Framebuilders - Brazing Vs. Welding

My friend and I want to build an alt. bike this summer. Maybee a tall bike, or a chopper.

However, we don't have a welder. And renting one isn't an option, plus, I have been told that place won't rent to people who don't have experience with the equipment. We are only 15, and only know how to weld from quick lessons, internet, and shop class.

Although, we do have the tools to braze the frame, (MAP gas, oxy-acetaline whatever) and we have experience brazing.

My question is, would brazing work, and would it hold well? Do any of you braze frames? What exactly would we need? Any tips? Or any other east methods?

Thanks

brazing is fine. in fact I would say more hobby/amateur/small builders braze compared to welding.

Brazing, I assume you mean filet brazing since I doubt you can find lugs for a chopper. Yup should work fine. OA torches are pretty dangerous and it it's set up for cutting it presumably isn't appropriate. Another pitfall is it's set up with those small bottles that run out before you haev put down the striker. If someone in the neighbourhood has the tanks, then you can buy a relatively cheap torch for exactly the kind of work you are talking about. With this you can weld metal and aluminum, and do brazing etc...

http://tinmantech.chainreactionweb.com/html/meco_midget_torch.php?cart=30b82db6f914ffa87c25195285f5333d

If you use MAPP, I'm guessing the prefered option is a high silver braze which can be a little expensive. I weld so presumably the adults will show up here to fill you in.

This guy has some home info on brazing

http://www.sonic.net/~maryking/

if youve got no lugs and no experience, then don't worry about laying it on thick!!
If your technique isnt the best, then buy more tube than you need and practice for a day or two to get it down.. You might also try adding some gussets (plates cut to fit over the sides of the joints to add stiffness)
15 and you want to build a custom bike! way to go!
have fun!!
~Steve

Thanks alot guys, I will deffinately give it a try. But another thing, would propane work aswell?

And are there any other gasses I could use?

No, you need OA. OA gets to 6500 degrees, propane only gets to about 4500. Not hot enough.

ok

You can learn to weld on the Internet?

What a frightening concept...

:eek:

Well of course the stuff on the net is backed up by all that stuff on the discovery channel.

I think it is safer to learn to weld from a close relative or a proffesional welder...

"I think it is safer to learn to weld from a close relative or a proffesional welder..."

It's also better to learn your bike handling from Armstrong, but it isn't possible for everyone.

Good Point

you can use oxygen/propane.

"I think it is safer to learn to weld from a close relative or a proffesional welder..."

It's also better to learn your bike handling from Armstrong, but it isn't possible for everyone.

Heh that's where I learnt my Bike handling skills...

One trick that we used on simple hobby soldering:

when trying to build a fillet of solder between 2 round surface, we often use a piece of wire to "bridge" the gap. For example, we are trying to solder 2 pieces of brass tube next to each other, we drop a piece of brass wire or a half piece of tube (of smaller dia) into the gap and let the tin solder the whole thing together. We found that this technique produced a stronger joint and it was easier to manage the fillet too. What in effect this does is to make a crude "lug". I'm not stating that this is directly applicable to bicycle frame building, but just sharing an idea.

I've lived in Ireland a fair bit, both Belfast and Dublin. Been a while. There were bikes all over the place. Both UK and Ireland are different than NA in having the tradition of driving small roads at much higher speeds than are legal on the freeway here. In the south it was pretty comon, when I lived there, for people to pass down the middle on narrow 2 lane roads, you would swear there wasn't room for a third car, but it would just proceed down the middle and nobody minded. The West was pretty desolate when I lived there, so I have a hard time imagining the trafic will be a big probelm. You will have a great time.

If you want something suitably weird to read on the plane over, of no possible relevance to your trip, try Round Ireland in Low Gear , by famed travel writer Eric Newby. This is an odd book, and they make some odd choices. As the lowest rating guy on Amazon said:

"Why oh why does he complain about the weather when he chooses to cycle around the westernmost outpost of Europe in Winter?"

Because that's when he went, and that is how he felt, I guess...

I'm not sure how much I liked the book when I read it, but it stuck with me.

http://www.amazon.com/gp/product/0864426275/qid=1152426101/sr=1-14/ref=sr_1_14/102-5911271-1384940?s=books&v=glance&n=283155

No, you need OA. OA gets to 6500 degrees, propane only gets to about 4500. Not hot enough.

If they were referring to brazing, it is more than hot enough. bronze flows at 1600-1700 degrees f, silver flows at 1100 degrees f. the steel frame tubes will start to "damage" at around 1900 -2100 degrees f. The problem is not how hot the flame is, but how much heat you can apply over a large area. Therefore, many torches are shaped like shower heads vice pencils