sokyroadie

I ordered a KVA stainless frame from a fairly well known builder who does NOT do lugged stainless. I wanted a non painted frame for ease of maintenance. I was floored when he sent some pictures last week - the frame is fillet brazed rather than Tig welded. I was under the assumption that you were not supposed to fillet braze Stainless. I am not at all happy with how it looks. His reply is that he finds it distorts the tubing less with brazing than with Tig welding. I never asked if it would be Tig welded I thought that was the only option if it was not lugged.

Opinions please, is this an acceptable joining method?

Jeff

Live Wire 

It's acceptable, as a matter of fact, using the new fillers like Fillet Pro has made fillet brazing the new stainless steels a very common practice. What is it you don't like about the fillets? The color?

Scooper

Completely acceptable. Here's a Simoncini fillet brazed 953 frame.

sokyroadie

I am not sure, it may just be the fact that I was expecting Tig and not prepared or a different color joint. I am going to wait until I receive it Thursday to decide if I want to paint it.

Thanks,

Jeff

unterhausen

I'm putting these questions on my order form:
Have you looked at my gallery? y/n
I only use lugs or fillet braze, does this meet your expectations? y/n

unterhausen

I hope the builder didn't spend too much time polishing if you end up painting it.

tuz

here are some pics of a SS fillet-brazed bike

https://www.clockworkbikes.com/track.html

rodar y rodar

I didn`t know that was possible either. I`ve seen some of the Fred Parr threads on FF, but mostly pass them by since I`m still trying to get my head around the "normal" way of doing things and don`t need any further complications.

FWIW, I`m surprised that both the builder and the customer went on the assumption that both were on the same page as far as joining method goes. You`d think that both parties would specify their intentions beforehand.

edthemechanic

Please check out this one.

Six jours

For my money, any builder who is willing to sell you an unpainted frame is probably a pretty good builder. Paint hides a lot: a builder willing to let you see his "naked" joinery is confident in his work.

unterhausen

I'd say. Making a fillet look nice unpainted is a big step up in effort from what it takes to make a fillet look nice under paint.

ruzmeem

I am pretty interested in lugless/fillet brazed SS frames. I was hoping some one could shed some lights, as I am doing a small research. Which of brazing alloys are generally used for fillet brazing SS frames? Thanks.

niknak

Live Wire already mentioned the filler capable of fillet brazing stainless: Fillet Pro

unterhausen

It's possible to use nickle silver. I'm not confident enough with it to build a stainless frame though, I've built racks and bottle cages. A builder said they used it for frames, but I don't remember who

ruzmeem

Thanks. I was wondering if Fillet Pro works with Reynolds 921, 931 or 953 ranges. Have anyone tried that on Reynolds SS tubes?

unterhausen

I think you should ask Reynolds about that. Seems like there was some caution about silver and 921, but I can't think of where to find that information

8aaron8

Andy Newlands of Strawberry Cycles posted some information on his sight regarding 921 and silver brazing. I talked to a Reynolds rep. at NAHBS in Sacramento, CA earlier this year and he told me that the characteristics of 921 made it a poor choice for people who didn't have great heat control during brazing. I guess the prolonged heat made it brittle and they were made aware of some frames/forks cracking.

unterhausen

stainless is a real test of heat control, and if you overheat it is really bad. Stuff precipitates out that makes adhesion extremely poor. Not a good choice for one of your first 25 frames, that's for sure. Beginners often make the mistake of trying to build their dream frame as their first one. Probably why there are so many unfinished first frames out there.

tuz

I have a bit of experience with Nickel-Silver (bad name: it's brass with Nickel) and 304 stainless. It's a nice brazing alloy: cheap, good for fillets, doesn't tarnish and it's a good colour match to stainless. You need a special flux. As mentioned brazing stainless is quite finicky but if you practice you'll get the hang of it.

I don't know if you can use Ni-Silver on the Reynold tubes. I think XCR is okay, KVA not.

unterhausen

other than Cycles Design, is there a source of flux for nickle silver? I think I'm mildly allergic to nickle silver from my time at Trek, but it's still really useful sometime

tuz

Superior 609LB is the other flux I know of. Never used it but I think it should be quite similar to the CD stuff.

JohnDThompson 

I went looking for some recently, and it seems that what used to be a fairly common rod is now something exotic. I couldn't source any locally, so I ended up getting some "Fillet-Pro" from Cycle Design. It hasn't arrived yet, so I can't comment on how well it works.

David Tollefson

The only issue I've had with Cycle Design silver fluxes (both for 56% and Fillet-Pro) is that it becomes a slurry of tapioca-sized granules that don't dissolve, in a matter of a couple months. CD has said that this happens if the flux is allowed to freeze, which could be the case (though I believe that the Fillet-Pro-specific flux I have didn't freeze, but I haven't confirmed the purchase date). unterhausen stated on another thread here that he's used the Gasflux type U (I think -- whatever the silver flux is that Henry James carries) with Fillet-Pro, and I've never had an issue with any Gasflux product.

dsaul

Years ago I ordered a pound of nickle silver from Henry James and Hank told me to use Gasflux type B. I only used it once for some stainless dropouts, but it worked fine.

unterhausen

That's what I use, and I would say it works ok. However, I'd rather have something a little higher temp, since that's where nickle silver melts. I didn't go through aufhauser's fluxes to find what they recommend for nickle silver, they must have something Aufhauser - C773 Nickel Silver Alloy