The consensus on here from the research I have done is most think filler should go on good clean bare metal that is ground with 24-36 grit to create a good "tooth" for the filler to have the best opportunity for superior adhesion that will last years if not a lifetime.
Do you apply bare metal body filler?
For small repairs, you can bog directly over the bare metal. If the repair is larger, or you're looking for a longer-lasting job, apply a base coat of epoxy primer before laying on the filler.
Should metal be primed before body filler?
For maximum corrosion protection, exposed bare metal should be covered with another coat of epoxy primer prior to Primer Filler stage. 4 To more easily identify low areas, apply Guide Coat to body filler before final sanding.
Do you have to sand to bare metal for body filler?
First step: Prep the Surface
If you do not prep, the body filler will NOT stick to the surface well. Before applying, paint needs to be sanded to the bare metal. Make sure to sand outside of the repair area as Bondo will need to be spread and applied wider than the damaged area.
Will metal rust under body filler?
After many years of media blasting tons of stuff, and seeing tons of Bondo, I can confidently state that body filler on bare metal WILL allow rust to build up UNDER the said filler. So, after you blast your stuff, or get it blasted, get it in Epoxy primer, THEN do the bodywork.
16 related questions foundCan you bondo over bare metal?
NO, never. bondo goes over bare steel only. Never over any kind of paint, primer, etc.
What primer goes over body filler?
If spraying two coats, the product must dry overnight before applying over body filler. Wet sanding epoxy primer is usually the best way to prep it because epoxy has a tendency to clog paper when sanded dry. Polyester primer is a very thick two-part product and is used when there's a good deal of bodywork.
Can you put body filler over rust?
The mere application of body filler over a substrate won't stop rust, Miller said. Fillers might contain corrosion resistance and slow the process, “but they're not gonna stop it,” he said. Put filler on rust, and “(the rust) may continue to grow,” he said.
Can you paint straight over body filler?
They need to be primered with a fill primer (not epoxy). If you don't prime the filler then the filler will absorb the paint, which will end up looking like a bullseye in the paint after you're done.
Can you put body filler on top of paint?
Fillers and putties will normally work OK over properly sanded (80-180 grit) cured OEM paint. However, with so many different types of aftermarket paint available (lacquer, enamel, urethane, water-based). We recommend that all paint be removed where filler is to be applied.”
Is there a filler for metal?
Permatex Liquid Metal Filler is an easy-to-use filler that can be drilled, filed, sanded and painted. It forms a long-lasting, metal-tough bond and works on metal, wood, and concrete. This Liquid Metal Filler provides excellent adhesion to galvanized metal, and repairs cracks or porosity leaks in cast metal parts.
What is the best primer to use on bare metal on a car?
Both Epoxy Primer and Self-Etch primer (Self-Etching primer) can be used on bare metal. Both provide corrosion protection, and both can be top-coated with primer surfacer.
Can you fiberglass over bare metal?
Fiberglass is a very durable material that will bond to almost any surface, including plastic, metal, wood and Styrofoam.
Can you Bondo over por 15?
CAN I USE BODY FILLER OR PUTTY WITH POR-15? Yes. First paint both sides of the rusted area with POR-15; then use body filler or putty as soon as the POR-15 is dry to the touch.
Do you need to prime over filler?
You will need to prime the filler before painting to prevent subsequent coats being absorbed more rapidly than on other areas.
Why does bondo show through paint?
Yeah, that's totally normal. It's just that the patches of bondo soak up the primer differently than the metal but epoxy is the way to go. Just let it dry and give the entire truck a light sand with 400 grit and apply a couple more coats of epoxy.
What is the difference between body filler and putty?
“The difference between putty and filler is basically the “talc” in the product. Most of our Rage line of fillers have Eco-Resin technology. With that, we use similar ingredients to putty. Therefore, when using it, the putty is no longer necessary in the repair process.”
Can rust Reformer be used on bare metal?
Rust Converter is intended for heavier rust. If applied over bare metal, it will not cure properly and can actually cause light flash rust. If you have an area that you sanded off rust completely, Rust Encapsulator is the product to use in a situation where you have bare metal.
What happens if you put Bondo over rust?
However, Bondo shouldn't be used on every kind of rust hole. Because it can't support any weight or protect you in a crash, you should never attempt to use Bondo for rust holes in anything structural, such as frame rails or reinforced areas on unibody vehicles (i.e. most modern cars and crossovers).
How long does it take Bondo to dry without hardener?
When used according to the manufacturer's recommendations, Bondo takes 10 to 15 minutes to dry enough to form a sandable surface.
Is it OK to put Bondo over primer?
You can apply Bondo over primer, as long you sand the primer first. This ensures the Bondo sticks well. You should also sand the Bondo afterward to have a smooth finish. However, you must apply the Bondo once the primer has been cured.
How do you use metal filler?
Place a 3-inch diameter circle, approximately 1/2 inch thick of Metal Reinforced filler on a clean non-porous mixing surface, add 35 drops of the supplied liquid hardener to the puddle (using a push pin in the end of the hardener tube will create a hole that is best to the correct drop size.
What comes first primer or Bondo?
To answer your question: You can do it either way. Epoxy primer has better adhesion to metal than bondo does. Any other primer, you probably cannot use under bondo, check the tech sheets for exact info on it. Even if using high build urethane, you need to put an etch, or epoxy primer under it for best adhesion.
How long can body filler last?
If applied correctly, Bondo can last for more than five years. In most cases, Bondo filler lasts for two to three years. There are car owners who have had Bondo hold on to their vehicle's bodies for even eight years.
