rubber roof sealant/paint

[tugboater]

I know there are all sorts of threads on here that talk about elastomeric roof coatings. I'm looking for any feedback from folks that have attempted to solve a somewhat common problem.

I patched my roof exits a month or so ago. I did what I thought was a nice, tight job. WRONG! We got a couple days of heavy rain for the first time since they were installed. They both leak, one was bad...the other not so much. Fortunately I was watching & had buckets to catch the water before it ruined my nice new floor! I was able to figure the problem by blowing air up into the rivets...several of them were blowing bubbles topside. I drilled them all out & used 1/4" sheet metal screws (up from 3/16" rivets) to fill all the holes this time. I covered each hole & screw threads in sealant first, tightened them up & goobered around the heads with sealant as well. I'll let things cure overnight and simulate a downpour tomorrow to see how the second try holds up. I think I'll be good to go.

Anyway, as long as there are NO leaks... as insurance, my plan is to tape off each patch to about an inch our two either side of the rivets/seams & coat with Flex Seal or some other elastomeric like coating. I'm not going to paint the whole roof with the stuff. I'm looking for something with the consistency about halfway between the sealant that comes out of a caulking gun & just regular paint. I've got marine maintenance enamel for the roof, but want it sealed up good before I take that step.

What product have you all had luck with?

I think I'm going to buy a gallon of the white Flex Seal unless someone calls that out as a poor decision. Again, I'm only planning on using this as insurance, only applying once I know I'm leak free without it.

[o1marc]

Should work. I'm planning the same thing only once I mask off the vents inside the screw line, I will coat the whole roof at that time, should seal any leak that may have been left.
Were your rivets closed end?

[tugboater]

Originally Posted by o1marc

Were your rivets closed end?

Yeah, they are.

https://www.rivetsonline.com/closed-...4ffph/pr64ffph

I'm not sure where I failed. I didn't dip the rivet in sealant prior to setting them, and I should have. It was the first patch I did...fortunately I did put sealant on all the rivets for my skins. I ran the hose over the patch today & then had my wife run the air across each row from the inside. The bubbles were coming up around the collar, not from the center (because they are closed end). Anyway...live & learn. This is why I take my time. I must admit, it made me quite grumpy.

[tugboater]

Originally Posted by o1marc

Should work. I'm planning the same thing only once I kask off the vents

You pick out your vents yet? I need to start thinking about that. I liked the one Johnny Mullet put on his bus. Need to do some research. I feel like thats a good place to spend a little extra money if it translates to quality. The ones I’ve seen at rv shops all seem pretty flimsy. Easily cracked in cold weather.

[o1marc]

Originally Posted by tugboater

You pick out your vents yet? I need to start thinking about that. I liked the one Johnny Mullet put on his bus. Need to do some research. I feel like thats a good place to spend a little extra money if it translates to quality. The ones I’ve seen at rv shops all seem pretty flimsy. Easily cracked in cold weather.

I replaced the emergency hatch with tinted Lexan and then mounted the 14" MaxxAir fan/vent in the center of it. I may add the same to the front skylight.

[Native]

We sealed all of our seams with EternaBond tape. It works well. We also deleted the "fresh air vent" that was in front of the forward escape hatch. Used the sticky stuff from the EternaBond between the roof and the sheet patch. Once the self-tapping screws were in, it was SEALED ... the EternaBond goop oosed out from between. EternaBond was applied to these seams as well.

[Drew Bru]

We used butyl tape between the sheet metal patch and the roof, used self-tappers to fasten it down, then LOTS of Dicor lap sealant around the edge. I think I used 1/2 a tube of Dicor on each hatch and made a 2" wide strip around, kind of feathering it out from the patch to the roof. I've got another tube of Dicor, and I'll probably go over it once again this summer just to be sure. It's boogered on there pretty good but the stuff's cheap enough that it's probably good insurance.

[Sleddgracer]

this is what I plan on doing - I've used it for years with great success on a trailer - didn't even have it glued down, just a strip tacked around the edges - it self heals for things like screw holes etc, easily repaired if needed, and on a bus roof should last longer than the bus itself

https://www.youtube.com/watch?v=MxOzPtBSjHw

[tugboater]

Originally Posted by o1marc

I replaced the emergency hatch with tinted Lexan and then mounted the 14" MaxxAir fan/vent in the center of it. I may add the same to the front skylight.

How thick was your Lexan? I like this idea. If I hadn't already covered the exits with steel I'd probably give it a go.

[tugboater]

Originally Posted by Drew Bru

We used butyl tape between the sheet metal patch and the roof, used self-tappers to fasten it down, then LOTS of Dicor lap sealant around the edge. I think I used 1/2 a tube of Dicor on each hatch and made a 2" wide strip around, kind of feathering it out from the patch to the roof.

Drew-I used a similar method. I put the butyl tape around the edge of the existing hole, layed the sheet metal over it, then drilled and riveted about an inch outside the butyl tape. No water is getting past the butyl tape, but it is getting through the edges of my unsealed rivets. I've come to the conclusion that I didn't clean up enough of the metal shards & maybe didn't drill a clean enough hole for the rivet to make a good seal. ALso, when I placed the patch, the temperature was only about 40F. THe butyl tape didn't squish down much...it may have left a little gap between the sheets that didn't provide a good square surface to join. My repair yesterday, is almost identical to your method...self tappers, goobered sealant and all.

Originally Posted by Native

We sealed all of our seams with EternaBond tape. It works well. We also deleted the "fresh air vent" that was in front of the forward escape hatch. Used the sticky stuff from the EternaBond between the roof and the sheet patch. Once the self-tapping screws were in, it was SEALED ... the EternaBond goop oosed out from between. EternaBond was applied to these seams as well.

Native-I saw this stuff at Lowes yesterday when scouting for sealants. I bet you're good to go. I might use it if for some reason I have to do over...hopefully that's not the case.

Thanks for sharing your methods!

[tugboater]

Originally Posted by Sleddgracer

this is what I plan on doing - I've used it for years with great success on a trailer - didn't even have it glued down, just a strip tacked around the edges - it self heals for things like screw holes etc, easily repaired if needed, and on a bus roof should last longer than the bus itself

I wonder if you can paint over that stuff? I'm sure it works great in certain applications, but I'd surely destroy it during installation of either the membrane itself or a vent, solar panel or marker light...I might even forget about it and try to weld something to it.

[farok]

Originally Posted by Sleddgracer

this is what I plan on doing - I've used it for years with great success on a trailer - didn't even have it glued down, just a strip tacked around the edges - it self heals for things like screw holes etc, easily repaired if needed, and on a bus roof should last longer than the bus itself

My garage roof at my house doubles as a deck since it's set into the hillside, and the roof was covered with this about 10 years ago. We walk on it daily, and have some lawn furniture on it (without any sharp metal edges, of course) and it has stood the test of time so far! Great stuff, but probably not the best for radiating heat in the summer. Not that it matters on our garage roof...

Chris

[o1marc]

Originally Posted by tugboater

How thick was your Lexan? I like this idea. If I hadn't already covered the exits with steel I'd probably give it a go.

1/8", anything thicker is overkill and not necessary. 1/8" is what we used for our race car windshields. I won't crack or break. I fit the butyl tape to the Lexan and then predrilled holes for sheet metal screws. If you wait for the temp to go up and then reset the screws it will pull the patch tighter against the butyl tape.

[Sleddgracer]

Originally Posted by tugboater

I wonder if you can paint over that stuff? I'm sure it works great in certain applications, but I'd surely destroy it during installation of either the membrane itself or a vent, solar panel or marker light...I might even forget about it and try to weld something to it.

easy to paint ( and hard to clean up if you accidentally get paint on it ) a water based paint would eliminate any problems possible with oil, alkyd, or 2 component paints - does NOT weld well - lol - for lights etc, I've found it makes it's own gasket - the video shows how to deal with vents - I've attached boards to the roof of my trailer and in 15+ years it hasn't leaked through the screw holes

[EastCoastCB]

Originally Posted by tugboater

Drew-I used a similar method. I put the butyl tape around the edge of the existing hole, layed the sheet metal over it, then drilled and riveted about an inch outside the butyl tape. No water is getting past the butyl tape, but it is getting through the edges of my unsealed rivets. I've come to the conclusion that I didn't clean up enough of the metal shards & maybe didn't drill a clean enough hole for the rivet to make a good seal. ALso, when I placed the patch, the temperature was only about 40F. THe butyl tape didn't squish down much...it may have left a little gap between the sheets that didn't provide a good square surface to join. My repair yesterday, is almost identical to your method...self tappers, goobered sealant and all.



Native-I saw this stuff at Lowes yesterday when scouting for sealants. I bet you're good to go. I might use it if for some reason I have to do over...hopefully that's not the case.

Thanks for sharing your methods!

man I'm late to the discussion but that sucks!
Its best to drill it off the bus and make sure you de-burr everything.
Sucks to hear about your leaks.

I stuck a scrap of steel up with four screws as a temporary thing on my 2nd bus. No sealant just slapped it up there. It didn't leak!

Keep on keepin on man!

[tugboater]

Originally Posted by EastCoastCB

.

Sucks to hear about your leaks.

Keep on keepin on man!

No leaks the second time around[emoji1417]. Lesson learned.

[Native]

Originally Posted by tugboater

No leaks the second time around[emoji1417]. Lesson learned.

Lesson learned second, third, fourth time aroud is still lesson learned! Glad it only took one instructable.

[Tecchie]

I actually thought about (when I finally get my bus and start the project) paying for a company to do a spray in bed liner type coating. Like Line-X. Have them do white for the roof, and maybe a different color or colors around the sides. Ha way I’ll never have to worry about a leak or scratches. Plus it will add some strength.. yeah it may cost some change, but to me it would be worth every penny

[Pizzarco43]

I have used Lanco Ultra Siliconizer on a few projects including my living quarters horse trailer, a 1973 motorhome, and my "Reverse Skoolie" that started out as a Class C motorhome and ended up as a combination school bus and flat bed truck. I have found it easy to apply, attractive, and cost effective.

[o1marc]

I checked out a new off road truck outfit in town. When I stopped in I noticed they had a 35" paint booth, big enough to pain the bus. Talking to them and walking around a floor covered in bed liner I realized their paint booth was dedicated liner spray booth that they did more than just beds. They had a newer finer texture product they have been shooting. I'm considering ir for places on the walls, but am concerned any texture on the sides will collect dirt.
I wonder how the efficiency of bedliner would be compared to Henry's.