Cosmoline Failure?

JHZR2

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This is specifically in the door of my 96 Ram. I had the door card off when I was looking at how to push out some of the dent that was there when I bought the truck.

When I opened it up, I used some of the RP-342 heavy cosmoline. It has been a few months, and sitting outside. At the same time, admittedly the window squeegee on that side isn’t great, and doesn’t make a tight seal. So water does drop into the door.

Taking a close look at where the water seems to drop and sit, I saw this:

92521C34-FE27-4F15-9301-4E4001B6B241.jpeg


The orange-red color is NOT rust. The whole inside was black before I sprayed the product. This was some sort of delamination or reaction with standing water. The failed product will come off when touched, in orangish-white bits.

2E46D81D-2CBC-42D6-B3F0-78DDC6F5E851.jpeg


This is an interesting outcome to me. Years ago I used amsoil HDMP on certain spots on my Saab, and I observed rust growth under this coating in one or two places. While that was outside and perhaps not sufficiently thick, this was, I think, applied to a good thickness.

I’ve used this when I had the door card off on my 82 MB 300CD. It had some wax on the vertical sections of the panel interior from the factory. But not a lot at the seam.

I think cosmoline is good for well drained areas, and locations that see incidental contact with moisture/humidity/water. But something else is up here...
 
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That sucks. I was actually thinking of giving it a try this summer, instead of the Coretec product I currently use, to save a few $$. Now I'll pass. Thanks for sharing.
 

JHZR2

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Nothing says this is bad stuff, or that any other product might have the same type of result when stagnant water is sitting on it.

IMO it primarily proves that water will diffuse into/through these waxy coatings, which explains why I had rust under the Amsoil HDMP on my Saab. I suspect it has to sit, and areas that readily drip/dry won’t have such challenges. But spots that can stay perpetually damp, like inside doors and rockers, might be better served with oily or lanolin type products.
 

Astro14

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Yes, the Cosmoline failed, but I don’t think it would have worked in this case. Cosmoline is great for keeping moisture off things when they’re in storage. So, condensation, humidity, etc, sure.

But where water is dripping? Cosmoline isn’t going to hold up to mechanical action of flowing water.
 

JHZR2

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Yes, the Cosmoline failed, but I don’t think it would have worked in this case. Cosmoline is great for keeping moisture off things when they’re in storage. So, condensation, humidity, etc, sure.

But where water is dripping? Cosmoline isn’t going to hold up to mechanical action of flowing water.

Many folks on here and elsewhere recommend waxy coatings, including cosmolene. One person on here has had good success with cosmolene on their undercarriage, including observing that sand and dirt washes off quicker.

I don’t know how other waxy coatings do. GM dips their frames in a wax. So there must be some level of precedent... or perhaps GM frames aren’t boxed so there is always a good opportunity for drying out.

Like I mentioned, my W123 cars have a waxy coating on the upper sections of the door skin, but not much of any at the lower seam. Maybe it’s eroded over 40 years, or maybe they knew this already. To me, it’s an interesting outcome. I think I’ll clean it up with spirits, re-spray the upper section, and either try woolwax or just oil, which is my usual preference.
 
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If you rust protect using any method, (oil OR cosmoline) like anything .... you have to monitor.
Looks like you caught it in time, so now try some woolwax (thicker than Fluid Film ... right ?)
Let that 'oil' soak in and monitor some more.

I'd also suggest fixing the Window Seal to reduce any water getting in.
 

JHZR2

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If you rust protect using any method, (oil OR cosmoline) like anything .... you have to monitor.
Looks like you caught it in time, so now try some woolwax (thicker than Fluid Film ... right ?)
Let that 'oil' soak in and monitor some more.

I'd also suggest fixing the Window Seal to reduce any water getting in.
Of course the window seal will be replaced now.

That failure isn’t a matter of monitoring. It wasn’t a few weeks old. I agree that watching and maintaining coatings is important, but this situation is different.
 
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JHZR2

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Did you clean and degrease the area before applying the cosmoline. If not, it probably just washed off.

I wiped down with mineral spirits and let dry.

It didnt wash off, as its not a wash area. Water can drop in from the window squeegee, like it can on any car.

Water sat, stagnated, and absorbed into the cosmolene.

This happens with any grease. Here’s some blue marine grease on an outboard engine. Same sort of whitening.

31545069-242F-4D74-B80E-4736EC84BAD0.jpeg
 
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One of the reasons I use CorrosionX; it's chemically more attracted to the metal than the water, so it'll stay next to the metal with any water on top of the CX.

Won't stay on in a slipstream, but in the door, no issue, and it'll also creep into any voids in the bottom weld seam which IMO is the real issue- water gets trapped in there and the weld is done.
 

JHZR2

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One of the reasons I use CorrosionX; it's chemically more attracted to the metal than the water, so it'll stay next to the metal with any water on top of the CX.

Won't stay on in a slipstream, but in the door, no issue, and it'll also creep into any voids in the bottom weld seam which IMO is the real issue- water gets trapped in there and the weld is done.
Agree, I have corrosion x and their hand I spray system. Actually I just bought a gallon of their new, heavier XD version. Still flows, doesn’t harden like the HD, but more staying power than the regular red version.
 
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This is specifically in the door of my 96 Ram. I had the door card off when I was looking at how to push out some of the dent that was there when I bought the truck.

When I opened it up, I used some of the RP-342 heavy cosmoline. It has been a few months, and sitting outside. At the same time, admittedly the window squeegee on that side isn’t great, and doesn’t make a tight seal. So water does drop into the door.

Taking a close look at where the water seems to drop and sit, I saw this:

View attachment 39121

The orange-red color is NOT rust. The whole inside was black before I sprayed the product. This was some sort of delamination or reaction with standing water. The failed product will come off when touched, in orangish-white bits.

View attachment 39122

This is an interesting outcome to me. Years ago I used amsoil HDMP on certain spots on my Saab, and I observed rust growth under this coating in one or two places. While that was outside and perhaps not sufficiently thick, this was, I think, applied to a good thickness.

I’ve used this when I had the door card off on my 82 MB 300CD. It had some wax on the vertical sections of the panel interior from the factory. But not a lot at the seam.

I think cosmoline is good for well drained areas, and locations that see incidental contact with moisture/humidity/water. But something else is up here...
I wonder if the cosmoline softened the paint or whatever coating was inside the door, allowing the metal to be exposed.
 
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Don’t know where you live but did the water freeze? If so that changes things...the expansion, scraping of ice, melt and holding of stagnant water. That’s a lot of flexing and potential damage to a surface.

Cosmoline is usually very good under a car going up against salt, water, heavy splashing/traffic spots, but sitting water I guess is just too much to ask.

I use fluid film on all my cars, but fluid film won’t hold up under a car for more than six months without re-applying it. Cosmoline - in my experience - is stronger, but the cost per can to do an entire underside is just too much.

So, I’m surprised the cosmoline failed like that, but I’d be willing to venture that Fluid Film would have too (and probably quicker).
 
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Hudson, NH
If rust is coming through something wrong with the application. It was sprayed on a wet surface which trapped moisture. Or sprayed over a former oil coating. If none of these are true then the area in question was not treated. Which is what it looks like to me. A miss. Because that's not what rp-342 looks like when dry.
 
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Here's a before and after of the Nissan Altima. Yours does not look like the bottom it looks like the top which is untreated. You probably just missed that area. Or it didn't get enough coverage which is normal for any undercarriage treatment. Just add a little more. No big deal it doesn't mean it failed. Just wasn't enough. 2 coats and then it's just a little bit of touch up after that for several years
 

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JHZR2

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If rust is coming through something wrong with the application. It was sprayed on a wet surface which trapped moisture. Or sprayed over a former oil coating. If none of these are true then the area in question was not treated. Which is what it looks like to me. A miss. Because that's not what rp-342 looks like when dry.
It certainly was treated. I sprayed the entire inner door. No rust where it failed. It is now flaking off.

There is a chance that there was an OE coating in there underneath.

It’s reddish brown color, just like it sprays out, except where it failed due to absorbing water, where it becomes orangish white.
 
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Cosmoline doesn't "absorb water". It repels it. The US military has been using Cosmoline to protect military gear from salt water since WW2. Something went wrong with your application. Maybe the black stuff sprayed inside your door chipped off taking the cosmoline with it. When the door dries and there is no water spray it again and take a picture. Let's see what it looks like. 2 coats.
 

JHZR2

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It looks worse now then it did before. It’s flaking off. If you want to blame the black primer that was OE inside the door, that’s on you. But it should have adhered like any other product does.
549EB8CF-0218-4EE8-AC16-1B24D68F503E.jpeg
 
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I've sprayed 12 vehicles over 5 years. I had a couple spots bleed through on a Toyota but that was my fault because it was still wet. A second coat fixed that. Another had adhering problems and that's where I learned any oil like fluid film has to be completely removed. Wax can't stick to oil. Not sure anything can. Yours doesn't look like anything I've seen before. Doesn't even look thick like what I use. Like it's contaminated. Who knows. It didn't work for you. Nothing's perfect. Just go back to the oil or use it somewhere else that doesn't have that black stuff on it.
 
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