I have a 76 elky that I am restoring and I'm working from the front to the back. I am curently on the interior and need some tips or advise on molding fiberglass, I'm useing a fiberglass resin and hardener (from Bondo) but I can never get it to work just right, and I end up sanding all the fiberglass away. Any help would be nice.

What exactly are you working on? It's pretty tough to fix a dash pad, but if you are modifying it, well that's different. If you are making new parts, like a consol, I'd say that it is at least 1/2 way up the scale on the difficult range. Remember, fiberglass is just like regular bondo, you ussually end up taking most of it back off, unless you're an expert at it. Just try to mold it as close to the end shape as you can, don't try to pile it all on in one coat, and DON'T mix it so that it dries too quick as it will deffinately crack out on you.
Keep us informed and we want pics too. 8) I'll be making a consol to fit in between my 80's bucket seats after I get it home from paint. And I will send pics of that too. It will be made of thin plywood, cloth and resin. Can't wait!

Try using fiberglass mat soaked in resin, this will give you extra strength and you can add on as many layers as required to give you the shape you want. You can also use clamps and plastic to get the shape you need .
When you get close switch to chopped fiberglass in a can like bondo it spreads eaisly and will give you any shape you want but apply in thin coats so you will sand small amounts each time.

You need to give us more information to work with here on exactly what you are trying to do and what is going wrong.

Are you having problems with the resin? Getting the right shape? What are you making? These all will get different answers and suggestions.

I have done some amount of fiberglass work and might be able to give you some basic pointers but not without more background.

I'm glad this post is still alive. Here are just a few things to watch out for, and think about when we are working with fiberglass.
PLEASE do yourself a favor and wear a respirator when sanding. You don't want to have these fibers in your lungs. They will hook on and never leave.
We have all seen the shows on TV, and it really only takes some practice and foresight when laying out what you intend to do. There are alot of books and web sites that will help with the basics. The best way to learn is trial and error. And of course the more you do the better you get, well,,,,, for most of us. :-)
It'll take a little woodworking skill, (unless you are working on body parts) ALOT of patience, and a vision. Don't be affraid to ask people questions where you live. If they are cool, they will take the time.
If you can build a frame of thin wood, glued or screwed, and get the fabric spread over it, you can then start adding the resin. It's not all THAT easy, but pretty close. Give it a try, you might be surprised.

When working with polyester resin, you need to remove the paraffin wax that forums on the surface when it cures, so that the next application adheres to each other and no just sits on it. you can sand it off or use acetone to remove it. it will clog up sand paper.
I build airplanes from wood, and then skin them with fiberglass cloth, and resin, (I prefer Epoxy resin instead of polyester resin. It doesn't have the fumes, and works the same) If you take saw dust or micro balloons or ground up styrofoam, and mix it into your resin it will be alot easier to sand and shape, then top cover with spot putty to seal the surface.

My two cents worth! Pat

When working with polyester resin, you need to remove the paraffin wax that forums on the surface when it cures, so that the next application adheres to each other and no just sits on it. you can sand it off or use acetone to remove it. it will clog up sand paper.

Or use the laminating version of the polyester resin which contains no wax and thus leaves a sticky uncured surface.


I build airplanes from wood, and then skin them with fiberglass cloth, and resin, (I prefer Epoxy resin instead of polyester resin. It doesn't have the fumes, and works the same) If you take saw dust or micro balloons or ground up styrofoam, and mix it into your resin it will be alot easier to sand and shape, then top cover with spot putty to seal the surface.


Yep done that too. You don't mention that Epoxy is compatible with foam while polyester will melt it. This can be worked around by laying a couple coats of latex paint over the foam before glass and polyester resin.

Another gotcha is to never try and mix epoxy and polyester resin in the same project. The epoxy sucks stuff out of the polyester and prevents it from ever curing.