To all regarding uses of alloy fillers.
Alloy selection even in the nuclear industry is re-visited on a regular basis for the following reasons.
New developments
New Regulation Mandates
New Parent alloy Combinations and Conditioning
Advances in pre-joining fit up
The various welding societies do a very poor job of updating any changes in common practice.
Factors affecting the Bicycle FrameBuilder are availability and information.
Like Garro, my hat has been off to Kieth Aufhauser for making some rather obscure not common place alloys available.
Bronze made under the CDA 680 and 681 normally require that one orders hundreds of lbs of it but is very std
in realtime industry, good luck finding it at your local store.
Kieth like myself has made premium A56T available in small amounts to frame builders at very modest coast as
we did direct from the mill last year at cost to supply builders here and some very well known builders are stocked up.
To understand the issue of Brass vs Silver the correct use of the percentage of silver, be it 40% or 73% is only the tip
of the issue, the alloys combined also dictate resulting strength but so does the flux re-action.
This is of very little concern to the vast world of bikes until you get into very light tubing and SS alloys.
This is were my experience working aerospace parts joining lead me to re-investigate and after being fully involved with G.P.Wilson a few years back of course SS is my bag, the quest George and I had then is now solved with the Stainless Light Flux.
If we would have know then how to create a formula, the SS products would have been more broadly accepted.
Last year three Jet engine makers moved turbine blade production along with formulas that mirrorthe elements that are tailored to our hand torch silver work with SS.
One of the largest flux providers in the US has added these elements to all their silver fluxes and Eurpoe and India is doing it
As I write you all this note.
What stands out is the question, which is stronger? Both depend on the copper deposit left in place and the number of micro adhesions to the parent, under the Electon modern silvers are adhered up to hundreds of times. The CDA bronzes are well above common lead bearing ones found in LWS and silver ratio dictates how large a gap can be filleted securely.
56% was adopted for cloe fits many years ago and is almost an ideal eutectic formula providing very low temp use.
Fully Filleted bicycles have been successful using this thin flowing alloy and just building up fillets, (Dennis Kilfoy)
This is silly as the surplus silver in a large gap requires the total radius be larger than if one were to use A40T for example.
The use of 56% with cast close fit lugs should be declared a national holday for the ease and dependability.
Steel grain is upset by brazing at higher temp and once again this is being compensated in constant development by
tubing makers, modern tubes are designed and conditioned to take more heat and a longer cycle of it but the claims of improving
at post joining would be over the top, in controled furnace conditions? well maybe, under spotty hand heating it is a wash.
CDA series rods and the rods that SIF make overseas are well below melt/flow temps of LWS rods and offer a great improvement in post joining parent grain upset. I just milled a modified CDA681 for our group that is re-visited and all I can say is it has a bit more tin, Jeff Lyons of Lyonsport Beta tested it and Quote says it is the "Champion of the World" ? The target temp is met using any flux and it is a true Medium temp, below 1500 and with a prototype flux reads 1450- the flux is in production
By Superior for release soon.
In summary the adhesion dictates the strength as was proven by Castilon 40+ years ago, high reactive floride flux (Not Alcohol)
and fine rod purity can result in a 56-7 silveralloy tensile of over 85,000 @ up to five thou clearance.
Poor quality flux and 56 wire can flow without adhering and be ripped apart at will.
I don't care if you buy from me, or Kieth or Hank or Castilon, beware of what seems to be a good deal and I will answer off list about which ones of these companies (Popular ones, with past good records) have outsourced for these and are not dependable.
Richard Sachs may want to comment off list, he knows about what I am writing here.
In the last ten years what was possible and what is now possible are two different pages, you can do more with Brass offerings today and with Silver offerings today.
And more will come, I love cycling and never did and never will look at using my time to explore as a business, and as most of you know I run out of goods because we only special order in concert with demand.
In the last three months 150 oz of Fillet Pro Silver (The 3t N one) have been shipped over to england, and another is on it's way.
Strange but true, and that is were Bronze is a household word?
For questions about my rambling here, please do not run this topic into the ground here.
Compare results with some current members, like Chris Bishop or Vincent Dominguez, or Spencer Wright or Wade Barosci or Dave Bohm or Greg Townsend or James Valiensi or Sam Whittingham or Tim O' Donnell and so on.
Just remember that rods don't fall into general usability, a special order rod made to exact specs will always out perform a stock one and a LWS rod is just generic for brazing nowdays, use me or Kieth or Hank if you want quality 99.9% of the time.
And keep your good thoughts so we can all enjoy improvements you are always welcome to send me a personal email or phone.
[email protected] 520-364-1334 retired somewhere in Arizona?