Look at what this FOOL did to my bus !!

[silvermachine]

Hey all,
So- when I first bought my bus two years ago a very dumb friend of mine ((me)) got a little overzealous with the angle grinder.

At that point in time, the bus was leaking like crazy and I was caulking all the side rails, rivets, you name it. I ground off the excess caulk with a grinding wheel after it had dried instead of wiping it off while it was still wet. Aaaaannnd that’s the tragic mistake I now have to deal with. Oh well, it is what it is.

Anyway, as you can see in the photographs, there are some pretty severe scars on the body. The metal is definitely gouged pretty bad in some places, but it’s mostly just affecting the paint.

I don’t have any crazy expectations here; I know it’s an old bus and some of the damage may be irreconcilable. But I want to get the body as smooth as I can before I begin painting it.

What would you do here?

I tried spraying filler primer on the body ‘scars’ but it just masks the damage and in the light, you can still see the marks clearly.

I was planning to bondo the scars and sand off the excess gently with an electric sander. But is there a better way?

Thanks for any and all input/ideas!

(For some reason all the photos uploaded sideways)

[rg1220]

Bondo and then block sanding is likely your best bet. The block sanding is what will level it out and leave a smooth finish. For the rounded surfaces you'll want to sand using a rubber pad or sponge to hold the sandpaper to prevent uneven pressure from your fingers. Just make sure to follow the prep instructions to make sure the Bondo gets a good bond to the metal. Also I believe so people have tricks with letting the Bondo dry but not fully cure when they start to sand in order to reduce the amount of sanding they have to do (I'd watch some people on YouTube do it).

[o1marc]

You have to sand the filler primer until it builds enough the fill the recesses.

[Flipmode]

That looks like a cool old bus. Good advice already given. I'm definitely no expert on this department but if it were me I'd be focusing on using glazing putty. You can find the bondo version at most auto parts stores in tooth paste looking tubes. The glazing putty fits the bill for something that's deeper than what primer can fill but not quite deep enough for regular bondo. The best part is it's a one part product so its quick to apply.

First I would prep and shoot a coat of primer. Then hit the spots with glazing putty, sand with the techniques described above. After the putty looked good I would use the high filling primer technique marc mentioned. I've found that even though the products are claimed to be little to no shrink; that is fairy tales. If you try to knock the primer and putty out in one day it may not be as perfect after a week. It shrinks as it off gasses so space the steps out over a few days to minimize the noticable shrink. Also, get a few different colors of primer, it helps to identify high and low spots when sanding if each coat is a different color.

[Danjo]

I agree with glazing putty, but get the catalyzed version from an auto body supply.

Roughen the surrounding paint surface with 220 grit. Apply thin. Add coats as you need. Sand back with a long block sander.

If you’re patient, you’ll get pretty good and will get close to the original surface

[musigenesis]

Bondo glazing and spot putty didn't work very well for me. I over-used it because it's so much easier than mixing the regular stuff with the hardener, but any place where it wasn't just in literally tiny pinholes has tended to crack and peel up underneath the paint layer. I think if it's applied thick enough to fill in these gouges the same thing would happen, YMMV. I would use regular Bondo and an orbital sander. Or maybe just buy a new bus because this work would be an enormous PITA.

[EastCoastCB]

Originally Posted by musigenesis

Bondo glazing and spot putty didn't work very well for me. I over-used it because it's so much easier than mixing the regular stuff with the hardener, but any place where it wasn't just in literally tiny pinholes has tended to crack and peel up underneath the paint layer. I think if it's applied thick enough to fill in these gouges the same thing would happen, YMMV. I would use regular Bondo and an orbital sander. Or maybe just buy a new bus because this work would be an enormous PITA.

glazing putty is that final very thin layer after sanding filler. Filler can have porosity so the glazing putty smooths it over. Or like you said- for very minor imperfections before the final primer coat.

[BeNimble]

Look into using lead to fill those gouges.
Gotta keep that steel school bus all metal.

https://www.youtube.com/watch?v=TvPr4ldiJRY

[Simplicity]

We all do silly things (stupid even sometimes), but what you did is fixable.

The first thing to remember is that paint will not hide any of the problems, it just makes them look nicer.

You must smooth and level the surface, then fill it, smooth and level those areas (which for you is pretty much your whole bus), then fill it, smooth and level those areas again until it's smooth like a baby's butt.

You can do guide coats. Basically you're coating the areas you're working on to show imperfections, then leveling/smoothing them.

The best thing you can do for yourself is watch YouTube videos for the basics. Learn what things are, what the process is, which steps you do first, what tools you need and how to use them properly, etc..

There are things you can do to hide small imperfections, using a lighter color, flat paint somewhat helps or do like some people have and coat it in truck bed liner.

Good luck.

[Danjo]

It’s probably a good idea to get yourself a wire wheel to knock the rust off then put a very thin skim coat of bondo and block sand it. You’ll know pretty quickly what it’ll take to save it

[BeNimble]

Actually, you can just paint it camo and the battle scars will fit right in.
Or go the route of Rock(n ruth) and insulate on the OUTSIDE and put a whole new external layer.

[Dirtdoctor]

Might be a job for spray on Bedliner. It comes in other colors than black
Cheers.

[Ronnie]

I would strip all the old paint/rust off before doing anything to this.

[Timeline]

A friend who paints cars gave me this advice.

Sand the rust off and coat with a sealing primer (not the sandable type- it's porous), Bondo is porous too and not a good choice as a first filler coat, use Duraglass fiberglass filler.