Anyone know what's on the lid?

[flyu2there]

Sent two men out this morning to wash and wax the bus. They started with the roof and as the pressure washer was doing its thing, I noticed sheets of clear coat in the wind. OK, understand, bus is about to be ten years old and the clear coat or whatever was shot on at the factory over the "bare" metal on the very top of the bus has decided it is time to leave.

Here's the question, again not a paint issue per say, but what is the best "stuff" to recover the top of the bus? My quick peek tells me wax and to blow off shooting some form of clear...............Ideas and suggestions would be sincerely appreciated.

John

[sawdust_128]

I just had a conversation with a painter. I am doing some touch up work and consulting with him about paint and clear coat. He was very firm in regards as to how clear coat applications must be made because of the potential to delaminate the clear with a presure washer. He stated that people using presure washers don't understand the limitation of clear coats and that he has had to reapply clear to parts of his boss's coach because they blew the clear right off of it. That coach is 2 years old.


I know it's too late on this one, but it's a tidbit for consideration in the future.

P.S. Not 100% on this, but I thought that there was a roof coating spec in the body section of the Maintenance manuals.

[Jon Wehrenberg]

John,

Are you sure there is not a painted surface beneath the clear coat?

My roofs have been painted and then clear coat applied.

If it was my roof and the peeling did not propogate to the sides or caps I would ignore it. If there was a risk of the peeling migrating to a visible surface I would get the bus to a paint facility to take preventive measures.

[flyu2there]

JON,

No paint on this lid....looks to me like 1/4 or greater aluminum butted up against the caps and the edges. Someone cleared the thing and obviously that clear has failed. I was looking at shingles as a viable solution () but do not know if GAF Timberlines, 30 year, would be wise because the roofing nails might be tough!

Seriously, looks like clear over metal, not good. I am thinking of a clear again after I wash, blow or sand the remnants............ I think it might polish very well with carnuba, not sure if it is even an event. Not really sure what a clear over bare metal was doing there in the first place...............but, hey, its a Country Coach.

John

[flyu2there]

Wood Shavings (),

Thanks for the reply. I know that pressure washing is kind of a no-no but, at the end of the day, it did show that the clear over metal had failed. As I mentioned to Jon, my first thought is to grind it all off and go with Carnuba however a two part clear, not to be confused with two stage, may well be the answer. The first coat of whatever (probably an aging can of Man O War) lasted ten....I'll be lucky if I last another ten

John

[Jon Wehrenberg]

Aluminum is a tough substrate to coat. It requires a suitable pretreatment if there is to be any hope of adhesion, and any lapses in the quality as you are well aware will result in corrosion beneath the surface.

As a plane guy you are very much aware of that. Aluminum is also lousy when it comes to corrosion. Untreated aluminum gets covered with white corrosion fairly soon. The only solution is frequent polishing.

Finally, if you live in a warm part of the country, bare aluminum will absorb heat while a white coating will minimize that heat absorption.

You have some hard decisions to make John.

[Joe Cannarozzi]

I do not think it is necessary to have the coating sprayed on.

I would get one of the numerous products available that can be brushed on.

Jon what was that product I used on EriCs it was clear, also sealed seams and is a way more durable coating than clear coat. You would never blow that crap () off with a power washer.

[Jon Wehrenberg]

That was a flowable sealant available at Camping World.

http://www.campingworld.com/shopping...-sealant/21208

It will peel off. If you dig at it with a fingernail and start peeling it you can pull it off. I cannot do that with paint that has good adhesion, such as a well applied clear coat.

[sawdust_128]

So Jon, are you saying the sealant is no good or good in your opinion? Would you use it again?

[Jon Wehrenberg]

I would use it again and without fear. I limit its use however to roof seams and around roof penetrations. This stuff will not loosen without physical effort, and a lot of effort at that, but once you get a bit of it peeled up a little you can pull it and break the adhesion.

If comes off about as easy as the label on a jar. If a leak occurs in an area previously coated I would try to lift the old sealant off before reapplying it. It cures to about 1/64 to about 1/32" thick and doesn't really harden, but remains flexible. It does flow to an extent so it will not show brush strokes. I suppose it could be used on an entire roof surface but if the aluminum beneath it were to begin getting corrosion it would be a mess.