks getting non tacky if you don't.. some claim this is to help cure it... but I don't believe that...
I suspect DCM means ' fiberglass resin' instead of polyurethane..

Leathermag

I did mean resin but it has been about 40 years and I forgot. Thanks

Dave