welding bicycle frames with thermite?
- Thread starter monster
- Start date
AussieJester
1 TW
LMAO i seen thermite cut a car in half... i think the chances of you getting ultra thin wall tubing 'welded' with thermite highly unlikely BUT please try and video it Thermite is soooo freakin cool, GREAT way to get back on that cheating wife/girlfriend, can size amount on the bonnet of her car light it up and watch it burn through the bonnet....and engine block hehehe
KiM
KiM
Malcolm
10 kW
Thermite might just be a little over the top for a bicycle frame. The reason it's used on rail lines is because of the massive heat input required. A bicycle frame typically needs a very low heat input that is carefully directed, which is why TIG and MIG are so widely used.
Brazing and oxyacetylene are also good.
Is your frame steel or aluminium?
Brazing and oxyacetylene are also good.
Is your frame steel or aluminium?
AussieJester
1 TW
magnesium strips are usually used to light thermite dunno how a blow torch would go, you need to
get thermite might freakin hot before it ignites...
KiM
get thermite might freakin hot before it ignites...
KiM
Malcolm
10 kW
Matthew
Not trying to discourage you from trying something different, but why thermite? It's basically a casting process, with the alumina slag floating to the surface. I can't visualise how it would work on typical bike frame joints. I'd suggest brazing if you want to do it yourself, or make friends with a welder if you don't
Not trying to discourage you from trying something different, but why thermite? It's basically a casting process, with the alumina slag floating to the surface. I can't visualise how it would work on typical bike frame joints. I'd suggest brazing if you want to do it yourself, or make friends with a welder if you don't
AussieJester
1 TW
Oh please dont discourage him! i want too see another thermite video gone wrong damnit!! (as long as hes doing it on a 'test' frame and not destroying his pride and joy) 
I can visualise how it will go, he will struggle to ignite the thermite, it will be falling off the joint & when finally monster gets ignition the joint will fuse, then melt onto the floor in a puddle of molten metal as the two tubes fall apart and accompany the pool of glowing slag on the ground, the whole time monster is watching with a WTF have i done look on his face at whats hes witnessing hehehe... Hit up a weld shot buddy be cheaper in the long run and you will get a good job done
KiM
I can visualise how it will go, he will struggle to ignite the thermite, it will be falling off the joint & when finally monster gets ignition the joint will fuse, then melt onto the floor in a puddle of molten metal as the two tubes fall apart and accompany the pool of glowing slag on the ground, the whole time monster is watching with a WTF have i done look on his face at whats hes witnessing hehehe... Hit up a weld shot buddy be cheaper in the long run and you will get a good job done KiM
liveforphysics
100 TW
AussieJester said:Oh please dont discourage him! i want too see another thermite video gone wrong damnit!! (as long as hes doing it on a 'test' frame and not destroying his pride and joy)
KiM
I predict he wouldn't be capable of getting such a small quantity of thermite to light. I like to light it with Potassium Permanganate and glycerin oil, because it can ensure ignition of small amounts, but I sure as hell would never weld with it. lol
To weld correctly, you need something to shield the iron from oxygen while it's molten. You also need correct alloys and purity, or you end up with cast iron, which is an extremely poorly suited material to anything on a bicycle frame.
If you were local to me, you could stop by and I would weld whatever it is up for you in 5mins at no cost. I'm sure there is somebody on your side of the pond who would weld the parts for you for free or some trivial sum.
Tiberius
10 kW
Matthew,
Gas, man, gas is the way to go.
I welded up some brackets and then brazed them to the frame. That way you can get the detail structure you want and its not destroyed when you do the final assembly. Bring it down to Somerset and we can have a go.
If you're really set on thermite, I'll use the gas to ignite it. Bring a video camera too.
Nick
Gas, man, gas is the way to go.
I welded up some brackets and then brazed them to the frame. That way you can get the detail structure you want and its not destroyed when you do the final assembly. Bring it down to Somerset and we can have a go.
If you're really set on thermite, I'll use the gas to ignite it. Bring a video camera too.
Nick
boostjuice
10 kW
If its an alloy frame you've got then you cant go past HTS-2000 Brazing rod. The low heat required won't even change your frame's temper. The brazed joint is stronger than the parent metal. Feels similar hardness as T6 temper 6061 when filing it. I've used this stuff to braze motor/gearbox mounts on my project. It does live up to the hype. Not sure why they market it exclusively as "Alluminium repair", as far as im concerned it's the poor mans Alloy TIG/MIG. It's good $#!T. Some guy on ebay US sells small quantities at a reasonable price. You don't need many sticks for a few brackets. Maybe 10 sticks to be sure??
[youtube]N-cv3R4fWZc[/youtube]
[youtube]N-cv3R4fWZc[/youtube]
vanilla ice
1 MW
Yep IMO brazing it is the way to go, whether its steel or aluminum.
Drunkskunk
100 GW
Would never work, but it would sure be fun to try!
Film it!
Film it!
nicobie
100 MW
I sold my oxy-axc torch years ago after buying a wire feed welder. I wonder if a mapp gas torch would work with this stick?
Drunkskunk
100 GW
Better than propane, but I've used propane with mine too.nicobie said:
It doesn't hold as well as a true weld, and the heat softens the aluminum, but it works brilliant for some things. Amung other things, I've repaired a patio umbrella, built a brake mount, and fixed the crack on a headtube on a bike. But I've also managed to pull joints apart soldered with this stuff, and found if you need to drill or grind it after, you can cause the parts to seperate. The motorcycle brake handle I fixed with it broke again quickly.
vanilla ice
1 MW
I've found the same with the ally rod. It doesn't stick well on some alloys, works great on others. Cast non welded parts I've had problems.
AussieJester said:Oh please dont discourage him! i want too see another thermite video gone wrong damnit!! (as long as hes doing it on a 'test' frame and not destroying his pride and joy)
KiM
Yes, Yes, use lots of thermite and make sure to take a video.
Brazing is amazingly easy and quite strong. Maap gas is the best if you don't have oxy-acetylene.
Maap gas works great for tennis ball cannons too.
Chalo
100 TW
Here's another alternative to using thermite welding for a bike frame. To me, it looks almost as practical:
http://en.wikipedia.org/wiki/Explosion_welding
http://www.youtube.com/watch?v=ldl6fIDGQ5E
http://www.youtube.com/watch?v=QDNX6PcKr7I
http://en.wikipedia.org/wiki/Explosion_welding
http://www.youtube.com/watch?v=ldl6fIDGQ5E
http://www.youtube.com/watch?v=QDNX6PcKr7I
AussieJester
1 TW
monster said:
Nice girlfriend, take some practise and skill to arc weld bicycle tube, i would strongly
suggest getting few old frames and do ALOT of practise before trying to weld your 'proper' frame
your in for a lot of hole blowing me thinkz LoL...
KiM
