Stern Glands - Deep Sea Seals or Traditional Type

[oliverkinchin]

Hello,

I have a question about Stern Glands. We have a Rival 32 and have just had her hauled out in The British Virgin Islands for some repairs. Now, she currently has the traditional stuffing box with the greasing screw. The hose that distributes the grease to the gland has split so grease is going everywhere accept into the gland. I am quite reluctant to repair the old system but replace it with a new Deep Sea Seal. I know there are pros and cons to both but I would really enjoy having clean dry bilges again. I know the cost of Deep Sea Seals are a lot more but I am not worried about the cost.

Has anyone here changed the system to a different type of stern gland, if so what is it and are you happy with it. If anyone has any advice on both types of system it would be welcomed.

Best wishes,

Oliver Kinchin

 

[robmcg]

Volvo drip less seal is not as eye wateringly expensive and requires minimal maintenance. Easy to change too. Worth googling!

 

[oliverkinchin]

Thank you Rob, I have over-looked Volvo but will google now. Cheers for this.

 

[Tranona]

There are broadly three different types of "modern" seals. Face seals such as the PSS (and Deep Sea, but that particular design has fallen out of fashion) where the seal is made by pushing two faces, usually stainless and carbon together by pressure of a bellows. One face is fixed and the other rotates with the shaft. Lip seals such as Tides Marine and Vetus which has replaceable lip seals in a housing attached to the stern tube with a rubber hose. Moulded rubber bearings with integral lipseals, of which the Volvo design is the most common.

All of these have their supporters and offer many advantages over the traditional stuffing box, but not all can be fitted to every boat.

Not clear what it is that is failed on your boat. If it is just the hose from the greaser to the housing and not the hose that holds the stuffing box to the stern tube, then just replace it (assuming the stuffing box itself is still sound). If it is the hose to the stern tube, that is a much bigger job as the shaft needs to be disconnected from the gearbox to replace it. Then worth considering changing to a modern seal as you have done most of the work required to fit it. The simplest and cheapest type is the Volvo seal, but you need to check the diameter of your stern tube as the moulding only fits one size tube. Other designs such as Tides and PSS have more flexibility in that respect.

 

[john_morris_uk]

These threads are almost as bad as anchor threads for dividing opinion. We have a PSS seal and are very happy with it.

 

[pvb]

Go for a Radice RTMA seal - it's an improved version of the excellent Volvo rubber shaft seal and has a vent tube so it doesn't need "burping" on relaunching. You can get them from places like Sillette http://www.sillette.co.uk/price_pdf_files/sillette_marine_propulsion_catalogue.pdf

 

[oliverkinchin]

Great information. I can always guarantee great information from this forum. You have all already opened my eyes to the bigger picture. Yes, the stern gland on our boat has seen better days therefore I would prefer to move to a modern option. I am eager to find out more about the listed types, and thank you all for your time.

 

[uxb]

I would have fitted a Volvo if they made it in the size I needed...

Ended up fitting a PSS and am very happy with it.

Last boat had a Halyard seal which was excellent but is sadly no longer made- any one know why?

 

[vyv_cox]

I am eager to find out more about the listed types, and thank you all for your time.

You will find a great deal of information about most types on my website at http://coxengineering.sharepoint.com/Pages/Sternglands.aspx

 

[oliverkinchin]

Thank you vyv_cox

 

[pvb]

Last boat had a Halyard seal which was excellent but is sadly no longer made- any one know why?

I replaced a Volvo seal with a Halyard, and in hindsight I wish I hadn't! The Halyard seal is very good, but isn't in any way repairable (the Volvo isn't either, but it's a fraction of the price). Today, I'd fit a Radice RTMA seal.

 

[Resolution]

My seal has caused an immense amount of disruption and expense this year. My US made Sabre has had a PSS type seal since new, never a drop has leaked past it. The big plan for 2013 was to sail to Stockholm via the Kiel canal and Denmark. Motorsailing somewhere off the Fresians, a grumbling rumbling noise built up and was eventually traced to the deep seal. It was shaking like mad and throwing off a spray of graphite. About turn to nearest port, call up engineer and book the travelhoist quickly!
Dutch engineer very keen on tideseal type of seal, but replacement required propshaft removal which in turn required rudder dropping, which in turn required replacing a cracked quadrant which in turn connected to the knee bone, the leg bone and my wallet.
Long and painful story.
On the good side, we now have all sorts of beautiful new kit down underneath, which worked perfectly for the rest of the summer. And we got to Stockholm and it was just superb.

 

[oliverkinchin]

Thank you Resolution. Can I ask how much you paid for the tideseal. After reading all the information sent I am very interested in the PSS or tideseal. We have a BETA 30 if this helps.

 

[Suttle]

I have a Deep Sea Seal on my R32, main reason for fitting was limited space between stern tube and shaft coupling. Fitted in 2009 and have had no problems with it.

 

[charles_reed]

Thank you Rob, I have over-looked Volvo but will google now. Cheers for this.

Preference to Deep Sea seal (which has had some bad press in the past) the PSS seal which is probably cheaper where you are, or the Volvo seal.
Both result in considerably less friction, less wasted power and are more reliable than the old-fashioned stuffing box.

 

[Neil_Y]

If it is just the greaser...there is a school of thought that says the grease is not needed, a well adjusted gland and packing drips when the shaft is rotating but should be dry when at rest. Grease can cause more problems than it solves as it can block up water ways in bearings and cause them to over heat. Grease is a poor conductor of heat, water alone is a great lubricant and also conducts heat very well, personally I had a sail drive. I like the traditional water only and packing set up, but the volvo seal also does what it says on the tin.

 

[macd]

Hi Oliver, glad to see you've got the miles you hoped for.
I fitted a PSS to my R32: easy job (providing you can get the flange off the shaft) and it worked well for many years. I've not used a Volvo seal, but have heard good things about them, not least their simplicity and (relatively) fail-safe construction. That would be my first choice if I were replacing mine on the Rival. However, they're only available in a small range of sizes. These dimensions & prices from TE Norris, http://www.tnorrismarine.co.uk/sterngear.php

25mm x 42mm tube £82.80
30m x 47mm tube £98.88
1” x 1 ¾” tube £75.39
Spare tube of grease £4.00

 

[Resolution]

Thank you Resolution. Can I ask how much you paid for the tideseal. After reading all the information sent I am very interested in the PSS or tideseal. We have a BETA 30 if this helps.

Oliver
From my Dutch invoice it looks like I was charged Euros 400 for the tideseal and another Euros 100 for fittings, modifications etc. All plus Dutch VAT.

Suppose someone is going to come along now and say I was ripped off on the price......

 

[uxb]

Thank you Resolution. Can I ask how much you paid for the tideseal. After reading all the information sent I am very interested in the PSS or tideseal. We have a BETA 30 if this helps.

When I fitted my Beta 30 I changed the shaft also- the old stuffing box seal part on the shaft had made a deep score in the shaft (and the shaft was also worn under the cutlass bearing)

Shafts aren't expensive and it may be worth careful inspection before you order up a PSS seal.

BTW- I had just enough room to fit the seal between the shaft log and coupling...at least I don't need to worry about the grub screws moving!

 

[Tranona]

Shafts aren't expensive and it may be worth careful inspection before you order up a PSS seal.

Probably not an issue if a PSS is chosen as the seal is not made on the shaft itself but on the faces. One of the "advantages" of the design is that it can be fitted to worn shafts. Wear could however be an issue if fitting a Volvo or a Tides, depending on where the wear is on the shaft as the lip seals need to run on a clean unworn area sufficient to allow for the fore and aft movement of the shaft.