Light Duty or Medium Duty Torch Kits?
I built my first lugged frame in a frame building class and am very new to brazing (no experience aside from the class).
I'm hoping that someone can help me make a purchasing decision. I have been reading this thread, http://www.bikeforums.net/archive/in.../t-256180.html, and am under the impression that most people are using light duty torches. Is this true?
I've been shopping around for a torch kit and have narrowed it down to these two kits.
Light Duty: http://www.sjdiscounttools.com/fpw0384-0656.html
Medium Duty: http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT
I noticed that the medium duty torch handle has a built in flash back arrestor while the light duty torch handle does not. Is flash back less of an issue in light duty setups or should a flash back arrestor be added? And is one set at the torch end sufficient or is another at the regulator end recommended?
This question is in regards to lugged construction, but at some point I would like to try to fillet braze. So hopefully one kit will work for both lugged and fillet brazed construction.
I have flashback protectors at the regulators. I am reluctant to say that the small torches are light duty just because they are small. But I guess they mean the torches only work on thin workpieces. It would be silly to put a cutting attachment on my torch. The 100FC torch in the medium set is pretty heavy, but obviously it will work. It's really nice to be able to flick the torch off the work when it is getting hot too fast. A big torch will make that a lot more tiring.
A torch like the Smith AW1A or the Victor J28 or the Esab equivalent will run you more money, but it might be worth it. They are plenty big to do fillet brazing or any brazing you might want to do on a bike.
Thanks for the info! I was thinking of getting the Victor J28 based off of another thread, but thought maybe getting a kit would insure that I don't mismatch parts.
I noticed that someone recommended Victor S-250 series regulators to go with the Victor J28. Any recommendations for the Smith AW1A? And are hoses and tips universal as long as they are the correct brand?
you can get any regulators to go with any torch. Some regulators are made for high gas flow, and you may find that it's hard to adjust them. I'm guessing that is the basis for the recommendation. It's also possible that you wouldn't need to buy adapters to a smaller line with those regulators.
ESAB sells a combo kit with their W200, but IIRC it doesn't have any welding tips, just a cutting attachment. That might save you money over either the smith or Victor. I got a quote for the kit: 558005266 Prest-O-Lite GT-200 Welding & Cutting Outfit $335.00
The tips were $25 each, and you probably want two. I liked the fact that you can get a dual head and a rosebud head for the W200. They may be useful for repair. The don't mention hose, so I suppose you have to buy that separately.
The guy at the welding store indicated he might be willing to trade the cutting torch for some welding tips, but was a little non-specific about that. I really see no reason to have a cutting torch, your needs might be different.
I bought a Smith AW1A because someone offered it on the framebuilder's mailing list. Otherwise I was going to get the ESAB.
I like the Smith "Airline" AW1A myself. It runs a bit more $$$ than a light duty torch, but it's quite versatile and built to last.
You probably don't want any torch that comes in a kit with a cutting torch head. Some of the small aircraft torches will cut, but they tend not to be boxed that way because they are used by a different segment of torch users. You want an aircraft torch, though for lugs etc... you can use a bigger torch also. It just weighs more.
You need anti backflow valves or something truly Biblical may happen to your shop. It won't be locusts. Some guys do not use the flasback arrestors because a properly set up torch (big if) probably won't flash back. Still the hot set-up is probably some heavy lines running from the regulators to flashback arrestors, connected to light hose, connected to the torch. That way you have flash back arrested well before the bottles, and you have a light in the hand hose set. Some folks have FBAs at the mid hose and the regulators. FBAs can stop working.
Without the FBAs at the torch you run the risk of blowing the lines back to the arrestors, but that should not happen. If it does the main risk should be fire.
One should always keep in mind amateur vs. industrial needs. In a domestic setting you are putting at risk your shop, house, family, adjacent dwellings, etc... In a shop that probably is not designed with the idea that high pressure flammable gases will be in use. Extreme care needs to be taken. In a light industrial setting will all concrete floor and wall it is somewhat different.
I've used one of those Victor Firepower setups for a number of years, and I still use the hoses, torch handle and tips. The needles on the regulators didn't return to zero after a while but that never caused any problems. I eventually replaced the regulators with some nice Harris ones purchased brand new off ebay, paid less than $100 for both. I'm not using any flame arrestors but will based on what people are saying in this thread. I've head about the need before but grew complacent which is never a good thing.
You probably could go through a lifetime and never have a flashback as long as you don't run a given orifice way too hard, and are using smaller torches. The real bad news is no one way valves since running the O2 into your Acet can could prove disturbing. But as far as I know the Flashback thingies I have protect against both. Some of the better regs also have one way valves in them, I think...
Reg needles don't even need to be used. According to White, the classy way to set up the torch is to open the handset valves all the way (without loosing the packing) Then open the Acet reg until you can feel the gas coming out of the torch on your cheek (kinda creepy). Then remove torch to safe location and spark it, never use a lighter or match. Then adjust the O2 reg until you get your flame just as you like it. Then boost both a little until the flame is noisy. Then bring the flame back to where you want it with the handset. This ensures not over running the head. Also ensure lowest pressure in the system, which is good all around. This is where you will find out if your regs are good and can hold a steady pressure. It is also important to use enough orifice, because if not you will probably be running the torch hotter, and get more pops. When set up as described one can just turn both handset knobs to equal open and spark both fuel and O2 at once, for fast starts. This is how I learned to do it from small torch videos, your mileage may vary. I certainly like the regulator setting.
Since this might seem to contract what I said, I'll chime in again noting that the Esab kit I recommended has an aircraft type torch that is similar to the other aircraft torches people always recommend. It's a small, light torch with adjustment knobs on the tip end. Doug Fattic mentions it in his list of appropriate torches.
Originally Posted by Peterpan1
Thanks for all the info!
I ended up getting a Victor J-28. I purchased the Victor FB-1 flashback arrestor for the handle, but it turns out that they have different sized connectors. I wasn't able to find any of the sizing info based on the online product description. The sales guy from Weldfabulous recommended a FBR-1 flashback arrestor for the regulator side.
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The J-28 uses 3/8”-24 "A" fittings. The larger torches generally use the larger 9/16"-18 "B" fittings. You can get A to B adapters if necessary, or plumb nearly any reg by swapping to "A" fittings". If you don't plan on using a cutting attachment, I'd strongly encourage the smaller 3/16" hose - it's lighter weight and not nearly as 'stiff' and awkward to use. There is also a short kevlar leader hose available to make life even sweeter, but it's spendy.
I would never recommend the absents of flashback arresters, but I personally don't use them (although I do have reverse flow check valves at the regs). If I were to use a larger torch such as the Victor 100 or 315 w/cutting attachment, then I'd consider the FB arresters a necessity (the 315 handle has FB's built in).
Not to haggle, but I don't agree - especially with noobs.
Originally Posted by Peterpan1
1) (A) It's not uncommon for regulators to fail, either the diaphragm ruptures or the high-to-low-side valve leaks, driving the line pressure to dangerous levels. The low side gauge will show this happening by creeping upwards (and doesn't show any signs of stopping) when the torch handle valves are closed. Suffice to say, NEVER use a regulator that continuously 'creeps' much above your setting when the torch valves are turned off. A 2-3 psi variation is common, but a continuous rise in line pressure is NOT.
(B) When shopping for regs, the gauges can reveal potentially damaged and unsafe regulators. Avoid ANY regulator that display any low side pressure reading - (i.e. a seemingly stuck gauge that does not read ZERO when purged and not in use). This happens when the line pressure rises above the low side gauge's limit and ultimately damages the needle movement. See note (A).
2) First timers should be taught how to read gauges and reference the reading to tip size and desired flame setting.