What caused this on door sill protector rubber?

What could have caused this? is it possible salt caused this?

I saw this little marks almost looked like glue drips but never took attention last year. Now its like bubbles on rubber. Its definitely not heat because this is the only door, besides the little marks were there last year, i just never took attention thinking it was drip of glue or something



I pushed it down, it burst a bit and is now pressed down but rubber is torn in some places.

The red marker is what it looked like last year in other locations , I assume it will bubble there too now

 

That’s wierd.

 

Use of a cleaner that may be a bit too strong … caustic even?

 

Its leaking from here, I have no idea wtf this is. Its not water, its almost like melted battery acid or something , smells like plastic and is oily. Its not fluid film, I applied that inside the door panel on steel on all 4x doors and this is the only door with this.

 

I have not cleaned the sills ,i just clean interior

 

Wow. I hope none of the mechanicals or wiring inside are affected. You may want to remove the door card/panel to make sure.

 

As opposed to frozen battery acid?

 

can you pop it off to see what it looks like underneath?

 

I thought I might have an answer to your question before seeing the 4th post. I believe I have seen some posts in the past about rust forming under the black threshold applicant.

 

you fluid filmed inside your doors?

that appears to be the butyl door sealant. used to attach the plastic film to the door panel to prevent water ingress to the interior.

more than likely, the fluid film is reacting with it, and breaking it down. not all that different than applying dawn dish soap to an oil spill.

 

Given the location it’s probably not related to what I’m going to mention but I’ve seen several clients vehicles get ruined interior pieces from air fresheners. Especially those little cube looking ones you put by the vents. And it’s not just discoloring of plastic, sometimes it actually causes pretty bad damage. You never know what you’ll find these days.

 

I've seen bug repellant spray melt/bubble plastics

 

It's not cavity wax? if it's coming out of the door that's what I'm thinking.

 

Like trail limo said Bug spray does do weird stuff to plastics. But it’s kind of in a weird location for that. Also iv seen air fresheners react with the plastic air vents Like big al said. But also in a weird position. For that. Can you think of any thing spilled there? Cosmetics maybe from your significant other?

 

Brake fluid will peel paint but dunno how it would get in door panel unless someone sabatoged ypou

 

That's what it is... I had one in the driver side door storage and it seems to have leaked thru that down on the rubber during the heat wave... Too late to mourn now, ill just try to cover it somehow because there is steel beneath it and i dont want rust there

I checked and even the smell is same, this is the cause

 

Just a side note:

DEET (a very common insect repellant ingredient) is famous for attacking paint, varnish, plastic, nylon, spandex etc. I've switched to products containing something called Picaridin which doesn't have the same negative effects but still seems to work well as a repellant.

 

Also available in a spray. Amazon, Walmart, etc etc.

No offensive smell, won't hurt fabrics or things like plastic watch faces. Works great for me in areas where there is no pest control, such as Guatemala and Cuba.

 

DEET is a great insect repellant but is actually a solvent. Using a 30% spray on my arms ruined a plastic watch crystal. Effective against bugs but not great for plastic and synthetic fabrics.

 

Anyone had extensive experience with Picardin and tick prevention?