When to Paint?

[gs1949]

OK, so I'm getting ready to paint the bus, which means getting everything I need.. And I think I will just paint the roof at first, because it's the most important; so I think I'll put a primer and 2 top coats on the roof before I do the rest of the bus..

So what I'm wondering now is whether I should put seam sealer on the seams, and maybe on the rows of rivets where there is no seam between the panels too. I have several of those too.
So I've been looking at seam sealers today. 3M tends to be very expensive. Dynatron is noticeably less and has very good reviews too.

https://www.amazon.com/Dynatron-570-...94/ref=sr_1_31
And then there's the paint on stuff:

https://www.amazon.com/3M-08656-Brus...4I2/ref=sr_1_3
OR
https://www.amazon.com/Dynatron-552-...5C/ref=sr_1_22


There's no signs of any leaks in the roof of the bus that I can see. But I'm not sure how much that means. I know there was a pretty good leak around the rear emergency hatch because it rained almost 7 inches that first weekend after I brought it down to the coast in early April. There was waterlogged fiberglass, but it hasn't rained hard since and I can't see where the water came from before it got absorbed by the fiberglass. I can just tell it came from somewhere near the hatch. No water around the other hatch. but I am nearly ready to get rid of both of them and will do that before I paint.

So basically I am wondering whether I should use painted or caulked seam sealer. I think the easiest would probably be just running a bead with the caulking gun.

And I am also wondering if I might not be missing something that could be obvious to someone with more experience.

And maybe some help estimating. I have about 9 or 10 seams plus maybe 4 rows of rivets where there is no seam.

Comments appreciated. Thanks

[EastCoastCB]

I'd do the seams with that dynatron. Its a 3m product, I think.

[gs1949]

Thanks, I am leaning to that one. I think the caulking woud be the simplest, less messing around probably.

And I want to put some of that same stuff on the seams of my newly painted floor before I start gluing insulation to it, so I will get enough to do that too.

[PeteinSF]

I just got sited in Willits CA.

They gave me 30 days to not be yellow.

[gs1949]

I guess you mean cited, and if so that would tell you when you need to paint. Good luck with that.

[Sleddgracer]

Originally Posted by PeteinSF

I just got sited in Willits CA.

They gave me 30 days to not be yellow.

- that must have come as a bit of a shock - I don't know that I've ever been called yellow

[gs1949]

I used to get called yellow sometimes. Then I would do something outrageous so they'd stop calling me that. Looking back on it, I was certainly predictable.

[PeteinSF]

citation was CVC-27603: "...it shall be painted by the purchaser a color different than that prescribed by the Department of the California Highway Patrol for schoolbuses before it is operated on any street or highway..."

[gs1949]

You get a fine for that?

[PeteinSF]

No, just 30 days to address and get signed off by a peace officer.

Much sooner than I intended to paint.

Primer gray may be my selection to buy time.

[gs1949]

Well, at least now you know when to paint.

[Sleddgracer]

Originally Posted by PeteinSF

No, just 30 days to address and get signed off by a peace officer.

Much sooner than I intended to paint.

Primer gray may be my selection to buy time.

that would change the colour, but primer breaks down quickly when exposed to the environment - I wouldn't leave it more than a week, two TOPS, before at least putting the first top coat on it or you'll wind up dealing with peeling paint in a year or two

[Doktari]

I’ve painted a few buses and worked in a body shop a long time ago. Prep work is key. I like to do the prep work as others will often take shortcuts. But I prefer a good painter to shoot it as I suck at it. I wouldn’t primer it as it’s twice the work and unnecessary. Taping off a bus is a lot of work so I like to only do it once. Spot primer as necessary. Only bare metal needs primer if the rest of it is prepped well. Sand the heck out of any plastic you are painting. I have a plastic grill on my Chevy I painted a few years ago. No flaking as I sanded thoroughly.
If you do the roof first then the overspray drifting down onto the body doesn’t matter much as you will be painting over it.
If you want a very tough paint the best bargain I’ve seen is Equipment Paint $40/gallon. There are limited colors where I’ve shopped but I bet it’s available in tintable color. And it’s tough as nails.
One trick I learned for sanding on a hot day is to wet sand with a bucket of water with dish detergent in it. It works wonders. Gets out oil, silicon, dirt, and makes the sandpaper work better. Keep rinsing of the soap before it dries. And keep yourself cool too. Thoroughly pressure wash the cracks, crevasses, seams before wet sanding.

[Mekanic]

I painted my wood sheet sided back wall with a very good water base ext paint and it has held up quite fine. I have about 5 years on first coat and 3 years on the second. IIRC it was $38 at lowes. and it was ultra white semi gloss.

[peteg59]

Per Summit Racing: Painting a vehicle is 95% preparation and 5% painting...

[Sleddgracer]

Originally Posted by peteg59

Per Summit Racing: Painting a vehicle is 95% preparation and 5% painting...

^ agree with the above - once you have spent several days patching holes, fixing various dents, sanding, spot priming or priming in full, masking, setting up suitable scaffolding, or having wands of the right length for the tip of the gun, spraying a full sized bus using a commercial airless sprayer, should take less than 1/2 hour per coat, or less - when I was painting the interior of spec houses with no colour changes, the first coat took 1 hour, 15 minutes, the 2nd coat just over 1/2 hour, to paint the interior of a 3 bedroom, 2 bath, stair well, hallway, and entrance in a 1200 sq' house - no fixtures, no flooring, cupboards, or woodwork to worry about - plastic covering the windows left over from the dry wallers - those machines pump a LOT of paint and the painter has to move fast to prevent getting runs - using latex, you can use a 21 thou tip for painting a building - painting a bus with enamel, you'd use a 13 thou tip on the gun - the sprayer I was using was capable of supplying two guns with 21 thou tips each spraying a 2' wide fan of latex, each with 100 + feet of paint line feeding the guns - if access was good, 2 men could paint 40,000 sq' on a light stucco surface in one solid day of work

[PeteinSF]

Doktari, thanks for the info.

By Equipment Paint, do you mean something like tractor paint/heavy equipment paint (cat yellow would clearly not work for us as a group [grin])

international “FARMALL” tractors were a deep red.

https://youtu.be/iQ00AG9d42c

[Sleddgracer]

Originally Posted by PeteinSF

Dokteri, thanks for the info.

By Equipment Paint, do you mean something like tractor paint/heavy equipment paint (cat yellow would clearly not work for us as a group [grin])

international “FARMALL” tractors were a deep red.

https://youtu.be/iQ00AG9d42c

'cat' yellow uses a different yellow colourant than school buses - school buses use a chromium yellow - while cat yellow uses yellow oxide - you'll be happier painting with oxide yellow colours than chrome colours because they cover much better - you can damn near see through paints that have chromium yellow, like greens and reds, and yellow of course, that have that colourant in them - laws in some jurisdictions dictate not using chromium yellow, some say not to use yellow known as school bus yellow, and some just say yellow - ( and some don't seem to care one way or another )

John Deere uses green *

[Rock-N-Ruth]

In most jurisdictions they don't care if you are yellow, many don't care if you say School Bus. Most want you to remove the stop sign and disable the curb flashers, especially the red.

[Sleddgracer]

Originally Posted by PeteinSF

Doktari, thanks for the info.

By Equipment Paint, do you mean something like tractor paint/heavy equipment paint (cat yellow would clearly not work for us as a group [grin])

international “FARMALL” tractors were a deep red.

https://youtu.be/iQ00AG9d42c

often referred to as 'Industrial Enamel'