Steel Boats and Welding

[haidan]

Originally Posted by Matt sachs

Thanks for all the Ideas.
The boat is nothing but the steel hull and lead filled keel. It was buillt in 1989. It has been completly gutted, bead blasted and primed. The epoxy on the out side is very good in most places. But its been sitting on dry ground for several years. The hull was stacked full of lumber and trash (In New Hampshire). I cleaned it up, washed it out and put it next to my shop. (In Tennessee)
I have the origional drawings from Mr. Roberts. By email he has offered his help with the refit.

You're going to either re-blast and paint or find a paint that is compatible with what is on there currently, any ideas what it is that's on there? Most zinc primers are compatible with a wide variety of paint and if you can get away without having to blast again it'll save you quite a bit of cash. When you get the material for the decks and what ever else your going to weld on if you can get the material wheel abraded and shop primed it'll save you having to blast the mill scale off, though it seems like it's a hard thing to get down your way, for some reason. You could always blast and prime the material on the ground before working with it then you'd just have to clean up the welds after, which is much cleaner and cheaper.

[Matt sachs]

Originally Posted by toodleoo

Where in East Tennessee are you? I am located in Huntsville, AL.

Im on the Tennessee River about 10 miles upstream from Watts Bar Nuclear plant. I should be able to motor her with the masts stepped down to Mobile in a few years when I giter done.

[Brent Swain]

After you have blasted , don't skimp on interior paint. Most do, which is why steel boats have a reputation for rusting from the inside out, an undeserved reputation, if only people painted the inside adequately.

[Matt sachs]

Originally Posted by Brent Swain

After you have blasted , don't skimp on interior paint. Most do, which is why steel boats have a reputation for rusting from the inside out, an undeserved reputation, if only people painted the inside adequately.

agreed. I think Im spending way to much time on the inside paint prep, but I want it right.

[bob kingsland]

There's really no such thing as too much time on the inside paint prep... as Brent points out, that's where it can all go wrong if it's not done carefully. I used Devoe (now Ameron) Bar-Rust 235 over a coat of their 302 zinc rich epoxy primer, and it's holding up very very well... but it's important to prep properly and do many different color coats, using a mirror to check behind angle iron frames and get at least several coats on every inaccessible nook and cranny. The different colors tell you whether you've actually covered it or not... and you have to move pretty fast to get multiple coats on within the overcoat time window so you don't have to stop and sand between coats, which would be nearly impossible.

It's a 2 week burnout, but done right it will stand up for many years.

You might also check out MetalBoatbuilding.org • Index page

Best, Bob S/V Restless

[chala]

I think the zinc, if applied properly, is the way to go
b.[/QUOTE]

if applied properly. This is valid for any paint scheme.

Originally Posted by barnakiel

- just look at our anchors
b.

I have not tried to dip a boat in an hot zinc bath yet.

[Brent Swain]

I just cleaned out the low point of my bilge. She's in as good a shape as she was when I built her 26 years ago. The trick, many coats of epoxy tar on carboweld zinc primer. I welded a zinc in the lowest point of the bilge
I made the entire floor easily liftable, instead of those goofy little lift out panels. I did the same with my bunk tops . Less work too.

[Matt sachs]

Thanks for all the advise. My nearest neighbor is a half mile away. When I started with the needle scaler he called to see what the heck I was doing that was so loud. :-) It looks like it will take a week of scaling after work everyday to get the paint and rust out of her. One piece of angle iron has to be cut out and replaced. Then I'll get on the rust prevention.
Thanks again.
I'm sure to be back with more newby questions.

[Matt sachs]

Newby question
Is there a reason to have the rudder electrically isolated? I just took the rudder off my Roberts hull. It sits on a large neoprene (or nylon) bushing and has a large bushing between the steering mechanism and the rudder. It has a zinc annode on the port side also. Where can I get replacement bushings?

[boden36]

Matt, our rudder is electrically connected to the hull with a flexible approx 5/8 diameter multi strand copper cable. It has been like that for 25 yrs no problem with the stainless pivot pins. Nylon type material makes a good bush, and is easy and cheap to make on a lathe if you can't get a standard size from a bearing supplier. it does swell in water so make sure you have sufficient clearance around the pins, otherwise it may grab.
Regards, Richard.

[Matt sachs]

Thanks Richard. I guessed I would be making my own bushings - and many other parts. Thats why I parked the boat next to my CNC shop.

[Yachts66]

Would someone please explain to me why you'd want the rudder isolated from the hull?

Thanks,

Thomas

[SaltyMonkey]

Chalk another one up for steel boats.

News - General: Whale lands on yacht*(Page 1 of 2)

Originally brought to us through thread:

http://www.cruisersforum.com/forums/...cht-43971.html

[Yachts66]

LOL well.....I guess that was one right surprised whale, that was! ;-)

Thomas

[ConradG]

Originally Posted by Yachts66

Would someone please explain to me why you'd want the rudder isolated from the hull?

Thanks,

Thomas

I can't see any reason to keep your rudder electrically isolated except for the electric potential difference that might cause galvanic corrossion between dissimilar metals. The plastic or nylon bushings, in addition to being non galvanic, are ussually to provide less frictin than using the same material that the post is made from and also to provide a noncorrosive material that will wear instead of the post itself...The zincs added to metal on rudders are there because they are isolated electrically from the zincs on the hull and therefore not protected by them.