Stuffing box repacking problem

ereuter · #1 (**permalink**) 05-13-2008

My boat is a '78 Pearson 30.

I pulled apart and cleaned out the stuffing box to repack it for the first time. I haven't ever done this on any boat. The packing that came out was flax, and appeared to be 1/4". Yes, I'm positive that I got it all. I can see into the nut with a mirror.

I bought enough 1/4" Teflon packing for 3 rings, cut it at 45 deg angles, etc. It was VERY hard to stuff into the nut (my box is the type with the packing in the nut only). When I got all 3 rings in, there were not enough exposed threads to reassemble it.

I need to get this done today, as I'm going in Wed.

Should I get some 3/16" and try that? Should I just do 2 rings of 1/4"?

Thanks!

trantor12020 · #2 (**permalink**) 05-13-2008

if you have a 1" shaft, its likely to take 3/16" flax. Another things is I think you're suppose to pack in 1 ring at a time. That is, put 1 in then tighten it to push the flax in then open up and put another 1 then retighten to push it in then a 3rd.

ereuter · #3 (**permalink**) 05-13-2008

Thanks. I'll get some 3/16" and see if that's a better fit. I did try tightening it after each ring, but no luck...

There were at least 4 rings in there that I pulled out, which makes me think that the last service involved adding a ring without removing what was in there. Definitely time for service!

I've heard talk of a grease that can be used to ease installation. Anyone know about that?

Maine Sail · #4 (**permalink**) 05-13-2008

Use Gore GFO or West Marines GTU packing it's blackish gray in color. The teflon impregnated stuff is only marginally better than wax impregnated as the fibers are still exactly the same on both. With Gore the woven fiber is the lubricity and it does not need to be "impregnated" to work.. Many 1" stuffing boxes are 3/16" and many are 1/4". DO NOT over tighten when seating the flax or you will ruin it. Also, twisting the nut to seat it can often cause problems and your better off if you use some sort of home made tool to seat it without spinning until every ring is in place..

This reference may help: Re-Packing A Traditional Stuffing Box

ereuter · #5 (**permalink**) 05-13-2008

Thanks. I actually used you page as a guide. I just wasn't prepared for it not fitting!

SEMIJim · #6 (**permalink**) 05-13-2008

ereuter,

Unless Pearson made a change between 1976 and 1978, you have the wrong size packing material. Our 1976 P30 has a 7/8" shaft and the stuffing box takes 3/16" material.

Spend the few extra $$$s and get the Gore GFO or GTU material. (The latter is available at WM.)

I just did our boat's packing gland for the first time ever, and the first time ever doing a packing gland, period, and had absolutely no problem.

Btw: It'll be far easier if you pre-cut the rings on the prop shaft outside the boat, rather than in the cramped engine space.

Jim

Maine Sail · #7 (**permalink**) 05-13-2008

Measure the ID of thread to thread of the stuffing nut with a set of calipers.

The nut on my old box measured 1.38 inches and I know my shaft is 1". Simply subtract 1" from 1.38" as in:

1.38 - 1 = .38 inches

Now divide this number (.38) by two as in : .38 divided by 2 = .19 inches.

3/16 of an inch in decimals is .1875!! So I know my packing is 3/16 not 1/4 because that would be .25"

ereuter · #8 (**permalink**) 05-13-2008

Thanks guys. I got some 3/16" GTU from West Marine this morning and fit 4 rings into the box. Not too tight, but snug enough. I had measured the thickness of the stuff I pulled out and that's where the 1/4" came from. It had obviously been distorted over time.

I think I'm all set. We'll find out Thursday morning!

I'll feel a lot more confident changing it on the water if I ever have to now that I've been in there. Not easy to get both arms in there from the quarter berth!

Eric

SEMIJim · #9 (**permalink**) 05-13-2008

I put only three rings of 3/16" Gore GTU in our P30's stuffing box. Snugged it down just a tiny little bit by hand, backed it off. When we put the boat in the water I tightened-down until there was about 1 drip every 7 seconds or so. After the 1st 15-minute run, the drip rate the next day was way down. When we took her around to her own slip two days later, the drip rate while running was right around one every 10 seconds or so. The next day the static drip rate was every 25 seconds.

I'll keep an eye on it, of course, but it's kind of looking like I might not have to perform any further adjustments.

Jim

ereuter · #10 (**permalink**) 05-16-2008

Thanks for all the advise, guys. The boat went in yesterday, and all is well. It doesn't seem to be dripping at all at rest, and every 10 seconds or so when the shaft is turning. Cool to the touch after 15 minutes of motoring.

Great to be back on the water!