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2002 Framebuilding Workshop
12 January 2002

It's become somewhat of an annual event now to have a framebuilding workshop in January at Jerry Onufer's house on Tiger Mountain in Issaquah. It originally started as a design lecture, but now has evolved into more of a hands-on affair. This year Jerry was teaching the technique of MAPP gas brazing. Using materials you can buy at the hardware store for under $50 and techniques that take just a few minutes to learn you can do most of the brazing required to install cable stops, brackets and even build a complete bike. As testimony to this Don Hoskisson brought pictures of the Tour Easy clone he built after attending the workshop 2 years ago. This type of brazing is can come in handy. Besides being able to brag to your friends that you can "fuse steel with fire" you'll also be able to fabricate many metal parts that you would have to buy or do without otherwise.

The equipment required for MAPP gas brazing includes:
1/16" Brass Rod - from any welding supply store at about 25 cents ea
Boric Acid - from any grocery or pharmacy for about $5
MAPP gas tank - from any hardware store for about $5
Torch head - Get the good one with pushbutton igniter - about $30
Firebricks - Get 2 or more for about $1 each

Note: DON'T buy brazing flux or fluxed rod. Although it has boric acid it has alot of other additives that mess things up for MAPP brazing

Our host Jerry Onufer. All of these pictures were taken in Jerry's basement where he has a complete wood and metal-working shop as well as a full-size brazing setup. Today he was showing us how to get by without all that stuff. The pole stand in the background is his holding stand for brazing work.

Show and Tell: Nick's new bike - Formerly the "Pacific Hammer" - now the "NonsPacific Hammock". Click here for more details.

Show and Tell: Item 2. Dick Stemwell brought this transmission that uses 2 BMX freewheels with the chain wrapping around on opposite sides to produce continuous rotation in the same direction when the input is reciprocating. He plans to use it to power a rowing bike.

Tools of the trade: Metal Lathe - WARNING: when you buy a tool like this you'll spend as much money on the tool bits as you did on the tool.

Tools of the trade: Milling Machine

Now the good stuff. Tubes have been mitered at about 90 degrees using a 1" half-round file. This part of the demonstration included techniques to miter tubes of different diameters at all angles. After cutting and filing and sanding the paint off it's ready to join.

Begin by holding the torch flame close to the metal, heat until the base metal glows orange. For larger tubes and big joints you may need two torches to get enough heat on the joint. A propane torch can be used for the second one.

Then melt some brass onto the surface and continue heating as the brass sweats into the joint. It is OK to melt the brass directly with the torch flame initially, then let the heat on the tube surface draw the brass into the joint. This will make the structural bond between the two pieces of metal.

Then melt more brass on top of the joint to create a fillet. Don Hoskisson stands in the background. Look for pictures of the bike he built using the techniques shown in this workshop - coming to this site soon.

Thanks to Mike Lampi for taking all of the pictures - you can see all of the photos on his website click here. Special thanks to Mary Onufer for providing wonderful snacks.

Note: In these pictures it looks like Don and Jerry were the only ones there. Actually we had a great turnout of about a dozen people, including several new recruits. They were....

Jerry Onufer - host
Don Hoskisson - brought pictures of the homebuilt Tour Easy clone he built using MAPP gas brazing.
Nick Hein - brought new homebuilt FWD conversion bike.
Dick Stemwell - brought a new transmission for use on a rowing bike based on stock components
Mike Lampi - took digital photos
Christopher Lampi - (14 years old) showed what a wonderful thing it can be to hand a teenager a flaming torch
Lee Brown
Joe Kochanowski - asked awkward questions

New recruits:
Mikel Warner
Joaquin (new recumbent convert - I met him at Bikeworks)
Jonathan Marcus (I met at a New Year's Eve party)

Thanks to all of you for coming.

	Our host Jerry Onufer. All of these pictures were taken in Jerry's basement where he has a complete wood and metal-working shop as well as a full-size brazing setup. Today he was showing us how to get by without all that stuff. The pole stand in the background is his holding stand for brazing work.
	Show and Tell: Nick's new bike - Formerly the "Pacific Hammer" - now the "NonsPacific Hammock". Click here for more details.
	Show and Tell: Item 2. Dick Stemwell brought this transmission that uses 2 BMX freewheels with the chain wrapping around on opposite sides to produce continuous rotation in the same direction when the input is reciprocating. He plans to use it to power a rowing bike.
	Tools of the trade: Metal Lathe - WARNING: when you buy a tool like this you'll spend as much money on the tool bits as you did on the tool.
	Tools of the trade: Milling Machine
	Now the good stuff. Tubes have been mitered at about 90 degrees using a 1" half-round file. This part of the demonstration included techniques to miter tubes of different diameters at all angles. After cutting and filing and sanding the paint off it's ready to join.
	Begin by holding the torch flame close to the metal, heat until the base metal glows orange. For larger tubes and big joints you may need two torches to get enough heat on the joint. A propane torch can be used for the second one.
	Then melt some brass onto the surface and continue heating as the brass sweats into the joint. It is OK to melt the brass directly with the torch flame initially, then let the heat on the tube surface draw the brass into the joint. This will make the structural bond between the two pieces of metal.
	Then melt more brass on top of the joint to create a fillet. Don Hoskisson stands in the background. Look for pictures of the bike he built using the techniques shown in this workshop - coming to this site soon.