anhizer

I am looking in to getting into frame building and had some questions on tools and filler materials. I have a small oxy/acetylene torch setup (the HVAC style small bottle setups) with a couple of different torches that I inherited, but I don't know if its appropriate for frame building. I'm planning on purchasing some equipment and filler materials to round out my kit but i don't know what I need vs what I have.

This is the brazing equipment I have:
oxy acetylene bottles w/ appropriate hoses, striker, PPE, etc.
a small Gentec 10ST torch handle (its like a jewelry size) with tips in sizes 2-6
a Harris Model 85 torch handle (full size) with a D85 mixer with a size 3 Harris tip attached (brand new)
Harris cutting torch head
a OLD (probably from the 60's) Victor 100 torch handle w/ "type - 13" nozzles in sizes 000, 00, 1, & 2. These all are in need of cleaning and seals. I need to look into cleaning these up.


On the filler materials front I have some Wolverine Silvaloy A56T (cad free) in 1/32" size. I also have a small tub of stay-silv white flux.

I am planning on ordering some Low fuming bronze to learn how to fillet braze for some home projects (and eventually frames), but I plan on building lugged frames to start. I do have some experience brazing (i built a frame in a workshop class several years ago with Sanner cycles) but its going to take me a while to get back up to speed. For the bronze I'm probably going to get something online- i was looking at the Gasflux C-04 Henry James sells.

So I guess my questions are:
1) what torch/tip should i use for silver brazing and brass brazing (I assume i need to use different tips depending on material?)
2) is my silver filler okay for lugged frame construction? I would prefer to use it as i have a basically new package and its quite pricey.
3) Anything that i should get that isn't on this list?

Thanks!

GrayJay

Learn using the LFB and thicker tubes, save the expensive silver rod until you have built a few frames and need it for working on thin-wall tubing.

Refilling small acetylene bottles is fairly expensive and inconvenient. For brazing temperatures, consider using propane as fuel (along with O2) works fine, is much less hassle, and will keep your shop cleaner (no soot).
https://www.velocipedesalon.com/foru...ane-30480.html

The gentec torch looks awfully small for meal work. The other 2 might be larger, more clunky that optimal for framebuilding but should be fine to get you started.

unterhausen

I built my first couple of frames with a torch the size of my forearm. The more you practice, the less the size of the torch tip really matters

I usually use whatever tip is on the torch, unless it's too small for the job. But if I actually thought about things a little more, I would probably use an AW201 for braze-ons, 203 for lugs, and 205 for fillet, fork crowns, and bb shells. There are better tip conversion charts than this one, but it will probably tell you what you need: https://www.tinmantech.com/products/...-tip-chart.php I could live with a 205 for most everything except LFB on lugs, and then I use a 208, which is right on the verge of over-drawing my acetylene tank. Generally, someone that has a lot of experience can use a bigger tip than someone that is less practiced. The 208 delivers a lot of heat though, it's more comfortable for me to go to a smaller tip if the job doesn't require max heat. It becomes second nature to pull the flame off of the workpiece to keep it from heating up too much. That's what practice gets you.

With your small tanks, you really need to be careful about over-drawing the acetylene tank. Figure out the volume and look up the draw rate for your torch tip. The old standard was 1/7 tank capacity per hour. Over a decade ago, OSHA changed that to 1/10 intermittent and 1/14 continuous. This is to keep the acetone from escaping and cooling the flame.
What that means is if you have a 10 CF tank, then you can draw 10/7 CF/hr. This is the big advantage of propane. If you get an oxygen concentrator, it will save money fairly quickly with a small oxygen tank.

One more thing, I think silver is affordable enough that you can use it if you like. Up to you and your finances, of course. The gasflux LFB and Cycles Design LFB are both really nice.

anhizer

Thanks for the replies. I actually have an oxygen concentrator and propane regulator that i might try and mess around with but i figured that as i have acetylene already i might be able to just use this right away. To run oxy-propane i think all i need to do is get propane specific tips for my torch as well as some hose. i stopped by my local airgas yesterday and they didnt seem to know much about the different torch offerings... it seemed like they mostly knew about arc welding.

Im not too worried about the cost of the silver, but i have a spool of the wolverine silvaloy stuff and would prefer to use it if its appropriate for bicycle applications. Any thoughts on if its OK? i plan on using the brass for fillets and general shop repairs only... lugs/brazeons will be done with silver.

Also, the victor torch i have seems like a smaller one- the harris torch is quite a bit bigger. Looking online the victor torch i have looks most similar to a J28 torch but with the knobs on the bottom of the torch instead of near the top. its last patent date is stamped 1920; ill have to see if i can figure out what needs to be done to make is usable.

Live Wire 

56 silver is a good alloy for lug brazing, but a 1/32" wire is too thin, especially when you're just starting out. Use it for practice and I think you'll find the commonly used 1/16" wire to work a lot better.

unterhausen

You can get J28 clones for not much money.