Bus Painting Advice

[the.struggle.bus]

Hey everyone, just took my bus out for its first camping trip this past weekend—had an amazing time! Got a couple repairs done right before and now I’m looking to make this baby last and look good. I’m not great with spray-painting (brush I can handle), so I’m wondering: does anyone have guidance on painting the exterior? Do I need to sandblast? What type of metal is the shell usually, and should I be using a specific kind of primer, paint, or gloss?

I don't have a ton of money to spend so please offer advice with that in mind.

Also open to fun design ideas—want this rig to be proud of herself!

 

[nikitis]

Painting doesn't have to take a lot of money but it depends on what you have available to you.

I bought a harbor freight spray gun worth $150 for $25 on clearance. It can take 3M paint buckets or I can 3D Print me a bucket for less than $1 of plastic. The paint is gonna cost the same regardless of using brush or spray. The spray method requires an air tank. A 6 gallon pancake air compressor is enough with breaks in between sections. A decent 6 gallon pancake will cost about $150. So you're at $175 with the gun and compressor. Paint is like $40-60 depending on type of paint and branding, and you'll probably need 2-3 gallons if not more. And add Sand paper. So for you let's say about $280 for the cheapest paint job with spray that can look automotive if I put in the effort to sand the missing paint areas. If you decide to sand blast the whole thing then add about another $250 in materials, so $530 for the best automotive DIY looking job you're capable of achieving on your own without a bus sized spray booth. A professional is gonna charge you about $3000 to paint the bus, and the quality won't be that much different between the DIY Spray job and his job. I also already have the 6 gallon compressor so for me I'm $25 for gun, and $120 for paint, so $175 with a sandpaper buy. So it depends on what you have available to you.

Brush can work but the paint job will look artistic but bad according to automotive standards. So it's really about what you care about. The artistic look is fine, and buses have a history of it so it's kind of iconic because hippies in the 1960's did it all the time, but you will see imperfections all throughout the body. With spray you will typically see imperfections mainly if you overspray, or have multiple layers of paint with the inner layers exposed before paint and where it meets the outer layer. Sanding can help with this with a high grit paper along the edges to smooth things out first.

A sand blaster can be made relatively cheap. There are youtube videos on DIY Sandblasters out there, Stripping the paint will better ensure even paint with spray method. If you are just going to brush, don't bother and just brush it on. It will be the easiest, look decent, but not the best looking because you will see brush strokes solidify permanently, but it will also hide any imperfections that sand blasting would have removed so there's no point in sand blasting if you use brush. The Brush look for most people who have slightly off vision won't notice the imperfections either unless they get right up to your bus. It will only bother people with 20/20.

If you are looking for that automotive smooth finish, you're going to have to spray.

They do make self-etching primers you can use which help paint adhere to the body. It sprays on rough so you don't have to sand. Only sand the areas where paint was missing prior to blend in the layers.

Those are your options. Again it depends on what you are going for. If you don't mind imperfections, just go with the brush stroke. Colors will be what you want them to be, but the rig will look more DIY and less showroom like.

 

[Timeline]

It will be a big job for sure, especially the prep work! I'll tell you what I did but everyone does it differently.

I washed the bus with a mixture of strong Dawn detergent water and 10% bleach. I used 3M scratch pads and scrubbed it very well and rinsed it.

I bought an orbital sander like this:

2.8 Amp, 5 in. Random Orbit Palm Sander

Amazing deals on this 2.8A 5In Random Orbit Palm Sander at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Also got several packs of 320 and 220 grit sand paper.
I sanded the entire bus lightly just enough to remove any shiny/old surface, don't sand down to bare metal, if you do hit those spots with a spray can of sealing primer. I used sponge sanding pads from Sherwin Williams they are foldable and work good for around rivets and other places the sander can't reach.

3M Pro-Pad Sanding Sponge | Sherwin-Williams

www.sherwin-williams.com

You're looking at a week or more of prep. I'm not sure if you should sand the new galvanized metal. Ask Sherwin Williams or Google! After it's all sanded, wash it again.....

Brush and roller can turn out alright, get some paint reducer and add some to help keeping the texture and brush strokes down. A short nap roller (1/4") can work better than a fat roller for me.

Your bus will need some primer, the roof and new metal, and maybe the old blue paint too. Not sure....

I used solvent based paint from Sherwin Williams they will help you pick the right product. They have a paint on sale right now save 30-40% I paid about $80 a gallon not on sale.

You'll need to brush and roll 2 coats, maybe a 3rd if it looks sketchy.. 2 gallons might be enough. If you spray it can get covered in one step, brush and roller takes more time, you will need to masking tape it again between coats as well.

Good Luck!

 

[TheHubbardBus]

I'm not sure if you should sand the new galvanized metal. Ask Sherwin Williams or Google! After it's all sanded, wash it again.....

Galvanized steel is a real pain point in terms of adhesion. I've had good success by choosing commercial direct-to-metal primers that specifically give directions for use on galvanized metal, and then follow those directions to the letter. In our case, part of that prep involved ospho, which I've learned is a very common prep procedure for galvanized-compatible DTM primers. But I wouldn't assume that's the case unless seconded by the TDS. The difference between commercial and consumer-grade within a product type might just come down to little more than a detailed TDS (technical data sheet) and informed tech support, but those both easily justify the potential bump in price IMO.

When we primed the interior of our gutted shell, I reached out to a few commercial reps telling them my requirements: Bare galvanized steel of varying condition (from like-new to lightly-rusted), roller-application (cuz I don't have a remote-air supply and don't want to poison myself), & no topcoat required (since we're insulating over the top). 4 years later I can't remember the brand, the rep, or specific product we went with (probably mentioned somewhere in our build thread), but I can say this stuff is bulletproof. There still remain areas of our build where it has been exposed the entire time and subjected to constant abrasion / bumps / tools falling / etc and it's effectively indestructible. Find the right rep and they know better than anyone what works & doesn't.

the.struggle.bus... As @JenniferWillow wrote in another thread, if you invest in great prep and an equally great primer, you can always save $$ on the topcoat and just re-do it sometime in the future when necessary/afordable. But if you skimp on the foundation, whatever you save now will likely end up costing you more later, assuming you keep the bus long-term and/or care about it's appearance and corrosion-resistance.

 

[Timeline]

Thanks Hubbard!

Struggle, I know you don't want to spray but it may be easier then you're thinking....
After watching some Youtube

and saw how well these work, I bought a cheap ($40) electric (no compressor needed) HVLP (high volume low pressure) sprayer similar to this:

Amazon.com

It worked really well, but you'll need to buy a respirator. The paint will need to be thinned with the appropriate reducer so it will spray out nicely. I did my bus a section at a time, first a light coat that looked a little spotchy then about ten minutes latter I sprayed more paint until it was coated nice. It was my first time spraying and it turned out pretty nice with only a couple runs.

There's a chance one gallon will cover the bus, so I'd just get one and see where you get to. Are you going to paint the roof white and the bus another color?

You wondered what you bus shell is made of, it's steel. You will have no need for a sand blaster to paint your bus!

 

[TheHubbardBus]

Thanks Hubbard!

I meant to comment on your thread, but don't think I did. Your bus turned out looking awesome!

 

[nikitis]

I personally woudn't put Ospho on perfectly good galvanealed metal. It's Galvanealed so that you don't incur rust, otherwise you could of just bought rolled cold steel instead which is also cheaper. Rolled cold steel will flash rust in a day or so, so definitely use Ospho on that and you can spray right over it as it roughs up the metal automatically converting it to Iron Phosphate. But the whole point of buying Galvanealed is so that it doesn't rust quickly. It takes years to rust.

For Galvanealed I'd use a Self-etched automotive primer. It sticks fine to the metal in my experience and only use that on your added sheets. It drys really fast, but can come off of the metal if you don't let it dry for a day if you are rough on it, and you don't even need to sand it because it self-etches. Just paint an enamel coat over it. This only applies to any exposed galvanealed sections of metal.

An Enamel based coating will also bond to the self-etched primer making it stronger after the Enamel dries

 

[the.struggle.bus]

I think I’ve decided on the direction I want to go with the bus. I’m leaning toward a floral / geometric finish with a southwest twist. I’d like some floral elements as accents on the bus, with plants and geometric patterns tied in. That seems like the right vibe, and it doesn’t need to look like a showroom finish — more artistic and hand-done.


With that in mind, I don’t think I need to pay for a professional spray job. It’s probably better (and more budget-friendly) if I go with roller/brush application, since the look I want can embrace a more artistic, painted style.


A couple things I’m still unclear on:

• Priming: Do I need to prime anything if I’m mostly keeping the existing background (the light blue areas), except for the grey panel which definitely needs covering?
• Galvanized/Galvanealed metal: I’m not 100% sure what parts of the bus that applies to — can anyone clarify where I should expect that, or how I’d recognize it?
• Prep for the blue areas: If I’m going to use the existing background as part of the design, what’s the best way to prepare it? Light sanding, washing, or do I still need to hit it with primer before painting over it?

Thanks everyone for the advice so far — this is helping me a lot to figure out the right approach!

 

[nikitis]

Any of the original bus metal is likely galvaneeled. Cold rolled steel wasn't used.

If you are keeping your current blue as a background, I'd trace layout the area you want to paint and only scuff up that blue area then roll your design on that sanded area and call it good.

 

[TheHubbardBus]

I personally woudn't put Ospho on perfectly good galvanealed metal...

For Galvanealed I'd use a Self-etched automotive primer...

Etching primers use an acid component to do the etching. In most cases this acid component is phosphoric acid. As 'ospho' and similar products are, in fact, phosphoric acid solutions, the advice to use an etching primer but avoid ospho is contradictory, and (potentially) incorrect.

The fact is, it's very common for paint/primer manufacturers to recommend using ospho & similar treatments to prep galvanized steel for coating, which is by its very nature a real challenge to get anything to stick well to. YMMV, but to me, the smart money is on listening to what the manufacturer says, and doing exactly that - to the letter. Neither you nor I know better than they do.

An Enamel based coating will also bond to the self-etched primer making it stronger after the Enamel dries

This isn't (necessarily) accurate. If you lay down a layer of 'X', allow it to cure fully, and then apply 'Y' over the top, the only 'bonding' that's going on is purely physical in nature. Which is why nearly every paint product available advises you to sand appropriately before top/re-coating once outside the recoat window of whatever you're applying.

Likewise, if you lay down a layer of 'X', and then apply 'Y' over the top within the recoat window and prior to full cure, then chemical bonding is possible, but only if the products in question are compatible in this manner. Considering the multitude of paint chemistries, the potential for poor results is great if you're not careful choosing products meant to work together.

Regardless, a topcoat doesn't do anything to make the underlying primer 'stronger'. If your primer isn't adhered well - it isn't adhered well - and nothing you put over the top will change that.

I once again caution against generalities. Lots of things qualify as 'enamel coatings' and 'etching primers'. Just save yourself some grief, read through the product literature, and do what they say. Then remind yourself the next time you paint that those instructions were only applicable to the product(s) you used, and in the capacity in which you used them.

 

[TheHubbardBus]

• Priming: Do I need to prime anything if I’m mostly keeping the existing background (the light blue areas), except for the grey panel which definitely needs covering?
• Galvanized/Galvanealed metal: I’m not 100% sure what parts of the bus that applies to — can anyone clarify where I should expect that, or how I’d recognize it?
• Prep for the blue areas: If I’m going to use the existing background as part of the design, what’s the best way to prepare it? Light sanding, washing, or do I still need to hit it with primer before painting over it?

Thanks everyone for the advice so far — this is helping me a lot to figure out the right approach!

For best results you should probably apply a primer, but that assumes that you use a quality product and prep/apply as required. If there are any areas of bare metal it is essentially mandatory if you want the job to last. In this case, the primer you'd choose would be one that is made for direct-to-metal applications. If no bare metal at all, that opens up the possibility to use other primers, or possibly no primer at all.

Like Nikitis said, if it's in your bus, it's almost certainly galvanized / galvanealed. Plenty of references online that explain more in detail.

Roughly-speaking, the prep process should go like this: thoroughly remove anything that's not paint (sealers, sticker-goo, etc), clean/degrease, mechanically prep (sanding / media-blasting / etc), clean again, prime, topcoat. The specifics of what you use to 'clean / degrease', and how you mechanically prep, are something you should look to the paint manufacturer to provide. In the absence of such info, water-based degreasers that are thoroughly rinsed-off prior to coating are likely to be less trouble-prone than volatile solvents, and if you work your way down to at least 220 grit, you'll probably be good for adhesion, though not necessarily ideal for a 'factory-finish' topcoat... which it doesn't sound like you care about anyway.

 

[blueskybluebird]

Struggle Bus….did you do YouTube videos….sounds familiar? I used a random orbital with 220 grit and red scotch brite pads for the uneven surfaces and hard to get to areas. Washed with TSP-PF detergent and painted with BEHR Direct to Metal semigloss paint. No primer. All available at Home Depot and Amazon. Rolled and brushed. I did have some clear coat areas that I used paint stripper on before sanding. I used Dicor metal roof paint for the roof with the same prep. Mine is a 36 year old weekend warrior so, wasn’t looking for showroom quality. I’ve been very happy. It’s far from perfect but perfect from afar.

 

[Shortbusjohnny65]

Hey everyone, just took my bus out for its first camping trip this past weekend—had an amazing time! Got a couple repairs done right before and now I’m looking to make this baby last and look good. I’m not great with spray-painting (brush I can handle), so I’m wondering: does anyone have guidance on painting the exterior? Do I need to sandblast? What type of metal is the shell usually, and should I be using a specific kind of primer, paint, or gloss?

I don't have a ton of money to spend so please offer advice with that in mind.

Also open to fun design ideas—want this rig to be proud of herself!

No primer needed unless bare metal. Was bus with dawn dish soap. Then get a box of maroon 3m scotchbrite pads just dull the paint. Wash again with dawn start painting. I have painted two of my buses with single stage paint the first was painted 10 years ago and still looks good.

 

[LargeMarge-TC]

2003, after a couple months full-time live-aboard, we painted our ExpeditionVehicle...
...on the shore of a reservoir in Arizona.
Rattle-cans.
Two cases from Wal*Mart.
.
No sanding, no worshing, no prayers to deaf deities nor sacrificial offerings at the altar of nomadity.
.
With over two decades full-time live-aboard, bashing through over-grown logger tracks nobody in their right mind has any business tackling, we can recommend our system.
.
After that success, we shot our ancient BMW motorcycle in a matching scheme...
...on a beach in Baja.
.
.

.
.
With air-brakes and an in-line filter, tap a tank, add a common air-line fitting from any hardware store.
You've little need for a second compressor to run your gxn.

 

[1dmpo]

So I'm gonna tell you how to keep it simple. All the advice about the random orbital sander is right on, I used 180 grit paper, some are saying 220, either is probably ok. Wash the bus, sand to get rid of anything shiny, wash again. Then I bought six quarts of Rust Oleum tractor implement paint in different colors and brushed my whole 28' flatnose bus. I used different colors and mixed some regular colors, like Ford Blue and International Harvester Red makes a really nice purple etc., and just brush it on. taping and spraying and all that is a hassle in my opinion. I can hold a brush and paint a straight line without tap and saved a bunch of time. Looks good, If I knew how to put pictures on here I would.

 

[nikitis]

You can literally drag and drop your picture file into the text were you type.

 

[1dmpo]

You can literally drag and drop your picture file into the text were you type.

How does that work when my pictures are in my phone and this is happening on my laptop? Keep in mind I'm an older person that's not real technically savvy.

 

[nikitis]

How does that work when my pictures are in my phone and this is happening on my laptop? Keep in mind I'm an older person that's not real technically savvy.

Not an issue. You can plug your charging cable with USB A type port (The larger rectangular one), and plug it into your laptop, then on your phone plug the other end into it.

If on android, bring down the upper messages window by swiping down, and select USB debugging towards the bottom, then select MTP File transfer, or File transfer. Then on your PC you'll see a new drive under "My Computer" which is your phone, open it and go to Pictures then DCIM folder and you should see your pictures. You can select and copy to your local Harddrive, or simply drag and drop from there onto the website text editor area.

 

[QuixotryHugger]

It’s far from perfect but perfect from afar.

^this gave me a chuckle. Perspective is a heck of a thing, eh. Hard sometimes when our heads are stuck in the build though...

 

[Ozbozz57]

Not an issue. You can plug your charging cable with USB A type port (The larger rectangular one), and plug it into your laptop, then on your phone plug the other end into it.

If on android, bring down the upper messages window by swiping down, and select USB debugging towards the bottom, then select MTP File transfer, or File transfer. Then on your PC you'll see a new drive under "My Computer" which is your phone, open it and go to Pictures then DCIM folder and you should see your pictures. You can select and copy to your local Harddrive, or simply drag and drop from there onto the website text editor area.

I'm a similar dinosaur. I seem to only be able to post pictures if I do the whole post on my phone.