acetylene vs propane

[Krus]

Here are another couple of low output regulators(single stage) that may interest people from NZ/Aus, as our tanks have different connectors.

https://www.nichegas.com.au/product/...en-601ed-4-o2/
https://www.nichegas.com.au/product/...-601e-1-5-lpg/

Just in contact with them now and apparently the oxy reg has a max output of 100kpa, that would be more than enough for brazing?
They also sell connection adaptors to be able to use American torches and hoses.

[jclay]

Here are another couple of low output regulators(single stage) that may interest people from NZ/Aus, as our tanks have different connectors.

https://www.nichegas.com.au/product/...en-601ed-4-o2/
https://www.nichegas.com.au/product/...-601e-1-5-lpg/

Just in contact with them now and apparently the oxy reg has a max output of 100kpa, that would be more than enough for brazing?
They also sell connection adaptors to be able to use American torches and hoses.

It's enough for acetylene brazing. Not sure about LP; it's enough for the fuel but I don't remember what sort of O2 pressure was required for my torches (midget, av-jet, aw1a). Others here will know.

I'm gonna add my perspective: I see LP & oxygen concentrator decisions as properly driven only by logistics & regulations or fear of acetylene (which is not terribly merited given that you should know what you're doing before firing up). We all have our preferences but at the end of the day, in the equipment spectrum being considered (easily up through Vic 100 class torches), chasing brazing performance via fuel gas, torch choice or hoses is a poor use of time and resources. Practice and experience make you good; the super-duperest torch or hose or fuel gas, won't.

My brazing skills would have gone farther, faster if all the time and $ I spent chasing the perfect torch, fuel & hose had, instead, been spent purchasing practice material and practicing. And that's using equipment requiring zero modifications or doo dads to make it all work. For the record I settled not on my favorite torch (Midget), or my second favorite (Av-Jet); I settled on my third favorite torch (AW1A, which is, in the hand, like a bunch of others) because a cutting head was available.

[e-RICHIE]

Ah Grasshopper -

<snip> We all have our preferences but at the end of the day, in the equipment spectrum being considered (easily up through Vic 100 class torches), chasing brazing performance via fuel gas, torch choice or hoses is a poor use of time and resources. Practice and experience make you good; the super-duperest torch or hose or fuel gas, won't.

My brazing skills would have gone farther, faster if all the time and $ I spent chasing the perfect torch, fuel & hose had, instead, been spent purchasing practice material and practicing. <cut>

If only (sic) people understood this ^ at the beginning of the online framebuilding tsunami zeitgeist when so many were veering into this trade with no experience, and without the patience to learn the basics. Everyone wanted to be a framebuilder after asking some questions, buying a fixture, blogging about it, and starting a label.

Your words are a mellifluous sound to both of my ears.

To surpass the master is to repay the debt.

[jclay]

Expanding just a little:

1) Being able to gas weld has been handy for lug modifications, making small framebuilding fixtures, unrelated shop work); you can't weld steel with LP (according to everything I've read).

2) Round bodied torches are slippery and easily rotate in sweaty (or not) hands. That's the most compelling reason to use ultra lightweight hoses....but, I use conventional (T grade) 1/4" BB hoses with an AB adapter at the AW1A and I hold the torch by those adapters (not the round body) which won't rotate in my hands (like this, ignoring the rectangular torch bodies...hmmmm: https://www.tinmantech.com/faqs/weld...h-fittings.php

I prefer the extra length that grip location affords when using AW1A or similar, too.

I'd have preferred 3/16" hose but my second set of Smith Kevlar hoses didn't have the courtesy to start leaking on a day that my LWS had 3/16" hoses in stock! I suspect that the Tinman lightweight hoses are tougher. I ended up with 1/4" BB T-grade hose (I still had LP as well as Acetylene) + AB adapters ('cause that's what was available) which ended up being an excellent accident though 3/16 BB hose would have been even better! Conventional hoses are tough, durable.

3) The Meco Midget is rectangular and if you configure it so that the tip tube bend is co-planar with the torch body you'll find that it doesn't rotate in the hands, isn't at all slippery, and that the valves are perfectly located for thumb and forefinger, one handed adjustment without repositioning your hand on the torch (a minor preference...it didn't make me a better operator). In terms of being an essentially mass-less wand you can't really beat it. I prefer the longer tip tubes available from Tinman. It does require higher O2 pressure if using LP (LP requires several times more O2 than acetylene); can't remember how much higher and it's inconsequential if using compressed gasses but for garden variety oxygen concentrators it might be an issue.

Doug has done a seriously fabulous job with the LP/concentrator/tips work so if logistics, regulations or comfort level favor that approach, go for it. Just don't make the mistake of thinking that LP will make you a better operator. Only practice does that.

[bikebones]

I have been using the multiports tips for a while and I was thinking if anyone has compared how small is the heating area of a recessed oxypropane tip compared to the multiports. I notice with multiports I have to be a lot faster in my movements to control the brass melting to form a constant fillet. It came to my mind that maybe the recessed tips get the hottest part of the heat in a smaller area hence simulating more a oxy acetilene flame for fillet brazing.

thanks for your knowledge
Francisco Serrano
Bristol UK

[Doug Fattic]

I have been using the multiports tips for a while and I was thinking if anyone has compared how small is the heating area of a recessed oxypropane tip compared to the multiports. I notice with multiports I have to be a lot faster in my movements to control the brass melting to form a constant fillet. It came to my mind that maybe the recessed tips get the hottest part of the heat in a smaller area hence simulating more a oxy acetilene flame for fillet brazing.

thanks for your knowledge
Francisco Serrano
Bristol UK

Francisco I haven't had a chance to get to your question because I'm in the middle of teaching another 3 week frame building class. I'm going to presume your multi-jet propane tips came from Welder's Warehouse in the UK? The reason I ask is that every brand of multi-port tips have a bit different side flame pattern. In the States the most common multi-port tips are Meco, Paige and G-tec. It has been awhile since I've used the ones from Welder's Warehouse. Each of these brands have a different size and shape of side holes that provide a different amount heat compared to the central flame.

I've observed the same thing that a multi-port tip has a wider heating area than a single recessed tip (both designed to use with propane). And how much heat beyond the primary center flame depends on the brand. The Meco tips have the smallest side holes and as a result act more like a single flame. What I recall is that the WW tips are similar to the Mecos but just a bit bigger.

The advantage of a multi-port tip is of course that it is easier to light and more difficult for gas bounce back to blow out your flame. This can especially be a problem when fillet brazing and your small tip will be very close to your work. So it is an advantage to use a multi-port tip especially when fillet brazing. However their disadvantage is a bit wider heating pattern. My solution was to use a smaller multi-port tip when fillet brazing. When I am brazing a forged dropout to a chain stay or fork blade, I prefer the slightly wider heat patter a multi-jet tip provides.

We all get used to what equipment we are using. Sometimes I reach for my Victor Ten series of recessed single flame tips just for the reason you mentioned that the heat pattern is in a smaller area. I just have to be aware of the angle of my flame that gas bounce back doesn't blow out the flame.

[bikebones]

Francisco I haven't had a chance to get to your question because I'm in the middle of teaching another 3 week frame building class. I'm going to presume your multi-jet propane tips came from Welder's Warehouse in the UK? The reason I ask is that every brand of multi-port tips have a bit different side flame pattern. In the States the most common multi-port tips are Meco, Paige and G-tec. It has been awhile since I've used the ones from Welder's Warehouse. Each of these brands have a different size and shape of side holes that provide a different amount heat compared to the central flame.

I've observed the same thing that a multi-port tip has a wider heating area than a single recessed tip (both designed to use with propane). And how much heat beyond the primary center flame depends on the brand. The Meco tips have the smallest side holes and as a result act more like a single flame. What I recall is that the WW tips are similar to the Mecos but just a bit bigger.

The advantage of a multi-port tip is of course that it is easier to light and more difficult for gas bounce back to blow out your flame. This can especially be a problem when fillet brazing and your small tip will be very close to your work. So it is an advantage to use a multi-port tip especially when fillet brazing. However their disadvantage is a bit wider heating pattern. My solution was to use a smaller multi-port tip when fillet brazing. When I am brazing a forged dropout to a chain stay or fork blade, I prefer the slightly wider heat patter a multi-jet tip provides.

We all get used to what equipment we are using. Sometimes I reach for my Victor Ten series of recessed single flame tips just for the reason you mentioned that the heat pattern is in a smaller area. I just have to be aware of the angle of my flame that gas bounce back doesn't blow out the flame.

Doug thanks so much once again for your knowledge. I will add a couple of recessed tips to my collection aiming for better fillets

Francisco Serrano
Bristol

[smontanaro]

Coming very late to this thread and yes, know I'm replying to an 8yo post, but I am an excellent example of the student(s) Doug described here:

The majority of my framebuilding class students struggle in the beginning with their brazing motions. Some are not naturally gifted with coordination.

Maybe that's why I now ride a bike instead of playing ball sports. Riding a bike requires much less coordination. ;)

I finished Doug's class recently. I could sorta do the big stuff, but Doug did all the fine work. I have a nearly complete brazing setup, just lacking an oxygen source, so hopefully I will be able to start practice melting metal again soon. (Why doesn't Facebook do a better job of notifying sellers that they have a fish on the line???)



I'm in the midst of switching from Flickr to Google Photos. Please let me know if the above image doesn't display.

[TonyP]

Coming very late to this thread and yes, know I'm replying to an 8yo post, but I am an excellent example of the student(s) Doug described here:



Maybe that's why I now ride a bike instead of playing ball sports. Riding a bike requires much less coordination. ;)

I finished Doug's class recently. I could sorta do the big stuff, but Doug did all the fine work. I have a nearly complete brazing setup, just lacking an oxygen source, so hopefully I will be able to start practice melting metal again soon. (Why doesn't Facebook do a better job of notifying sellers that they have a fish on the line???)



I'm in the midst of switching from Flickr to Google Photos. Please let me know if the above image doesn't display.

Looks good. Got a coupla questions...

Is all the brazing done? You planning on painting it and what color?

Have you ridden it yet and if yes, how's it ride.

I built the bike that I've been riding about a year now and want to tell you that no matter how much you enjoy riding now it's gonna pale compared to riding a bike that you built yourself.

[smontanaro]

Looks good. Got a coupla questions...

Is all the brazing done? You planning on painting it and what color?

Have you ridden it yet and if yes, how's it ride.

I built the bike that I've been riding about a year now and want to tell you that no matter how much you enjoy riding now it's gonna pale compared to riding a bike that you built yourself.

Tony,

Yes, the brazing is all finished. I've not yet ridden it. I have one more thing to do – drill and tap for the cable guide (hopefully today or tomorrow) – before I can ride it on rollers (still too much salt on the ground here to ride a nekked bike outside).

As for paint, Doug and I discussed it ever-so-briefly during the class, but I've not yet decided exactly what I'll do yet. I'm leaning toward blue (that covers a lot of ground ;)). My family name (Montanaro) has yielded two nicknames (Monty – my dad, and Monte – my son, Chris). I'm thinking of maybe "MONTI Special" in Masi-like fonts. ¯\_(ツ)_/¯

[smontanaro]

I'm still working my way through 19 pages of this thread...

I am thinking that the day you are here we will do a rear triangle the old British way before expensive fixtures with a true wheel, a straight edge with an adjustable pointer and a homemade T tool. It is a very accurate method just slower.

I would be interested in seeing pictures and/or description of this method. As Doug is aware, I don't have a fixture of any sort at this point. Understanding alternatives would be useful. I'm in no great hurry. My next few tasks involve repairs or adaptations of existing frames, not construction of a new frame.

Skip

[smontanaro]

I've not yet ridden it.

Still not finished, but I did manage to get it up on rollers today with the rear derailleur connected (no brakes, no front derailleur). Another small milestone reached...

[TonyP]

Still not finished, but I did manage to get it up on rollers today with the rear derailleur connected (no brakes, no front derailleur). Another small milestone reached...

Skip, when I got mine built I gave it a coat of Harbor Freight primer and that got me thru half the summer before the primer started failing. At that point tho I had to strip it all down and re-prime before painting.