how to use bondo

First step: Prep the Surface

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. (36-grit to 220-grit should do the trick for body filler application).

How do you smooth out Bondo?

Cut and sand

Once the Bondo cures, it’s time to sand. Power sanders are OK to break the surface and knock down any high spots, but hand sanding with the body contour is the best way forward. Cut in with heavier grit sandpaper and work out to about 80 grit to leave a tooth for the following skim coats.

Do you sand Bondo between coats?

Between each coating, sand the hardened putty with 80-grit sandpaper to remove excess Bondo. The coarse sandpaper will also rough up the surface giving it the tooth needed for the subsequent coating of Bondo to achieve good intercoat adhesion.

Can you use Bondo without hardener?

Can I Use Bondo without Hardener? Bondo needs a hardener and vice versa. You can’t use one without the other. If you have a project that needs Bondo filler, ensure that you buy a hardener as well.

Should I prime before Bondo?

NO, never. bondo goes over bare steel only. Never over any kind of paint, primer, etc.

Can I paint right over Bondo?

Can You Put Bondo On Top Of Paint? A direct application of Bondo Ultimate over sanded or cured primer and paint is possible. After applying this filler, it is easy to sand.

Should I prime before body filler?

End of dialog window. Put your fiberglass or body filler on bare metal first, work it to near perfect, then prime on top and do your spot putty. The reason for this is the body filler wont stick to paint or primer.

How long should Bondo dry before sanding?

Allow the putty to dry 15 minutes at 77 degrees F (25 degrees C). In cooler climates, putty may take 20-30 minutes to dry. 7. Using 3M™ Sandpaper 80 grit, sand and shape the filled area to the contour of the surface.

What grit sandpaper do I use for Bondo?

Directions for Use

If grinding is needed use a 3M™ 36 or 40 grinding disc followed by 3M™ 80 grit sandpaper if no grinding is required, sand the surface with 3M™ 80 grit sandpaper to remove all primer, paint and rust 1 to 2 inches beyond the outer edges of damaged area. Remove all dust created from sanding.

How long does Bondo last on a car?

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. If you want it to last that long, then you need to apply it correctly and thoroughly follow the manufacturer’s instructions.

Is spackle the same as Bondo?

Spackle is soft and is intended for interior use. Bondo is for larger areas and can be difficult to use.

Is Bondo stronger than wood?

Accordingly, Bondo is a very stiff product when cured, which makes it well designed for auto bodies. That same rigidity makes it a terrible choice to fill wood, which can move a lot with seasonal changes due to temperature and moisture content.

What is Bondo good for?

Perhaps the most useful substance in the DIYers arsenal, Bondo can be used for everything from repairing rotted window sills to patching drywall to restoring old furniture. The two-part resin was originally formulated for auto body repair – but its unique characteristics also make it ideal for repairing damaged wood.

Can you put body filler on top of body filler?

Do not proceed to Primer Filler stage until filled area is even. Adding body filler AFTER primer filler should be avoided to prevent possible adhesion, staining and shrinkage concerns. 6 Ready for Primer Filler PD-1510 when body filler is completed and the car is straight.

Can you layer body filler?

If you are filling dents all over or one big one you need to rough out those FIRST before laying a “skim coat”. If you do this roughing with coarser paper (80 or even 40) you can perfect the whole panel little bits at a time or smaller than one big one at least.