I am going to be bondoing some spots i scraped rust from and there are bumps in the steel, can i just bondo over these tiny spots? do I need to do anything special to the area? I had to gouge some spots with the dremel so there's pits where i did that.



as you can see, theres just tiny spots in it, its not a hole or huge dent, will bondo stick to this?

 

I am not a bondo experet. But remember, if you are going use POR15, apply that BEFORE the bondo. As I understand, bondo can stick to bare steel and/or painted steel. For tiny pits, I think you can get a filler cream (something easier to apply that is as good as bondo), but don't quote me. You are a bit outside what I know.

 

Tiny pits in the Bondo? Usually from bubbles, but a scuff by a dremel could do that.

@The_Maniac is referring to or similar name, It's a filler that is about the consistency of drywall mud.

 

No there's pits in the bare steel where i gouged out the rust damage, doesn't go all the way through and they arent very deep, but if you run your fingers over that spot in the picture i posted, its bumpy and it will definitely show through the paint. I'm just wondering if bondo will even stick to that. I do have some bondo brand glazing and spot putty, the exact same thing as in that link to fill in the pinholes and minor imperfections. I could get some filler primer as well just as added coverage.

 

It's completely fine to bondo over the pits. Bondo wants a very rough surface to adhere to, so if anything they'll help with adhesion.

Are you 100% sure none went through? That would be my biggest fear as most normal body fillers like regular Bondo will soak up moisture if they have a path to get it. As long as they're just tiny dents, you're good to go.

 

Yeah I got all the rust out, it's just tiny specs I need to get, I just wanted to get the majority of it. I can go over the whole surface with 80 grit a few times just to make sure the surface is rough enough and give the Bondo the best chance possible. I will most likely replace both driver and passenger side fenders so I'm not too concerned with how it looks, but I wanted to do them just to practice bondoing.

Now that leads me to my next question. What kind of Bondo should I get? I have some gold body filler at home and some Bondo metal reinforced filler as well, and I know there's Bondo glass filler, but which one is best for this job?

I put a couple coats of Renaissance wax over the bare metal to help protect it from the elements. That was over a week ago I applied a new coat to it and it's holding up pretty well

 

If you've already got Rage Gold, I'd just use that. TBH almost any kind of filler would work fine for this job, as this is a pretty simple application for it.

Also, I personally wouldn't have used any kind of wax on the bare metal. You run the risk of not getting all the residue off and causing the potential for delamination. Id be sure to clean it well with a strong solvent and re sand before you put anything on it (filler or primer). Id rather deal with having to knock off light surface rust than have to deal with removing invisible contaminants.

 

Rage gold? I just have regular Bondo gold body filler. I don't really know what the difference between the three bondos is. As for the wax, yeah not my brightest idea but I will sand it all down good before I do any work, and if it doesn't turn out good, that's ok too, because like I said, I plan on replacing those front fenders at some point.

 

Ah, I see now. I read gold and just assumed Rage Gold since that's such a popular filler.

Bondo Gold is fine for this application too. Bondo brand stuff certainly isn't the best, but its been used with success on plenty of cars and this is such a simple / small application that most any normal or light weight filler would work just fine. I wouldnt waste money buying anything different since you already have something.

 

Yeah, had I knows about Rage Gold before I bought the Bondo, I would have went with that. Although I see it goes for $91 on Amazon haha. Not sure if this stuff is just that expensive or if someone is marking it up to crazy prices. I hear that Rage Gold is the best stuff out there though.

These are the bondos that I currently have in my inventory.