Go Back  Bike Forums > Bike Forums > Framebuilders
Reload this Page >

Brazing capped seat stay to lug

Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

Brazing capped seat stay to lug

Reply

Old 08-09-18, 06:32 PM
  #1  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 1,281
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 226 Post(s)
Brazing capped seat stay to lug

I am capping the seat stays with scrap pieces of tubing so that the caps are silver brazed to the angled cut on the stays. When I attach to the seat lug will the silver holding the caps to the end of the stays run and ruin the attachment to the tube?
TiHabanero is offline  
Reply With Quote
Old 08-09-18, 07:26 PM
  #2  
Live Wire 
Framebuilder
 
Join Date: Dec 2007
Posts: 559
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Yes, it will melt the silver holding the cap. If your heat control is good, it will only melt near the tip and you'll probably be able to touch it up while everything is still hot.
Be a lot easier to use brass, or nickel silver if the caps are stainless.
Live Wire is offline  
Reply With Quote
Old 08-09-18, 08:06 PM
  #3  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 1,281
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 226 Post(s)
Thank you for the info. Is it OK to use brass on the caps or will it require too much heat? They are simply cromo scraps.
TiHabanero is offline  
Reply With Quote
Old 08-09-18, 09:25 PM
  #4  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 16,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
brass will be fine. Practice on scraps first if you are unsure.

I have spent days on end brazing caps to stays at Trek. Somebody had to do it. Back then, we only used nickel silver on everything that we didn't use silver on. I have always been curious why. Brass would be a lot better, some people develop a sensitivity to nickel silver. Nowadays I only use nickel silver when I'm working with stainless.
__________________
Randonneuring -- it's touring for people that aren't smart enough to stop for the night.
It's a wonderful sport when you can make up for a lack of ability with a lack of sleep

Last edited by unterhausen; 08-09-18 at 09:28 PM.
unterhausen is offline  
Reply With Quote
Old 08-10-18, 07:04 AM
  #5  
8aaron8
Member
 
Join Date: Dec 2013
Location: Stockton CA
Posts: 37
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
If you are using non stainless steel then brass is the way to go for sure. If the caps or stays are stainless you can also use a lower percentage silver rod such as 35% or 45% because the melting temperature is higher than what you will use to join the seat stays to the seat lug assuming you use 50% or 56% on that joint.
8aaron8 is offline  
Reply With Quote
Old 08-10-18, 02:34 PM
  #6  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 9,812

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1148 Post(s)
For lugged frames I'll brass both the lug and the caps. I, too, make my own from tube shorts or plate and will use silver (56%) to attach the stays to the lug sides. I've melted out silver from a lug, while using brass to attach the stays. Andy.
__________________
AndrewRStewart
Andrew R Stewart is offline  
Reply With Quote
Old 08-10-18, 07:24 PM
  #7  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 1,281
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 226 Post(s)
Andy, I never considered the affect of heat on the lug. Suppose it is possible to lose the filler from the lug joint. Welding supply store is closed and the only brass is an 1/8 rod. Too thick for the caps I think. May wait for Tuesday to get the correct rod. I will use brass on the cap and silver at the lug so that I reduce the chance of bleeding out the filler from the lug/seat tube joint.
TiHabanero is offline  
Reply With Quote
Old 08-11-18, 09:19 AM
  #8  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 16,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
I use silver in the lug and brass to attach seat stays. Every Trek built up to the point where they switched to brass lug brazing was built that way. There is some possibility of flowing silver back out of the lug. Flow it back in, it's not going to hurt anything. My expectation is that you might pull silver into the lug and have a gap on your shoreline. If that happens, fill it with more silver.
__________________
Randonneuring -- it's touring for people that aren't smart enough to stop for the night.
It's a wonderful sport when you can make up for a lack of ability with a lack of sleep
unterhausen is offline  
Reply With Quote
Old 08-11-18, 10:42 AM
  #9  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 34,987

Bikes: 8

Mentioned: 126 Post(s)
Tagged: 0 Thread(s)
Quoted: 4896 Post(s)
In Art metalworking, we use several different melting point silver solders,
going from high to low, Aka 'hard to easy'

so sub-assemblies don't come apart while you are attaching them..

I used a single wrapover piece , on the (Aelle) frame I built , Brass brazed, in the mid 70's..

Silver is needed for stainless steel lugs you using those?
fietsbob is offline  
Reply With Quote
Old 08-12-18, 04:06 PM
  #10  
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 19,327

Bikes: Several, mostly not name brands.

Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 1264 Post(s)
If you're going to use silver to attach the stays to the lug, it's a good idea to file a little trough into the side of the lug for the stay to seat into. This will give a larger surface area for the joint. Plus, it looks pretty nice.
JohnDThompson is online now  
Reply With Quote
Old 08-12-18, 08:26 PM
  #11  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 16,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
John, I have never done that, I am going to try it on my next frame
__________________
Randonneuring -- it's touring for people that aren't smart enough to stop for the night.
It's a wonderful sport when you can make up for a lack of ability with a lack of sleep
unterhausen is offline  
Reply With Quote
Old 08-12-18, 09:33 PM
  #12  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 9,812

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1148 Post(s)
Another cool thing about filing a shallow trough in the lug's side for the stay is that the stay tends to not slip about during brazing. Not a problem if you've jigged the stays well to the frame. But many here don't know the tricks of have much tooling yet developed. Very good tip, John. Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Reply With Quote
Old 08-14-18, 09:02 PM
  #13  
TiHabanero
Senior Member
Thread Starter
 
Join Date: Nov 2012
Posts: 1,281
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 226 Post(s)
Picked up a brass rod at the local hardware store on Saturday. Fortunately we still have a couple of real hardware stores left around here. Made a practice cut and then was promptly interrupted! Will be playing some more with it in a day or two and will let you all know the results. The file a trough into the seat lug is a good idea.
TiHabanero is offline  
Reply With Quote
Old 08-14-18, 10:05 PM
  #14  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 9,812

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1148 Post(s)
TiH- I would strongly suggest you try the GasFlux C04 bronze rod available from Henry James, and others. Their type B flux is a standard for many builders too. Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Reply With Quote
Old 08-15-18, 05:50 AM
  #15  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 16,621
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
the bronze I bought from my local welding shop doesn't flow very well. I can make it work, but the Gasflux or Cycles design bronze is much better
__________________
Randonneuring -- it's touring for people that aren't smart enough to stop for the night.
It's a wonderful sport when you can make up for a lack of ability with a lack of sleep
unterhausen is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service