Sealing Beck's Cylinder

[Nathan]

Hello, Experts! This is my first post so please forgive any errors, please. I have a question about sealing a Beck's cylinder. In case you don't know it has 2 tubes on either side of the ballast tank, which means there are 4 seals that need to remain watertight. My first water test found water coming in through all 4. I did the best I could with centering the tubes on the rubber(?) on the faceplates and the nuts were tight. I am wondering if there a trick or something for getting all 4 right at the same time. How did you all solve this problem?

[Nathan]

Maybe I got the name wrong then. Perhaps a picture will help? This is a photo of the tube and of the ballast bulkhead.

[redboat219]

Oh you mean a Sheerline cylinder from Becksmodelmarine. Sorry if I mistook you for Chainsaw guy.

[Nathan]

Thank you. Do you have any experience with them? Do you have any suggestions I can try?

[redboat219]

Tried replacing rubber gasket?

[Subculture]

These are the same design as the old Sheerline cylinders, Matt Beck took on the business from Sheerline.

The seals you have there are moulded bespoke by the manufacturer, but you may have trouble obtaining replacements at the moment as I think Matt is otherwise engaged. You could make new seals by cutting some from flat silicone rubber sheet. I've known owners experience issues once the seals get a bit older- have you had this cylinder a while?

You may wish to check the seals for any contaminants which would prevent a seal. I personally favour using o-rings, as they're readily available from multiple sources and cheap. However with this design of endcap, you really need to use the flat seals.

[Nathan]

Thank you very much. The seals are older, though I do not believe they have ever seen water. I'll make sure they are nice and clean. I like the idea of cutting more from a sheet. Is it possible to pull the old out and use silicone in the well to make new ones? I think I remember an article that said something about not doing this? Seems like a viable solution thougth...

[Subculture]

I don't know the exact process that is used to make the seals. I would guess it's a single or two part mould with a 2k silicone rubber poured in, but that's just a guess.

The method you describe of replacing the seals can work, but has some potential issues. First the end result would depend enormously on the skill of person applying the rubber and you could easily get voids in the seals from trapped air as the sealant is caulked in, secondly a lot of silicone sealants are of low quality, adequate for sealing around the bathroom sink, but not so great for this application, so you would need to be mindful of the rubber quality.

[Nathan]

thank you very much. I'll do some research into what sealing material will be best, both your idea of a sheet as well as what it would take to pour some new ones. I really appreciate the assistance. Are there any practical things I should make sure to do/not do to get a good seal once I am sure the seals themselves are good?

[Subculture]

Just keep the seals and faces clean, don't use grease, it shouldn't be necessary with axial seals. Give the seal faces a careful inspection for any damage, nicks etc.

[RCSubGuy]

I've built many boats with the Eden/Sheerline/Beck's cylinders. They're robust units and work well with proper maintenance and upkeep. I have to say I've rarely had issues with the seals, even with older Eden cylinders that are decades in age.

Andy did a great job going through the ins and outs of seal maintenance: inspect often, keep clean, no grease. The rubber gasket material is likely the best choice for replacement, though it may affect the spacing for your main clamping bar threading.

Bob
The RCSubGuy

[Nathan]

I'll give everything a fresh cleaning and try it again before I go too crazy. Thank you all for the help!