Seeking help -trying to remove a snug boiler steam dome

[emeraldhillsrailway]

The boiler is a few years old, and trying to open it up and inspect for wear. Steam dome should unscrew normally (not reverse threaded). Any advice? Breaker bar with a chain wrench isn't budging a thing. I don't see any external locking pin(s) of any sort. Any ideas?


Thank you kindly.

[Bill Shields]

It you are sure it unscrews...heat it with a torch.

If will not move ..try soaking joint line with atf and warm slightly.

Once off...coat with never sieze

[pete]

Another trick that works but by the looks of it you'd have to start with the boiler upside down. Heat the parts above the melting point of wax, press the end of a large candle against it and allow the melted wax to wick into the parts and threads. The heat helps to break up any rust or sealing compound and the wax is thin enough to get into and help lubricate any rust caused grit that binds up the joint. If the joint does start to break loose it still might take working it back and forth to move the grit around enough as you unscrew it.This seems to be a fairly new to you item that you didn't build? Someone may have also used loctite, if so it takes at least 500 F to get the bond to release. I'd also do that outside because it's not impossible the fumes from the loctite it it's been used and while it's breaking down are poisonous. Most or maybe all cyanoacrylate based glues are.

[NP317]

If not Loctited,
use Kroil.

https://www.amazon.com/s?k=Kroil&crid=3 ... _sb_noss_1

I have also found it over-the-counter at NAPA and other vehicle parts sales location.

I've used it successfully for many decades, including on 4 full sized steam locomotive rebuilds. 'Takes about 5 gallons per loco.
A little bit lasts a lonnnnggg time.
RussN