Sanding/Treating rivetheads before Seam Sealer

[rydawg3000]

Hey Everyone. I am planning to put some seam sealer down on top of the roof at the joints and rivet lines but I was wondering if it is necessary to sand down or convert the rust on the rivet heads before putting down seam sealer?

After that we are going to lay down our Henry’s roof paint!
For the Henry’s application, does the current white roof paint need to be sanded down to metal or just roughed up a little bit?

Thanks all!

[family wagon]

If you want any coating to stick to those rusty rivet heads they'll have to be cleaned up. Wire brush at least (I'm thinking a wire wheel or cup brush in an angle grinder or maybe a drill, actually). It's hard to clean a rivet head by any means except media blasting because the head is domed and it's down in a dimpled depression in the metal. Brush to remove loose stuff followed by an acid converter might work; I haven't tried that.


As to removing the white paint: I think it depends on how well the existing paint is bonded. On my bus the roof paint was peeling off the primer. Big spots were missing, but the metal hadn't rusted because the primer was intact. I sandblasted the whole roof, and while doing it, sometimes saw chunks of paint as big as a quarter breaking off. If your paint is still bonded well then a simple wash, degrease, and scuff may be all you need.

[EastCoastCB]

wire brush on a drill will knock out that rust on em. But then you'll need to sand a bit then paint.

[rydawg3000]

Thanks familywagon and EastCoastCB!

Awesome, I’ve been wanting to use a cup brush on something! I’ll try one out with my angle grinder or drill.

Our paint is in very good condition on top, no peeling or chipping of any kind so that’s good news. For the degrease, should we use acetone or mineral spirits or denatured alcohol or something else?

[rydawg3000]

Originally Posted by EastCoastCB

wire brush on a drill will knock out that rust on em. But then you'll need to sand a bit then paint.

Also, super lucky to doing the build in Florida so we can do projects like painting and spray foam even during the winter!

[tugboater]

Originally Posted by rydawg3000

Hey Everyone. I am planning to put some seam sealer down on top of the roof at the joints and rivet lines but I was wondering if it is necessary to sand down or convert the rust on the rivet heads before putting down seam sealer?

Thanks all!

Probably a good idea to clean those up before coating. Our factory seams didn't leak (only my own did), but looked just like yours. I dug out the old sealer as best i could then laid a couple beads of new stuff. After it cured I rolled a strip of Flex Seal over them. We still need to paint the roof, but when the time comes we'll use a marine maintenance enamel for that.
IMG_3425.jpg

[EastCoastCB]

Originally Posted by rydawg3000

Also, super lucky to doing the build in Florida so we can do projects like painting and spray foam even during the winter!

Yep. Sure is nice here.

[musigenesis]

The rivets on the back of my bus were all rusted pretty severely. I removed the paint from all of them and the skin around them with a painter's tool, then treated them with Ospho a few times, cleaned and painted with POR-15 (which adheres extremely well to post-osphoed pitted metal).