carbon fiber and flame

I will be working on a project where I am covering brass pipes with carbon fiber and then soldering the pipes together. The torch will be about a half inch from the dried carbon fiber. Does the fiber react to heat or flames in any nasty way?

LLB

Reply to
LLBrown
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"LLBrown" fired this volley in news:EGU6l.16487$ snipped-for-privacy@nlpi067.nbdc.sbc.com:

Is it just pure carbon fiber, not a carbon fiber composite (with epoxy or polyester resin)?

IF it's just pure fiber with no plastic binder, you can protect it by totally excluding oxygen from the hot area -- by sealing it up in metal tape, putty, a flood of inert gas... whatever.

But if it's a carbon-reinforced composite... forget it. It's going to bubble, swell, burn, stink, smoke, and generally go all to pieces at soldering heat. (unless you got lucky and used an epoxy designed to the purpose, like that used in PCB material).

LLoyd

Reply to
Lloyd E. Sponenburgh

The carbon fiber part will just burn, producing CO2.

The plastic that it's laminated with (the part that "dries") will burn, producing whatever nasties it produces. What's it laminated with? Epoxy?

Reply to
Tim Wescott

Great answer, thanks!

Reply to
LLBrown

I think your best bet would probably be resistance soldering, and not flame. Resistance soldering is often a tweezer/tong like tool that creates heat at the contact points well, between them, actually, using the contacts to create a path for the low voltage current.

With the RS method, the heat is generated within the workpiece itself, not transferred or conducted into the workpiece from a source, such as torch or electrically heated tip. This has been the preferred method of assembling mulit-conductor connectors with many solder connections.. such as military and aircraft avionics connectors.

You would need to practice with some pieces of the same size to find the best heat range to attain full solder penetration of the joint, but the RS method would accomplish the job with the least amount of damage to the nearby composite material.

American Beauty is one maker, but there have been numerous others, and maybe there still are a few.

A little added margin of protection could be had by using a cooling material on the composite material, such as heat barrier foam or putty which could easily be removed.

Reply to
Wild_Bill

Ive got an elderly resistance soldering device. A big transformer attached to a pair of tongs resembling a handle for a bullet mold.

Graphite blocks in the end of the tongs are milled out to about 3/8 half rounds.

Anyone can have it if they want to come and get it.

Gunner

"Upon Roosevelt's death in 1945, H. L. Mencken predicted in his diary that Roosevelt would be remembered as a great president, "maybe even alongside Washington and Lincoln," opining that Roosevelt "had every quality that morons esteem in their heroes.""

Reply to
Gunner Asch

Makings of a stick welder sounds like it. Add a high frequency spark and away you go.

To far away for a visit. :-)

Mart> >

Reply to
Martin H. Eastburn

the transformer only puts out about 2 volts, but at signficant amps.

"Upon Roosevelt's death in 1945, H. L. Mencken predicted in his diary that Roosevelt would be remembered as a great president, "maybe even alongside Washington and Lincoln," opining that Roosevelt "had every quality that morons esteem in their heroes.""

Reply to
Gunner Asch

Reply to
Martin H. Eastburn

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