It was, 70 years ago
But corrosion & errosion from pulling pipes out & shoving them back in then differential expansions have all taken their toll
If you turn a slug nice ant true then try to put it in the exhaushole you will see just how out of round they have become.
Then there is the problems of correct sized tube
Tube sizes are the hole size, not the outer diameter and over the years pipe walls are getting thinner thus the need to to either use triump style inserts or expanding the tube to make a tight fit
I prefer to get the pipe to fit the barrel correctly if humanly possible so no sealant is needed...However, have you tried silicone sealant?...It seems counter intuitive that it would stand the heat but it does, and it's flexible...I have a pal who always uses it on the exhaust of his Matchless pre 65 scrambler...Ian
Another vote here for silicon sealant. I have used in in my siamese A10 pipes for years and it has even held the the finned exhaust rings in place.I used one designed for engines so can't comment on bathroom sealant.
Yes I use ordinary bathroom silicon on headgaskets after being told by an engineer that it worked!
You can of course use whatever silicon you want on your own bike but did you ever wonder why the end of your silicon gun goes rusty, that's because your standard silicon is corrosive. If you want to be kind to your bike use automotive silicon, yes it might be more expensive but there's a reason why.
Correct...'Neutral cure' silicone cures in a different manner than, for example, bathroom sealant. More specifically, neutral cure releases alcohol upon drying rather than relying on highly corrosive substances such as acetic acid...Ian
