Dave, you can braze just about anything together. I regularly braze together steel sheet, with great results, usually the brazing is stronger than my fusion welds. I'd recommend getting separate flux and rod, it makes life a lot easier when brazing in my opinion, because then if you stuff up, you don't end up with a pile of useless brass with no flux, and it also makes repairing joints easier. I use powdered flux and then mix it to a paste if I'm using high gas flow and it blows the flux around, otherwise I just pop some on where I'm brazing and then melt it, I also heat up the rod and dip it in the powder to coat the rod. As Darrin said, get a pair of goggles or welding glasses, personally I prefer the Ray Bans (what we call the welding glasses), as they give you a much wider field of view.
I've never actually tried brazing with a propane torch before, so I can't really give you advice for the actual technique, but if it's anything like an oxy welder, you want to get a slight oxidising flame, if you can adjust the air-fuel mixture, you want to get as much air in as possible. -Gregory On Tue, Jun 19, 2012 at 1:33 AM, SmithD <[email protected]> wrote: > ** > Norman, > > The brake lines are a low grade of stainless steel, meaning they glow red > at a lower temperature than mild steel. > > The braze alloy reached its melt temp. but not its flow temp. > > For practice, you should start by coating a piece of steel with braze. > > The braze should not be melted directly with the torch, it should be > melted with contact with the hot steel. > > While heeting the steel, a small amount of flux should be melted onto the > steel, also NOT melted directly with the torch. > > Test the temp. of the steel by touching the braze to the steel, when the > braze melts and flows you have enough heat to coat the parts. > > After the parts are coated, allow them to cool so the braze is solid. Then > reheat, reflux and test the temperature with the rod until the braze melts > without flowing and then fill the gap. > > If the temp gets to high and the braze starts to flow, remove the heat, > allow to cool. > > Once the braze has melted and cooled it requires a higher temperature to > remelt. > > If you are not using a pair of oxyfuel welding goggles, find a pair, use > them. The flame and glowing steel are hard on the eyes(you will destroy > your night vision and worse) and the brazing process is easier to watch > with goggles. > > Good luck > > Darrin Smith > > ----- Original Message ----- > *From:* Norman James <[email protected]> > *To:* [email protected] > *Sent:* Sunday, June 17, 2012 3:35 PM > *Subject:* [TANKS] Brazing, Round 1. AKA Oooo! Glow-ey Hot Stuff! > > > First go at it. > Given large coiled sections of brakeline are cheaper, the working medium > is a 25 foot section of 5/16ths coated steel brakeline from Auto-zone: > costing a grand total of some $20. > ** ** > > While in lengths, it’s fairly flexible, I hacked off a ~4 inch and ~2 inch > chunk to test with. The brass brazing rods were flux coated, so I didn’t > bother with fluxing the joint, but I did grind off the anti-corrosion > coating to get down to the base metal with some emery paper. Also, a > cut-off wheel mounted in a hand drill was very useful for fish-mouthing the > end of the test piece for a nice, clean fit. > > Note to self: Buy one of those sparky things. Matches don’t work well for > lighting torches. > > Heating up was fairly straightforward, getting the metal a nice glowing > orangy-red. And… That’s about where the easy bits ended. > > The brass rod melted down easy enough, but instead of nicely slipping into > the joint (like when working plumbing joints), it kind of globbed up, and > dripped off in useless blobs. Using plyers, I flipped it over and blobbed > some on the other side with much the same results. > > I then attempted to overheat the joint, to try and (maybe) melt the blobs > soft enough to run into the joint, but nothing doing: the torch just > doesn’t look to have the heat to get the thing done. > > Letting it cool, the joint did appear to hold, meaning there must have > been SOME adhesion there, despite the joint resembling a gold version of > something I might have blown out of my nose. > > Simple hand torquing was able to snap the joint relatively easily. > > Conclusion: More head scratching, and perhaps try something with a melting > temp less than 1600 degrees. I found some good alloy brazing rods at a > local Ferguson’s with 15% silver content, and a working temp of “only” 480 > degrees, so I’ll be giving that a try next. > > > > (Yes, I have a much better camera, but it was AWOL. So I used the > computer's Logitech chat camera for the pics. Better quality next time) > > ** ** > > ** ** > > ** ** > > -- > You are currently subscribed to the "R/C Tank Combat" group. > To post a message, send email to [email protected] > To unsubscribe, send email to [email protected] > Visit the group at http://groups.google.com/group/rctankcombat > > ------------------------------ > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2012.0.2178 / Virus Database: 2433/5077 - Release Date: 06/18/12 > > -- > You are currently subscribed to the "R/C Tank Combat" group. > To post a message, send email to [email protected] > To unsubscribe, send email to [email protected] > Visit the group at http://groups.google.com/group/rctankcombat > -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat
