Thanks to your book and MAP gas I successfully completed my Cyclocross frame and bike in 2010 and at 263lbs. at the time I put that bike through a bunch of stress so I can attest to the strength of your construction techniques. Frame components from NOVA Cycles their monthly specials! Many Thanks for great book and videos!
@barbalote2 Basically, we heat the steel until it reaches the melting temperature of the silver brazing alloy. The molten alloy gets pulled into space between the lug and tubes via capillary action where it froms a very strong metallurgic (alloy) bond with the steel. If done properly (few voids) the resulting joint is stronger than a welded joint.
I think a MAP-air flame is around 2500 F. Silver has a low melting point and flows into small cracks like water. For lugged bicycle joints, silver cannot be beat. You can use brass but it doesn't penetrate deep into the lug as good as silver. Furthermore you will need to use an oxy-acetylene torch for brass because it has a higher melting temp.
MAPP is *definitely* hot enough for brass brazing. The right torch and some refractory bricks help a lot in cutting down the time required, but smaller parts can be done in open air with relative ease.
Very impressive! I recall reading that one can braze a bike frame using MAPP gas, but this is the first time I've seen it done. I wonder how the process and results vary with the temperature of the frame. I noticed it looked a cold winter in the background. I know my welds tend to come out a lot better if the entire area is pre-heated.
I think people are here(like me!) because they're looking into (attempting) brazing without full blown oxy acetylene rigs. In the absence of that, MAPP seems like the most common option. Do you have any suggestions that aren't acetylene? Fair if you think acetylene is the minimum though.
Last time I refilled my oxy-acetylene setup, oxygen is ridiculously cheap compared to acetylene. I was told the main US producer of acetylene had a huge explosion that destroyed the plant, so acetylene went up in price by something like 3x.
@filbone @filbone It is possible to joint tubes without a lug. It is called fillet brazing and it is a bit harder to pick up than lugged brazed frames. Generally, fillet brazing is performed with brass filler rather than silver. Brass requires on oxy-fuel torch. Fillet brazing with silver is controversial. Recycling tubes from other frames itsn't a good idea (I found out the hard way). Your savings in money is offest by alot more time and labor.
If you turn the lights down very low you should see a fait red glow when the steel is ready for brazing. Eventually I will build a proper shop so I can make a good vid about this.
@activenetzwerke You could probably use the MAPP torch for blueing or what not, but usually gun barrels are pretty thick walled. I doubt you could get a gun barrel up to brazing temp (1200 degrees F) with a MAPP torch.
So then, Oxy-acetylene is a more desirable fuel? Should a 000 tip be used? And neutral flame? Great filming btw. I could actually see what was going on. Hard to see the details because of resolution though.
@phisean The method is similar to that decribed in the Paterek Manual, only he prefers Oxy-ace to MAPP-air. He also describes a method in which you use movements of the torch to draw filler into the joint, and the in the method he decribes, not all filler fills the joint simultaneously. Rather it is piecemeal like the method I use, only because you can heat a bit more evenly with oxy-ace, he would need to use fewer iterations. I do not have stress testing data.
Harris Safety Silv 56 is 56% silver. You can buy five 18" rods for $35 which is more than enough for an entire frame in the hands of a practiced brazier. Harris Safety Siv 45 (45% silver) will also works, is cheaper but does not flow as well as 56%. Do not use low silver (25% or less) or phos copper as these are meant for copper and make weak joints with steels.
@phisean Xrays? no. Beat the hell out of it? yes. The steel tubes fail before the lugged joint does. What you say is about the non-uniform heat source is true. In vids uploaded by pros using oxy-acetylene, it is apparent that they aren't even able to introduce all filler alloy at one time. The lugged joint (provided the lug is big enough) has a very high margin of safety.
Is this a good idea? You've got a non-uniform heat source, meaning areas of the silver crystallise at different rates and create polymorphs resulting in a disjointed silver matrix. Is this not like building-in fractures which will become all too apparent if the joint is stressed. Have you done a cross section and xrayed the joint or beat hell out of it to see where it broke?
@mchimonas Thanks for replying. Is this method discussed in the brazing and soldering book you referenced in another video or is there any stress testing research I can read? Thanks
@Psycojose Any oxy-fuel (oxy-propane, oxt-acetylene is going to be much hotter than an air-fuel flame--I prefer oxy propane to oxy-acetylene. propane is cheaper and safer then acetyelene--the point of this video is to show that you can do an okay job with mapp-air which is cheap). In regards to oxy-fuel torch tip sizes, you want a relative large flame. I use a #4 (victor sizes) for lugged joints. Of course there are six or so different sizing schemes just to create confusion.
@Paulhenri80 Here in the U.S., the overall price for small quatities of oxygen and propane is cheaper than for small quantities of oxygen and acetyelene. I cannot make any assessments about bulk purchases or purchases in the EU as the economics and regulations are quite different. Sorry.
Used your book and same methods. Ive been riding and abusing both frames i built for touring for two years now and they are still rock solid. Thanks
Thanks to your book and MAP gas I successfully completed my Cyclocross frame and bike in 2010 and at 263lbs. at the time I put that bike through a bunch of stress so I can attest to the strength of your construction techniques. Frame components from NOVA Cycles their monthly specials! Many Thanks for great book and videos!
Thanks for the video. I bought your book last week, and I've learned a lot from it so far, but seeing it done on video is extremely helpful.
Nicely done. Clear and concise. Great info. Thank you.
@barbalote2 Basically, we heat the steel until it reaches the melting temperature of the silver brazing alloy. The molten alloy gets pulled into space between the lug and tubes via capillary action where it froms a very strong metallurgic (alloy) bond with the steel. If done properly (few voids) the resulting joint is stronger than a welded joint.
I think a MAP-air flame is around 2500 F. Silver has a low melting point and flows into small cracks like water. For lugged bicycle joints, silver cannot be beat. You can use brass but it doesn't penetrate deep into the lug as good as silver. Furthermore you will need to use an oxy-acetylene torch for brass because it has a higher melting temp.
I've done MAPP/air brazing with brass, but not on frame lugs. For smaller-diameter stuff like racks, seatstays, and chainstays, it works fine!
MAPP is *definitely* hot enough for brass brazing. The right torch and some refractory bricks help a lot in cutting down the time required, but smaller parts can be done in open air with relative ease.
THANKS for great vid!
Very impressive! I recall reading that one can braze a bike frame using MAPP gas, but this is the first time I've seen it done. I wonder how the process and results vary with the temperature of the frame. I noticed it looked a cold winter in the background. I know my welds tend to come out a lot better if the entire area is pre-heated.
Thank you for sharing the information. Thank you, Rock on
Just FYI if anyone is trying something like this. Don't use map gas. Use a turbo torch with acetylene
I think people are here(like me!) because they're looking into (attempting) brazing without full blown oxy acetylene rigs. In the absence of that, MAPP seems like the most common option. Do you have any suggestions that aren't acetylene? Fair if you think acetylene is the minimum though.
Last time I refilled my oxy-acetylene setup, oxygen is ridiculously cheap compared to acetylene. I was told the main US producer of acetylene had a huge explosion that destroyed the plant, so acetylene went up in price by something like 3x.
@filbone @filbone It is possible to joint tubes without a lug. It is called fillet brazing and it is a bit harder to pick up than lugged brazed frames. Generally, fillet brazing is performed with brass filler rather than silver. Brass requires on oxy-fuel torch. Fillet brazing with silver is controversial. Recycling tubes from other frames itsn't a good idea (I found out the hard way). Your savings in money is offest by alot more time and labor.
If you turn the lights down very low you should see a fait red glow when the steel is ready for brazing. Eventually I will build a proper shop so I can make a good vid about this.
just read your book excellent tks
@activenetzwerke You could probably use the MAPP torch for blueing or what not, but usually gun barrels are pretty thick walled. I doubt you could get a gun barrel up to brazing temp (1200 degrees F) with a MAPP torch.
Good demo. Thanks. Next time using a solid background, something black, or even cardboard would help a lot.
Can Romex Wire be strong enough to use as a brazing rod? To reweld the top of the cr-mo frame that was cut off and repositioned?
Awesome video
So then, Oxy-acetylene is a more desirable fuel? Should a 000 tip be used? And neutral flame? Great filming btw. I could actually see what was going on. Hard to see the details because of resolution though.
Well done.
@phisean The method is similar to that decribed in the Paterek Manual, only he prefers Oxy-ace to MAPP-air. He also describes a method in which you use movements of the torch to draw filler into the joint, and the in the method he decribes, not all filler fills the joint simultaneously. Rather it is piecemeal like the method I use, only because you can heat a bit more evenly with oxy-ace, he would need to use fewer iterations. I do not have stress testing data.
Harris Safety Silv 56 is 56% silver. You can buy five 18" rods for $35 which is more than enough for an entire frame in the hands of a practiced brazier. Harris Safety Siv 45 (45% silver) will also works, is cheaper but does not flow as well as 56%. Do not use low silver (25% or less) or phos copper as these are meant for copper and make weak joints with steels.
@phisean Xrays? no. Beat the hell out of it? yes. The steel tubes fail before the lugged joint does. What you say is about the non-uniform heat source is true. In vids uploaded by pros using oxy-acetylene, it is apparent that they aren't even able to introduce all filler alloy at one time. The lugged joint (provided the lug is big enough) has a very high margin of safety.
Is this a good idea? You've got a non-uniform heat source, meaning areas of the silver crystallise at different rates and create polymorphs resulting in a disjointed silver matrix. Is this not like building-in fractures which will become all too apparent if the joint is stressed. Have you done a cross section and xrayed the joint or beat hell out of it to see where it broke?
@mchimonas
Thanks for replying. Is this method discussed in the brazing and soldering book you referenced in another video or is there any stress testing research I can read? Thanks
@Psycojose Any oxy-fuel (oxy-propane, oxt-acetylene is going to be much hotter than an air-fuel flame--I prefer oxy propane to oxy-acetylene. propane is cheaper and safer then acetyelene--the point of this video is to show that you can do an okay job with mapp-air which is cheap). In regards to oxy-fuel torch tip sizes, you want a relative large flame. I use a #4 (victor sizes) for lugged joints. Of course there are six or so different sizing schemes just to create confusion.
@Psycojose neutral or slightly reducing (carburizing) should do.
@jimgskoop You should post a video about rack building or MAP-air brass brazing.
what metals are you brazing? chrome-moly?stainless?mild steel? kind of helpful if you know what base metal you are working with.
In this example, CRMO, but the methods presented here will work with all three of the metals you mentioned, (with some slight variation).
thanks...
man I have been having trouble with finding the right silver rods what kind r u working with and how much thanks
Where do you buy those tube?
That's how flux should be use, thank you.
How big is your MAPP gas tank? And how much are you using for a frame?
Also, look below. There is someone below who commented that he has a company that makes brazing rods. His phone number is listed.
@espcommunity you can probably get 40 min or longer of burn time with one bottle. With practice, you can build a whole frame with one bottle.
Hi,
So why did you used silver brazing instead of other soldering method? Are there any advantages to it?
Thanks
@blackhole1889 Yes, that's me. Glad you liked it.
What type of silver solder are you using? Is it the cadmium free stuff?
I usually use either BAg-5 (45% silver) or BAg-7 (56% silver); both are cadmium free.
Great to see the technique. Shame the poor vid quality blurs the silver flowing view.
@Paulhenri80 Here in the U.S., the overall price for small quatities of oxygen and propane is cheaper than for small quantities of oxygen and acetyelene. I cannot make any assessments about bulk purchases or purchases in the EU as the economics and regulations are quite different. Sorry.
damn, nicholas cage can braze pretty well!
Where can I buy lugs from please ? what size also ?
Frame building supply.com or nova-cycles.com
I recommend framebuildingsupply the owner is awesome give him a call he will help you choose the lugs and the right size tubing
Kevin zz many thanks
Sorry is framebuildersupply.com
What silver solder are you using? Thanks.
harris safety silv 56
why don't you use a fixture for alignment?
thanks, if you have any questions or there is a passage in the book that needs clarification, please drop me a line.
Do a google search and see if there is an "Airgas" franchise near where you live. They should have it.
Doing it outside in the cold, you are losing a lot of heat.
so what's going on?
no gloves?
Yikes
SORRY you made a serious mistake. You handled "clean" parts with your bare hands which have natural body and skin oil on them. WEAR GLOVES.