Bending hard brass.

[navarcus]

I have a 10" piece of 1/2" by 1/8" hard brass as a skeg for a Hartman Bunker Boat.

And it needs to be 3/4" lower at the middle to clear the prop -- sort of a short in height,

but long in length "Z". Is there a trick to how I bend it?

[Bob Cleek]

I'm sorry. Maybe it's me, but I can't figure out the bend you are contemplating. A picture is worth a thousand words sometimes.

 

I'm not sure how you want to bend it. If you're trying to do what I think you are trying to do, I'd have to answer "No can do."

[Scottish Guy]

I agree with you Bob, a picture would be helpful. But I think he´s talking baout a boat like that (even if you can´t see the hull properly on that picture.

 

 

There have been model ships sold as Hartman Bunker Boat which were based on the Menhaden Fishing Trawler (1900 - 1920)

 

 

The USCG used those as well as. There is a Wikipedia Log for the SP-328 USS Margaret which is also based on a Menhaden Fishing Trawler (1912-1919). I guess hes talking about one of those. But since we can´t see the hull I just don´t know exactly what he want´s to know, therefore I can´t provide any help.

 

Micha

Edited April 21 by Scottish Guy

[Bob Cleek]

1 hour ago, Scottish Guy said:

But I think he´s talking baout a boat like that (even if you can´t see the hull properly on that picture.

It's not about the type of vessel or style of hull.  He has as 10" x 1/2" x 1/8" piece of "hard" brass to use as a skeg which he wants to bend in order to make it "3/4" lower at the middle to clear the prop."  If the stock is to be a skeg, given it's dimensions, I'd expect he wants to know how to bend it 3/4" across the 1/2" wide vertical face of the skeg.  "Hard" brass can easily be annealed with a torch, but there are limits to "bending across the flat" which would seemingly be exceeded in this scenario.

 

[GGibson]

9 hours ago, navarcus said:

...sort of a short in height, but long in length "Z". Is there a trick to how I bend it?

 

8 minutes ago, Bob Cleek said:

"Hard" brass can easily be annealed with a torch, but there are limits to "bending across the flat" which would seemingly be exceeded in this scenario.

 

 

Totally NEWBIE input here, but from how "drastic" he is needing the brass bent into a Z shape, would it be better to simply solder three pieces in that shape rather than attempt to bend, even with the annealing process? 🤷‍♀️👍

[Bob Cleek]

30 minutes ago, GGibson said:

Totally NEWBIE input here, but from how "drastic" he is needing the brass bent into a Z shape, would it be better to simply solder three pieces in that shape rather than attempt to bend, even with the annealing process? 🤷‍♀️👍

Probably.

 

For a good example of brass skeg fabrication see: 

 

Edited April 21 by Bob Cleek

[Dr PR]

Like everyone else I have no idea what he is talking about. "Z" dimension? Is that vertical, longitudinal or transverse? Short in height? Lower in the middle?? Is the propeller amidships?

[allanyed]

Looking at drawings of various trawlers and boats I still cannot figure out what Navcus is looking for.   Attached show skegs that are below the prop so I assume (usually a bad idea) it is this area.  If the skeg has to be bent to clear the prop it seems like the prop reaches below the keel which is odd for these boats.  Hope he or she posts a drawing as now I am curious.🤔

Allan

 

      

 

Edited April 22 by allanyed

[navarcus]

I was hoping to use brass (in a simpler form) for this instead of pine.

 

[Toolmaker]

It might be worthwhile getting a larger piece of brass and machine the part you require. Saw and files or power tools if you have them. I think this method would be more easily controlled and offer you a better chance of success. Brass is quite soft and files to shape quickly.

[allanyed]

Angel,

It looks like your prop is in the wrong place or the diameter is too large.  Is it possible to relocate the propellor shaft or go with a smaller diameter prop?  Also, you can add a piece similar to the sketch below although it is probably not a good solution.  If the ship had a wooden keel then this would work well and could also take a false keel across the entire length of the ship as well.  

Can you tell us which vessel this is?

Thanks

Allan

Edited April 23 by allanyed