Fine white powder behind fridge

[cdmclaughlin]

Pulled the Dometic from my 1884 Westy and there is a fine white powder covering everything back there--cooling fins, top, wiring, floor, space between sheet metal in wall, insulation--I mean everything from the floor to where the flues start to bend. My first guess is that this is ash, but I have no idea where it would be coming from. I don't see any cracks in the flexible flues and the gasket on the firebox seems fine. There was no ash to speak of in the firebox, although the drain from the firebox to the front was pack with ash. If there is, indeed, a leak where the ash is coming out, it seems likely that combustion gases are coming out inside the van. But this would be a ton of ash (perhaps 34 years of accumulation?). The only other thing I can think of is that there was some amateurish body work done on the side panel of the van with a lot of bondo up to and little above the hookups, but it stopped before it reached the fridge intake and vent. I suppose this could be sanding dust. Have people seen this before and if so how common is it? Any suggestions? Am I right to be worried?

[dobryan]

Residue from lots of blow from the 80’s?
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[cdmclaughlin]

Only if they were smuggling back there and a brink burst.

[dobryan]

Touche! I know of nothing normal to cause that. You guess is as good as any. Clean it up and move on.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[Farf]

Check your fridge exhaust pipe, burner etc. for leaks, might be that the moisture in the flue gases created during combustion are condensing on the surfaces behind the fridge, this would be more pronounced if the fridge was operated during cooler/cold outdoor temps. This moisture is slightly corrosive too.

[Spezialist]

[Ahwahnee]

Could be something spilled on the (lowered) stove lid - flour, pancake mix, etc. - that went over the back edge.

[9.5isCanadian]

I found the same thing behind mine.
The Vacuum seemed to cure the immediate issues.
Though neither the vacuum or the absence of the white powder got my fridge to light.


_________________
9 1/2 - missing a few pieces.

1987 Getaway Hightop
1980 Sunroof Vanagon
2018 BMW R Nine T
2012 Golf tdi

[vwjetboat]

Sodium chromate

[cdmclaughlin]

Awhanee -- great though but I tasted it and am sure it is not a food product (chemical and bitter).

9.5is Canadian -- Could be a good thing that it didn't light if this means the exhaust or the firebox is leaking.

VW jetboat--can you say more about sodium chromate. How would that get back there. Or are you sugeesting it for cleanup. Cleaning up is no problem/

[cdmclaughlin]

Awhanee -- great though but I tasted it and am sure it is not a food product (chemical and bitter).

9.5is Canadian -- Could be a good thing that it didn't light if this means the exhaust or the firebox is leaking.

VW jetboat--can you say more about sodium chromate. How would that get back there. Or are you sugeesting it for cleanup. Cleaning up is no problem/

[vwjetboat]

[fxr]

[vwjetboat]

[B.O.B.Wanders]

Fire extinguisher residue?
_________________
83.5 WBX 2WD Assuan Brown Westy, B.O.B.

"It feels good to be lost in the right direction” - unknown

[cdmclaughlin]

B.O.B wanders -- I have been thinking about that one, too. Would have had to be something like a kitchen grease fire. No sign of damage back behind the fridge.


fxr: vwjetboot may be on to something, Sodium chromate in solution is a component of the fluid in the fridge. It prevent the pipe from corroding from the ammonia/hydrogen/water solution. This is, however, a whole lot of powder. It is hard to image that much sodium chromate was in solution, and I don't see any sign of a leak in the cooler. And the power is definitely white, not yellow. Still, I will look more closely for damage to the pipes. If it is sodium chromate, the fridge is shot.

vxr -- I found stuff about sodium chromate leaking and leaving a residue, but nothing about a fine white powder all over the place. If you found something more specific, please let me know. I really appreciate that you tried to track it down for me. I searched thesamba and other boards so sodium chromate. I also searched the Internet more generallyusing other key words and found some information but nothing clearly matching my situation.

9.5isCanadian -- did yoours cool on 110 or 12V even if the box didn't light on propane. If the coolant leaked out, it chouldn't work on any setting. If it works fine execpt on propane, that suggests it is not sodium chromate.

[cdmclaughlin]

vwetboat -- the few times when you've seen this in the past, was the fridge toast?

[Mellow Yellow 74]

[cdmclaughlin]

Only my mom thinks I'm smart. I don't share her bias.

[vwjetboat]