A Teenager attempts rust repair Part 1: Just a quick question.

"G_Body_Man: Sponsored by the number 3" (gbodyman)
10/28/2014 at 19:55 • Filed to: Oldsmoboat Gutbus Extreme

So I'm planning on fixing some rust holes in the Oldsmoboat Gutbus Extreme, and I was wondering if fiberglass-reinforced body filler is the way to go. Of course, I'll be sanding the larger areas of surface rust, and converting the rust using Naval Jelly, so apart from primer and topcoat, there isn't many other issues. Is fiberglass-reinforced body filler the way to go? Have a Grand National for your time.

DISCUSSION (18)

Zipppy, Mazdurp builder, Probeski owner and former ricerboy > G_Body_Man: Sponsored by the number 3
10/28/2014 at 20:06

first off, how bad is the rust? often times it's better to patch with metal. you can patch with Fiberglass filler if you want to be cheap, but it won't end up as nice.

crowmolly > G_Body_Man: Sponsored by the number 3
10/28/2014 at 20:06

Post pictures. I would not use Naval Jelly.

RamblinRover Luxury-Yacht > G_Body_Man: Sponsored by the number 3
10/28/2014 at 20:06

You're dealing with outright holes through the body? Fiberglass *might* be right for the job, depending on where you prep what you're working on. Not filler/Bondo alone for anything big, it cracks too easily. A lot is going to depend on where it is. Any pits and roughness, you may be looking at just Bondo on.

I don't really have that much background on how well Bondo(r) sticks to metal surfaces that still have rust or converted rust. I only have extensive background with aluminum. The general rule with Bondo is, I think, that you really are supposed to hit bare metal with it, and if you've got rust that's converted, you're still breaking its film layer when you grind through for the Bondo, so I don't know how secure it is. I think it's okay if it gets *sealed*, but if it spends any time exposed and all avenues aren't closed off, moisture can pass through the Bondo and continue the rust. No. Fun. For areas with minimal smoothing required, you might try a high-fill primer and sanding it smooth.

RamblinRover Luxury-Yacht > crowmolly
10/28/2014 at 20:09

Yeah, there are residue-leaving issues for a first-timer to learn to deal with, and may be other issues I'm not thinking of.

cletus44 aka Clayton Seams > G_Body_Man: Sponsored by the number 3
10/28/2014 at 20:17

I love your car SO much I'm gonna help you out. I used bondo before with the same result every time. It looks good and works good for one year and then it starts bubbling out again and I have to start over. Maybe I didn't grind all the rust out so make sure to be very thorough there.

It did however look awesome for like 10 months.

RamblinRover Luxury-Yacht > cletus44 aka Clayton Seams
10/28/2014 at 20:28

If there's any way for moisture to get to the bondo surface, there will be pain. Somebody patched up my Falcon's panels with scrap, didn't seal anything, and Bondo'ed up - and surprise surprise, just about every bit of it they patched has gone south.

Oddly, Bondo sticks to properly scuffed aluminum like the devil's own business.

Frank Grimes > G_Body_Man: Sponsored by the number 3
10/28/2014 at 20:28

replace metal with metal. then if you suck at welding get better and try again. then worry about using body filler. you will absolutely need to make sure both sides are sealed with a paint or ecoat something to keep it from rusting out again.

Go to your library and try to find an autobody bookor buy this one http://www.amazon.com/Collision-Repa…
this will show you how to do it right and doing it once will save a lot of time having to do it again and it feels good to do a good job.

Klaus Schmoll > G_Body_Man: Sponsored by the number 3
10/28/2014 at 22:04

If there is an actual hole, the only way is to cut and weld! Or you can go Tijuana body shop style and slather it in bondo, chicken wire, and old newspapers to flog the car off to some unsuspecting victim.

G_Body_Man: Sponsored by the number 3 > Klaus Schmoll
10/29/2014 at 10:23

Not really holes, just big gashes in the metal.

G_Body_Man: Sponsored by the number 3 > Frank Grimes
10/29/2014 at 10:24

Unfortunately, I can't afford a welder.

G_Body_Man: Sponsored by the number 3 > cletus44 aka Clayton Seams
10/29/2014 at 10:25

Okay, i'll let all the moisture dry out for a week in a sealed garage before I go FRBF on this thing. Thanks for the tip.

G_Body_Man: Sponsored by the number 3 > RamblinRover Luxury-Yacht
10/29/2014 at 10:27

The main issue is that the quarter panels are worn right down, so I'm thinking FRBF. I'll let it dry for a week, though.

G_Body_Man: Sponsored by the number 3 > Zipppy, Mazdurp builder, Probeski owner and former ricerboy
10/29/2014 at 10:29

I can't afford a welder, so Fiberglass filler would be fine. the perforaations are anywhere from 1/2 to 1.5 inches in diameter.

RamblinRover Luxury-Yacht > G_Body_Man: Sponsored by the number 3
10/29/2014 at 10:41

I'm going to be replacing the lower third of the quarter panels on my project with fresh steel, and sealing both sides. Can't get new patches, so I'm going to be making them. If only you had access to a welder, patch pieces for a Cutlass are available if a bit spendy.

As long as you seal both sides, get out pretty much all rust (grind away), and don't have to patch a spot that flexes too much, you'll be okay for a while. How much of a while will depend.

G_Body_Man: Sponsored by the number 3 > RamblinRover Luxury-Yacht
10/29/2014 at 11:47

Thanks man. The frame is solid, so I think i'll be fine.

uofime > G_Body_Man: Sponsored by the number 3
10/29/2014 at 12:08

bondo should never be thicker than 1/4" if you have holes that large you need to fix them another way

Pixel > G_Body_Man: Sponsored by the number 3
10/30/2014 at 10:32

Here is a solution that will be fairly solid last a long while but will be a bastard to reverse if you ever decide to fix it properly(ie weld some new metal in).

-Buy a quart or 2 of Masterseries Silver .

-Pull off any trim and go at the rust with one of these paint stripping discs (auto parts stores sell them) until you've removed any loose rust and have gotten back to solid steel all the way around the rust. Do the same on the inside. If you can't reach with the disc, use a wire brush. If you don't get both sides all this work will be pointless.

-Brush a coat of the Masterseries silver on both sides. Wear a long-sleeve shirt you don't care about and WEAR RUBBER GLOVES. Use the cheap foam brushes lowes/home depot sells. Buy a pile of them in 1" & 2" sizes. Be generous and make sure you force it into all holes/pits/etc. You want to completely seal the rusty metal.

-Get some fiberglass mat (you want the stuff that looks like this , not the woven kind , it is easier to work with for this job), cut it to the size & shape of the area that has the rust holes, plus about 1" all around, you want it to overlap onto solid metal.

-Using a brush, get the mat absolutely soaked through with Masterseries, you want it saturated. Brush another coat of Masterseries onto whichever side you are applying the mat(backside is best, but use whichever), then stick the mat to the metal. Use a brush and you GLOVED fingers to push out any air bubbles, and get the mat firm against the metal.

-Wait and hour of so for the paint to set up enough that the mat isn't sliding around, and put another generous coat of paint on both sides to seal it all in.

-The Masterseries will contain the rust, the mat will structurally reinforce the panel and the whole thing will be much more permanent and long-lasting than Bondo. Once you are done painting the final coat, mist the whole repair inside & out with automotive primer, you want a very light coat you can still see the silver through, this is just so the final paint will have something to grab onto as the Masterseries doesn't take paint well.

-Once the Masterseries has dried for a few days, you can bondo/paint/etc. over it to make the panel look nice.

Further notes:

This isn't as good as a proper fix, but will do much more than just slathering bondo on.

The Masterseries is very moisture-sensitive,so don't use it in rainy or very muggy conditions. Always pout out what you think you'll need into another container, then immediately re-seal the can with 2 layers of plastic wrap between the lid & the can(if you don't the paint with permanently stick the lid in place and you will never get it open again).

The paint sticks to skin really good, and can only be removed when it is still wet and even then only with lacquer thinner(nasty stuff), so be careful to not get it on you, but disposable vinyl/latex gloves and always wear them, and use disposable brushes, because you aren't going to be cleaning them and reusing them. Dump all the glove/brushes in a small plastic bag before you throw them in the trash or them may stick themselves to the bottom of the trash can forever(ask me how I know).

G_Body_Man: Sponsored by the number 3 > Pixel
10/30/2014 at 10:51

Thanks!