Need Fiberglass repair help

[acesneights1]

I have 3 Motorhomes. All near Identical. 2 Have major Damage to the fiberglass. All three have serious cracking of the gelcoat. I have done a decent amount of autobody stuff on non professional level but have never worked with fiberglass. My questions are:
Should I make the repairs from the back of the panel or the front or both ?
Do I use Cloth or gorilla hair ?
Polyester resin or Epoxy ?
Also Is it work trying to redo the gelcoat or should I just shoot it with enamel ?
Every one of these motorhomes I have ever seen cracks like mine did. I plan on painting the green Travco in a Camo pattern. The white one with the blue stripe I want to paint back close to original.
How do I do the fiberglass repair ? Grind it out ?
I stripped some of the gelcoat off the parts travco to see what would happen. i comes off pretty easy with a high speed air grinder with a 6 in disk but has to be done carfeully so's not to gouge it. I tried using a DA with 80 grit but it took forever. The grinder was much quicker. I was told to skin the fiberglass with bondo and paint it. Is Gelcoat not worth it ?
Thanks.

[acesneights1]

More pics. The one busted up around the headlight will most likely be dismantled for the other two. Also the green ne looks like it was near a fire or something. I want to fix the green one where it was "beercanned" also it has damage by the back bumper. Do I fix it from the back or front ?

[Len]

When we have bad gel coat we usually sand it until it's gone then apply a filler primer over the raw glass then sand it smooth and paint it.

When the glass is broken we prep and reinforce the back side using fiberglass mat and resin and after it hardens we "V" out the cracks on the front side and fill them with fiberglass paste then prime, level the primer then paint.

[acesneights1]

Thanks. What resin is best ? Epoxy or poly ?

[Len]

Thanks. What resin is best ? Epoxy or poly ?

I use SMC resin because it can be used on SMC or other types of fiberglass.

[acesneights1]

And the fiberglass paste what is that ? Just resin ?

[LS6]

They stopped using Lacquer ???? When ???

You can still get lacquer, but it is NOT very durable. A lot LESS durable than it used to be, and it wasn't very durable even then. TCP Global still carries it. http://www.tcpglobal.com/autocolorlibrary/
LS6

[acesneights1]

Oh the lacquer thing was just a joke . Im behind the times...
Then again I still use brazing rods.

[Len]

And the fiberglass paste what is that ? Just resin ?

These types of products come in long strand, short strand or milled. I use mostly short strand. It's used similar to bondo but it's moisture resistant and gets much harder than standard body filler. It's good for certain jobs but it's much harder to sand smooth and other types of body filler.

LINK

[acesneights1]

I was looking at it again over the weekend. It will not be easy to get to the back of it. Can it be fixed from the front ? Also do you sell or have you ever used evercoat vettefill ?

[Len]

I was looking at it again over the weekend. It will not be easy to get to the back of it. Can it be fixed from the front ? Also do you sell or have you ever used evercoat vettefill ?

To fix it from the front I would grind around the damage in order to lower the surface then coat around the damage with resin and place a precut piece of mat in the wet resin and allow it to harden then coat the mat with more resin. Allow the resin to harden then grind off the glaze and either apply more resin or apply fiberglass paste on top then level it. You want the mat to be below the surface level so that you don't need to remove any of the mat in order to level it.

[acesneights1]

Ok I started in the back. I can get to that one. the PO did a really lousy attempt with chicken wire and bondo. I cut the damaged area out and will attempt rebuild it. I have some smooth plastic I will coat with wax and tape to the outside and start form the inside.DSCF0011.jpgAttachment 9364DSCF0009.jpgDSCF0010.jpg

[Len]

Ok I started in the back. I can get to that one. the PO did a really lousy attempt with chicken wire and bondo. I cut the damaged area out and will attempt rebuild it. I have some smooth plastic I will coat with wax and tape to the outside and start form the inside.DSCF0011.jpgAttachment 9364DSCF0009.jpgDSCF0010.jpg

Lookin good, keep us posted.