What type of body filler do you use?

[JPSmit]

Was at my night school body work course last night and our teacher showed three different types of filler.

1. long strand fibreglass filler
2. short strand fibreglass filler
3. polyester filler.

He actually mixed the fibreglass strand filler with some regular filler to make it creamier.

I must admit that I cringe when he proposes fiberglass as I remember bodged repairs from my youth. At the same time, I remember when any "bondo" was a derogatory term and now even the best Chip Foose design has a skim coat of bondo.

So, what do you use?
What do you recommend?

 

[Grantura_MKI]

I use Rage. Mixing filler with products like Marglas, etc Has been done for years. I have in the past mixed fibreglass resin in with the filler. This process helps to eliminate pin holes and aids in the application of the filler.
Cheers,
D.

 

[DiamondShine]

I use polyester filler most of the time

 

[DrEntropy]

USC AllMetal for most stuff, fiberglass for patch work.

NO filler other than fiberglass on the plastic cars.

 

[Britishautobody]

I use Base/Coat Clear/Coat USC plastic filler as my over all.
Evercoat glaze coat 0417 for a final putty.

I also use All Metal for base fill or Duraglass short strand fiberglass or in rare cases Long strand .

A couple of things about fiberglass filler, It has excellent adhesion over a properly prepared surface. Always use this or all metal over patch or welded areas before a plastic filler. The reason is Fiberglass is a waterproof filler unlike regular bondo, it will fill the small imperfections in your weld areas that will keep your patch areas from developing a bubble from moisture wicking through into regular bondo. It will take only one small pinhole you won't be able to see too ruin a finish on a panel. All it takes is a finger full of glass or All Metal smeared across the welds etc, then use the filler of your choice.

I have also mixed fillers in the past, I don't recommend it if you need a moisture proof barrier.
A properly worked plastic filler or Bondo job can last decades. The people who abused it years ago gave it the bad name.

My 2 Pence!

 

[EinsteinsDad]

What about lead (or lead-free equivalent)?
Are the synthetics better, or just easier?

 

[Gray_Cat]

Do you use the filler directly over the weld; that is no primer first?
Thanks!
Roy

 

[Britishautobody]

Dealing with lead,good question,aside from the harmful after effects it is much harder to work with. I prefer the above mentioned products,most people won't pay out the time and money it would take to metal finish or lead a car mostly because their cars value won't warrant such a process. Synthetic products if they are used properly will last decades, I have dug into 20 year old plastic filler that would probably have lasted another 20 years.

Yes, I use fiberglass filler directly over a welded area or possible pinhole potential area, the bond to bare metal is fantastic! Use right over bare metal, then i prime etc.