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-   -   Oxy/Propane welder setup? (http://www.risingsun4x4club.org/forum2/showthread.php?t=21223)

smslavin 04-25-2014 04:28 PM

Oxy/Propane welder setup?
 
With the FJ gone and a replacement vehicle not on the horizon for awhile, I need something to do. Our new place has a great garage space for a workshop so, I'm looking to learn how to do some brazing and build some bike frames. Thinking about learning TIG as well but that's a ways off.

Anyway, I've been doing some digging around and have seen recommendations for an oxy/propane welding rig vs oxy/acetylene. I can use a regular propane tank and combine it with an oxygen concentrator. On paper, it seems like a pretty good setup. This is what the Google gave me for a parts list:

Quote:

1. Propane tank from a local store
2. Propane regulator with 2 gauges for both line and tank pressures with CGA 510 tank fittings
3. 5 LPM Oxygen concentrator (it does not need an oxygen regulator)
a) or an oxygen tank from a local welding supply store
b) They come in 20, 40, 60, 80, 125, 150 and 251 cubic feet sizes with prices from $75 to $350
i) which requires an oxygen regulator. It is preferable to get one with the least wide oxygen pressure settings (like 0 40 psi instead of 0 100)
4. Type T 3/16" hoses (the smallest) with B fittings on each end (probably 12 foot length 25 or 50 ft. is also an option)
5. "B" size flashback arrestors to connect the 2 hoses
6. Smith Kevlar 10' hose with A and B fittings ($70+) (Smith part # 14779-4-10) (this is optional since you can run a T hose to the torch)
a) or TM technologies light hose (item # AWS-0052) ($45)
7. "A" size check valves that stop the back flow of gas but not a flame (can be optional).
8. Uniweld 71 "airline" torch handle
a) or the Gentec or Metalmaster 140T or the Victor J-28
9. Gentec 881 elbow (the equivalent to the Victor UN-J) (Victor part # 0325-0101) (this unit also needs a separate screw-on TEN tip)
a) with Gentec 883TEN-2 screw-on tip (the equivalent of the Victor 2-TEN tip Victor part # 0311-0485)
i)one might also want a size 3 and maybe a 4 (Gentec 883TEN-3 & 883TEN-4) or (Victor 0311-0486 & 0311-0487)
a)Another elbow tip all in one option is the Uniweld 17-2 all fuel brazing tip (one might also want the 17-3 size)
Do any of you have or used this setup? What are your thoughts? Does that above list make sense?

I'm going to run over to General Air next month for their oxy/acetylene class. Figured that would make a good intro.

Rzeppa 04-26-2014 12:20 AM

My neighbors across the street from me are both glassblowers and we've discussed regular propane versus propane with oxy boost. Both of them say that the oxy makes it too hot for glass and harder to control.

In my personal experience brazing stainless steel, butane is just fine (not as hot as propane).

I have turned away from General Air over the past several years as my personal experience is that their customer service has deteriorated and has left much to be desired. I'm not going to flame them here but let's just say I don't give them my business any more.

I have an O-A rig and had the Victor torch rebuilt at US Welding a couple years ago, really happy with their work. US Welding is pretty pricey for their consumables but their rebuilds are good quality. For consumables I have been using High Plains Welding for the past couple years and have been really pleased. In fact I need to go pick up my freshly tested (and passed) refilled CO2 tank from them Monday morning before I head out to Moab.

Bottom line is, I don't see the justification for the brain damage and expense for an oxy boost for propane for brazing. I've done plenty of brazing and soldering with a regular propane torch or occasionally mapp gas and have never felt that I needed an oxy boost.

DaveInDenver 04-26-2014 06:53 AM

I thought it depended on what type of brazing you're doing. Bike frames are often silver brazed so you'd need the oxygen boost with propane to get the concentrated heat (1200F) for the joint to flow right and quickly. I think bronze brazing might be less intensive. Most frame builders I think use oxy/acetylene for the precision and speed, so you minimize the impact to the tube's heat treatment. Depends, too, if you're doing lug-less fillets.

But lugs, dead sexy. Henry James, Richard Sachs, oh hell yeah.

http://www.peterwhitecycles.com/imag...s/SEATCLU3.jpg

http://ruedatropical.com/wp-content/...fork-crown.jpg

My understanding of the brazing process is it takes a fair bit of practice to get it right on bike frames. If you use lugs, they are heavy, the tube walls thin and the solder temperamental so you can easily get too much (ruin the tube) or too little heat (bad joint). This is one reason why high volume frames and even custom frames now are TIG & MIG, a lot less black magic to attaining a good looking and safe connection.

But the hard part isn't even the joining of metals necessarily but fabricating a jig that lets you do it so the frame is straight enough and doesn't require much (ideally zero) cold working after to align. That is one advantage of lugs, they tend to be self aligning and all the tubes cuts are less critical. Fillet brazing and welding you'd need more tooling to cut the miters and hold the tubes. That is again why higher volume is lug-less, investment in the table or jig is one time and amortized over all the frames. For a one-of, lugs make sense.

Just a hint, you might want to talk to John Henley and Terry Holben. John is a wizard with artistic metal in general (and has made bike frames) and Terry has been threatening to build us all fat bikes for, like, ever. If we can get you two into a race maybe we'll finally start seeing some frames coming out.

smslavin 04-26-2014 09:54 AM

Quote:

Originally Posted by DaveInDenver (Post 249898)
lugs, dead sexy. Henry James, Richard Sachs, oh hell yeah.

My understanding of the brazing process is it takes a fair bit of practice to get it right on bike frames. If you use lugs, they are heavy, the tube walls thin and the solder temperamental so you can easily get too much (ruin the tube) or too little heat (bad joint). This is one reason why high volume frames and even custom frames now are TIG & MIG, a lot less black magic to attaining a good looking and safe connection.

But the hard part isn't even the joining of metals necessarily but fabricating a jig that lets you do it so the frame is straight enough and doesn't require much (ideally zero) cold working after to align. That is one advantage of lugs, they tend to be self aligning and all the tubes cuts are less critical. Fillet brazing and welding you'd need more tooling to cut the miters and hold the tubes. That is again why higher volume is lug-less, investment in the table or jig is one time and amortized over all the frames. For a one-of, lugs make sense.

Just a hint, you might want to talk to John Henley and Terry Holben. John is a wizard with artistic metal in general (and has made bike frames) and Terry has been threatening to build us all fat bikes for, like, ever. If we can get you two into a race maybe we'll finally start seeing some frames coming out.

Yes, lugs are awesome.

http://2.bp.blogspot.com/-xQaQGqqinW...5_modified.JPG

Planning on putting in lots of practice with 1mm tubing in a couple of different sizes so that one will slide over the other. From the research I've been doing the past couple of days, Columbus Chromoly Thron tubes are the ones to start with since they're a little thicker.

It's also possible to do it jig-less. A little more time consuming on the setup side but I've found a couple of articles that explain it. I came across an article last night for building a jig.

I'd like to start with something relatively easy and build a track frame. A fat frame would definitely be in the future. Wouldn't mind building something for the kids as well.

A lot of the setups I've been reading about use an oxygen concentrator instead of a tank. Refurb'd concentrators are readily available and not too expensive. I also like the idea of just being able to run to Home Depot for a refill. I just need a little shed or something in the backyard for storage to reduce the potential for the house going boom.

DaveInDenver 04-26-2014 10:27 AM

I built a frame many years ago, it was done as a TIG practice at my first job (they sold welding gases, MG Industries). It was terrible. I had a fab'd jig but things didn't work like I expected.

Terry's idea for a jig seems a lot more solid than I what I hobbled together which was wood blocks I drilled through and cut in half and then screwed to a plywood table. The only way I would attempt a frame without a jig is with lugs personally, although a track frame is probably not nearly as critical. You can focus on the weld/braze without worrying about how the tube align and are held in place. You at least need some sort of fixture for that I'd think.

But with a full jig holding all the tubes you can make sure things are straight. This was the basic problem with my frame, the rear wheel was off axis to the front, so it tracked odd and drifted left. Not to mention the blow through spots... If I was to try again it would 100% be a lugged steel that was brazed.

smslavin 04-26-2014 04:52 PM

Lugged track frame is what I'd like to do first. Since we've moved downtown, I have this weird urge to find my inner hipster... :hill: :rant: :eek:

Found a few commercial jigs that are pretty awesome. One is done by a guy in Golden, Anvil. The Arctos was also recommended in several places. Pricey stuff but it may be worth it in the long run depending on how deep I get into this.

Trying to figure out what I want to be when I grow up and writing software is not it.

:cheers:

art hog 04-26-2014 05:40 PM

Fat bikkes are a fad. Most bike companys are dropping fat bikes from thier sales line.

DaveInDenver 04-26-2014 06:22 PM

650b is where it's at.

rover67 04-26-2014 11:28 PM

Quote:

Originally Posted by DaveInDenver (Post 249923)
650b is where it's at.

:thumb:


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