A copper model T was re-done recently on a tv prod here in the UK. And I think the pipes were Copper. john
i was in a jewelry design class in school and i tig welded some copper sheet...16 guage i think...i don't know what my specifics were but it worked just fine... i used copper wire that was laying around the metalsmithing shop... Annealed copper is like butter. I, sure they would have to get really hot to distort. But like flexicoker said it looks really cool when polished. Nice welds that are polished just reek of good craftsmanship.
I'd try cast Silicon Bronze. I think it melts at around 2250, will show a wide variety of patinas, and could be cast like the old Fenton cast iron headers.
I may be wrong here BUT copper exhaust plus heat = poision fumes of some kind i seem to remember a Myth but maybe someone could bust it
Bronze works good. I've seen a few T and A headers in bronze, and of course it's used a lot on locomotives. Looks pretty too. Cast's real well and if you've got something to work from the mould wouldn't be so expensive.
I've done lots of moulds (I have a masters in Sculpture). Make a pattern of easily-combustible material like wax. The mould can be as simple as standard investment, or as complex as ceramic shell. I'd keep it simple with standard investment: 50/50 plaster and sand, and make a the mould 2-3 inches thick just to be sure. You could have a usable mould for just a few bucks. It will have a core. A core is the void you want inside the item being cast. In this case, it's the exhaust ports in the manifold. The core needs to be made of the same material as the mould, and is suspended in the mould by pins of the same material (or similar) as the casting. Make the core first, with core pins made of silicon bronze welding rod if you're pouring silicon bronze. The heavier the better on these pins, because they will be in contact with molten bronze, and wimpy ones will melt before the piece cools, resulting in core shift. The core pins will need to be cut off after it is cast, so put them where you can get to them later, like near the exhaust flanges. Lay out the pattern in microcrystaline wax the thickness you want the piece. I'd guess somewhere between 1/4 and 3/8 inch thick over the core. You can either melt the wax and dip it like a candle until you have your thickness, or just pour sheets and roll it over the core and smooth it out with a hot butter knife. Pay special attention to the surface, because this will be the surface you get when it's cast. Sprue it up with 1 or 2 styrofoam cups fused to red wax sprues where the metal will enter the mold. The styrofoam cup will fuse to the red wax better if you first turn the cup upside down and pour a little wax on the bottom of the cup. Now you can put a hot butter knife between the wax pad on the cup and the sprue to get them both soft, and stick them together. Don't forget to place vents in it, so there will be no trapped air (think plumbing). The vents can be smaller than the sprue, because the sprue handles the molten bronze, but the vents only handle trapped air. Now you can pour the mold around it. Make the box large enough to house the pattern and at least 2-3 inches more around it. Place it in the box, suspended by the cups with your 2-3 inches of space on all sides. Make a 50/50 mixture of plaster and sand with the appropriate amount of water. Make enough to pour the whole mould in 1 shot, mix well, and pour. Let it sit for a couple days to cure, then take a propane torch and SLOWLY melt out the wax, starting at the sprues and vents, and working towards the piece itself inside. Then you will need a kiln to burn out any residue, or let the foundary do it. You're now ready to cast. If you want help with this, PM me.
I'm thinkin if you build a lakes style header you won't have to make any real sharp bends which is ideal for an header anyway. if you keep your bends long and loopy you shouldn't have the heat build up problem that you would have with a short tight bend. I don't think I would button them to an iron flange, you'd be better off with mild steel if you're going to mix metal. Maybe snag an old thrashed set of headers and clip 'em off close to the flange leaving stubs to slip the copper over. You'll need to use hard copper like used for refrigeration lines as opposed to soft copper like you would use for pluming your house. They are going to need to be supported, but the truth be known we should support our steel headers anyway. I'd probably use some sort of a rubber mount to suppoer them somewhere out near the end of the collector. You're not going to melt them down trust me. Copper transmits heat real well and it will transfer the heat from your hot spots to the rest of the pipe very quickly. I thought about using my 3" copper for lakes pipes on the Pusher, but the truth of the matter is that it couldn't get much louder, maybe the big copper would actually be quieter than my steel exhaust.
This is looking like the best idea yet, but where do I get the heavy-duty refregeration-type copper pipe from? Or what do I even ask for? Is it just a different wall thickness, or is it a copper with more/less impurities? Also, copper plating just seems like a cop-out (wait...is that a pun??) so I've kinda just put it out of my mind.
It just dawned on me that Gas stove-bolt's next door neighbor is part of a family business called LEES SUMMIT SCRAP METAL, I bet he could be our main man for copper pipe! I need to talk to this guy.
its just called hard copper you won't find much that's big enough at a refrigeration supply house. You might try a large plumming supply house or someplace that peddles metal. The larger diameter stuff is normally used on cooling towers for high rise buildings and drain pipes and the like. Itys gonna be pricey at best and you're probably better off to hit the scrape metal salvage places.
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