Remember to use antiseize on unions!

[barts]

As part of my recent boiler firebox rework on Otter, I needed to remove all external plumbing on her boiler. Two of the unions were frozen solid - not even a propane torch and 18" pipe wrenches would release them. I fortunately had two 200 lb unions left over, and was able to reassemble the boiler today - with ample antiseize (two with lead-based, two with copper based goo) over all the mating surfaces. Otter sees salt water quite often, and gets her fair share of salt spray. Turns out hot salt water is pretty corrosive to cast iron unions - who knew ?

Hydro passed today, still waiting on some new fittings and a replacement pressure gauge for the oil burner and we'll give her a try this weekend.

- Bart

[fredrosse]

If Hi-Temp Anti-Sieze is not available, mix in a good amount of powdered Graphite, that can take temperature well.

[marinesteam]

Turns out hot salt water is pretty corrosive to cast iron unions - who knew ?

- Bart

Or buy that newfangled, stainless cast iron

Looking forward to the sea-trial report.

Ken

[DetroiTug]

It's good practice to use it anywhere between steel mating parts on a boat. I needed to remove the shaft coupler from the crankshaft on the tug, after only one season, it took about 2 hours to get it off. Wound up making a special puller and using an acetylene torch. When it was originally installed it slid on with a light push. I also use it on one side of engine and all other gaskets now so they can be disassembled without destroying the gasket. Once they come up to steam temp, they get bonded here and there to both surfaces without it.

-Ron