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For long, fixed runs I have used HVAC grade 3/8" copper tubing, but for the ram connections I have used the SeaStar Nylon tubing.

I'm thinking about a half tower station and need to know if there is a generic spec for the 3/8" nylon tubing? I think SeaStar is really high on their tubing.

Thanks

When I did my steering over this winter, I got the Seastar tubing off of EBay for around $1 foot, which was alot less than local vendors here. The Seastar connector fittings work really well also--got those off of EBay also. Just a thought.

Thanks John,
A buck a foot is definately tolerable. I had not considered ebay. I have avoided setting up an ebay account because I am seriously affraid I can not control myself, just too much stuff on there I want.

I'll take a look....just one round of cards, just one drink, just a few minutes on ebay!

What about Synflex hydraulic hose?

Don't know.

The hose is very thin wall and has the correct OD for 3/8" tubing fittings. I live in an industrial area and I'm thinking about taking a piece over to one of the many hose supply houses and see it they can match it.

If I find a match I'll post the make & model.

How much pressure are we talking about in the hydraulic steering system lines???? 10PSI or 1000PSI???? Anyone know

H

Harry,

I "assume" that the pressure is under 500 psi, were it higher the HVAC grade copper tubing could not handle it. What is the high side pressure on an AC freon system? I would assume it is in the same range...(+)(-) 50-75 psi.

Here some on ebay.
http://cgi.ebay.com/ebaymotors/50ft-Nyl ... iesQ5fGear

I've installed Seastar on at least 3 boats and always used the nylon hose and hardware store brass 3/8 compression fittings with zero issues. The hose appears to be nothing special, as Scot says probably available at most any industrial hose supply store. As mentioned, the stock hose is fairly thin wall and I've been careful to put chafing gear around it wherever it passes thru a hard spot....half inch rubber heater hose slit and wire-tied around the nylon hose does the trick.

I'm sure the hose is marked up out of sight by Seastar as is their hyd. fluid.....20+ bucks a quart vs. 20 bucks a gallon for the aviation stuff.

Overall a very fine steering system.....just keep the ram clean and a little CX on it and the seals will last a very long time....let dirt and salt build up on the ram and that will cut the seals and cause leaks....Turn the wheel to fully extend the ram and wipe the rod down with a rag and some Cx now and then and save yourself a heap of trouble...oh yeah, another trick is to install a clear vinyl hose between the two bleed fittigns on the ends of the ram cylinder and leave it there so you can do major bleeding without making too big a mess, just open the bleed fittings and crank the wheel back and forth (if you have an autopilot, let it do the work) until the bubbles in the clear vinyl tube are gone, then close the fittings....minor bleeding is done from the helm filler.

UV

Scot wrote:What is the high side pressure on an AC freon system?

Hey Scot! ! ! I know this one! ! ! ! Just had my shop AC's serviced.....the coils were very dirty and the head pressure on one of the units was just over 400 PSI. After the AC guy cleaned it the head pressure dropped to 275 PSI.....he tells me that's good.

When I worked at Mack Trucks we used some Nylon Tubing that was black on the OD but when you cut it the ID was white. It was fairly thick material. It was the material of choice for running down the frames to supply air to the brakes. We used some semi transparent thin wall plastic tubing (I assume nylon) for all other applications like.....but were instructed NOT to use the light stuff on brakes. Just as Vic stated we used Ferrel compression fittings but backed up the ferrel with sleeve insert that fit on the ID....sort of lookeed like a 22 Caliper Brass......Air on a truck never exceeds 125 PSI.

I would try a Truck Air Brake parts store.

Always wondered what the inside pressure was in our steering systems.....

Harry

I think it's safe to say that it is under 400 psi or the HVAC service copper tubing would not be suitable. The system would run at much lower pressure under normal turning. The harder it is to move the aft ram & rudder, the higher the pressure you are generating at the helm via the leverage of the wheel. Should have a bypass at the helm pump or the input pistons are sized for the average guy's ability to grut on the wheel.

I think ID is an issue here also, as the ram needs the volume to fill the internal space.

Thanks for the help and inputs guys. The ebay price is definately a usable number and much less than Sea Star's standard NASA type pricing. Maybe an industrial offering will be less than a buck a foot? I will find out and post.

Scot - google up "high pressure nylon tubing" and you will hit the jackpot....places like protubing.com have what you need for short money...the "nylon 11" is food grade and the "nylon 12" is the less expensive grade for industrial fluids like steering.

UV

Men - the othe day i was reading the manual on my hynautics system...which is aofcourse a little different that the SeaStar system. But, the hynautics system has a pressure relif valve in it that opens at 950PSI. (that valve sits under my fluid tank). So...i'm assuming that the components would have to withstand that much pressure. That said, i notice that the black nylon tubing in my boat is the same stuff that was in my Topaz, which had the seastar system.

...just throwin that out there...for whatever its worth to you guys

Thanks Guys, good low dollar options.

I priced 3/8" copper and it was cheaper then ebay for the plastic stuff.
Just saying.

I use 3/8 copper for the long, straight, secured runs and for the last few feet at the ram I use nylon. Also use nylon going to an upper station.

But your right Charlie, it's the cheapest way to route the fluids where flexibility is not an issue.