Hi! Does anyone here have any suggestion fixing this minor rust problem. I sand off the rust and now there holes. What should i do? Oh damn! Wrong section. Can some put it in the paint department?

 

Should i apply bondo unto it then primer it down?

 

Can you reach the back side? Make sure all the rust is gone from the front and back. Ideally, you should either fill it with weld or cut out the area and weld in a patch. Grind it down flat and then cover with filler. Scuff the back of the area and cover with self-etch primer. If you cant reach the back, use weld-through primer and either self-etch or honeycoat the back if possible through any openings. The easier way is to score the area with a grinder and slap on some filler. Regular body filler alone doesn't usually do well in holes but from the pic it looks like the hole may be small enough. Bigger holes should be at least filled with a fiberfill before applying body filler. Cover the back as best you can then block sand it level, apply finishing glaze, sand smooth, prime, wet sand and paint.

 

It needs to be cut out, or it will almost definitely come back. It should be replaced with a new piece and then painted.

 

NEVER use filler to cover any holes up... u gota weld it closed... it looks small enough to just weld closed.. i dont think u need a patch panel... but please do not use bondo only... use that after you've welded it closed and grinded it smooth.

 

That's true...if you cut away the affected area it could be welded. Definitely don't use Bondo to cover it up though. It has a tendency to wick up water and will make the rust much much worse.

 

Thanks for letting me know but the problem's that i don't know how to weld. It probably not go good idea to add bondo on the holes, but curious to know if will be o.k. I'm thinking the holes is small so it should give any problem adding body filler.

 

If you get all the rust off, score the front with a grinder, the back with coarse sandpaper, apply short-hair fiberfill and smooth it on both sides, level & block the front, finish the front with filler, block the front, scuff the back side well and prime both sides, the rust should never return and you should have a strong repair. Always make sure to scuff every tiny spot before applying any coating or it won't stick.

 

Yes i can get all the rust off with mostly a grinder. Curious to know what do you mean by short-hair fiberfill? Is that some sorta fiber mat?

 

You don't have to cut and weld. Cutting and welding is a traditional method which is used most commonly to replace large areas that are rusting. Replacing the metal. If you have a small area like that, you can use something like Everglass (my personal favorite) to fill the hole. It's a Kevlar re-enforced filler so you won't have to worry about it falling out or anything like that. I would sand/grind out the area beyond the affected patch, clean and sand/grind the reverse if you can reach the inside. Then fill it sand it, use a glaze, or regular evercoat liteweight, then primer it with something like a epoxy primer. I guess you'll probably be using a spray can, look for something that will create a good water proof barrier between the environment and the repair. Expect to spray a couple of coats of primer on there.

 

Fiberfill is fiberglass feinforced epoxy body filler. It's sold in a can like regular filler at most auto parts stores. It comes in long strand and short strand. The strand length you want depends on the size of the repair and you'd be looking for the short with this job. When it dries it basicly becomes fiberglass. It is stronger and more flexible than regular filler but does not level as well so standard filler should be used on top after the fiberfill has been leveled. It's used primarily to fill holes and build up surfaces when more than a half inch of filler is required on jobs where welding is either not economical or not possible. The Everglass Eyger mentioned is also a fiberglass-reinforced filler made by Evercoat. Eyger is talking about Evercoat's "Fiber Tech" filler which has kevlar and other fibers reinforcing it. There's no need for the more expensive high-tech fiberfill because such a small area of filler on a rigid corner of bent metal is not likely to actually break. The worst that could happen is the repair could pop out, and that is mostly prevented by smoothing the fiberfill on both sides. Make sure all of the outer fiberfill is sanded to just a hair below the metal's surface before applying regular filler. You want the filler to completely cover the fiberfill after it's blocked level.

 

Alright, I think i know exactly what you mean about fiberfiller. It sorta like bondo stuff. I have been looking at it and seen very good to use. Somehow, i live in area that don't really seem to sell these stuff. I might have to go some regular bondo filler stuff. Anyway, i think i gonna finish chip and grinding the rust metal on both side.

One more thing i need to know about primer. Do i need to sand it down then clear coat it?

 

Yeah Bondo of course makes a popular fiberglass-reinforced filler. Ideally you want a small can of this, a small can of (premium if possible) body filler, and a little bit of finishing glaze. The glaze fills in the pores of the bondo. Hammering primer on to accomplish this can cause the applied filler to swell. Use a very thin layer of glaze, it is only for filling pinholes and not for building up or leveling the surface. You want to be able to see the filler underneath the glaze. Tape eveything off and spray primer-surfacer. As I said, spraying the primer on too heavily is bad. Before removing the tape, get a can of black spray paint and gently spray the finest coat possible over the primer. Spray just above the surface so a fine mist falls on the primer. This is called a "guide coat." Wet sand the primer with 500 grit quality wet/dry paper without a block. Start by blending in the edges of the primer and work your way inward, doing the metal corner last and carefully, until all of the black has been removed. At this point all of the primer is smooth. You don't usually sand between color and clear, you put the clear on before the color fully dries.