Steering Cables sealed and lubed??

[scopeusa]

Steering cables and Caribbean salt water!!!

As some of you know I tried a stainless steel compression fitting with a rubber seal fitted to the end of the cable in an attempt to seal out the water. This did not work for two reasons one the seal was not made out of the right stuff and I had ignored the problem of where the guide tube meets the outer cable adapter adjacent to the hull another potential salt water leak. This is a second attempt. I machined a piece of nylon 1 1/4" round stock to accept the cable nut as a tight push fit. The outer dia being the same as the outer dia of the bellows. I stepped it down to an 1" long enough to fit a nylon clamp and a zip tie. The other end needed a sleeve adapter machined to bring the diameter of the steering rod up to 3/8". This was internally tapped to allow it to be threaded on to the rod. The adapter end closest to the bellows was over bored to allow it to be sealed with 3M 4200. The outside of the adapter was given a course thread so that the screw clamp could grip properly. The transom end was over bored internally to allow 3M 4200 to bond and seal around the nut and bond the step in the cable before the steering rod guide tube. Silicon grease was injected into the bellows before fitting the screw clamp to give constant lubrication and hopefully work its way back up the guide tube with each operation of the steering.

Will it work ask me in a few months as to whether its holding up ask me in a year or so. If I do it again I would replace the nylon with SS 316 and machine a thread in it to replace the cable transom nut. I have an SX230HO I guess it might work for some other boats with similar cables.

 

[scopeusa]

Missing pics

20171217_170648

• scopeusa
• Jan 21, 2018

Compressed bellows greasing the rod, original rubber cover removed to aid silicon grease to...

20171217_170614

• scopeusa
• Jan 21, 2018

Nylon billet adapter 1 1/4" steering cable to 1" grommet stepped to 3/4"

20171217_170356

• scopeusa
• Jan 21, 2018

Steering Neutral Position, nylon insert from steering rod to

 

[RedBarron55]

What happens to the air or grease as the bellows and cable is moved?
I thought about adding a bellows to my Sport Jet 90 and I wondered about this.
If filled with grease it would tend to swell when collapsed and pull a vacuum when extended, perhaps pulling water into the bellows.
On systems in industry where we are trying to seal from dirt we sometimes have to make a small hole to allow for equalization of pressure.

 

[swatski]

What happens to the air or grease as the bellows and cable is moved?
I thought about adding a bellows to my Sport Jet 90 and I wondered about this.
If filled with grease it would tend to swell when collapsed and pull a vacuum when extended, perhaps pulling water into the bellows.
On systems in industry where we are trying to seal from dirt we sometimes have to make a small hole to allow for equalization of pressure.

Good point!
Lectrotab trim tab actuators (not hydraulic) have a conduit (running inside the cable) for the same reason.

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[scopeusa]

There is no significant air pressure upon compressing the bellows, there is no significant vacuum upon opening the bellows. Obviously the bellows are clamped to the rod fixing when the cable is in the ahead position minimizing any compression/expansion from its original state. Put it this way I think I would have discovered those problems three months after the install otherwise I would not have published it on the forum. You certainly would not fill the bellows with silicon grease that would obviously give rise to compression problems. I used about 20% bellows capacity and have no significant distortion of the bellows. The rubber cap on the end of the steering rod guide tube was removed to help facilitate the silicon working its way up the guide tube. They are a pretty useless seal anyway and coupled with what can best be described as shrink tubing between the guide tube and the main cable joint offers little resistance to water penetration. With decent clamps there is no way that level of vacuum can pull water into the bellows, if it had a vacuum the first sign would be the bellows collapsing which the photo does not evidence when the bellows are extended. I think you would need a ridiculously sensitive pressure gauge to even measure the pressure/vacuum difference. Lets face it you trust hoses and clamps to stop your boat from sinking at way higher pressures. As to making a whole in it that would rather defeat the whole object.

 

[scopeusa]

Another thought before worrying about whether the bellows can withstand the pressure/vacuum created by compression/extension think about the water pressure rushing past these bellows at 40 MPH. If they don't get washed off in that the other arguments fade into insignifiance!

 

[RedBarron55]

I don't doubt that the bellows work for you and might well keep the grease in and water out ,but if the bellows don't tend to balloon when collapsed and suck in when extended then there is equalizing taking place, probably through the seals of the rod, not necessarily a bad thing.
If this is happening the grease used will work it's way into the rod and help lubricate it.
It may well be a happy circumstance that will both protect the cable from water intrusion and corrosion, but keep the shaft lubricated as well.
If the internal volume of the bellows changes then the pressure must change if there is no path for equalization. I doubt that any pressurization of the bellows would pop the bellows anyway, but when they are sealed it is unsightly is it is out in plain sight
I think you are onto something removing the seal as it probably takes care of the swelling problem. A little more lube in the cable would not hurt anything!

 

[scopeusa]

I have been down in DR for a couple of days and not able to reply. I relate to what you are saying, I originally started out with a much larger volume of silicon grease which caused distortion of the bellows. Now I guess the grease only really contacts the rod when the steering is hard to starboard. As I said I do not now see any significant distortion of the bellows which giving the removal of the manufactures cap seal may answer that question. I guess pushing the grease up the guide tube would require relatively significant amounts of pressure in comparison to just an air transfer but then again you have the constant movement of the rod in the tube to assist grease transfer.

 

[Beachbummer]

I used a similar bellow on my old boat. It worked. It stays outside jet stream while planning, and kept grease on the right places. I sold the boat 2 years after install, so I can't comment past that time.

 

[scopeusa]

Its now 11 months since I installed the bellows, so upon returning to the islands, having been away for three months I thought I would undo the clamps and inspect the NAPA silglide grease. After releasing the 316 SS screw clamps and pushing the bellow back down the cable there was no sign of water ingress, the silicon had no signs of emulsification and the steering moves as freely as I have ever known. I figure its a pretty permanent solution much better that messing around trying to gravity feed cables with oil from the steering head, that does not stop water from getting in. The only thing to do here is inspect the bellows now and then. I machined another set of parts for another guy with an 230 on island. He made the mistake of over tightening one of the screw clamps which let water in as it cut into the rubber. The bellows kept the silicon grease in place and $3.50 replaced the bellow.

 

[swatski]

Its now 11 months since I installed the bellows, so upon returning to the islands, having been away for three months I thought I would undo the clamps and inspect the NAPA silglide grease. After releasing the 316 SS screw clamps and pushing the bellow back down the cable there was no sign of water ingress, the silicon had no signs of emulsification and the steering moves as freely as I have ever known. I figure its a pretty permanent solution much better that messing around trying to gravity feed cables with oil from the steering head, that does not stop water from getting in. The only thing to do here is inspect the bellows now and then. I machined another set of parts for another guy with an 230 on island. He made the mistake of over tightening one of the screw clamps which let water in as it cut into the rubber. The bellows kept the silicon grease in place and $3.50 replaced the bellow.

That's impressive it held up so well.

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[Julian]

Its now 11 months since I installed the bellows, so upon returning to the islands, having been away for three months I thought I would undo the clamps and inspect the NAPA silglide grease. After releasing the 316 SS screw clamps and pushing the bellow back down the cable there was no sign of water ingress, the silicon had no signs of emulsification and the steering moves as freely as I have ever known. I figure its a pretty permanent solution much better that messing around trying to gravity feed cables with oil from the steering head, that does not stop water from getting in. The only thing to do here is inspect the bellows now and then. I machined another set of parts for another guy with an 230 on island. He made the mistake of over tightening one of the screw clamps which let water in as it cut into the rubber. The bellows kept the silicon grease in place and $3.50 replaced the bellow.

Next time I'm on the Island I'm going to have to inspect this in person and of course confirm on the water (with an extended test) that it functions as designed!

Nice mod! Can you post links to the parts?

 

[scopeusa]

The extruded Nylon rod stock was purchased from Online Metals, the clamps were two nylon 1" snap grip clamps Mcmaster Carr, the SS 316 1/2" screw clamps are AWAB these being preferred as the edge is lipped up and reduces the risk of nicking the bellow. A zip tie was used at the large end of the bellow with the grip clamp sitting just behind. The gaiter/bellows is a Marpac product # 7-0678, I buy wholesale but they should be available from most marine outlets, or eBay for sure for about $8 inc delivery. The sealant used was between the hull and the nylon was 3M 4200. This gives just the right amount of flex at the hull to nylon connection. The bellows to rubber connection used silicon to allow easier removal than the 4200. The 3/8" end of the bellows is secured with the SS 316 screw clamp. The silicon grease was Napa Silglide. Keep the silicon off the small end after injection to stop the rubber to nylon end connection having reduced friction. Its important to clamp the bellows with them set half way between the two extremes of travel to minimize the pressure variance. Likewise don't over fill the bellows with grease, inject just enough to encapsulate the cable rod when the bellows are collapsed, this will smother the rod every time you turn a starboard lock.

Julian give me plenty of notice, I am always travelling. I am in the middle of remodeling my house which has a separate one bed cottage, you would be more than welcome to use it, but I need to get a bit further down the road with the remodeling, I am in the process of replacing 60 windows and doors buried in concrete, that's why the 232 is not looking as it should!