Roof line/rain gutter rust treatment and high-top painting

[bpeck]

Hey there folks, I'm about to put in some work on my van and figured I'd throw a couple questions by you guys/gals to see if anyone with more experience than me/anyone who's done it before has any suggestions, tips or opinions worth listening to. My 1994 Ford E-150 high-top conversion van (Mark III) has some rust along the rain gutters that needs treatment, and I've also found the dark green color is way too dark in the sun so I figured I should attack the rust and give it a white paintjob at the same time.

To be clear, I understand that rust is always a losing game, and that this is a ticking time bomb with my van. That being said, I've had this thing for a few years already and even as bad as it looks, leaks have yet to be an issue. I'm only looking for 3-5 more years out of my van, anything more than that would be a bonus at what I paid for it, and I'm pretty confident she'll take me there no worries.

Plan of attack:
1. Attack the rust mechanically with a wire brush, wire wheel on a drill, etc. Get all the loose stuff off and out of the way.
2. Rough sand the gutters and basically the whole fiberglass top to get rid of imperfections, flaking existing paint, and to rough up the surface for new paint.
3. Treat the rust with phosphoric acid to hopefully slow the spread down as much as possible. So far I like the look of Klean-Strip Prep and Etch from HD.
4. Use some kind of sealant/caulk to add some level of weatherproofing/water resistance to the seams on the top and to encourage water drainage instead of pooling. What will bond well between the metal of the roof body and the fiberglass of the high top? So far I've read good things about 3m 4200, Sikaflex 221, Dicor Lap Sealant, Dynaflex 230, etc... I want something that will last a few years in the sun, something that's easy enough to work with and make look decent, and hopefully paintable.
5. Paint from under the roof line all the way up the top with a couple nice, thick coats of white rubberized elastomeric roof paint. I'm not too picky on finish or texture, I'm looking for something thick that I can put on with a roller, texture for grip is almost desired. I want to fully encapsulate the rust underneath with this top layer of paint. Again, any suggestions for brands? Kool Seal?

Today I pulled off the gasket that goes all the way around the high top, covering the screws that mount the top to the roof of the van. Half of the screws were backed halfway out and just snugging those up all the way around already makes me feel a bit better. Does anyone know if there's a conversion or roof company around that sells the gasket for a Mark III top? I might just use whatever sealant/caulk I get to run a couple beads and do a DIY gasket myself.

To anyone who has used the phosphoric acid rust inhibitor... I understand it's a liquid and the easiest way to apply is to just brush it on or even use a spray bottle. What will the phosphoric acid do to the painted metal of my van body underneath the rain gutters? What kind of tape should I use to keep the acid off the good metal of the body?

Any brand/product recommendations for the stuff I asked above or general feedback on the procedure would be appreciated. Thanks y'all!

 

[BradKW]

Rust converters basically far under two categories and 3 flavors. The two categories are 1) acid only, and 2) acid + a copolymer that serves as primer that protects converted metal.

The 3 flavors are 1) tannic acid base, 2) gallic acid base, and 3) phosphoric acid base. For large surfaces and dip tanks, phosphoric is a good choice...Ospho and the one you linked are this catagory. These products are too watery and acidic (less than 1 PH) for what you want to do I think, and can certainly damage stuff below it.

I generally choose Corroseal for a converter/primer in one. It's gallic acid based, is a manageable consistency for chip brushes, and the copolymer seems to be a good primer...and it's readily available in most hardware or paint stores. Only downside is it can require oil based primer on top if you're going white finish, as it likes to bleed.

I've been recently testing adhesion of various "elastomeric roof coatings" on various substrates, and in general I'm very unimpressed. I would avoid anything that says "siliconized" at this point, having played with three that I was able to remove in sheets. Check out Sherwin Williams Industrial/Marine line for some good choices... Shercryl is a solid product.

 

[highdesertranger]

I will try.
1. to quote Neil Young, "rust never sleeps".
2. you must get all the rust, 100%, you cannot not leave any or you are wasting your time.
3. the make the rust converter in a paste/jelly to minimize it running down the side of your van.
4. a good painters tape(3M) and plastic will keep it off your paint.
5. use a mechanical rust remover then the converter.
6. I feel you need to unbolt the top and raise it up enough to get all the rust.
I am not sure what you mean by a gasket. the high top is sealed with caulking like 3m 5200 or Dicor. there is no gasket. oh, I just reread your post I think you might be talking about the trim seal that is standard size(I believe there are 2 sizes) available everywhere. use stainless hardware to reattach the top. it will help with the rust. seal every screw hole and screw. highdesertranger

 

[SternWake]

I use ospho. Available at ace hardware
I dig out rust with chisel. And apply ospho with 99 cent store q tips.

Rust will turn black in time. Will lift some paint missed with chisel.

Dental pic black spots. Chisel more. more.q.tips.

One can repeat this abrading of black spots applying more ospho until one reaches bare pitted steel. Or.just paint them. If one gets to bare steel and paints correctly. Best chance for longevity of repair.

Ospho lightens my oyster white paint to slightly.whiter.

Ospho really preps.paint and steel well for . subsequent adhesion. When q tips stay green instead in steady of turning black or brown. Let it.go overnight. Keep it dry. Paint.

I use.rustoleum topside marine enamel.

Many parts.of.my.roof.gutter and windshield. Area are repaired improperly. Ive use aluminum fiberglass and epoxy, and 3M 5200.

Best results have been the surfboard grade epoxy on properly prpped surfaces.

5200 has quite the reputation but its adhesion is nothing compared to epoxy, and removing old failed 5200 is not that difficult with a pic razor and needlenose pliers.

I am working a section of roof gutter now. Been applying ospho a little each day to get to bare pitted steel.

Keeping it dry with white duct tape covering blue masking tape. I used wicking rope.wedged into gutters to lock drainage.under tape. Use binder clips to hold wicking .rope in place.

will rebiild some of gutter with fiberglass saturated with epoxy once it is all bare steel and roughed up with 100 grit for . maximum mechanical tooth.

When cured, Sand then paint. And wait for next battle somewhere else on gutter.

 

[LeeRevell]

The "gasket" is a vinyl strip available in various widths and colors, and can be found via Amazon. Check which width you need, and order. I think I remember the length is 25 feet or so. RV suppliers probably have it too.

 

[bpeck]

Thanks for all the replies so far, I appreciate it.

"Trim seal" is a much better term/description of what I'm looking for instead of gasket, but I still can't find anything online that's the same profile as what I pulled off my van today. Let me try to grab a photo tomorrow...

 

[highdesertranger]

her you go, https://www.amazon.com/s/?ie=UTF8&k...hvqmt=e&hvbmt=e&hvdev=c&ref=pd_sl_2llufolmb_e . you can pick this stuff up at any RV supply. highdesertranger

 

[DannyB1954]

I used phosphoric acid on the roof of my van, it did run down and "modified" the paint job where it ran down. I really didn't care as the sides are the next thing to get painted. You could use plastic to mask off the body. I put in a couple of drain holes in the gutter to let the water find it's way out. I don't know why the factory doesn't do it.

 

[steamjam1]

Whenever I have rust to repair, I normally just cut it out and weld in new steel. If I can't do that for whatever reason, I'll scrape, chip, and grind as much of it off as I can, then use a one part white vinegar to four three of four parts water, and spray, or pour it on. Wait about 1/2 hour, then scrub off using red scotch bright. Ill use spray rust converter anywhere its still rusty I can't get too, and then etch primer, followed by high build primer, then color... clear etc etc.

 

[SternWake]

Roof gutter rust is not so easy to cut out and weld in new. These roof gutters are of convoluted construction and structural too.

The Ospho is the best product i have used yet so far, but it is very thin, as thin as water.

I've tried naval jelly to dissolve rust, but find the Ospho gives me better results, I just wait for rust to turn from brown to black, then scrape the black back to brown, then re apply ospho turning reduced brown spots back to black and closer to pitted steel.

The process can be speeded up applying Ospho with a detail wire brush or some wet sandpaper and a tool to reach inside the gutter and apply pressure, and the addition of heat like from a hair drier.

Part of the repair issue is one cannot see the inside of the roof gutter without a mirror. and rust goes undetected, untreated and and then unpainted. Making tools to fit the inside of the gutter is wise.

Also, use some car wax on the paint below the gutter to give one more of a time buffer if Phosphoric acid does drip onto good paint.

My epoxy/fiberglass method is not a correct method of metal/ rust repair and is likely only an option for those with good epoxy and fiberglassing skills. Proper surface prep is always key. Rust is a battle I will lose, but must fight, and My battles have consumed much effort over the years, caused a lot of cursing and frustration that devolve into things worse.

Regular polyester resin, commonly called fiberglass resin has very poor adhesion to steel and other surfaces compared to epoxy. I would not expend ANY effort using polyester resin when the substrate is steel or aluminum.

Also not talking 5 minute store bought epoxy, but more specific epoxies like this:

http://www.fiberglasssource.com/sunshop/index.php?l=product_detail&p=88

https://www.amazon.com/System-Three...1473447233&sr=8-1&keywords=system+3+epoxy+kit

Epoxy generally does not like heat above 150f or UV light, so paint soon after cure/sanding and use a light color.



Just prolonging the inevitable.

Those without rust or having only minimal rust, go clean and wax your roof gutters. If you wait until rust streaks drip down van walls, you are in for a nightmare.