strange looking debris inside the edge of the loading area

On my BRW i found some strange looking deposits inside at the rear edge where the carpet ends and is clamped by the rails down to the floor. It looks like white salt debris and fells a bit humid. The car is inside absolutly dry, no leakages from anywhere. I wiped it away sometimes, but after a few weeks it comes back. Is it a chemical reaction from the rail to the screws or the steel floor plate? What can be done to prevent that?

Pics would be nice. Your description is confusing.

Pictures would help.

The carpet backing usually becomes friable with age.
It could be "crumbs" from the backing.

Don`t think it are crumbs to be honest. Looks more alike salt what is a bit moisty. Very small amounts in the edges.
Tomorrow I will take some pics and post them. Never saw that on other cars during the last 40 years

BuickRM wrote:

Don`t think it are crumbs to be honest. Looks more alike salt what is a bit moisty. Very small amounts in the edges.
Tomorrow I will take some pics and post them. Never saw that on other cars during the last 40 years

First call fluid ??

No pictures yet?

Made a pic just now, but don`t know how to upload. Hope it will work tomorrow....

Select "host an image"
Drag and drop image to box
Click blue "up arrow" box to upload
Click "insert all" box.

You're done.  It works every time....see:

Then you have your very own cadillac picture

Here we go, it´s really no cocain

salt/ice melter has a slight blue tinge
hot water will fix it

Maybe, but what´s the real cause for it? I´m worried there´s a chemical reaction involved, however i´ve no idea whats the reason. I removed it with the vaccum cleaner, but it came back. Will rinse it with hot water and watch it again.....Probably if there are remaining some particles, the stuff will come back due to the reaction, I think at least.....

Wipe it away and open and close the tailgate a few times, and see if it is coming from the inside of the cavity in the tailgate.

Ok, well worth a try. Next days I will report.

From your earlier description, I thought it migh tbe some kind of mildew, but it looks more like efforescence or some kind of crystalline substance.  It might be accumulated inside the gate and dropping out under the lower edge of the plastic/carpeted panel on the inside of the gate.  If you lower the gate you might be able to see it at the lower edge of the panel aligned with where it's appearing on the edge of the floor.  

I'm assuming the floor is never wet in this area when you find the powder, and that the powder is dry, correct?  Did you ever put some of the power in warm water to see if it dissolves?

If you run a CarFax on the vehicle, did it make a lot of trips from Mexico to Southern California?  If you remove the panel and see lots of plastic bags of white powder, I'd keep an eye out for this guy:

Is it coming from the carpeted seat/footwell cover or is it coming from the jam that the cover sits in where there is that rubber strip? Anything spilled at the rear of the cargo area would go down in between the seams there.
You say it keeps coming back, how long has this been happening?

I went out to the garage to see where the gate interior panel on my Caprice wagon lines up with the area shown in the OPs pictures. That looks like a pile of dry crystals to me. I don't think it resulted from a spilled liquid that then evaporated. It more likely dropped from above as a solid to form those piles. The seam between the interior panel of the tailgate and the gate itself is almost directly above that spot. Look at the bottom edge of that panel in the area of those piles. Remove the panel is necessary (easy, but be careful: that's old plastic, and it does not like to bend, especially when cold). My money is on something inside the tailgate falling out on the edge of the carpet.

dmg4 wrote:

From your earlier description, I thought it migh tbe some kind of mildew, but it looks more like efforescence or some kind of crystalline substance.  It might be accumulated inside the gate and dropping out under the lower edge of the plastic/carpeted panel on the inside of the gate.  If you lower the gate you might be able to see it at the lower edge of the panel aligned with where it's appearing on the edge of the floor.  

I'm assuming the floor is never wet in this area when you find the powder, and that the powder is dry, correct?  Did you ever put some of the power in warm water to see if it dissolves?

If you run a CarFax on the vehicle, did it make a lot of trips from Mexico to Southern California?  If you remove the panel and see lots of plastic bags of white powder, I'd keep an eye out for this guy:

Its definitly no mildew, it´s looking crystalline.
When I rebuilt the car 2 years ago I sprayed lots of body-cavitiy sealing inside and I don´t think that there´s any bare metal what causes any reactions to create that kind of debris.But anyway, I wan´t to find it out over the weekend.

Funny, I never rode the car from Mexico to SC, I´m about 5000 miles away...remember I´m German....I bought the car from a German guy, it was from Florida where the pre/pre owner brought it to Germany 6 years ago. And there´s no stuff at all hidden in the tailgate cavities, as told before I removed all panels and did the body sealing by myself. Pity, i would have making a lot of money if it would really be as it looks like