Page 6 of 39
Re: DetroiTug's Tug is going together
Posted: Thu Oct 28, 2010 1:22 am
by mtnman
Man that is SWEET! It just keeps getting better and better!
Re: DetroiTug's Tug is going together
Posted: Thu Nov 04, 2010 1:27 am
by DetroiTug
Mtnman and kno, thanks...
Well, I finished up the exhaust manifold/heat exchanger and learned something, bronze is not easy to tigweld. Not for me anyways. I'll have it brazed professionally after the test. I'm going to go ahead and use the pumps for the short test run. I'll make a new feedpump out of a block of bronze and a 1.25" diameter piece of stainless for a ram.
Bought all the seamless schedule 80 pipe and fittings for the main steam line and blow downs, the valves, braided hose, marine hose

. I'm not going to say how much it cost, but if I was married, it would have made for a very quiet evening.
If everything cooperates, I may be able to test fire this in a few days. Then it's off to the nearest lake for sea trials. Man I'll feel better about all this at that point. Operating on too many guesses and hunches, need to see some results.
-Ron
Re: DetroiTug's Tug is going together
Posted: Thu Nov 04, 2010 7:11 pm
by artemis
DetroiTug wrote:...If everything cooperates, I may be able to test fire this in a few days. Then it's off to the nearest lake for sea trials. Man I'll feel better about all this at that point. Operating on too many guesses and hunches, need to see some results.
-Ron

As long as she floats and moves under her own power she's a success.

Re: DetroiTug's Tug is going together
Posted: Fri Nov 05, 2010 10:21 pm
by DetroiTug
Ron, That is exactly what I was thinking
Making a little more progress, getting close to a test fire.
-Ron
Re: DetroiTug's Tug is going together
Posted: Fri Nov 05, 2010 10:46 pm
by Johnlanark
Your boat looks fabulous we are all holding our breaths for the maiden voyage video.
John
Re: DetroiTug's Tug is going together
Posted: Sat Nov 06, 2010 2:52 am
by fredrosse
A beautiful job you are doing, very nice hull. Make sure you get the very best interior coating system. We used zinc-chromate primers years ago, and I think the chromate is now outlawed. Some research in the marine industry might shed some light on the best protection for steel.
Do you plan on a Monel Shaft? I was always taught that Monel is the enemy of steel, and that steel boats should have a steel shaft, or a 400 series stainless steel shaft, to minimize corrosion.
My electric boat has a one inch diameter cold rolled steel shaft, about 8 feet long, and shows very little corrosion after 5 years service (trailered and in fresh water).
Re: DetroiTug's Tug is going together
Posted: Sat Nov 06, 2010 1:58 pm
by DetroiTug
fredrosse wrote:A beautiful job you are doing, very nice hull. Make sure you get the very best interior coating system. We used zinc-chromate primers years ago, and I think the chromate is now outlawed. Some research in the marine industry might shed some light on the best protection for steel.
Do you plan on a Monel Shaft? I was always taught that Monel is the enemy of steel, and that steel boats should have a steel shaft, or a 400 series stainless steel shaft, to minimize corrosion.
My electric boat has a one inch diameter cold rolled steel shaft, about 8 feet long, and shows very little corrosion after 5 years service (trailered and in fresh water).
Thanks Fred..
I didn't know that about Monel, I was considering it from wood boat experience. Electrolysis IS an issue with a metal boat. I'm avoiding mounting anything bronze to it for that very reason. I'm thinking this steel propshaft will rust and destroy the rather delicate strut bearing. I could shoot it with white lithium before and after. Or maybe just go with some stainless as you suggest.
I've done some research into primers and paints. Not sure what I'll go with at this point. Looking around some steel boat forums for ocean going sailboats, it seems differing opinions are plentiful on what is best, so far, I know it needs to be sandblasted with a coarse grit, beyond that I have some decisions to make.
-Ron
Re: DetroiTug's Tug is going together
Posted: Sat Nov 06, 2010 9:59 pm
by farmerden
Wouldn't putting a number of "Zincs" on the boat ,shaft,rudder,etc allow the electrolysis to occur on the zincs? Also returning all grounds back to the source rather than thru the hull.These areas are not my specialty and that's about the limit of my knowledge! Someone who's really smart could jump in here and fill in the blanks

Den
Re: DetroiTug's Tug is going together
Posted: Sun Nov 07, 2010 2:02 pm
by DetroiTug
Den,
Yes there will definitely be zincs on the hull. Thinking more about this last night, The engine is not isolated electrically, nor is the boiler, and both have a lot of bronze mounted on them. Considering how to insulate them from one another, it just doesn't seem practical.
I have about 3 hours work and then I can test fire. Maybe today.
-Ron
Re: DetroiTug's Tug is going together
Posted: Mon Nov 08, 2010 3:39 am
by DetroiTug
Fired it up tonight! What a thrill..
It took about an hour to get up steam. Starting with about 40 gallons of ice cold city water and too it was 45 degrees outside. Only took it up to 30 PSI, the engine ran just fine, it ran all the way down to 6 PSI. That's what the Westinghouse Test gauge said anyway. I checked it with shop air prior and it appeared to be accurate. It seems this boiler makes plenty of steam, I was running around 500 rpm for a short period, there wasn't much fire and pressure was holding. When I get it in the water, that will be more conclusive. This engine is really powerful, I rigged up an makeshift friction brake against the shaft coupler, it would bear down, but I couldn't stop it at 30 PSI.
I took some video, I'll try to get it posted. It sounds really nice exhausting out the stack, especially when a load was put on it.
-Ron