How many layers of flax for a Hunter 336 stuffing box?

[Sea-ker]

I have a 1995 Hunter 336 with the 3GM30F engine and 1 inch shaft. I am in the process of repacking the stuffing box since I just acquired the boat this past year and it was leaking more than it should. According to the specs, it should take 3/16 in packing but a new stuffing box seems to come with 1/4 inch. So not sure on that. Now, the real quandry I have is that I expected to find 3-4 layers of flax when I pulled the old stuff out. What I pulled out was 6 layers. It does seem to be 3/16 inch stuff (or at least close...I know it gets compressed etc. ). In looking at the article that many reference, he seems to indicate that one may expect 4 layers but the more important part seems to be that there be about 4 peaks in the nut where the packing is contained.
So, are 6 layers too much? Should I put in fewer layers and tighten the nut further? I can only move the locking nut so far before it binds since it appears the threads are too corroded which I assume I can clean with PB and a wire brush.
So, any thoughts would be appreciated.
John

 

[Alan]

Before I changed to a PSS shaft seal I had (2) 3/16" packings in my shaft log. Six seems far too many. They get installed with the split ends at 180 degrees apart. Tighten only enough to allow a slow drip when the shaft is turning.

 

[Sea-ker]

Before I changed to a PSS shaft seal I had (2) 3/16" packings in my shaft log. Six seems far too many. They get installed with the split ends at 180 degrees apart. Tighten only enough to allow a slow drip when the shaft is turning.

Hey, thanks for the confirmation. I was really surprised to find 6 of them and was expecting four at the most. Two seems more along what I have seen in my research. Thanks.
John

 

[navigator97]

On my 1 In. bronze shaft with a Yanmar 2GM20F engine, I have always had 3 rings. When I changed to the dripless Teflon compound as the middle ring I also went to Teflon impregnated Flax for the first and third rings. As to size, 3/16 In. sounds small. I can't remember for sure, but I thought mine was 5/16 In. But, any way, use a calipers and measure the inside diameter of the stuffing box. Since the shaft is 1 In. (measure that to be sure), subtract the shaft Dia. from the inside Dia. of the stuffing box and divide by 2. That should give you the correct size of the Flax packing. But consider the Teflon impregnated flax.

 

[Tom J]

The Teflon impregnated flax works great. Lasts a long time and seems to require less dripping to stay cool. First time I re-packed my stuffing box, I put in the three layers Catalina recommended, but when I launched the boat, the shaft leaked a lot, and it looked like the nut was threaded on pretty far. I could have tightened up the nut, and it would have been fine, but I thought there wouldn't be much room left for future adjustments. So, I added a fourth layer, and that worked out very well.

 

[Roy10289]

I used 4 layers on mine also. Boat has been fine for 2 years now and has required no further adjusting.

 

[Bill Roosa]

The count should be three and three should be the count, the count will not be two unless you proceed on to count to three, four and five are right out.
If you had more than three you had packing that was too small in diameter, if you only had two then somebody Conan'ed the too large a diameter packing in there and got lucky. Space the ends at 120 degrees from each other, make sure the ends are square and clean and that the "nut" is clean of all old packing.
To tell if you have the right size (always double check) as you are putting the packing in the nut it should slide in between the shaft and nut with just a little friction. a snug fit. If it goes in with out both sides touching you need to go up one size, if you have to force it in then go down one size.

 

[Sea-ker]

Great feedback. Thanks. All set to go on this....

 

[John T1594]

I changed from the regular flax to the PTFE Gortex and found that I had to add more than three layers. With three, I could barely get the shaft to only slowly drip so I added an additional two layers and have been happy with that for about five years now. I have to tighten it a slight bit more each year and I will change out the packing for the 2012 season.