Trojan Boat Forum

Stuffing box maintenance, replacement

what are the ins and outs of these things i have never had to deal with before...
do you repack them yearly?
after so many hours?

thanks for any tips and help!!

Svend

I repack or adjust as needed for leaks ( slight dripping normal )

With flax packing you should have 1 drip every 10 seconds or so at rest (engine off). When the flax packing wears out, I would highly recommend GoreTex GFO packing ( https://www.emarineinc.com/categories/G ... ft-Packing ). The GFO packing has a 10,000 hour lifetime, so you'll never need to replace it. Also, with the GFO packing you can tighten the packing nut so the stuffing box doesn't leak at rest but still leaks when underway. You want the stuffing box to leak a little bit when underway for cooling purposes.

2-3 drips per minute is more than a suffecient rate.

Yet another reason to have an IR temp sensor onboard. Shaft temp should be within 10 degrees of the water temp. If so, your drip rate is fine (but could be higher than it needs to be).

great information all!!

what is an IR temp sensor? is it a handheld device?

thanks!!

Svend

IR stands for infra red, and IR thermometers basically measure the wavelength of light that is too long for you to see. Just point the laser dot at what you want to know the temperature of, and shoot (being mindful of spot size vs. distance). Great to use all over the engine room, or to see if you have fever, or more often, to pick the coldest beer out of the fridge. Take it home and measure the temperature of all of your electrical circuit breakers and their connections too, to see if one is going bad or the connection needs retightened. Go to ebay and type in "IR thermometer". Don't buy the cheapest one, but you don't need Fluke brand either...

I have the GFO packing. My mechanic does the Baltimore Water Taxis, which get tons of use. They "make" him replace the packings yearly, and he says if you put an old packing next to a new one you couldn't tell the difference.

I have a small pen type IR thermometer that works very well ( https://www.amazon.com/Temperature-Non- ... hermometer ). It doesn't have the laser dot to tell you where you are measuring, but on my boat I'm typically holding it only a few inches from the surface I'm measuring so the lack of the laser pointer isn't really an issue. For less than $20 there really isn't any reason not to have it.

BobCT wrote:Yet another reason to have an IR temp sensor onboard. Shaft temp should be within 10 degrees of the water temp. If so, your drip rate is fine (but could be higher than it needs to be).

BINGO!
I always read about people being so concerned about the drip rate at rest when the real concern is what's going on when under way. IMO how it drips at rest is irrelevant, what the temp is when underway is what's important. If it's borderline too hot while underway but is dripping once every 5 seconds, what are you going to do, tighten it even more? If you do, you solve the dripping at rest but create another problem. If you can't get a happy medium such that you're dripping enough to make your pump come on all the time while at rest but temps are correct, then it's time to replace your packing. If you don't want a drip at rest or worry about temps, get dripless shaft logs, otherwise this is a regular maintenance item.

great advice! I agree it makes sense it is about performance under loan, not how many drips are coming out at rest...

is it an easy job to repack?
what is involved?
does it require special tools?

thanks!

Svend
1977 F30 Express, dual 318's

YouTube......

Svend wrote:great advice! I agree it makes sense it is about performance under loan, not how many drips are coming out at rest...

is it an easy job to repack?
what is involved?
does it require special tools?

thanks!

Svend
1977 F30 Express, dual 318's

http://www.pbase.com/mainecruising/stuffing_box