MTFCA Forum

I am closing in on my metal work on the touring.

I assume body filler has advanced since I was young.

What do you guys find "friendly" to work, sand?
Also that will not pop off. I used lead on major areas of wear, but I need to skim coating it for all the minor low spots.

I will be using Acrlic Lacquer I snuck into Kalifornia.

I have restored many vehicles, including paint, and prefer to only use Evercoat Rage Gold. Sands easy, lightweight. No shrinkage or lifting. I never use Bondo brand filler on serious restorations. It’s heavy, and eventually will shrink and lift. Only use professional products. I use epoxy primer on bare metal.

Make sure you clean the area really well and rough it up a little. It will last as long as your T.

Mr. Halsey.

You are correct to assume that polyester auto body filler is far removed from the early days of it's introduction to widespread use right after WW II. It was an inexpensive replacement for the difficult to use lead body filler that existed before the war. It was much easier to use and required fewer tools and experience. I've even heard stories about shady used car lots using plaster of paris and cardboard as a quick fix for rusted out, or damaged body work.

The difference between today's polyester body fillers and the "Bondo" of the post WW II era is several things. The biggest difference between yesterday and today is the dry media that's added to the polyester or, as it's sometimes called boat resin. The original additive to give the material some body was simply- talcum powder. The same material that you put on your baby's south side to keep it dry. It was unstable and constantly moved and shrank. Several years after its application, it began to move and shrink resulting in cracking. Often times it would wind up on the road as you drove along. To exacerbate the situation, amature users failed to properly prepare the surface and the polymer failed to bond to the base surface.

Today's automotive body filler is far and away from the products of the past. Today's fillers no longer use talcum powder. They use what are called "microballoons". These are microscopic spheres of glass and are not porus or unstable when mixed with resin. The resin has improved also. It's no longer simply polyester resin. The resin of today is an advanced formula that is much more stable than earlier versions of the old "boat resin".

One thing that must be stressed is the prep. The surface that is getting the filler must be CLEAN and free of wax and silicone. It also should be hammer and dollied out needing minimal body filler. You shouldn't have to roll the car on it's side to pour on the half gallon of filler you just mixed up.

One last bit of advice. READ THE DIRECTIONS ON THE CAN! The ratio of filler to catalyst (that comes in the little tube) is important. While the mix ratio is very forgiving, everything has it's limits. Be aware.

I hope my run-on explanation didn't put you, or anyone else that read this to sleep. Good luck.

Best Regards,
Mike "modeltspaz" Spaziano.

I was told by an expert restorer that primer goes on before the bondo. That the primer will seal the metal better than the bondo and prevent rust in the future. Then proceed as normal after the bondo is sanded. Makes sense.

There are fillers that are specifically designed to apply over primers. Make sure that you do your research first to avoid failure.