RCCrawler Forums

Jeeprockcrawler · 08-22-2005, 12:39 PM

I just when down to the Home Depot and bought a Bernzomatic Cutting/Welding/Brazing touch Kit for $39.95. It uses a mix of Oxygen and MAPP Gas.

Then I bought Bernzomatic Nickel Silver Brazing/Welding Rods designed for carbon and alloy steel.

Now I tryed to practice on a few pieces of 1/8 steel tubing with no result

All I got was the rods nice in black..... :? WTH am I doing wrong?

The flame was a nice blue about 3/4" long and a nice white/Yellow flame about 6" long...and all the happen to the welding rod was the blue coating (FLUX???) was burning off and the rod was not melting....

So was the temp not hot enough? PLEASE HELP>>>I SUCK

Jeeprockcrawler · 08-22-2005, 12:44 PM

Here is a link to the kit
http://www.bernzomatic.com/bernzomat...rnzoProd100044

and to the rods
http://www.bernzomatic.com/bernzomat...rnzoProd100063

Please let me know if I am all flocker up????????

BUBBA069 · 08-22-2005, 01:56 PM

I use a white flux paste and Harris Safety Silv #56 with my propane/oxy kit, its a small brazing wire.

I have never tried the rod you have with a small mapp/oxy or propane/oxy kit.

start out with the mapp gas, get about a 5" flame, then add in the oxy slow. will change to a blue flame, with yellow tip about an 1" to 1-1/2"

seth556 · 10-01-2005, 04:54 PM

Do you know how to weild, where you get the little puttle of metal and put the filler in and go really really slow it's not a quick thing.

SPEED_RACER · 10-01-2005, 08:13 PM

THE metal your trying to weld needs to be red hot.red as in the color glowing red.kind of sounds like it's not hot enough

radishkid · 10-02-2005, 06:20 AM

Guys? He's not welding. He's BRAZING. There is a difference you know. Does he have the correct brazing rod for the application? I'm unsure of the answer, but I believe this may be where he's going with his question.

BultacoJim · 10-02-2005, 07:44 AM

Jeeprockcrawler,

Here is a chart showing the color transitions that metal goes through as it is heated.

The Nickel-Silver Brazing rod you purchased melts at a temperature between 1250 °F and 1750 °F, therefore the metal you are trying to braze should be heated to a “Cherry” color before applying the brazing rod. Brazing is done at temperatures greater than 840°F (450°C) but below the melting point of the metals being joined. Welding is the process of actually melting (temperatures around 2750ºF for steel) the metal at the junction where the two pieces of metal are to be joined at.

Do not attempt to braze up your carefully bent chassis with your first attempts at brazing. Practice for a few hours on some scrap pieces and experiment with your technique. Arc, Mig, & TIG welding (for a right hand person) is usually done left to right. Gas welding (and brazing) is usually done right to left. You hold the torch in your right hand at a 45º angle with the tip of the flame pointing in the direction of travel (to your left if you are right handed). This is to preheat the joint of the two metals you are “joining” together. Do not apply the brazing rod until both metals to be brazed have reached the temperature needed to melt the brazing rod. Make sure you are using flux.

I have always used oxygen/acetylene torches for welding/brazing, but I see no reason why your MAPP/oxygen shouldn’t work. Just make sure you have the flame adjusted properly as per the instructions that came with your Bernzomatic unit.

Take BUBBA069’s advice and purchase some Harris Safety Silv #56. This is better suited for brazing up RC Tubers using Brake line than the brazing rod you purchased. Use this rod to practice with and the more expensive Harris Safety Silv for your “good” stuff.

Info on Harris Safety Silv: http://www.jwharris.com/welref/techguide/silver_braz/

Read Jay’s article: http://rccrawler.com/tuber.htm

Also: http://www.phred.org/~josh/build/brazing.html

Remember: practice, practice, practice

-- Jim

Jeeprockcrawler · 10-02-2005, 07:47 AM

Thank you for all your response. I gave all that up and bought a MIG welded and do all my chassis that way. It is alot easier I do not have to wait for the matel to get hot. Just hit it and its there....LOL...But thanks for the great info. Hope it helps someone.

Speed Demon · 10-02-2005, 10:29 AM

Hi guys.. I too have a question regarding the equipment ..

before I decide to buy.. can I use this type of torch??

and using this type of canister gas.

will it work?? I am using the brass rod instead of the brake line tube for the begining.. another thing is, if I cant find a MAPP gas, can I use the Propane gas instead??
thanks

BultacoJim · 10-02-2005, 12:50 PM

Speed Demon,

There are two broad classes of gas torches: Air-Fuel and Oxy-Fuel (oxygen-fuel).
A propane torch is an example of an Air-Fuel torch. As the fuel gas moves through the torch body enough air is mixed with it to enable it to burn with a clean flame.
Oxy-Acetylene and Oxy-Mapp Gas are examples of Oxy-Fuel torches. In them, pure oxygen is used instead of air. This is done to create a higher temperature flame.
Since air is composed of about 70% nitrogen and 30% oxygen and since all gasses involved in the flame are heated to a high temperature, it is apparent that using part of the heat of the flame to heat up the 70% nitrogen (which contributes nothing to the production of heat) is wasteful. So while it is possible to achieve high temperatures with an air torch , you can do even better with an gas/oxygen torch and there is no waste of fuel to heat the nitrogen.

The maximum possible temperature of a propane/air torch is 3700 F, this is after waiting, & waiting, & waiting.

The maximum possible temperature of a mapp/gas torch is 4700 F aka "supertorch"

The maximum possible temperature of a Oxy-Acetylene torch is 6296 °F (Rrr Rrr

this is a torch)

Some metals are good conductors – and consequently carry off heat faster into cooler areas. Others are poor conductors and tend to retain heat and overheat readily. The good conductors will need more heat than the poor conductors, simply because they dissipate the heat more rapidly.

When you do any brazing, you want to apply the heat, braze and be done with it (quickly). You do not want to set there applying heat for a long period of time. All welding/brazing will cause heat-affected zones (HAZ) that will compromise the weldment by the coarsening or dissolution of precipitates in the alloy of the parent metals. Translation: the brazed or welded joint will fail “next” to the welded/brazed union.

Yes the air-fuel torch can be used to braze, but you risk changing the metal characteristics of the metal you are brazing by applying the heat too long (i.e. making it weaker). With an Oxy-fuel torch, you will be able to apply the heat, braze and be done.

An example: Bicycle tubesets comparable to Reynolds 531 will have a workable temperature limit of 2000 °F. Some tubesets have a workable temperature limit as low as 1300 °F, after which the properties of the tubes will change from heat. Since most brass brazing rod melts at about 1300 F or higher, this is why on super high-end bikes, silver is used for brazing. The high end of mountain bikes are either welded using Tig or Mig to eliminate any failures from heat saturation that torch welding can cause.

Speed Demon · 10-02-2005, 05:31 PM

BultacoJim,

Wow! that was a detail explanation. Thanks.
After reading it, I am not too sure what to do again.

Getting the Oxy/Acetylene torch might be the solution. But if I only use it to fulfill my hobby, that might be costly to me. Furthermore, I know nothing about welding. The most I am able to fork ou t is probably the MAPP gas.is that enough for brake line brazing?

I may try JB Weld too.. has anyone tried that?? I know its too slow..

08-22-2005, 12:39 PM	#1
Jeeprockcrawler Rock Stacker Join Date: Aug 2005 Location: Between 2 Rocks Posts: 65	I just bought the following.....HELP!!!! I just when down to the Home Depot and bought a Bernzomatic Cutting/Welding/Brazing touch Kit for $39.95. It uses a mix of Oxygen and MAPP Gas. Then I bought Bernzomatic Nickel Silver Brazing/Welding Rods designed for carbon and alloy steel. Now I tryed to practice on a few pieces of 1/8 steel tubing with no result All I got was the rods nice in black..... :? WTH am I doing wrong? The flame was a nice blue about 3/4" long and a nice white/Yellow flame about 6" long...and all the happen to the welding rod was the blue coating (FLUX???) was burning off and the rod was not melting.... So was the temp not hot enough? PLEASE HELP>>>I SUCK

10-02-2005, 10:29 AM	#9
Speed Demon Pebble Pounder Join Date: Sep 2005 Location: somewhere on earth Posts: 188	I too have a question. Hi guys.. I too have a question regarding the equipment .. before I decide to buy.. can I use this type of torch?? and using this type of canister gas. will it work?? I am using the brass rod instead of the brake line tube for the begining.. another thing is, if I cant find a MAPP gas, can I use the Propane gas instead?? thanks Last edited by Speed Demon; 10-02-2005 at 10:49 AM.

08-22-2005, 12:44 PM	#2
Jeeprockcrawler Rock Stacker Join Date: Aug 2005 Location: Between 2 Rocks Posts: 65	Here is a link to the kit http://www.bernzomatic.com/bernzomat...rnzoProd100044 and to the rods http://www.bernzomatic.com/bernzomat...rnzoProd100063 Please let me know if I am all flocker up????????

08-22-2005, 01:56 PM	#3
BUBBA069 Pebble Pounder Join Date: Jan 2005 Location: st. louis Posts: 115	I use a white flux paste and Harris Safety Silv #56 with my propane/oxy kit, its a small brazing wire. I have never tried the rod you have with a small mapp/oxy or propane/oxy kit. start out with the mapp gas, get about a 5" flame, then add in the oxy slow. will change to a blue flame, with yellow tip about an 1" to 1-1/2"

10-01-2005, 04:54 PM	#4
seth556 Rock Stacker Join Date: Feb 2005 Location: Orlando, FL Posts: 73	Do you know how to weild, where you get the little puttle of metal and put the filler in and go really really slow it's not a quick thing.

10-01-2005, 08:13 PM	#5
SPEED_RACER Quarry Creeper Join Date: Nov 2004 Location: MANVILLE Posts: 413	THE metal your trying to weld needs to be red hot.red as in the color glowing red.kind of sounds like it's not hot enough

10-02-2005, 06:20 AM	#6
radishkid Quarry Creeper Join Date: Nov 2004 Location: In the saddle... Posts: 473	Guys? He's not welding. He's BRAZING. There is a difference you know. Does he have the correct brazing rod for the application? I'm unsure of the answer, but I believe this may be where he's going with his question.

10-02-2005, 07:44 AM	#7
BultacoJim Pebble Pounder Join Date: Oct 2004 Location: Colorado Posts: 165	Jeeprockcrawler, Here is a chart showing the color transitions that metal goes through as it is heated. The Nickel-Silver Brazing rod you purchased melts at a temperature between 1250 °F and 1750 °F, therefore the metal you are trying to braze should be heated to a “Cherry” color before applying the brazing rod. Brazing is done at temperatures greater than 840°F (450°C) but below the melting point of the metals being joined. Welding is the process of actually melting (temperatures around 2750ºF for steel) the metal at the junction where the two pieces of metal are to be joined at. Do not attempt to braze up your carefully bent chassis with your first attempts at brazing. Practice for a few hours on some scrap pieces and experiment with your technique. Arc, Mig, & TIG welding (for a right hand person) is usually done left to right. Gas welding (and brazing) is usually done right to left. You hold the torch in your right hand at a 45º angle with the tip of the flame pointing in the direction of travel (to your left if you are right handed). This is to preheat the joint of the two metals you are “joining” together. Do not apply the brazing rod until both metals to be brazed have reached the temperature needed to melt the brazing rod. Make sure you are using flux. I have always used oxygen/acetylene torches for welding/brazing, but I see no reason why your MAPP/oxygen shouldn’t work. Just make sure you have the flame adjusted properly as per the instructions that came with your Bernzomatic unit. Take BUBBA069’s advice and purchase some Harris Safety Silv #56. This is better suited for brazing up RC Tubers using Brake line than the brazing rod you purchased. Use this rod to practice with and the more expensive Harris Safety Silv for your “good” stuff. Info on Harris Safety Silv: http://www.jwharris.com/welref/techguide/silver_braz/ Read Jay’s article: http://rccrawler.com/tuber.htm Also: http://www.phred.org/~josh/build/brazing.html Remember: practice, practice, practice -- Jim

10-02-2005, 07:47 AM	#8
Jeeprockcrawler Rock Stacker Join Date: Aug 2005 Location: Between 2 Rocks Posts: 65	Thank you for all your response. I gave all that up and bought a MIG welded and do all my chassis that way. It is alot easier I do not have to wait for the matel to get hot. Just hit it and its there....LOL...But thanks for the great info. Hope it helps someone.

10-02-2005, 12:50 PM	#10
BultacoJim Pebble Pounder Join Date: Oct 2004 Location: Colorado Posts: 165	Speed Demon, There are two broad classes of gas torches: Air-Fuel and Oxy-Fuel (oxygen-fuel). A propane torch is an example of an Air-Fuel torch. As the fuel gas moves through the torch body enough air is mixed with it to enable it to burn with a clean flame. Oxy-Acetylene and Oxy-Mapp Gas are examples of Oxy-Fuel torches. In them, pure oxygen is used instead of air. This is done to create a higher temperature flame. Since air is composed of about 70% nitrogen and 30% oxygen and since all gasses involved in the flame are heated to a high temperature, it is apparent that using part of the heat of the flame to heat up the 70% nitrogen (which contributes nothing to the production of heat) is wasteful. So while it is possible to achieve high temperatures with an air torch , you can do even better with an gas/oxygen torch and there is no waste of fuel to heat the nitrogen. The maximum possible temperature of a propane/air torch is 3700 F, this is after waiting, & waiting, & waiting. The maximum possible temperature of a mapp/gas torch is 4700 F aka "supertorch" The maximum possible temperature of a Oxy-Acetylene torch is 6296 °F (Rrr Rrr this is a torch) Some metals are good conductors – and consequently carry off heat faster into cooler areas. Others are poor conductors and tend to retain heat and overheat readily. The good conductors will need more heat than the poor conductors, simply because they dissipate the heat more rapidly. When you do any brazing, you want to apply the heat, braze and be done with it (quickly). You do not want to set there applying heat for a long period of time. All welding/brazing will cause heat-affected zones (HAZ) that will compromise the weldment by the coarsening or dissolution of precipitates in the alloy of the parent metals. Translation: the brazed or welded joint will fail “next” to the welded/brazed union. Yes the air-fuel torch can be used to braze, but you risk changing the metal characteristics of the metal you are brazing by applying the heat too long (i.e. making it weaker). With an Oxy-fuel torch, you will be able to apply the heat, braze and be done. An example: Bicycle tubesets comparable to Reynolds 531 will have a workable temperature limit of 2000 °F. Some tubesets have a workable temperature limit as low as 1300 °F, after which the properties of the tubes will change from heat. Since most brass brazing rod melts at about 1300 F or higher, this is why on super high-end bikes, silver is used for brazing. The high end of mountain bikes are either welded using Tig or Mig to eliminate any failures from heat saturation that torch welding can cause.

10-02-2005, 05:31 PM	#11
Speed Demon Pebble Pounder Join Date: Sep 2005 Location: somewhere on earth Posts: 188	BultacoJim, Wow! that was a detail explanation. Thanks. After reading it, I am not too sure what to do again. Getting the Oxy/Acetylene torch might be the solution. But if I only use it to fulfill my hobby, that might be costly to me. Furthermore, I know nothing about welding. The most I am able to fork ou t is probably the MAPP gas.is that enough for brake line brazing? I may try JB Weld too.. has anyone tried that?? I know its too slow..

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