I have a 98 Xj with a leaking roof. I've narrowed the problem down to rust underneath the drip rails between where the top of the door closes under the roof's drip rails.

I haven't yet removed the cargo rack rails to determine if there are rust issues there as well. However from what I observed when it rains is water is seeping in from rusted areas underneath the drip rails on only the passenger side of the roof, inside to the headliner and then dripping down onto the passenger side floor.

The driver side under the drip edge appears to be ok with only one small rust hole, the rest of under the drip edge appears can be taken care of by sanding and painting.

However the passenger side drip edge rails appear once some grinding of the rust is going to require some sort of filler.

After a little research, some people are saying a fiberglass reinforced body filler would be the best type.

Evercoat has different types of body filler and two types of fiberglass stranded body filler.

A short strand with kevlar and a long strand sometimes marketed as kitty hair.

I've been told that the Evercoat short strands body filler (with kevlar) the strands are microscopic, whereas the long hair has more substance, but AFAIK no kevlar.

I wanted to get the best type of materials for this type of repair and am open to any suggestions.

Found this article Pros And Cons Of Premium, Short Strand, And Long Strand Body Filler

http://tindracoaching.com/2015/06/19...d-body-filler/

My rear passenger side door is stuck. Here's a not very good pic of rust spot from the front pass side door. (There is some silicon there where I tried to temporarily stop the rain water from leaking in.)

https://s25.postimg.cc/hccj5o8lr/DSC_9617.jpg

and other pic of from the driver's side that only has one badly rusted spot.

https://s25.postimg.cc/ire3ug74v/DSC_9624.jpg

 

I don't have access to a spot welder and decided to use some fiberglass matt and resin instead of a body filler.

 

Check out POR15---and some youtube videos on how to use it.....looks pretty promising ..

 

POR-15 is a coating, not a filler.

 

POR15 used with fiberglass tape is also used as a filler.... Search you tube. Theres a good video on pretty good sized hole fill....

 

here you go..check this out

 

Wear old clothes and some gloves (nitrile, for example) when using that stuff. You can use laquer thinner to get it off your skin if it hasnt cured. Dont get to it soon enough and you may be wearing it for a while if you have dry skin. And keep the lip of the can CLEAN. Get any on there and put the lid back on, have fun getting it back off.

Cover everything you dont want covered.

 

That's interesting. I didn't know Por-15 or similar paint could be used similar to a fiberglass resin with fiberglass matt.

I have some Chassis Saver and Miracle Paint which is similar to Por-15.

I also have a fiberglass mat with resin kit and also some Bondo 272 Bondo-Glass Fiberglass Reinforced Filler

I can see how applying Por-15 (or similar paint) to the bare metal perhaps with some rust left over after wire brushing and grinding would be beneficial as it will help prevent future rust from occurring.

I e-mailed Eastwood Tech support about the rust underneath the rain rails on the Cherokee and their reply was with recommendation of three of their products.

" Thank you for your response as well as for your patience. This looks to be pretty significant rust on both areas. I would recommend applying the Rust Converter: https://www.eastwood.com/eastwood-rust-converter.html. This will chemically convert the rust into a Black protective Polymeric Coating. I would then prime this with the Epoxy primer: https://search.eastwood.com/search?w=epoxy. You can then seal off the areas needed with this 2K Self Leveling Seam sealer which is a great option for drip rails: https://www.eastwood.com/ew-2k-self-...cartridge.html. Wait about 30-60 minutes depending on temperature and you can then topcoat everything with your paint of choice. Please feel free to let me know if you have any further questions or concerns. "

However I'm going to work with the products I already have which includes fiberglass matt, fiberglass resin, Chassis Saver or Miracle paint and some Naval Jelly.

Naval Jelly contains Phosphoric Acid (10 to 30 percent by composition) and minute amounts of Sulfuric Acid (0.1 to 1.0 percent by composition), as well as other hazardous chemicals—Phosphate ester (1 to 5 percent), Polysaccharide (1 to 5 percent), and Isopropyl alcohol (1 to 5 percent)

Perhaps I'll purchase some of the Eastwood rust converter as it's description shows,

Rust Converter stops residual rust, and turns it into a black, protective, ready-to-paint coating, without sanding

However I'm uncertain if their rust converter is anything different from other rust converters that use an acids such as phosphoric acid, etc.

Since I already have some Chassis Saver and Miracle Paint I don't see any reason for a epoxy primer which I've been told these paints including Por-15 don't require a primer. Since I'm using fiberglass matt I don't see any reason to use a seam sealer.

I haven't decided whether to use a Por-15 type type paint (Miracle or Chassis Saver) as a fiberglass resin.

Perhaps I'll cleanup the rusted areas and then paint with Chassis Saver or Miracle Paint and then apply the fiberglass matt with fiberglass resin and then apply a second coat of the rust paint and then a top coat?

A fiberglass resin should be at least slightly harder and stronger than trying to use a rust paint as a fiberglass resin, with the fiberglass matt?