Wiper cowl floor rusted pretty bad

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mjdriver
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Wiper cowl floor rusted pretty bad

Post by mjdriver »

New guy here with a 73 J2000. When i got it the cowl was full of leaves, i cleaned them out and found the floor is badly rusted, paper thin in some spots, i wire brushed everything i could and treated the rust with neutralizer. I bought some bondo and was going to seal it up the best i can but figured i would see if you guys had any better ideas. (Not trying to go all out and weld in new stuff). Pictures are before i wire brushed and chemicaled it.
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superdave
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Re: Wiper cowl floor rusted pretty bad

Post by superdave »

I repaired some disc brake dust shields one time with fiber glass cloth and POR 15. It worked pretty good.
Dave Knoerzer
1977 Wagoneer 360/400/QT stock as far as I can tell
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tgreese
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Re: Wiper cowl floor rusted pretty bad

Post by tgreese »

Looks pretty bad. Fortunately it's hidden, so your repairs won't show much, but it's also a place that's going to be wet with debris and standing water a lot.

I have an air compressor, and I would buy a small media blaster and remove as much of the rust by spot-blasting as I could. https://www.harborfreight.com/21-oz-hop ... 95793.html Coal slag media is available at tractor Supply, $7 for 50#. Then I would flood the area with a tough rust-encapsulating paint. I like Aluthane. http://www.epoxyproducts.com/aluthane.html I would seal up all the bare steel and rusty areas with a heavy coating of this paint. If you want to use a chemical treatment, I have gotten good results from the Permatex product https://www.permatex.com/products/speci ... treatment/ - I would still top coat with Aluthane. There will be holes, and you'll need to seal them. Fiberglass would be ok, but not over bare or rusty steel. Bondo is the wrong thing to use for this, since it is polyester putty filled with talc and absorbs water if exposed to the air. If you want to use a putty, get one of the glass-fiber filled polyester putties like USC Duraglas http://www.uschem.com/index.cfm?page=pr ... tail&id=52
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
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mjdriver
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Re: Wiper cowl floor rusted pretty bad

Post by mjdriver »

tgreese wrote:Looks pretty bad. Fortunately it's hidden, so your repairs won't show much, but it's also a place that's going to be wet with debris and standing water a lot.

I have an air compressor, and I would buy a small media blaster and remove as much of the rust by spot-blasting as I could. https://www.harborfreight.com/21-oz-hop ... 95793.html Coal slag media is available at tractor Supply, $7 for 50#. Then I would flood the area with a tough rust-encapsulating paint. I like Aluthane. http://www.epoxyproducts.com/aluthane.html I would seal up all the bare steel and rusty areas with a heavy coating of this paint. If you want to use a chemical treatment, I have gotten good results from the Permatex product https://www.permatex.com/products/speci ... treatment/ - I would still top coat with Aluthane. There will be holes, and you'll need to seal them. Fiberglass would be ok, but not over bare or rusty steel. Bondo is the wrong thing to use for this, since it is polyester putty filled with talc and absorbs water if exposed to the air. If you want to use a putty, get one of the glass-fiber filled polyester putties like USC Duraglas http://www.uschem.com/index.cfm?page=pr ... tail&id=52
I was planning on returning the bondo, bondo makes a fibirglass infused filler, it was right next to what i bought, i watched some videos of it bieng used and i think it'll work, im going to see if they have the metal mesh reinforcing panel when i go as well. I treated the rust with locktite brand rust neutralizer. I have some heavy duty oil based rust oleum brush on paint, think that will work? Should paint it before the filler or after?

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rocklaurence
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Re: Wiper cowl floor rusted pretty bad

Post by rocklaurence »

I repaired a Cowl on the '80 Cherokee and it took a long time with 3 layers to do. If I were to cheat with your vehicle, I'd rivet some sheet metal over the holes sealed with Body Seam Sealer. Then POR or Bed Liner the inside.
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tgreese
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Re: Wiper cowl floor rusted pretty bad

Post by tgreese »

I've used the Rustoleum rusty metal primer, and two things. It does not seem to stop rust very well, and it takes forever to harden. The seam sealer works pretty well to waterproof a patch. I've used this https://www.amazon.com/gp/product/B00H2 ... UTF8&psc=1 and it works well.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
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mjdriver
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Re: Wiper cowl floor rusted pretty bad

Post by mjdriver »

Okay just remembered i have a couple cans left of ruberized undercoat, im thinking fiberglass filler mabey with some sheet metal patches then spray everything with undercoat.

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tgreese
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Re: Wiper cowl floor rusted pretty bad

Post by tgreese »

Make sure that you remove all the loose rust and treat any of the remaining rust so that it's completely sealed before you cover it with undercoating or whatever. Rust expands when it forms, pulling away from the substrate and exposing fresh material to the air and water. This is why they call it "body cancer" - it continues to progress unless you seal it completely from air (oxygen) and moisture. Most coatings do not stick to rusty surfaces, loose rust or not, but loose rusty surfaces are the worst. (One reason why I like Aluthane - it penetrates rust very effectively and sticks. Don't get it on your skin - it will have to wear off.)
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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mjdriver
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Re: Wiper cowl floor rusted pretty bad

Post by mjdriver »

tgreese wrote:Make sure that you remove all the loose rust and treat any of the remaining rust so that it's completely sealed before you cover it with undercoating or whatever. Rust expands when it forms, pulling away from the substrate and exposing fresh material to the air and water. This is why they call it "body cancer" - it continues to progress unless you seal it completely from air (oxygen) and moisture. Most coatings do not stick to rusty surfaces, loose rust or not, but loose rusty surfaces are the worst. (One reason why I like Aluthane - it penetrates rust very effectively and sticks. Don't get it on your skin - it will have to wear off.)
I understand, was just wanting to get this pretty much done this weekend. Don't really want to order anything.

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letank
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Re: Wiper cowl floor rusted pretty bad

Post by letank »

tgreese wrote:Make sure that you remove all the loose rust and treat any of the remaining rust so that it's completely sealed before you cover it with undercoating or whatever. Rust expands when it forms, pulling away from the substrate and exposing fresh material to the air and water. This is why they call it "body cancer" - it continues to progress unless you seal it completely from air (oxygen) and moisture. Most coatings do not stick to rusty surfaces, loose rust or not, but loose rusty surfaces are the worst. (One reason why I like Aluthane - it penetrates rust very effectively and sticks. Don't get it on your skin - it will have to wear off.)
2x, as Tim pointed out, rust is a very difficult cancer to fight. It is not a weekend project, you will have to repeat in a few months or a year.

I had good success with the permatex converter (the one listed by Tim #81773) carried by any autoparts supplier (Oreilly or autozone), rough up the metal to remove the flakes, treat twice as per instructions. Rustoleum red for rusty surface, drying time is fairly long for the paint to stick, usually 24hrs on a warm summer day, 3 days on cold fall damp weather.

Metal will rust, even under painted areas because the paint or the clear coat become porous with age. I have done many rust prevention campaigns... grinding a rusty spot larger than its initial point of attack reveals that the rust has extended twice the size of the area near the bubbly spot under the damaged paint.

Otherwise for touch up the small holes such as the rivet holes, I use the 5min marine epoxy, or the 15 min version

Eclectic 5300031 GOOP Marine Epoxy Paste 4, found at plastic supply store, between $10 on line and $15 at local places

Image

and the proof before

Image

during

Image

I guess I need to take a current picture after 4 years, the above are 2014 picts, so current shot:

Image
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
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mjdriver
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Re: Wiper cowl floor rusted pretty bad

Post by mjdriver »

Well i filled the rust outs best i could, just need to finish painting. Then ill see if its water tight. Might block off the cowl vents if it fails. Any tips on getting paint on the driver side area thats covered up by the cab corner?

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candymancan
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Re: Wiper cowl floor rusted pretty bad

Post by candymancan »

Bondo and fiber glass filler aint going to do jack shiat... In 1 year itll fall apart again. You need to cut that metal out and weld new metal in.. Or at the very least cut that out and rivet new plate sheet metal in.. Then bondo the crevices and paint.

Trust me.. Dont listen to people who say to bondo or fiber glass over rust like that.

do it right.

That rust is bad but it would take me a day to fix that cutting and welding... Maybe 2..
1998 Jeep Grand Cherokee 5.9L Limited 219k
1998 Jeep Grand Cherokee 4.0 I6 laredo 430k
1990 Jeep Grand Wagoneer 155k
1976 Jeep J10.. 85k(repaired)
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tgreese
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Re: Wiper cowl floor rusted pretty bad

Post by tgreese »

letank wrote:
tgreese wrote:... Metal will rust, even under painted areas because the paint or the clear coat become porous with age. ...
I would guess that's not the problem so much, rather that the rust is a hydrate (Fe2O3·nH2O), and contains an excess of water. (This is the main reason why heavy, chunky rust is bad and thin, tightly bound rust is ok for some paints - less hydrate means less water). Your MCU coatings like POR-15, Rust Bullet, Aluthane and Eastwood scavenge moisture from the surface and bind it up in the urethane matrix. I'd suspect any polymer coating is going to seal pretty well to H20, but be a little bit permeable to O2, even when new. The MCUs work to enhance that seal by using an impermeable and overlapping pigment, like aluminum powder, or a metal oxide.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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