Does anyone know what kind of paint was used on the roof, back in the day? Did they use an automotive type paint, house paint, or a type of Kool-kote/Roof-coat rubberized covering?
What products have you used recently for the roof and color stripe; and how are the results?
I plan on using some kind of cool coat, possibly as soon as this weekend if the rain stops. Contrary to the past few weeks Florida actually gets a lot of sun and anything that will help keep the roof cooler is a must.
I just finished putting on the kool-coat a few days ago. My concern now is the texture of the finish. Directions say to use a 3/4"nap roller, which left an "egg shell" or "pebbly" type of finish. I can see already it holds the bits of dirt and pine needles. I am afraid I will have moss growing in no time. As for cooling, I think the only benefit is from the reflectivity. Next I want to do the color stripes and wonder what kind of paint to use.
Quote from: mung on September 30, 2014, 10:11:05 AM
I plan on using some kind of cool coat, possibly as soon as this weekend if the rain stops. Contrary to the past few weeks Florida actually gets a lot of sun and anything that will help keep the roof cooler is a must.
I am going to do the same I have read that you can get something at Home Depot for around $60 that will do the whole roof, I just hope that the peeling paint that is on there will come off easily.
Quote from: John Z on September 30, 2014, 11:28:32 AM
I just finished putting on the kool-coat a few days ago. My concern now is the texture of the finish. Directions say to use a 3/4"nap roller, which left an "egg shell" or "pebbly" type of finish. I can see already it holds the bits of dirt and pine needles. I am afraid I will have moss growing in no time. As for cooling, I think the only benefit is from the reflectivity. Next I want to do the color stripes and wonder what kind of paint to use.
I am going to "try" to do the stripes on mine as well, I am going to try the tip and roll method using thinned Rustoleum or something like that. I am only going to do the stripe where it currently is and it is about a foot tall, it does not need to be perfect but my only concern is floating junk in the air hitting it when it is wet that always ruins things I paint around here.
My roof paint was badly peeling, so I took it all off down to bare metal, sanded, degreased, etch-primered, recaulked all the seams, primered, sanded, then two coats of Rustoleum gloss white with Thermacells ceramic insulation added, then two more coats of plain Rustoleum to smooth the surface. I brushed on the Mar-Hyde etching primer, but rolled on with a short-nap 4" roller the primer and top coats. A LOT of work, but it now keeps the interior cooler than before. Hand-scraping paint off 400 sq.ft. of roof and 1,630-plus rivets was not fun!
John
I did the Bus-Kote 3-part system. Good sanding (not obsessive about it, tho), then their primer, two coats of white and the clear sealer. After the two coats of white (sprayed - I had weekend access to a not-really-paint-booth bay), it was pretty grainy and I was worried about dirt etc. sticking to it but the clear sealer did a good job of smoothing it out. I wish I had recorded 3PM ceiling level temp for a week of clear days before I did it and then the same number for a week after and compared the averages. I'm convinced it's cooler. If it will stick on, I'll be very happy with it.
To the original question, I don't have a clue what paint was used on your roof. But to the comments since, I have used Henry's mobile home elastic roof coating for the last 8 years and I found it took 4 gals to put on the original coat and a follow up every other year takes less than a gallon and keeps the roof cool and looking good. I put it on with a 3" soft bristle paint brush that you find in the dollar shop for a buck and the lines flatten out before it dries leaving it relatively smooth. I wash the roof yearly with a mild bleach solution and a soft car wash brush to keep moss from growing on it. Walmart carries the Henry's product for under $15. a gallon or $50. for a fiver. The key is to put it on thick and let it flow out smooth. A coat of wax goes
HTH Will
Bruce, you did a much more thorough job of prep than I did. I had called the manufacturer and they said to just scrape it and sweep it. So I knocked the loose flakes off and painted. I'm sure your job will outlast mine. Will, I like your maintenance schedule, and will probably do the same, wash annually and recoat every other year. After reading up on the new 100% acrylics I may just try a good house paint for the color stripe.
Quote from: John Z on September 30, 2014, 05:25:03 PMBruce, you did a much more thorough job of prep than I did. ...
Oh, not really. But my bus roof had been painted with a pretty heavy coat of ordinary NAPA standard white body paint and it wasn't weathering well. I redid it before it actually cracked or flaked but it was very powdery on the surface and had been contaminated by tree sap, dust and dirt that has been dissolved in dew and rain water, and the chemicals from tree leaves, etc.. It seemed a good idea to do a "coarse sand" to take off most of the thickness of that layer. I think it was a good smooth thin coat that was left in most places (went down to the metal in a few places of course) but it was a quick hit instead of a real prep. But I think that it was a good base for the BusKote primer.
I guess we will know what kind of a job we did in a couple years. I may look into the clear sealer you used. I like the idea of it smoothing out the surface a bit. I had a problem waiting for the right weather to put on the kool-cote. They say it should be at least 65, and stay that warm for 48 hours with no rain. That hardly ever happens in northern Minnesota, unless your indoors! The house paint for the stripe can be put on down to 35 degrees. That's Minnesota friendly paint!
zinc chromate that's what was originally on Bus roofs because of Electrolysis with the aluminum roofs. Marine primer like Toplac and then Imron type paint over that with ceramic roof treatment in that and a top coat over that would be good these days.
My aluminum roof appears to have been painted with regular automotive paint. They even clear coated it. Mine is a 1995 so what they did in the 60s, 70s, or 80s may be totally different.
Quote from: Dave5Cs on September 30, 2014, 09:23:39 PM
zinc chromate that's what was originally on Bus roofs because of Electrolysis with the aluminum roofs. Marine primer like Toplac and then Imron type paint over that with ceramic roof treatment in that and a top coat over that would be good these days.
zinc chromate...is that kind of white and wears powdery ? ... (thats the best i can describe it)
Quote from: Dave5Cs on September 30, 2014, 09:23:39 PM
zinc chromate that's what was originally on Bus roofs because of Electrolysis with the aluminum roofs. Marine primer like Toplac and then Imron type paint over that with ceramic roof treatment in that and a top coat over that would be good these days.
I used to prime window panels for buses (transit) with zinc chromate. It's kind of limey-puke green. :D
I am finding it harder to get my hands on it locally nowadays. They do not sell it in aerosol cans here any more. Still available in gallons but expensive.
eagle, when it gets old it does get powdery and white may just be the over coat of whatever the sun over time does to the ZC, But yes it is a weird light green color when it goes on. Can't get it here either in Cali anymore but there are a lot of paints you can't get here anymore. I am surprised paint doesn't just fall off cars here because of all the things they have taken out of it here. LOL ;D
Quote from: Dave5Cs on October 02, 2014, 07:11:38 AMeagle, when it gets old it does get powdery and white may just be the over coat of whatever the sun over time does to the ZC, But yes it is a weird light green color when it goes on. Can't get it here either in Cali anymore but there are a lot of paints you can't get here anymore. I am surprised paint doesn't just fall off cars here because of all the things they have taken out of it here. LOL ;D
Dave, I don't know if zinc-chromate was developed for aluminum airplanes in the 1930's-40's, but if not, it was sure adopted widely by then (and continues to be used). I don't know if it's still "the gold standard", but it was surely the best thing available for many decades. And, yeah, the color is about the weirdest you'll ever see.
And you don't need paint in California! You just move your painting stuff offshore to another place in the world and let them put the volatile stuff in the atmosphere. The fact that the industry, economy, jobs and money in circulation also go offshore -- that's OK, some environmental group said it would be a good thing so ARB and the politicians are all over it!
What about EDPM sheets VS paint, advantages one over the other?
Liquid EPDM is the way to go. It needs to be mixed in batches and troweled on 3/16" thick. It flows into every crevice and self levels as it cures. It is so thick, you won't be able to see the rivets or layers of aluminum on the roof. The higher upfront cost is justified when you consider its proven 15 to 20 year lifespan. On my previous RVs, I have tried to save money by using the cheap hardware store coatings. They roll on like water and peel every 1 to 2 years. It was just miserable having to scrape the loose coating and constantly redo the roof with the cheap stuff.
http://www.epdmcoatings.com/ (http://www.epdmcoatings.com/)
yvan - EPDM sheets or Liquid EPDM will seal leaky rivets and seams. Paint will not seal a leaky roof. My bus roof was painted by the previous owner. The paint around every rivet had a circular crack and every seam had a straight crack. Paint is more resistant to UV damage than EPDM, but can't be trusted to seal anything.
I wonder how Plastidip would work on a roof?
Quote from: mung on October 05, 2014, 12:11:03 PM
I wonder how Plastidip would work on a roof?
seriously ?
Yes, seriously. There are a HUGE group of people who are doing it to their cars. Makes a nice coating that can be pulled off easily if you want to change it out.
Why bother? You will need about 5 gallons of Plastidip to build up a layer thick enough to be waterproof and durable. 5 gallons of Plastidip costs about $300 and has to be sprayed on in many coats. It could be a costly waste or it might work just fine.
It would be wiser to spend the $300 on a purpose made roof coating. With only 350sq/ft to cover, $300 will get you the best that money can buy.
It was just a thought because of being able to peel it off if need be.
I plastidip cars in my business, and will more then likely end up doing the sides of James( not enough time to paint for now). I wouldn't even think of it for the roof though, application on horizontal surfaces is a real pain.
I was thinking of having the same material they use for lining truck boxes applied to the roof. I don't think I would use the DIY kits but rather have it professionally done. I am thinking it may reduce heat transfer and it should substantially reduce the noise level. Thoughts on this?
Sorry for the thread jacking....
We apply SEM Protex in my shops, enough to do the roof of a bus would run around $1000. Again application would be an issue. as well as prep. Good idea, but best stick to conventional, proven products.
Quote from: krank on October 06, 2014, 07:32:00 PM
I was thinking of having the same material they use for lining truck boxes applied to the roof. I don't think I would use the DIY kits but rather have it professionally done. I am thinking it may reduce heat transfer and it should substantially reduce the noise level. Thoughts on this?
Sorry for the thread jacking....
The bed liner is an interesting option with pro's and Con's. Pro would be the fact that the material is created to withstand weather and is pretty durable. Preparation of the bus is important for good adhesion. Also, it is waterproof. Con might be weight. The stuff, when applied to speck is actually fairly heavy compared to some other materials. Speck usually calls for 1/8 or more in thickness. Colors may also be limited, but seems like there are more options recently. also, the coating is not color fast and will fade with exposure and there really is no effective long term way to bring the color back. Finally, if you put bed liner on, you will not get it off again without damage to the metal.
Some of the problems with the roof is lay over panels and rivets as well as fans and AC units etc. to go around that will leave an edge. The roof for most of these rubberized coatings has to be really clean and de-greased, the powdery residue has to be stabilized. If these things are not done they will eventually get air under them and pieces will start to lift and when water gets in it will be a mess.
Bus Kote is not cheap but done right will give good results. Or painted with a good sealer and Automotive paint. House paint will peel might last a little while. Just some thoughts.