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disemjg · Joined: 10 Jan 2002 Posts: 474 Location: Washington, DC

I have in the past been able to easily straighten all the bent or distorted septums that came my way, but I now have a 23 Grafmatic that has one that defies me. This one had a groove that had been forced into it, and that evidently stretched the metal so the darn thing will not lie flat. It pops in and out like an oil can lid, and the distortion is so great that I would not dare to use it. The weird thing is that while I noticed the groove, it is really not all that big and the septum overall is in pretty good shape. I cannot figure out why it is behaving so badly.

While I have given up on it for tonight (hoping the septum fairy will drop by and slide a new one into the stack) the only other thing I can think of is to heat the septum with a torch and hope that relieves the stress. But the things are dead soft anyway, and I suspect that heating it will not solve the problem. Just mabye burn a hole in it or melt it.

Any ideas, other than throwing it out and getting a new one (ha!)?

[ This Message was edited by: disemjg on 2004-05-21 18:10 ]

[ This Message was edited by: disemjg on 2004-05-21 18:14 ]

t.r.sanford · Posted: Sat May 22, 2004 1:44 am Post subject:

If I were doing it, I think I'd set the septum on a hardwood block, perhaps a short piece of 2x4 set on its narrow edge, so that the deformation is facing up, or convex, and the flanges, if not facing up, are hanging out over the edges of the block. Then I'd tap it, gently and repeatedly, with a wooden or rubber mallet, or perhaps the flat face of a ball pein hammer. I have a feeling that heating it might make matters worse.

RichS · Posted: Sat May 22, 2004 2:07 am Post subject:

The wood block idea is a good one. I have straightened septums more by pressing down on them with the rounded handle of a large screw driver and moving over the area that needed the help. Hammering could be done, lightly...

If the metal is actually stretched, you may be out of luck, but you're very close with the torch idea. Since the spetums have such a close tolerance and hold film, dimpling the metal to shrink it can't be done. But metal can be shrunk with a torch.

The first trick with the septum would be not to melt it. It's probably not steel. The heat would have to monitored closely to not do damage. But try a magnet. If it's steel then there's a whole lot less to worry about.

Next trick is an ice cube!

To shrink a section of stretched metal, that exact area must be heated very hot. A torch is good. It must be heated as fast as possible to prevent the surrounding area from getting too hot. Once heated, quickly remove the torch and directly apply the ice cube! The procedure can be repeated until the metal is back to shape.

To be honest, I've never tried this on anything so small and thing! But it's a standard procedure for shrinking automotive panels...

I would personally look for more septums

As a last resort, maybe the torch? Good luck!

45PSS · Posted: Sat May 22, 2004 3:42 am Post subject:

[ This Message was edited by: 45PSS on 2005-12-26 18:46 ]

disemjg · Joined: 10 Jan 2002 Posts: 474 Location: Washington, DC

No-go. I tried heating and cooling the septum with a propane torch and the septum won. At least I managed not to melt it. BTW, I think it is aluminum. At least it is non-magnetic.

er, anyone out there got a spare 2X3 septum that wants to hang out with five other good ones??