Re: [CR] modern KOF fillet brazed builders

(Example: Framebuilders:Mario Confente)

Date: Sat, 3 Dec 2005 16:22:40 -0800 (PST)
From: "Peter Naiman" <hetchinspete1@yahoo.com>
Subject: Re: [CR] modern KOF fillet brazed builders
To: Steve Leitgen <sleitgen@charter.net>, Doug Fattic <fatticbicycles@qtm.net>
In-Reply-To: <c805163e9cdc73b8f1fae7ffbf4dadfe@charter.net>
cc: "classicrendezvous@bikelist.org" <classicrendezvous@bikelist.org>

Steve; I've been lucky to visit Doug's shop on more than one occasion, and the last two times, bringing a few freinds over to meet Doug. He has willingly brought out his gorgious Johnny Berry, and a few other frames for us to view, as well as his own handy work. The quality of Doug's work is second to none, and I will admit to finding his paintwork very striking, possibly the best I've seen.

I'm hoping to get over to Dougs fairly soon as he is touching up an Experto Crede for me presently.

Peter Naiman Glendale, WI

Steve Leitgen <sleitgen@charter.net> wrote: Greg (and others)

If Doug will have you it would be well worth the trip to see his shop.

I built my share of frames in the early 80s and I can tell you that without a doubt Doug builds some of the most beautiful frames you have

ever seen. (Doug, I remember you from RAGBRAI. Sorry for the shameless

plug)

Steve Leitgen La Crosse, WI

On Dec 3, 2005, at 5:31 PM, Doug Fattic wrote:
> Greg Parker from Ann Arbor, Michigan asked:
>
> What percent silver was your wire? What brand and part number? How did
> you
> get your miters good enough to use silver? Without any lugs, the gaps
> would
> be even more critical. How did you build a fillet with
> high-silver-content
> wire? That sounds a bit fishy to me, unless the silver content was
> actually
> quite low.... Professional framebuilders, what say you?
>
> That would be me, Greg, and IÕve been following these various topics
> regarding KOF fillet brazing frames with some interest and at times
> amusement. Let me first shed some light on silver brazing a fillet.
> It is
> possible to do this but itÕs not likely when using the latest tubing
> like
> Reynolds 853. This is because they have designed it to be tig welded
> and
> have combined the alloyÕs so that when it is heated over 1600 degrees,
> it
> gets stronger. SilversÕ melting point is 1200û or so, so itÕs greatly
> adde
> d
> cost wouldnÕt take advantage of the tubes properties. The most common
> silver used by framebuilders with lugs is 56% cadmium free (I use 45%
> with
> cadmium because it flows better but I will die younger for it). The
> temperature range with either of them between the liquid and solid
> state is
> very narrow Ð meaning that it doesnÕt have good Òbuild upÓ qualities -
> as
> soon as it gets liquid to melt, it will also start to run away.
> Keeping th
> e
> filler in between the liquid and solid state is how we control the
> build up
> of the filler so enough of it stays in the right place to create the
> shape
> we want. Now 35% silver has a broader temperature range between the
> liquidus and solidus states (I donÕt know why the brazing industry
> makes
> those words sound Latin instead of using plain English. Perhaps itÕs
> to
> market itÕs users as seeming to be intelligent.) so it will build up
> more
> easily. This silver can be used to fillet braze more easily than the
> typical ones we use. Of course itÕs broader range also means it gets
> to a
> higher temperature at the top end. The most likely candidates for
> fillet
> silver brazing was older thinner walled tubing like Columbus KL which
> wasnÕ
> t
> very commonly used. ItÕs thicker walled cousins SL and SP could
> withstand
> the higher temperatures of brass better so the trouble and expense of
> using
> silver wasnÕt as necessary.
>
> Fillet brazing is more common today than before among some KoFs
> because of
> the challenges presented by using a threadless stem instead of a quill
> stem
> .
> In my opinion, it looks better not to have lots of head tube above the
> top
> tube (which a threadless design requires). By putting a bit of slop
> (not
> compact style steep slop) to the top tube, it can place the top tube
> closer
> to the top of the head tube (keeping the length head tube the same) so
> it
> doesnÕt have that extended head tube look which I personally donÕt
> prefer.
> Remember this extra height is necessary for those of us that have more
> weight and less flexibility than we had in our youth and, as a result,
> need
> a higher handlebar height than the racing crowd this stuff was
> designed for
> .
> Keep in mind that another controlling variable is the need to keep the
> top
> of the top tube low enough so we can stand over it. There arenÕt many
> lugs
> available to accommodate this newer design variation. Also thrown
> into thi
> s
> mix is carbon forks which usually have 1.125Ó steerers that require a
> bigge
> r
> diameter head tube. These factors eliminate use of the older lugs.
> So an
> easy and common solution is the fillet braze. I also like to file my
> fillets. I can get close to an end look by brazing alone but think
> perfection can only be reached by filing. I also think it is easier to
> fillet braze than use lugs Ð but of course I insist on filing even
> investment cast lugs a lot to get the effect I find most attractive.
>
> Greg, IÕm not very far away from you in the southwestern part of
> Michigan.
> Come and see me if you want to learn how extremely accurate miters
> can be
> made. IÕve got a super nice mitering device sitting on my Bridgeport
> mill.
> IÕve also got a few nice old frame around that are mine or customers
> frames
> in the painting process. I like visitors.
>
> Doug Fattic
> Niles, Michigan
>
>
> _______________________________________________
> _______________________________________________

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