View Full Version : Cutting Bronze
01-17-2012, 09:42 AM
I'm installing hawse pipe, or chocks, through the bulwarks on WS. I've cut the holes and fit the hardware. The pipes are too long, standing proud inside the bulwark. They are oval, 3x5", 1/4" wall. I mean to cut them to fit and round the inner edge to prevent chafe. My first thought is to use the sawzall. I don't have a cutting torch. I think I have a cutting disk for the sander (5000 rpm, heavy duty). Any suggestions? Anyone done this? And how about rounding the edge? dremel? file? beat it with a hammer?
01-17-2012, 10:00 AM
You can rout a radius with a carbide bit. An angle grinder will remove a lot of material quickly with a sanding disc. Tablesaws and bandsaws will cut bronze, but it can be difficult to hold the piece.
01-17-2012, 10:02 AM
My first thought was instead of cutting the hawes hardware, is to increase the thickness of the bulwark, if it is less than say, an 1 1/2", you could add some renewable wooden cheeks of a harder type on either side that would also help to protect the rails and make a more fair lead.
Painted or varnished, which ever seems more appropriate.
Just my 2 cents. I work wood better (marginally) then metal.
01-17-2012, 10:15 AM
Hacksaw and elbow grease.
01-17-2012, 10:17 AM
Bronze/brass cuts easily. For a piece as small as you've got, you can have the job done in fairly short order with a hacksaw. Really. Lubing the blade with paste wax helps but isn't necessary. Just use a sharp blade. You can get more complicated if you want. An abrasive cutting disc in an angle grinder will make very short work of your job, as will a bandsaw with an appropriate blade (and set at a suitably SLOW metal cutting speed). Use a plasma cutter if you have one. Common metal files work great on brass/bronze for rounding edges. So too do grinding discs and/or sanding discs on suitable power tools. Putting a hand held router up to a metal fitting like that wouldn't be something I'd do (you've got a bigger pair than mine Jim :d) but I'm not saying it won't work. Just remember to expose a VERY TINY bit of the cutter at a time to the work piece and have it absolutely fastened down to something solid. Carbide burrs in a HS grinder are useful for working this material as well. The trick to fitting hawse pipes is to have the spigot halves mate perfectly within the hole in the bulwark, and also you'd like the transition between the two to be step free. Time and patience will get it done.
01-17-2012, 10:44 AM
insert the pipe and scribe/mark the cut line, making sure that there's an allowence for the sealent used to seal the outer flange. then cut with an hack saw aprox .062>.125" beyond the scribe mark. then with a grinder fitted with a grinding disk , grind to the mark. while grinding away, you should be dry fitting the part a few times to make sure youre on track. you can round over useing the grinder and finishing off with a hand file. frankly a .25 wall will only yeild a .25 rad. finish- not all that generous for rope protection, imho lacking a mfg'd trim ring for the inside, the wood idea seems like a darm good way to get a greater radius and if need be , to cover any mistakes...i bet the pipes will end up looking GREAT !!! either way
01-18-2012, 08:46 AM
Thank you all. There is no inside face, these are one peice. I agree that rounding will not give the same protection as the smooth outer curve. But I notice that many such chocks have edges that are right angles, slightly rounded. In theory, the line will mostly bear against the outer curve, as I have lined it up perpendicular to the bulwark. In practice, (now) this seems to work. I still don't want the cut edge to cut line. I like the idea of wood pads, but I think a shorter pipe will chafe less. That's because the bulwarks flare, the pipe angles upward. So I'll cut and round and report back.
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