Bondo Advice?

[JR_Charger]

I've got the typical rusted quarter panels that need to be patched, and they eventually will be. For the time being, I want to try improving the bondo job the previous owner did 30 years ago. I've lived with it this long, I can live with it a little longer and put the money saved into go-fast parts.

I've got a few holes like this one -

Can this be bridged with fiberglass bondo alone, or does it need a mesh support under it? How thick should the bondo be?

I've also got this mess -

It's all going to be replaced, so no need for perfection. Just a reasonable amount of improvement.

 

[Kern Dog]

Old timers will tell you that they used screen from patio doors, aluminum foil, newspapers and just about anything as a backer for applying body filler.
In the 90s when I made a few VHS home- movies, I had some beat up cars I used for stunts. The atrocities perpetrated with body filler were shameful in the effort to make bashed cars look presentable on video.

 

[eldubb440]

Old timers will tell you that they used screen from patio doors, aluminum foil, newspapers and just about anything as a backer for applying body filler.
In the 90s when I made a few VHS home- movies, I had some beat up cars I used for stunts. The atrocities perpetrated with body filler were shameful in the effort to make bashed cars look presentable on video.

picked up a 68 barracuda notch back in the day........ 1/4 was mashed bad. someone screwed a couple pieces of vinyl siding to it and buried it in bondo...... it looked like ****

 

[WileERobby]

You can grind all the metal to remove the rust & corrosion, then fabricate a fiberglass patch. Bondo is not that. Any use of bondo/body filler, other than as a skim-coat application, is butcher work. ( with all due apologies to those who carve their craft in the meat industry )

 

[hammond472]

I had a friend who's dad owned an auto parts store back in the day. There was a guy who came in and always asked for a big stack of STP stickers and a can of primer. Finally my buddy asked why he needed so many. He told him that his car was rusty from the salt on the roads and whenever a new hole popped up he would simply slap on a couple stickers and a shot of primer and it was good to go.
There are drains in the rear quarters. If you plug them up with Bondo you might have a bigger problem with the wheel arches, tail panel and the trunk extensions later. I would at least treat the rust so it doesn't spread and make sure the drains are clear and don't hold water along the lower edge.

 

[Charlie Hughes]

A cheap and easy fix would be to sand it all smooth, put some kind of rust treatment on it and spray spray foam in the holes until they’re full. Cut off whatever excess pops out the hole when it hardens and then skim coat it with bondo and paint it

 

[Photon440]

Old timers will tell you that they used screen from patio doors, aluminum foil, newspapers and just about anything as a backer for applying body filler.
In the 90s when I made a few VHS home- movies, I had some beat up cars I used for stunts. The atrocities perpetrated with body filler were shameful in the effort to make bashed cars look presentable on video.

I remember sanding down a '67 Mustang back in 1983, under the paint and bondo was adhesive aluminum metal duct tape used to bridge some holes in the sheetmetal. It actually did a passable job.

 

[4406bbl]

If you buy the thick 3m aluminum tape at a body supply, prep the area, get it stuck down good with a little heat and a plastic tool, lightly sand it, duraglass it, it will outlast a piece of welded in metal in the rust belt sometimes. Once you weld on metal it rusts like crazy. Sold a single post body frame rail puller to a guy that worked at Macco, told him that was our "budget" rust repair. He said no that tape is too expensive, he said put some fiberglass bondo on newspaper, slap it over the hole, let that dry, grind the paper off, skim coat with bondo and its good to go....a butcher, but at least he used duraglass.

 

[JR_Charger]

I had a friend who's dad owned an auto parts store back in the day. There was a guy who came in and always asked for a big stack of STP stickers and a can of primer. Finally my buddy asked why he needed so many. He told him that his car was rusty from the salt on the roads and whenever a new hole popped up he would simply slap on a couple stickers and a shot of primer and it was good to go.
There are drains in the rear quarters. If you plug them up with Bondo you might have a bigger problem with the wheel arches, tail panel and the trunk extensions later. I would at least treat the rust so it doesn't spread and make sure the drains are clear and don't hold water along the lower edge.

I'm familiar with the big drain plugs just behind the wheel opening. I haven't spotted any other drains yet.

 

[JR_Charger]

These rear quarters have been "butchered" for 30 years. A little more won't hurt. This stuff has all got to come out anyway, but not before the car is running with lots of good go-fast parts.

 

[tak419]

If you want a temp patch there's a couple ways to go. Yes the fiberglass patch will work and hold for some time. You could also grind out the area and pop rivet in metal and then fill over that. Obviously these are all temporary fixes but will work and have worked many many times over and over for people back in the day who had little money to work with. The purist will cringe and I will also, but on a budget they will work. Best of luck and post some pics. We'd all love to see the progress and help out as much as possible.

 

[Gus chiggins]

I'm a former body, and fender guy. I can't recommend any butcher job, even though it's temporary. It just needs to be dealt with. Rust never sleeps.

 

[Bighouse]

Fiberglass resin and mat. Then body filler work over that. It’ll look good for a while

 

[JR_Charger]

How do you all feel about bondo's self adhesive body patch - Link

I've been knocking the loose rust and scale off of everything and going over it with rust convertor. Will do the same here.

I do plan to have all this pulled out and replaced with metal later, but if it lasts as long as the previous owner's job, it will still be looking good when I'm 80. I have seen no deterioration in the previous owners work in 30 years of ownership. It didn't crack or fall off in 30 years.

 

[slimt]

I remember having to do a old Dodge Van right rear corner. . Reason it had some sort of crack and rust showing around the crack. Starting grinding all wondering why I was going the 24 grit grinding disks at a alarming rate. Well someone previous was good at there trade. My boss told me to remove what was there preventing the grinding discs from doing there job.

I hit the corner with a hammer. And nothing not even a mark. So my boss hit the corner with a sledge hammer. A 10 lb chunk of concrete hit the floor. This was in 1979. Someone moulding and scuptured the concrete to that corner. They had skills. Couldnt see anything inside as it was all panelled inside.

So ya. Anything was possible and doable back in the day.

 

[Bighouse]

Putty and paint and make it what it ain’t

 

[blue69runner]

Why can't you cut out that area and put metal back in. Fiber mesh or tiger hair fiber glass works well. Seen it all when growing up buying whatever car I could afford at the time. The worst thing with a ding in the fender they would drill a bunch of holes to make the Bondo stick. Under stand your going to fix it right latter but sound's like your just looking for faster parts on the car. Good luck with that.

 

[JR_Charger]

Can't weld, that repair is too advanced for my skill level.

The previous owner's bondo job has held up for 30 years, and in that time no one has commented on it. Even though it was lumpy and obvious, if anyone had looked. Here's the passenger's side -

I didn't add anything, that is just where I sanded down the bumps.

95% of the people out there don't care. 99.99% who are female aren't checking quarter panels for bondo. They don't even know if it's a Dodge or a Chevy.

My logic is that it's better to do a 5% job now and pay a pro to do a 100% job later, than to do a 70% job now and pay a pro to do a 100% job later. I'm a bodywork n00b, I don't have a 100% job in me. I think I can easily make an improvement that will please most of the people most of the time though.

If this car gets through the next few years, I'll throw more cash into the body. Maybe this part will get done sooner. Here's a fun story. There was a local guy, not too rich, who spent 20 years building his dream 55 Chevy. He got it done, took it out on its maiden voyage, and at the first intersection a drunk ploughed into him. He didn't have the means to repair the car, so a local rich guy bought the wreck off of him and fixed it up. Twenty years of effort just to get to watch another man ride around in his car! I don't want to be that guy! I'll be restrained in my investment knowing that Cellphone Sally and Danny Door Dinger are out there. If they bang up a bad panel, I won't be happy but at least I'll know I was replacing it anyway.

 

[1967coronet]

Depending on how much use the car gets and were it lives will determine how long a cave and pave job will last.
Short answer is yes you can ding in those areas and fill with a short stand fiber glass filler , top coat with regular filler.
Rust belt states , high humidity areas you will get a couple summers before it bubbles out.
Dry south west areas prob a year or so longer.
Rust never stops. Here in the midwest there are some real bondo artists.

 

[beanhead]

Putty and paint and make it what it ain’t

That's damn funny right there! My equivalent saying is, hammer n' hatchet, paint it to match it!"