Any new generation body fillers?

[Fordiesel69]

So I plan to help fix a truck that has blistered rockers, but they are not yet to a point of being rotted out needing a weld job just yet. We need to grind them down and expose some small holes, blow the debris out from inside, then my goal is to fill over the holes with a skim coat of some newer fillers, then a repaint, and texture coat. After say 30 days, my plan is to spray Krown on the inside, then hand brush on Woolwax / PB Blaster Shield on the outside just before winter. I assume this will get my friend 2 more winters before a re-weld will be needed.

I have personally used tiger hair, Dura Glass, and Bondo. I have also used Keystone / LKQ's store brand generics as well. The issue is, these fillers do promote moisture and the metal around the filler just rusts as if you have not touched it. Looking to see if there are any space age new products out of the market that work better.

 

[Trav]

Grind it down good with a flap disc, clean with IPA and use original JB weld on any rough looking spots and pin holes. Just put it on with a spreader like filler pushing it in with some pressure not just a skim coat. Short strand Tiger Hair is not talcum based and will not absorb moisture.

 

[doitmyself]

My experience with DIY body work decades ago led me to use fiberglass cloth with resin. It does not absorb moisture like the bondo products.

 

[Fordiesel69]

Anyone else have opinions? What about "all metal" by USC?

 

[cjcride]

I asked the owner of a body shop with very good reputation here in Toronto (rust belt) why his quote for some Corolla rust was about 30% higher than 2 other nearby shops.
He pointed out that his guys cut out the rusted area and weld new metal in.
He pointed out that they also use a metal filler paste, not the typical stuff.

His work lasted till I sold the car, almost 6 years later.

 

[Trav]

I asked the owner of a body shop with very good reputation here in Toronto (rust belt) why his quote for some Corolla rust was about 30% higher than 2 other nearby shops.
He pointed out that his guys cut out the rusted area and weld new metal in.
He pointed out that they use a metal filler paste, not the typical filler.

His work lasted till I sold the car, almost 6 years later.

That is one way but not the only way to repair rust, depending on if the rust is in a structural are or just cosmetic bonding with a product like Lord Fusor is IMO a much better way. Fusor is approved and recommended by OE and unlike mig wire does not attract rust on the back side of the repair.
The OP said..

So I plan to help fix a truck that has blistered rockers, but they are not yet to a point of being rotted out needing a weld job just yet

I have to assume that he doesnt want to get into a cut out and replace job but that is his call. We used to use a Ditzler product called Aluma-Lead which was pretty good, now USC has their metal filler but believe it or not for small stuff the original JB weld is just as resistant to moisture absorption and is at least as strong. I have replaced rocker skins on framed vehicles (not uni bodies) by bonding and by welding and the bonded ones were still rust free after 15 years.

Check it out..

https://www.parker.com/content/dam/Parker-com/Literature/Assembly---Protection-Solutions-Division/Product-Catalogs/Product-Catalog---Fusor-Repair-Adhesives-Catalog_PC3000.pdf

 

[Snagglefoot]

I highly recommend Rust Bullet on metal that has been ground down. It requires two coats since the first coat will out gas a bit. Your Bondo will go on top of that. Wear a cartridge mask when using it.

 

[JHZR2]

I had to fix something like this on my high mileage Ram.

You can see what I did here:

Minor floor rust repair

Here's a consideration that hasn't yet been mentioned. JHZR2 is in New Jersey, which eliminated its safety inspections for most private vehicles some years ago. For the rest of you with a similar problem in other states, that kind of rust could be a real problem during an inspection. In...

bobistheoilguy.com

Structural panel adhesive on the outside (all surfaces covered including non-bonding surfaces so the epoxy seals and adds corrosion inhibition), then POR Patch which is a thick coating that cures hard.

It wasn’t a rocker, and you may not want to do the metal. But the 303 patch may be another option that will provide some corrosion protection.

 

[JHZR2]

That is one way but not the only way to repair rust, depending on if the rust is in a structural are or just cosmetic bonding with a product like Lord Fusor is IMO a much better way. Fusor is approved and recommended by OE and unlike mig wire does not attract rust on the back side of the repair.

Since the OP doesn’t want to install new panels, what would the fusor adhesive do? Just be installed and set up on top of the rust and in the holes to clog them? Or would it be used for a cover panel?

 

[Wingo]

Short strand fiberglass filler. Just get the rust taken care of first.

 

[Trav]

Since the OP doesn’t want to install new panels, what would the fusor adhesive do? Just be installed and set up on top of the rust and in the holes to clog them? Or would it be used for a cover panel?

For a small patch over the area with minor/pin holes. Very easy and quick to do, once it has cured the patch is easily blended around the edges with a flap wheel.

 

[Nessism1]

I'm a fan of Por-15. Remove as much rust as humanly possible, and as the last step, cover up the area with a couple of coats of sealer paint before applying your primer and top coat. My experience with this method have been good...fingers crossed.