Thanks Frank, that's a good idea.

Mark, I always use anti-sieze when using stainless steel bolts, Didn't see any signs of trouble around the bolts. And I was mistaken, the intake manifold bolts are stainless also and the front four holes (around the water passages) DO see water. Again no sign of problems there except one looks like it had water seepage past the threads. I'll have to be careful to seal those in the future.

Lastly, I need to apologize. Earlier in this thread I stated that my Mr. Gasket thermostat was made in Canada. I was looking at the package for the Stant Radiator Cap... The Mr. Gasket thermostat is indeed Hecho en China

"The Master Cylinder"

Enjoying life at the beach in SOCAL

Master stainless and aluminum don't like each other but no problem if the threads are sealed. I wouldn't think that with blind holes it would be contributing to the goop you are producing.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

Master, a thought, check the marine section of ebay or amazon for sacrificial elements for boat motors. Might check the water for salt too.

Frank/Rebop

Bristol, In ( by Elkhart) 

No zinc or galvanized bolts, only stainless on the housing but they go into blind holes.

"The Master Cylinder"

Enjoying life at the beach in SOCAL

There might be dissimilarities in the aluminum alloys. But also the source of the goop may be elsewhere and only collects on the thermostat alloy. Do you have any zinc plated bolts threaded into the water jacket anywhere? I have a RV with a hot water tank that has a zinc sacrificial anode and after one camping season there is a lot of grey goop in the bottom of the tank. I also notice that anything made of pot metal (common in RV plumbing fixtures) eventually turn into stuff that looks like the goop in your thermostat housing.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

That's what I was thinking, dissimilar metals + acidic water = electrolysis. That's why I checked the water pH which is/was neutral at 7.2. Does anyone here use an anode in their cooling system such as this; Radiator Anode? I need to invvestigate further.

Strange it occurred only in the aluminum thermostat housing only and not in the Aluminum intake manifold.

"The Master Cylinder"

Enjoying life at the beach in SOCAL

I'll bet its the aluminum reacting with the cast iron. Mixed metals can do weird things.

Mark

1956 Mercury M100
1955 Ford Fairlane Club Sedan
Delta, British Columbia

Haha, I'll do my best to contain it. Should I call the HAZMAT team?

"The Master Cylinder"

Enjoying life at the beach in SOCAL

Whatever that disease is - KEEP IT OVER THERE IN CALIFORNIA!!!

 
 Steve Metzger       Tucson, Arizona

Hi Mark. No the Goop was just 'growing' on the aluminum thermstat housing.

"The Master Cylinder"

Enjoying life at the beach in SOCAL