Need advice on rolling on paint!

KC10Chief · 03-30-2007, 04:44 PM

I had worked out to use a paint booth tomorrow (Saturday) to paint my bus. So, I took the week off work and planned to prep the bus for paint. Unfortunately, mother nature has been kicking my butt. It's been raining for the past two days. One of the days I had to go out of town, and then it rained at the beginning of the week. So, the bus still needs a good day at least of work. Also, it turns out that the paint booth I was going to use is actually a big dirty garage. They open two big garage doors on either end for ventilation. I don't see the benefit of driving 80 miles to spray it in a garage. So, I'm thinking about just rolling the Dupont Imron paint on. Has anybody ever used a roller on their bus to paint with? Which kind should I use? Foam? I'd like the paint to be smooth and have a little shine to it. This is polyurethane paint and it doesn't require a clear coat.

Everybody always has these outrageous ideas on how to paint the bus and make it look spectacular. They always involve a LOT of work and a lot of money of course. Having a new car quality paint job would be great, but these people forget that this is a $2,000 school bus. It's supposed to be sunny tomorrow and about 70 degrees. I'll finish prepping the bus. Sunday the forecast calls for 81 degrees, 45% humidity and no wind. I'm thinking that will be the day. Any pointers?

Steve · 03-30-2007, 04:48 PM

The first time I painted my bus I used a roller. I do like the texture that it gave and it did look good. With a roller you will probably only need to paint it once as it automatically applies the paint the same thickness. I found though that it might be too thick and it came off after only a couple years on the bus. Might be because the large steel panels expand and contract a lot in the extreme weathers we have here. Since then I used rattle cans to paint it and each year I just get a can to do touch ups in the spring.

oldog12 · 03-30-2007, 06:02 PM

I'd still go with the "paint booth" big garage or not... I think you'll be pleased more with the sprayed on paint job than with the rolled on one... But if you've decided to roll it on, then roll it on...

Does the auto shop have any scaffolding so you can get up on top ? You got any contacts at the base engineers ? You might be able to beg some scaffolding from them...

It's up to you, but if it were mine, I'd go with the spray.

What does the paint say ? Is the primary application spray or roll on ?

Do what the paint says...

.

crazycal · 03-30-2007, 07:56 PM

If you don't want to drive the 80 miles, go to a Costco and buy a sprayer. They don't always have them but when they do, they are cheap. Or try Harbor Freight. I wouldn't roll on the paint. I'm not a painter but I did stay at a Holiday Inn Express last night. Good luck.

Elliot Naess · 03-30-2007, 09:19 PM

More info on spray guns, please. I saw a bunch of them at Harbor Freight, all the way
down to ten bucks -- which is about my "speed". But there are so many different
kinds -- High Volume Low Pressure and so forth. What would be easiest for a
rookie to use with a wimpy compressor and hardware store paint?

nyrockingchairs · 04-18-2007, 07:54 AM

Well you pretty much get what you pay for. An $80 air sprayer is going to have more bells and whistles (control over air flow, paint flow, spray adjustment, etc) than a $10 gun. That is not to say that a $10 basic sprayer is fine for what you are doing. I have used the $10 cheapies all the way to my current guns which were $120 for a pair.

The best way to ensure your gun lasts is proper maintenance. Always clean it zealousy after each use. I use the proper paint thinner and acetone to clean it out and then let it dry.

I find that I prefer the "can-on-top" guns versus the "can-on-bottom" guns. The bottom mount guns tend to clog more and have more difficulty keeping the paint flowing at a constant rate, the top mount guns allow gravity to do all the work. The only problem with the top mount guns is you have to always be mindful to not turn the gun upside down, they have lids, but the lids still have a 2mm hole in the top to allow air into the can and paint will come dribbling out if inverted.

As far as air compressors, most air guns like to see pressures in the 75 to 85 PSI range. A small pancake compressor is going to have a hard time keeping up with air spraying a bus, if you were doing a lawn mower deck or door then no problem, with the bus you are going to spray for about a minute and wait a minute for recharge.

I was spraying with a 25 gallon compressor and would get about 2 minutes of spray and wait a minute for recharging. After my 25 gallon portable died I upgraded to a 120 gallon permament install and never have to wait for a recharge, but I no longer have a portable compressor. I got my 25 gallon at an auction for $15 so if you can find them, then they are great for having as a throw-away compressor.

Filling the gun also becomes a concern. The gun can is only about a quart size. Each can full of paint should net you about 20 to 30 square feet give or take depending how thick you lay the paint. It scares me to think that I would have to be climbing up and down from the roof to keep mixing paint and filling my gun.

Make sure you read the paint and get the proper thinner, most paints are too thick straight from the can for a sprayer, oil-based rustoleum is always thinned, each paint will list what thinner to use and the mix ratio for spray application. So the thinner will add to your paint cost.

If you are planning to use the wimpy compressor definetely go with a HVLP gun, more paint flows with less air, these are almost always can-on-top guns.

Personally, I have no intention of spraying my bus, except maybe the hood. The rustoleum will finish just fine rolled on. At least the bus I have has so much surface junk, so to speak, meaning it is not flat and smooth like a car, but full of accents and screws. So the finer finish you would get from spraying will not make that much of an impact on this broken surface. Since the hood is a nice big flat surface and not that large, I will spray that. If I were going to use a glossy automotive paint then I would spray, but for the rustoleum, nah.

Elliot Naess · 04-18-2007, 09:48 AM

Thanks! I used a brush on the first bus, so I want to try something new. I think I'll roll the
roof and spray the sides. As for cleaning the gun -- you just helped me make up my
mind, because I know myself...: I'll get two or three of the "Ten Buck Chuck",
and drop them in the garbage can when I'm done (or it clogs)!

GoneCamping · 04-18-2007, 08:56 PM

I rolled the roof on mine, and sprayed the sides using Rustoleum with a 15% acetone mix... came out graat if you don't look too closely...have a few runs but I don't think anyone but me is going to put this thing under a microscope...

After rolling the roof it was then I decided it was too much work. And for all the rub rails and stuff, it was going to be hell to roll the sides of that bus, spraying was the only option for me...it managed to get in between the rails and other surfaces really easy....

BusNut · 04-19-2007, 08:24 PM

Cliff, I just had to say I like your sig line:

Quote:

You just might be a Redneck...
if you regularly check the brake lights on your house!

Hey! I resemble that remark.

nyrockingchairs · 04-20-2007, 06:33 AM

I just had to say I agree with Cliff for rolling the roof and spraying the sides. Thinking this is the way to go.

It was up to 55F yesterday, in a couple more weeks it will be painting weather.

fightingsiouxbus · 07-27-2007, 04:21 PM

We rolled the paint on with a very small napped roller. I think it was 1/4" or 3/8". We used Rust-o-leum professional grade paint because it adheres well to metal and it inhibits rust. It also is available in spray cans with the same colors. We used the spray cans first in areas where we knew the rollers would do know good. Then we rolled as smooth and steady as possible. We painted in a control environment (a pole barn) on a 65 degree day and it worked great. We used two coats most places. After a year there were a few areas that needed touch up, mostly in crevices and areas where we didn't sand good.

I think a key to a good paint job is the prep work. We spent 3 times longer on sanding and priming than we did on painting. Every inch was sanded first with 120 grit and then with 400 grit sandpaper. We also spent alot of time taping the edges. I get asked all the time what body shop painted it for us and the folks are all very surprised to find out we did it ourselves with rollers!

trx · 08-09-2007, 08:11 AM

If you don't have a compressor there's always one of these:

$50 - http://www.harborfreight.com/cpi/cta...emnumber=91772

I had one similar. It may not spray thicker paint too well so thinning would be required. I broke the gun on mine partially my fault and partially because they are very cheap guns. This happened before I painted my bus. I have a big compressor so I used a standard spray gun. It's still an option if you don't have a compressor and want to spray your bus.

On my bus I used implement paint made by Valspar (usually sold at farm and fleet stores). It was about $20 a gallon and gives a nice glossy smooth finish when thinned and hardener added. It does have adhesion problems with bare metal.

Chad

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