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-   -   Flux filled rods (http://www.bikeforums.net/framebuilders/930088-flux-filled-rods.html)

waterlaz 01-16-14 09:37 AM

Flux filled rods
 
Hi, sorry if this question has been asked here before.
The nearby supplier of brazing equipment surprisingly doesn't have any brazing fluxes.
They do have brazing rods that contain flux but couldn't give me much information about them.
I only know that these rods appear to be CuZn40 brass tubes filled with some flux.

I want to do fillet brazing and I wonder if I can get away without any additional flux, only using these rods. I've found some technics of using flux covered rods but these technics don't seem to be appliable when it's the other way around.

fietsbob 01-16-14 02:02 PM

flux/gas mix torches are a proven tool , by now..

back in the day dipping the hot filler rod in a tin of powdered flux picked up a little more to continue ..

tuz 01-16-14 04:29 PM

Usually the flux is coated on the outside of the rod...

Most people use paste flux for fillet brazing but I *think* that in principle it would work with a coated rod but I have not tried it. They can't even get powdered flux?

Otherwise I would suggest getting the cycle design stuff from the USA or Ceeway. It's much better than any powder or coated rod.

JohnDThompson 01-16-14 04:38 PM

I've never been a big fan of flux-coated rods or powder flux. They don't seem to protect the tubes as well as paste flux and tend to be harder to remove. It might not matter for brazing gas-pipe, but could for thin-walled bicycle tubing. My preferred fluxes are the "type B" paste for brass, and the "type U" paste for silver, both from Gasflux Co. Henry James will sell it to you if you can't source it locally:

http://www.henryjames.com/gasf.html

waterlaz 01-16-14 06:45 PM

Thanks! You got me convinced to go with the flux method. I'll try to order some flux and rods from cycle design. I hope shipping to be cheaper with a little help from my friends. Otherwise it would cost $100 only to ship the rods and flux, crazy :)

unterhausen 01-16-14 10:24 PM

seems like I vaguely remember that the Cycle designs folks have a flux that you can mix yourself if it makes sense

Doug Fattic 01-17-14 07:39 AM

Hi Waterlaz,

I see you are from Kiev. We build bicycle frames at a college in nearby Bucha (about 25km west of Kiev). They are for pastors to use all around Ukraine. The next group of frames we will be fillet brazing with Gasflux C-04 bare 1/16" bronze rod with their type B flux. The Cycle Design stuff works great too. I go over to Ukraine once or twice a year. Send me a personal email. The short answer is that you don't want to use flux coated rod because it won't give adequate coverage and flow out as nicely as the rod from either Gasflux or Cycle Design.

Doug Fattic
Niles, Michigan, USA

MassiveD 01-19-14 05:59 PM

That is good advice, but, some of that stuff only just came on the market, while some people have been doing this for a long time. I know one internationally known builder, with a son on the tour at one point, and he used powdered flux and water through his whole career. So if you can't get the premium stuff, life doesn't come to a stop. Flux coated isn't as desirable because the flux is tied to the rod. For fine tubing uses, it is always best to have as separable components as possible. Like TIG vs arc welding with rods. SO in this case, not only is where the flux goes limited by the rod, but also the flux brand.

Andrew R Stewart 01-19-14 07:43 PM

BITD we broke off the flux from the Allstate coated silver rods we could get. Then we ground up the flux and mixed with water to form a paste. Wasn't long before we found Harris powdered flux. Andy.


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