Correct size packing for stuffing box?

[Hilbert]

I tried 3/16" and it was loose, but 1/4" was tight.
How does one determine the correct size packing? How tightly should it fit?

The previous owner used 3/16" and it never sealed properly, however it was old and the shaft is not perfect. The box looks like a Buck Algonquin, which uses 1/4" packing for a 1" shaft.

[GordMay]

It should be a fairly snug fit.

Measure the (annular) space between the shaft and the inside of the packing nut to determine the correct flax size. Multiply the diameter of your shaft by 14 to get the approximate number of inches you need for 4 layers of new packing.

Buck Algonquin Bronze Packing Boxes are usually the following sizes and take the following packing size:
Shaft Size - Packing Size
3/4" - 3/8"
7/8" - 5/16"
1" - 1/4"
1 1/8" - 3/16"
1 1/4" - 1/4"
1 3/8" - 5/16"
1 1/2" - 1/4"
1 3/4" - 1/2"
2" - 3/8"

[HappyMdRSailor]

Hilbert...

Seems like you are looking for the elusive 7/32" packing huh ???

We're leaning towards 1/4", because we believe it's the right size from specs... It sounds like the shaft is so buggered that you're having a tough time getting 1/4" past scored ridges...

Proper tightness is a drip every 5+ seconds or so while spinning... None while sitting, but you may not be able to achieve this with a damaged shaft... at least right away... Warmish to the touch after running a bit is OK... Hot to the touch is not...

[Badsanta]

Once you cut to proper length, lay the piece flat on a hard surface and tap it lightly with a hammer to flatten the packing slightly. You can then easily wrap the shaft and slide the packing into the gap. Then tighten the packing nut slightly by hand, back it out and add another strip of packing and retighten by hand repeat untill you get 3 wraps. I could only fit two but 3 are optimum. Almost impossible to install unless flattened alittle. They will re expand easily under compression. Just slightly hand tight. Then recheck once in the water and tighten slightly as needed.

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[SVTatia]

To make it easier for you to slide/insert the packing, cut a piece of 1" PVC pipe in half and lay it on the shaft to push the packing equally around and inside the gap. The length of the piece will depend how much space you have between the nut and the flange but a couple of inches will do.

[Rustic Charm]

SVtatia's suggestion of the pvc is what I used to use. Though I didn't need to split it.

In my opinion, do yourself a favour and update to a dripless seal. I went to the PSS seal and the company is a fantastic support but there are others of similar design. No more stuffing around with the packing then and problem solved. No more drips in your bilge, no more greese (if you have a greese gun connected like I did).

[GrahamHO]

In the days that I had a stuffing box; before I fitted a sail drive I used a Teflon impregnated square section packing. I cut it into several short sections that would wrap around the shaft one turn with a tiny gap. Then I staggered the joins. It was much like piston rings and seemed to work better than wrapping a long length around and around. I'm not sure if that's common practice but it works well.

[Rustic Charm]

Originally Posted by GrahamHO

In the days that I had a stuffing box; before I fitted a sail drive I used a Teflon impregnated square section packing. I cut it into several short sections that would wrap around the shaft one turn with a tiny gap. Then I staggered the joins. It was much like piston rings and seemed to work better than wrapping a long length around and around. I'm not sure if that's common practice but it works well.

That's what I did too, but with graphite packing.

Back in the days I did my trade we used asbestos for packing pump glands.. we even used asbestos packing that was about a foot thick for furnace packing in a manganese mill

They frown on that stuff now days

[Hilbert]

Seems like you are looking for the elusive 7/32" packing huh ???

If I could find this, then I would rename the boat "Goldilocks"

1/4" is probably the correct size, but it was extraordinarily difficult to insert the packing. I like Badsanta's suggestion to flatten it with a hammer, unfortunately I hadn't read the post before leaving for the boat. I did tighten the packing nut by hand to push in the first rings. It took me several hours to get 3 packing rings into the nut. After inserting the third ring, I was unable to to clear enough threads to screw on the nut. I just ran out of time, patience and the ability to contort myself into the compartment any longer. I'm somewhat confident that I will be able to screw it together. Could it have been so tightly impacted during insertion, that water will not drip through?

After I returned home, I did some Internet searches. I read Maine Sails Compass Marine article on Re-Packing A Traditional Stuffing Box. Towards the end, he warns about using graphite impregnated packing with a bronze shaft. Having used Graphtex Ultra GTU packing with a bronze shaft, I am wondering if I have set myself up for more problems?

Maybe I should start over with a different packing flax?

[HappyMdRSailor]

Originally Posted by Hilbert

If I could find this, then I would rename the boat "Goldilocks"

1/4" is probably the correct size, but it was extraordinarily difficult to insert the packing. I like Badsanta's suggestion to flatten it with a hammer, unfortunately I hadn't read the post before leaving for the boat. I did tighten the packing nut by hand to push in the first rings. It took me several hours to get 3 packing rings into the nut. After inserting the third ring, I was unable to to clear enough threads to screw on the nut. I just ran out of time, patience and the ability to contort myself into the compartment any longer. I'm somewhat confident that I will be able to screw it together. Could it have been so tightly impacted during insertion, that water will not drip through?

After I returned home, I did some Internet searches. I read Maine Sails Compass Marine article on Re-Packing A Traditional Stuffing Box. Towards the end, he warns about using graphite impregnated packing with a bronze shaft. Having used Graphtex Ultra GTU packing with a bronze shaft, I am wondering if I have set myself up for more problems?

Maybe I should start over with a different packing flax?

Sometimes it's easy to forget how intimidating this stuff was, when it becomes second nature...

All your answers are in Main Sail's article, it's an excellent reference... cutting rings the right way answers questions in previous posts...

On to the question re graphite packing... I would pull it... you already have shaft issues, and this is an area that you really want to do it once and forget about it for a while... Plus... Things get awful expensive quickly with shaft replacement snowball trips to the yard...