What to do about a bus shedding it's paint

[Barn Owl]

Not sure what to do about this, but my bus is shedding it's paint. From what I can conclude, my bus has spent its entire life as a southern bus, mostly in the SW US. It is now experiencing for the first time some very large temperature swings with lows in the single digits just a few weeks ago. That I believe, coupled with some very high winds, is causing the paint to come off the roof in big chunks. The bus needs a new paint job so I wish it would all just fly off but its not. This situation is starting to make a bad paint job look even more hideous. Every time some paint comes off you can tell that the area is not as weathered as a spot that has already lost some paint. The question I have is: How do you remove paint from aluminum? Once removed, can it be left that way, or does the paint help seal the seams? I like the minimal paint, retro aluminum look, that I see on some GM buses. I don't want to mess up the anodizing, or whatever is done to protect the aluminum. What do I do?

[Buffalo SpaceShip]

Laryn, anywhere it's painted it's not anodized, unfortunately. So you'll have to repaint it. Old Blue Velvet suffered the same peeling-paint curse. I'm sure it wasn't prepped right. Maybe yours has the same problem(s). Most vehicle painters aren't used to painting aluminum... and probably use primers meant for steel.

Brian

[John Z]

Hey Barn Owl, sign me up for your team! My bus had a real hurry up paint job, painting over some windows, overspray on the others, spraying the window frames, etc, all apparently without any preparation. It is starting to come off in big chunks. I hope the list is able to provide some insight into methods and products to use in order to prepare the aluminum surface before painting. I too want to keep the nice classic looks, only giving some accent color to the bus. I also need to repaint the roof after getting rid of those ugly roof air units.

[Jeremy]

I cannot figure out how to provide a link to it, but there was a post called 'Rivets and patches?' on the 28th Dec 2006 that also covered painting of aluminium

Jeremy

[HighTechRedneck]

I cannot figure out how to provide a link to it, but there was a post called 'Rivets and patches?' on the 28th Dec 2006 that also covered painting of aluminium

Jeremy

Here you go.

Rivets and Patches?

[trailblazer2]

 Sounds like someone painted this coach without using a etching primer/or they repainted ,and did'nt sand the old paint. If it has a shining painted surface underneath,this is the case. If so, you will need to strip off the top flaking paint to a point where it is adhering good,and re-paint. Most of the time this can be done with a air hose and a lot of pressure(wear protection!)Sometimes a case like this requires sandblasting /or a acid stripper to do the job. Just keep in mind ,that you will have to have a good foundation when putting on new paint.I will be glad to give you more details if needed ;as I was once a Body/paint person for Piedmont Coach Lines in Winston-Salem,N.C.

[gus]

L,

I think most GMCs came with white roofs so it may have never been anodized like the sides. Your sides look ok so you are pretty close to the original paint schemes except for the dark around the windows and some bus companies probably did that also.

[Barn Owl]

My bus has two layers of paint. The first layer is coming off exposing the bare aluminum. The P.O. purchased the bus in '79 and started the conversion. At least for a while he didn't paint it leaving it in its charter colors. Looking at the photo album that came with the bus it was mostly white. Not sure when he did it but he eventually painted over that paint with the color scheme you now see (I do not like it one bit, it does not flatter the bus at all). So, until I brought it here, the charter paint job has managed to stay put for a minimum of 28 years. My conclusion is that it is probably not the prep that is at fault. Somehow the extreme temperature changes is causing more expanding/contracting than normal of the aluminum skin. For what ever reason (old age?) the paint is not keeping up and is flaking off. So after reading the replies I have started to develop more specific questions.

1. Where does the anodizing stop/start.?
2. Can the anodizing be painted?
3. What happens if I don't paint the non-anodized aluminum?
4. What type of stripper do I use?
5. Will stripper hurt the anodizing?
6. What type of special prep is required?
7. What type of primer do I use?
8. What type of paint do you all recommend?
9. I thought exposed aluminum would anodize on its own when exposed to the air? I assume that that is not the same as the "forced" anodizing that was done at the factory. Can anyone explain the process and/or difference?
10. I want to strip and paint this myself. It will have to be outside. Has anyone else done it this way?
11. Anything I am overlooking?

Other than trying to stop the rust that has started on the caps, I don't think that I will be able to do much this year. But, I would like to get an early start with the planning phase.

Trailblazer2, it sounds like you have lots of experience with this. What do you think?

Thanks in advance for any replies,

Laryn

[Hi yo silver]

Hey L.,
I don't know about the anodizing, but a hundred years ago, in the Vietnam era, when I worked on airplanes, we used a primer called zinc chromate for the aluminum.  FWIW

[Skykingrob]

Hi Barn Owl
See this link for an interesting stripper that I found used for aircraft/helicopters, http://www.m-tc.com/efs2500_home.htm. Maybe Trailblazer2 can give use both an opinion if this looks good to use. I haven't priced the cost so could be totally out of reach but liked the fact that I could use without any "monkey suit" precautions like most strippers.

[Barn Owl]

This is not a good photo because of the sun reflecting of the roof but you can still get an idea what I am dealing with.

[JackConrad]

1. Where does the anodizing stop/start.?  I think only anodized panels were panels that left the factory UNpainted
2. Can the anodizing be painted? Yes, with proper prep
3. What happens if I don't paint the non-anodized aluminum? They OXIDIZE
4. What type of stripper do I use? Aircraft (approved for aluminum)
5. Will stripper hurt the anodizing? Not sure, probably
6. What type of special prep is required? proper cleaning and proper primer
7. What type of primer do I use? Compatible with finish coat (check with paint supplier)
8. What type of paint do you all recommend? I like the poly urethane enamels
9. I thought exposed aluminum would anodize on its own when exposed to the air? I assume that that is not the same as the "forced" anodizing that was done at the factory. Can anyone explain the process and/or difference? Exposed aluinum wil OXIDIZE.  Anodize is a treatment to prevent OXIDIZATION.

10. I want to strip and paint this myself. It will have to be outside. Has anyone else done it this way? Yes, I have, but you need to get a day with no wind, best to build a temporary shelter using visqueen (plastic)
11. Anything I am overlooking Before painting the bus, practice painting on something else

NOTICE: All above opinions are those of the author and should not be considered gospel. These opinions are based on real world experiences and are not the result of hours of actual schooling on the subject. Author will not be responsible for any damage or injury that might occur as a result of actualy listening to these opinions.