Roof coating

[Lin]

JohnEd

My last bus did develop some roof leakage.  I believed it to be from a seam.  I used the Kool Kote and that took care of it.  I think that the normal torquing and twisting of going down the road can cause some seams to leak.  Although not as rainy as Oregon, I had the bus parked for a while under some oaks in central coast California.  It did not get any sunlight and did grow some mildew.  A pressure wash took care of that.  When the bus was not covered by trees, there was no mildew.  Generally, I have felt it lived up to its claims and was certainly easy to use.  I even had one of my daughters do the re-coat once as my Father's Day present.

[JohnEd]

Lin,

My heartburn is with the products being sold as "insulation". I don't think they are that any more than the foil on foam board is.  And the foil certainly does add to the performance of the foam.

I re coated my roof regularly and that returned it to "bright white" condition.  In the between years I used bleach and tide and a scrub brush on a long mop handle.  That worked well but it was never bright "sun reflecting white" till I painted it again.  The stuff makes a great "sealer coat" cause it is flexable.  I thought the bus roofs were sealed at the seams when they were built.  I think I would try to use seam sealer on the joints, if I had a problem with leaks, and then go with auto paint.  Good for 15 years with only a little scrub annually.  On the other hand, that single coat of Snow Kote is sure tempting and even more so if I could find a teenager to apply the followup coats.

I never washed my roof with a pressure washer because I am afraid that the water would get under the paint and lift it or bubble it.  Mine is a rood system though and that happening to me would be a tragedy.

Nice to talk with you about this,

John

[Lin]

John,

I would not use a pressure washer at full blast with a concentrated spray--just a fan pattern at just enough pressure to chase the crud away.  I have a friend that decided to pressure wash his house before painting.  He used it at high power with a concentrated spray.  He ended up with serious gouging on three of the sides before he realized he could fan the spray.  I agree with you.  I do not put much faith is the insulation value of the stuff, but it is a great sealer and a job that can be cheaply delegated.  A handyman just did mine for $12. an hour.  This was the first time using the product on this bus, so he had to put an hour into prep work like removing chipping paint.  The total was about $36. at about an hour per coat.  This freed me up to able to go and break something important.

[Dreamscape]

Have any of you guys covered the rounded part of your roof with auto paint over the elastomeric coating?

Paul

[JohnEd]

Paul,

Just my hunch but I don't think you can use a rigid paint on top of a flexable base.  It seems to me the paint would crack.

Would be nice if I were wrong on this, though.

John

[Slow Rider]

There is an elastomer  you can add to the paint to make it flexible.  They use it for plastic bumpers and such that have to flex on the car.  That should solve any cracking problems.

Frank

[Dreamscape]

Paul,

Just my hunch but I don't think you can use a rigid paint on top of a flexable base.  It seems to me the paint would crack.

Would be nice if I were wrong on this, though.

John

There is an elastomer  you can add to the paint to make it flexible.  They use it for plastic bumpers and such that have to flex on the car.  That should solve any cracking problems.

Frank

JohnEd,

Those were my thoughts too, that's the reason for the question. Thanks!

Frank,

That is an interesting concept, I will look into it.

Thanks,

Paul

[JohnEd]

Frank,

The parts of cars that I would expect to have those elastomers in the paint seem to go dull in a few years.  At least they don't seem to hold up as well as the rest of the car.  The exception is my 93 Lexus SC400 which proves that they have made a car that will outlast luggage.  Maybe it has to do with initial quality.  My 95 T Bird has dull and pealing bumpers.  Thanks for reminding me that that stuff was around.

John

[rwc]

What about the paint on a Saturn, The door panels are plastic you can push in with your hand and they pop back out. I have never seen one them get dull.

[Blacksheep]

To reply about method of application, let me add that if I recall, kool seal instructions recommended the 1st coat to be applied N-S and the 2nd coat to be applied E-W. When I did my Eagle, I used the webbing material on my seams and it never leaked again! Some light chalking but usually the bus needed washing anyway by then!
Ace

[Busted Knuckle]

To reply about method of application, let me add that if I recall, kool seal instructions recommended the 1st coat to be applied N-S and the 2nd coat to be applied E-W. When I did my Eagle, I used the webbing material on my seams and it never leaked again! Some light chalking but usually the bus needed washing anyway by then!
Ace

Is n't a hassle to turn the bus sideways in the driveway just to apply a coat of sealant?    BK 

[JohnEd]

Ace,

When I did my roof the "webbing" cloth(4 ft wide) was put down with a black rubber stuff that dried very smooth.  The instructions said that it was a tight seal and very strong.  They cautioned that it was NOT UV resistant in any way and that the white stuff had to be applied to reflect the suns energy AND protect the latex rubber from rapid deterioration.  I guess there must be a number of coatings out there but that stuff I used is 13 or 14 years old and showing no sign of surrender to the onslaught of the elements.  Mine chalks some each year but soap and water cleans it up nicely.

Thanks for your input,

John