All-Metal filler vs Lead or Bondo

[NY65Fastback]

I need to fill some body seams where there used to be lead. I dont want to use bondo, mostly because the stigma of old Mustangs that seem to trade their metal for bondo over the years until they are about 90% bondo, and partly because I have seen restored cars crack at the seams as the car flexes over time.
All-Metal is supposedly a better choice over lead since its a little safer to apply and easier to shape since it is spreadable and shapeable.
Here is what I have to work with.

Anyone ever used this or something like it?

 

[dsblk93gt]

Epoxy primer 1st then I would use a quality plastic body filler. Plastic filler actually is LESS likely to crack than the all metal fillers, contrary to what many think or hear. It is brittle and does not flex, so it cracks. Plastic filler will flex some. My father always used to lead cars back in the day but if you do not do it right you are screwed.

 

[NY65Fastback]

Thanks for the reply. I was thinking about going that way but wasnt sure if plastic filler was good for that application since it flexes but I guess the paint will flex with it.

 

[Chevy_Guy]

Urethane fillers are what I use if there is a chance of flex.

 

[dsblk93gt]

Body Filler vs. Lead

 

[1980rustang]

There is also fake lead you use it like lead but unlike actual lead its still legal I'm in classic car restoration in school so I've been using this crap lately

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[NY65Fastback]

Thanks everyone for the replies.

 

[ProjectPatsGarage]

I would try the lead or pay someone to apply it for you. You can buy the stuff right from eastwood. The problem with any plastic fillers is that they will crack at any thickness greater then 1/4 inch has been my experience. They are also very porous and do not protect the metal from rust. I've seen plenty of cars where filler was used instead of lead and the seams are always cracked and rotted out. Very common when people do vinyl roof to hard top conversions because they did not lead the roof seams when they put vinyl roofs on cars.