Frame design decisions - your opinions?
#101
Senior Member
I've been using oxy (via medical oxygen concentrator)/propane for over 5 years exclusively. Fillet brazing. No problems. News to me if it isn't suitable.
#102
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Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
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David- Now that you know that you have been doing the wrong thing for so long should we expect a recall on your frames? Andy (who is trying to not bite his tongue).
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AndrewRStewart
AndrewRStewart
#103
Senior Member
I'll just send out a mass email to all of my customers. "In the case of propane-use induced frame failures, survivors should contact me directly at..."
#104
framebuilder
I’ve come to prefer oxypropane more than oxyacetylene for any framebuilding application including fillet brazing as long as I am using the best propane specific brazing equipment. This was reinforced recently when a student came to make a fillet brazed transportation style of frame in a one week class. He already has an oxyacetylene setup so we started out using mine. He wanted to try propane after learning of its cost savings and buying convenience. It wasn’t long before he preferred it for brazing too – especially fillet brazing. It had been awhile since I had used acetylene to fillet braze (which I started using in 1975) and realized I prefer a multi-port propane flame pattern as well. I started using propane as a fuel in 2004 when we began to build transportation style frames ourselves for a charity project in Ukraine after the XB3 factory in the city of Kharkov stopped making the kind of frames we needed.
However, it is necessary to use propane specific equipment (especially multi-port tips) to get the sharpest and most stable flame pattern. I'll post pictures and explanations in a new separate subject thread so it is easier to refer back to when researching information in the future.
However, it is necessary to use propane specific equipment (especially multi-port tips) to get the sharpest and most stable flame pattern. I'll post pictures and explanations in a new separate subject thread so it is easier to refer back to when researching information in the future.
Last edited by Doug Fattic; 04-19-19 at 08:00 AM.
#105
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Thanks Doug
#106
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The frame has been back from the painters for a few days, built into a bike and ridden twice. Pic below and more on 'show us your builds'
I have to say I am more pleased with it than I expected to be. The 'blemishes' hardly show after powder coating and handling is just how I want it. Cornering is precise - no wandering, over-steer (wheel flop?) or under-steer, it feels very natural.
The ride is stiffer than my other bikes (as expected and intended) which I guess is what helps the handling. I did not expect this bike to be my first choice for longer rides, but after a fast 70 mile club ride yesterday, over a lot of poor road surfaces I didnt feel any more beat up than normal, so maybe it is good for a century or two.
My last build 15 years ago was completed with the help of little more than a couple of books, it was all a bit of a leap in the dark. The internet and this forum have made this build a completely different experience - for the better :-)
Thanks again for all the help and advice.
I already have plans for my next build but will be riding this one for a while before taking the plunge.
Mike
I have to say I am more pleased with it than I expected to be. The 'blemishes' hardly show after powder coating and handling is just how I want it. Cornering is precise - no wandering, over-steer (wheel flop?) or under-steer, it feels very natural.
The ride is stiffer than my other bikes (as expected and intended) which I guess is what helps the handling. I did not expect this bike to be my first choice for longer rides, but after a fast 70 mile club ride yesterday, over a lot of poor road surfaces I didnt feel any more beat up than normal, so maybe it is good for a century or two.
My last build 15 years ago was completed with the help of little more than a couple of books, it was all a bit of a leap in the dark. The internet and this forum have made this build a completely different experience - for the better :-)
Thanks again for all the help and advice.
I already have plans for my next build but will be riding this one for a while before taking the plunge.
Mike
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