Britbike forum Forums General discussion The Rod and Tappet Brazing

Looking at the prices of the equipment to just get started, I'm thinking I agree with that approach! A decent torch and hose set, along with tips, and tanks and rental and gasses and it's a $500 entry fee. Perhaps I should really be thinking of a starter wire-feed MIG welder? I have 220V wired all over the shop ....

I've got lots of great info here on this thread from guys who know exactly what kind of jobs I'm looking at doing. The "self-sufficiency" element is still in play, I just need to figure out what it's worth to me .....

Lannis

If you get serious about a mig welder go with a gas unit. Don’t mess with the flux core cheapies.

those people are just ignorant.

you need a compressor, a spray gun, and some sandpaper.

then youre a pro.

I once tried brazing on a frame lug using a MAPP gas torch, it turned out unsuccessful as I just couldn't get enough heat into the joint to get the braze to flow.

After that, I have been taking all my welding and brazing jobs to a local shop that charges pennies and is extremely professional.

So for me, outsourcing welding is the best approach.

I watched a couple of videos on YouTube with propane brazing and a Bullfinch torch.
I bought the torch but propane cylinders became hard to find.
I will get hold of a cylinder in a month or two.

I’m hopeful of success. A lot of old bikes were brazed, I wouldn’t do anything too structural but small pinholes or brackets should be fine

Master fabricator Paul Brodie uses gas flux for his brazing technique. Beautiful process but a bit more expensive. A trip to Harbor Freight will get you all you need for occasional home brazing projects.

"Occasional home brazing projects" is a pretty good description of what I need. Paul Brodie has been mentioned twice now, so I really need to spend a little bit of time in front of a YouTube screen, I reckon. Critical structural welds, I'd better hold off of. When I needed to have the originally furnace-brazed side stand bracket welded onto the frame tube, I took it to a race-car shop and the guy did a beautiful TIG-welding job on it.

Harbor Fright is a little light on quality and a little heavy on China for my tastes, but I'll find a place that has what I need and see if I can justify it .....

Lannis

I was just going to give up but then decided someone else might be interested.



He doesn't go into HOW to weld, solder, cut or braze.......BUT......at least it's not me telling you about it.

I've had and used this type of set up for decades......my tips (pun intended) are.

1. Have extra oxygen cylinders. $14 at Lowes Hardware
2. Have EVERYTHING ready to work with BEFORE you light the torch. The oxygen runs out fast. You'll need to be ready for that. IF you get things ready first.....it really doesn't take long to braze something.

It's mentioned on this thread that the Mapp gas isn't hot enough to braze with. Add oxygen and you can cut a frame in half with it.

IF.....you're looking for an inexpensive way to solder or braze and you're only going to do it occasionally ......this type of set up is a perfect fit IMO.

I hope I didn't say anything that makes you felt like you had to "give up" on me .... I'm listening to and paying attention to every piece of advice that's been given. Every post gives me a new idea to evaluate; and even if I decide "not to go that way", whatever it is, it's useful..... !!

Lannis

No problem Lannis......I just didn't want to "push" that type of set up.....that's what I was giving up on.

It's absolutely not the best set up. But how often do you braze or solder? I've had mine for decades but only used it a half dozen times. Wasted a couple of bottles of oxygen trying to figure out how to use it. But now I have two small jobs (both solder) on that bottle.

I'm thinking it's just a smaller version of what Windy was suggesting???

What kind of propane tank are you looking for? I just use a barbecue tank. Good backup for the barbecue and vice versa.

Or you could buy one of these.

https://seattle.craigslist.org/tac/tls/d/tacoma-make-your-own-acetylene-linde/7592752756.html

Just a BBQ sized bottle.
In the UK there seems to have been an issue with them and you needed an old one for exchange.
Possibly because Calor changed their cylinder sizes and loads of caravan / motor homes have fixed storage that doesn’t fit the new cylinders.

There’s a marina near me I just need to get over there

You really don't need to watch the whole thing........just to where it shows how quickly the oxypropane heats something up.......what you need when trying to braze.

This is what I hate about You tube videos from people with little understanding about what they are doing
Oxy-Map , oxy -propane are lamost identical
Air- map is only marginally hotter than air - propane
However comparing air propane to oxy map is comparing apples to watermellons
Also he is not "cutting" the Al can he is melting the can and the high pressure high volme flame is balsting the molten aluminium into the inside of the can
and of course the hardness of a metal has nothing to do with the way it flame cuts

The only advantage Mapp has over Acetelyne is it can be compressed where as acetylene has to be dissolved into a solvent ( which is why acetelyne bottles must always stand upright when being used .

Air propane was used extensively in brass work but never became easily available retail as it had little advantages over other guns

Mapp must never ever be used on high alloy steels as it has a hydrogen righ flame which will end up diffusing ino he steel and make the surface layer ( or weld pool if ou are stupie enough to try & weld with it ) very brittle so the weld can fall out under stress and the braized joint fall off leaving all of the bronze on one part .

I am now in the process of brazing a damaged BSA petrol tank.I am using propane torch with low temp melt brazing rods which you need a seperate flux, for this I am using Borax powder mixed into a paste with a drop of water. Just clean up area to be brazed then apply the paste with a soft brush , dip the rod into the Borax paste then heat the area until you get up to temp with the rod melting into whatever your brazing. I had to makeup a small cover plate as the hole in the tank I was brazing was to big to fill with braze alone, this was the rear mount which had fractured and left a hole approx 1" x 1/4". The torch I used had a large flame and would of been easier if smaller to concentrate the heat in a smalerr area, but did the job and is ideal for tinwork...

This is a great watch... makes it look so easy!
(It is not, for me)

Much more fundamental, this one...

[quote=PINEMONKEY]This is a great watch... makes it look so easy!
(It is not, for me)

Not easy for me either.

I thought this was interesting. The guy used brazing to repair a missing section. Someone had taken an angle grinder to the fender in order to make it fit the wrong forks. I would have welded in a piece of steel which would have been a pain with the bead there.

89475AA6-F907-46DB-A2D7-3446E5D937E9 by First Last, on Flickr



Some inspiration…

BB259273-6D65-4DED-B55D-2ABA63406675 by First Last, on Flickr

I did these tabs earlier this week. The zip ties work because I decided to use MIG. Probably wouldn’t be good for brazing, but maybe hose clamps? It helps keep the tab located out far enough that you can still get the bolt through the tab without hitting the tube. The tube is very thin and I don’t think I could have brazed it with the setup I have….it’s much too agricultural.

DB7C9968-FD20-4386-9360-00DFCAE1F81C by First Last, on Flickr]First Last[/url], on Flickr

27E75E2E-8EEB-4793-B028-A9F6427E3BB8 by First Last, on Flickr

The Vincent touring fender in photo was repaired using a tig welder and silicon bronze rod.

Then he’s a much better tig welder than I am. I would have to build that up with hundreds of little blobs. I can’t adjust the post flow, so that repair would cost me a fortune in argon.

For whatever reason, I had never thought about using bronze/ brass as a filler. I tried it the other day on a couple of pieces that needed some divots filled. They were going to be powder coated and I needed something that would take the heat. I have tried using JB weld as filler. It’ll take the 450 degrees, but the surface finish looked different over top of the JB. Before coating, the surface texture was the same. Apparently folks use it, so I must be doing something wrong.

I own a set of torches, an arc welder, and a 220V gas MIG welder. The MIG is better for larger jobs. I can do small tabs but practicing to figure out proper amount of heat and wire feed is the best way to not bodge your work.

I am not a welder. I play one on TV...

For structural welds, aluminum, and stainless I have a real welder friend.
The torch I use for silver soldering, brazing, and heating things up before bending, especially aluminum. With a little practice brazing isn't very difficult and I find it fun. If you look around on Craigslist etc. you can find the smaller cylinders for sale along with . If you buy used, make sure they have passed inspection at a place that fills tanks. Buy new-Harris torch set $400 with free shipping, cutting tip and brazing tip with accessories.
I also use the torch to heat up recalcitrant bolts axles, you name it.

BEAUTIFUL WORK, Cyborg !

The only work there that was mine is the fender brackets or should I say mudguard stays. I assume you are referring to the brazed frame and that is and will be beyond my reach. I just have the photo around to remind me how far I have to go.

As for welding the tabs with MIG, it’s easier to stitch them on. Basically a series of tack welds or pulse welding. The tubing is quite thin and best to double check the amp/wire speed on a test piece if possible.
The rear brackets on the left were made from scratch. For the front, I was able to use a stock bracket, but had to cut off the tabs, re-bend the radius to match the fender I’m using and then weld on new tabs. It was a PITA, but can’t imagine what it would have cost it I farmed it out. Finished in the dreaded powder coat.

7D246652-FC2C-42A7-B82E-F55460A222A5 by First Last, on Flickr