steel hull

timv

Well-Known Member
Joined
9 Jan 2014
Messages
143
Location
ludlow
Visit site
Could someone tell me realistically what is involved in maintain a steel hull is it a great deal more work that GRP ? And any other advantages/disadvantages ie. sea keeping etc.

thanks
Tim
 
Advantages
The big advantage with steel is when you build its cheaper especially for low volume or one offs, no plugs and moulds to build and fair.

Its very strong and relatively easy to get a good quick strong repair.

Absorbs all sorts of punishment that a grp or wooden boat would not.

Disadvantages

Its heavy so probably displacement speeds or semi displacement.

The paint system must be very well done in the first place both inside and out, degrease, shot blast, prime , uc, top coats etc and the paint system must be well maintained and touched up on an on going basis.

The hull needs for a yacht to be insulated on the inside, this needs to be well done.

A well built well coated steel hull will look good ( with good maintenance) and serve you well for a long time.

A poorly built and detailed boat with a poor paint system will be a nightmare.
 
steel hulls not necessarily heavier than grp. grp boats are much thicker than the 3,4,5 mm steel used in modern steel hull design. Thinner could be used in areas but welding distortion becomes an issue.
the advantages of steel are in boats above 40ish foot, smaller than that and plastic is definitely lighter.
modern paint systems basically plastic coat the hull these days.
 
many thanks for all the advise.So how often would you expect to do full repaint ?otherwise is it just a case of touching up any exposed steel with paint ?

thanks
Tim
 
As Bandit said, the devil is in the detail when the boat is built. There's no hard and fast rules as to when a paint job will be necessary.

I had a steel motor cruiser for almost 20 years. Bought as an ex-demonstrator which had laid somewhat uncared for for over a year. Built by a British yard who perceived a gap in the market to take on the Dutch builders. No previous experience at building in steel (had been a traditional yard building wooden boats). Their first attempt at painting a steel boat wasn't bad but a full repaint was needed after 10 years. 10 years later when I sold her another repaint was due. An equivalent boat from a Dutch yard probably wouldn't have needed a repaint even after 20 years.

Bits of damage where the steel becomes exposed needs immediate attention, even if it's only a touch-up. There's nothing worse than rust streaks to spoil the look.

Also, be aware steel boats can rust from the inside out if there's regular water ingress through stern tubes, rudder stocks or even leaks from the water systems on board if left untended. Most Dutch boats you see have plastic trays under the stern tubes to catch drips. Careful inspection of the inside of the hull and a survey by someone who knows their way around steel boats is essential.
 
Any exterior damage needs regular and thorough touching up to restore the protection to the steel.

On the inside obviously sort out any salt water or fresh water ingress immediately, don't use a stuffing box use a dripless sterns seal such as a Tides Marine unit.

Sort out any water leaks from the engine salt or fresh.

With salt water inside the hull don't just pump out salt water , wash it out with fresh to remove any salt and dry it.

Condensation is a killer, proper seamless insulation, no cold bridging , ventilation and a dehumidifier.
 
The engine room has apparently been sprayed with fire resistant foam which I understand also insulates reducing condensation, but the need of a dehumidifier is interesting as I had hoped to keep it on a deep water mooring so without shore power. I would be unable to leave a dehumidifier on a timer- or if the boat was on the hard over winter would this suffice ?

thanks for any advise
Tim
 
If it's properly insulated you won't need a dehumidifier as there won't be any condensation. My 30 year old steel hull still has the original two-pack and polishes up nicely every year. Steel is the only stuff to survive a serious fire at sea.
 
many thanks for all the advise.So how often would you expect to do full repaint ?otherwise is it just a case of touching up any exposed steel with paint ?

thanks
Tim
Tim, if the coatings are properly applied to begin with, maintaining a steel boat is pretty easy. Delfin was built in 1965 and was gutted in 2001, blasted and epoxied inside and Awlgrip applied outside. As a result, there is zero rust inside, and outside requires that I touch up areas that get dinged with an airbrush. I probably spend no more than 10 hours a year doing this. I described my technique here: http://www.ybw.com/forums/showthread.php?372892-Repairing-Awlgrip-LP-paints

The one thing that is true of steel is that you have to stay on top of any issues or things get unattractive pretty fast. That is the main difference I see between GRP and steel - GRP can be ignored and won't look great, but it will always look better than a badly maintained steel boat.

Hope that helps.
 
I much prefer the spray on type expanding insulating foams as they are quick and easy to apply and readily trimmed to a nice finish, in addition if you have a cavity it is quickly filled.
 
No, not all are and some of the newer products are fire resistant to a temperature higher than welding temperatures.
 
Top