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DannoXYZ · October 30th, 2021, 10:23 AM

Well, it's not just about end-results, he could've bought running bike. The challenge and learning experience is worthwhile as well.

These pieces need to be much, much cleaner, especially one on left. Sand surfaces all around at least 2-3cm away from joint. Use Dremel tools to get inside curve. Scrub with stainless wire-brush. Wipe down with acetone. Also V-notch joint all around both pieces to get channel for solder to flow into.

And you need A LOT more heat. You had to smear the stuff on with rod, it didn't flow. Even though aluminium melts at lower-temps than steel, its much higher thermal-conductivity means heat that's applied, flows away from joint super fast. When welding aluminium, I have to turn power settings up 2-3x higher than for welding steel. What you have in this case is peg only gets as hot as vise because all the heat flows away from joint. You'll want to insulate peg from vise with 3-4mm layer of fibreglass on either side, or silicone kitchen mat. V-notch also helps increase heat at joint.

One aid to show adequate heat is to coat joint with soot beforehand. Start with only yellow gas flame. Aim sooty end of it onto workpiece and coat joint until it's completely black. Then turn on oxygen and increase gas until you get 3" blue flame. Increase oxygen again until you get 1" white flame. Heat joint evenly moving flame back & forth across entire length of joint. When soot burns off and disappears, joint is up to temp. Then apply brazing-rod. It should melt and wet-out on contact. At this point, you want to heat from underneath to draw solder through joint. Apply more solder to top as it gets pulled in.

Notice how it flowed away from contact point in 1st section of this video? Shows proper clean surface prep along with adequate heat. Concave profile of solder at end of video shows clean surface and sufficient heat to flow.
https://he.aliexpress.com/i/1005001623898303.html
(copy & paste URL to new tab/window, if clicking link didn't work)

also... clean and LOTS of heat!

Link to original page on YouTube.

October 30th, 2021, 10:23 AM	#154
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Well, it's not just about end-results, he could've bought running bike. The challenge and learning experience is worthwhile as well. These pieces need to be much, much cleaner, especially one on left. Sand surfaces all around at least 2-3cm away from joint. Use Dremel tools to get inside curve. Scrub with stainless wire-brush. Wipe down with acetone. Also V-notch joint all around both pieces to get channel for solder to flow into. And you need A LOT more heat. You had to smear the stuff on with rod, it didn't flow. Even though aluminium melts at lower-temps than steel, its much higher thermal-conductivity means heat that's applied, flows away from joint super fast. When welding aluminium, I have to turn power settings up 2-3x higher than for welding steel. What you have in this case is peg only gets as hot as vise because all the heat flows away from joint. You'll want to insulate peg from vise with 3-4mm layer of fibreglass on either side, or silicone kitchen mat. V-notch also helps increase heat at joint. One aid to show adequate heat is to coat joint with soot beforehand. Start with only yellow gas flame. Aim sooty end of it onto workpiece and coat joint until it's completely black. Then turn on oxygen and increase gas until you get 3" blue flame. Increase oxygen again until you get 1" white flame. Heat joint evenly moving flame back & forth across entire length of joint. When soot burns off and disappears, joint is up to temp. Then apply brazing-rod. It should melt and wet-out on contact. At this point, you want to heat from underneath to draw solder through joint. Apply more solder to top as it gets pulled in. Notice how it flowed away from contact point in 1st section of this video? Shows proper clean surface prep along with adequate heat. Concave profile of solder at end of video shows clean surface and sufficient heat to flow. https://he.aliexpress.com/i/1005001623898303.html (copy & paste URL to new tab/window, if clicking link didn't work) also... clean and LOTS of heat! Link to original page on YouTube.