Has anyone ever tried bonding steel lugged frames with an adhesive? I know that early carbon fiber frames were often bonded to aluminum lugs but what about steel? I have worked many years in auto body shops and have bonded body panels (quarter panels, door skins, roof skins) on cars with great success. While I was in school for said profession a rep. for one of the companies that produce the adhesive stopped by for a training day and I personally tested the strength of the adhesive. I "glued" two pieces of sheet steel together and attached it to our frame machine. It took 12,000 pounds of pressure before the steel tore. I then welded (I-car certified welder) two pieces of steel together and re-did the test. It took 10,000 pounds and this time my weld broke before the steel. It seems that bonding the tubes would be better for several reasons. 1 No heat to destroy the carbon content (make them weak) of the tubes and or warp them. 2 Better corrosion resistance. 3 The adhesives are designed to expand and contract at the same rate as steel so a stronger joint could be had for a longer period of time. 4 Excellent paint adhesion.
Once I figure out how I want my frame set up I am going to do it.
bellweatherman
11-01-06, 02:20 AM
Instead of lugs, what about fillets? I don't know if this has been done before, but what about fillet bonding instead of fillet brazing?
LWaB
11-01-06, 03:43 AM
Has anyone ever tried bonding steel lugged frames with an adhesive?
Raleigh Technium frames were aluminium tubing bonded to steel lugs and (occasionally) steel tubing bonded to aluminium lugs. Not what you were thinking of though...
Erzulis Boat
11-01-06, 09:06 AM
Unless you have lugs specifically designed for adhesive application...what about the seatstay union with toptube/seattube? The dropouts?
4 percent (silver) solder, under proper conditions will resist shear to 28,000 pounds, and this is not the "strong stuff".
Solder and adhesives are not interchangeable in the context of a tubeset that is designed to be bonded via solder.
I am sure that you could "glue" a tubeset together with your commercially available lugs etc. but it WILL be inferior to a properly soldered framset (using conventional lugs that were originally designed to be soldered.)
Nessism
11-01-06, 06:43 PM
Unless you have lugs specifically designed for adhesive application...what about the seatstay union with toptube/seattube? The dropouts?
4 percent (silver) solder, under proper conditions will resist shear to 28,000 pounds, and this is not the "strong stuff".
Solder and adhesives are not interchangeable in the context of a tubeset that is designed to be bonded via solder.
I am sure that you could "glue" a tubeset together with your commercially available lugs etc. but it WILL be inferior to a properly soldered framset (using conventional lugs that were originally designed to be soldered.)
I agree.
You can not glue together a frame using lugs designed for brazing; the surface area of the joints is not great enough considering the lower bonding strength.
shawnzyoo
11-02-06, 07:02 PM
what type of glue are you using?
epoxy or polyester or vinyl based?
also does anyone know where to get aluminum lugs
kpug505
11-03-06, 10:13 AM
Both products that I have used (on cars) are made from a urethane epoxy. Following are some links.
I am glad I didn't waste tubing by trying this first. The only area that I think would really pose a problem would be the rear triangle. It seems to me that the surface are of the lugs for the main triangle would be large enough except there would need to be enough clearance between the tube and the lug to get enough material in there. After thinking about it I dont think that could happen without really reaming the lugs out which would compomise thier strenghth. Oh well. I'll get a torch and some practice tubes and lugs and go at it!
Blender
11-09-06, 03:48 PM
I posted on this some time ago and later found the Technium Brochure which describes the process used. See this old Post for the Brochure
http://www.bikeforums.net/showthread.php?t=215343
The bonded lug process was cheaper than the then common mass produced brazed lugs. Then the economics of the Al welding process /developmentskilled this technology.
As the previous poster said the Patented lugs used were the key. Mine is still strong 20 years later.
Now if someone were to develop a epoxy bike kit with the adhesive and lugs and then spec the tubing then one could build their own without the Brazing or welding issues and skills. The Bonding epoxies.adhesives have advanced considerably in 20 years.
bharnett
11-29-06, 08:22 AM
I have built a tandem with this process it is still going strong.
A link to the thread is here http://www.bentrideronline.com/messageboard/showthread.php?t=24475