Stuffing Box - How Warm is Too Warm?

[Sailing Steve]

I've had the bronze prop shaft replaced recently with a stainless steel shaft, which also included a new stuffing box using Teflon flax.  The shipwright told me to watch the stuffing box for the first while, and that he left the adjustment, "a bit loose."

I've searched the discussion forum and I've found numerous messages about how the stuffing box can be adjusted to get warm, but not "too warm".  I'm looking for a more precise definition on "warm" .

In my case, for the first couple of hours, the stuffing box is cool to warm as time passes.  After three or four hours, the stuffing box is "very warm", to the point that you can keep your hand on it, but it is a bit uncomfortable.  I was once told by a mechanic friend that if you can hold something hot in your hand, without having to let it go, it is below 200 degres F.

Can anyone expand on how warm is too hot?  I understand that Teflon is better at dealing with heat, and some posts/web searches I've found, suggest that Teflon flax does run "hot".

Thanks,
Steve
'90 L'Abri
Hull# 1080

[Jim Price]

I also just replaced with Teflon packing.  They key is to leave a littel loose to let it settle in and and then gradually tighten (maybe 1/4 turn at the time) until it stops dripping.  I would still run for a while and let it cool down before adjusting.  You may find the initial drippings are black staining water - this is the flax residue.  The beauty of Teflon is that you don't have to get the packing nut "too tight", just enough to stop dripping when it is hot and cools down in normal use.

[Ron Hill]

Steve : To answer you question:  If you can still leave your hand on the stuffing gland nut it's not to tight.  If you can't it's toooo tight!!
We posted the merits of the Gore drippless packing many many many times on this form.  It's head and shoulders above teflon/flax.  Guess we've failed with you two.   

[Sailing Steve]

Ah, but you did not fail my friend, as I had read the posts regarding Gore's product many times.  I planned on using it, but the problem was no one that I could find in Canada sold it in anything less than 1 lb amounts - and not for cheap.  I did not know that it would be so difficult to find locally, and by then there was not enough time to order it from the States.

Thanks to both of you for the input.

Steve

[Jim Price]

And Ron, you did not fail with me either. 

I was being rudely interrupted so many times by paying clients while I was reading through the board that my brain just locked in on Teflon.  No, actually, I did use Gore and the black residue is from the wonderful properties of Gore as it settled in.  By the way, I don't drip and the stuffing nut runs cool to the touch.