Quantcast

Welding Opinion

Henry

Chimp
Jul 19, 2008
5
0
I have an old Gary Fisher Piranha that I have stripped all the paint off and I have taken off the old brake line / shifter cable stays and polished them off to get an even more simplistic look. I also have drilled out the screw things (whatever they're called) that hold the bolts for the bottle holder, etc.

I went to Gary Fisher's archives and I found out what type of aluminum my bike was made of. (Gold Series 6061 T6 internally and externally butted aluminum)

If I have a friend with aluminum welding skills and the equipment, do you think it would be safe to try to plug the holes with aluminum and then buff it down?

I don't want to ruin the frame and I'd like to match the color of the aluminum as close as possible so that the welds plugging the holes aren't noticeable.

Also, if I'm converting it to a single speed, would welding on new horizontal dropouts be a good idea? My whole "theme" for this bike/project is minimizing the the clutter on the outside of the bike and I don't like the look of the chain tensioner.

(As for the buffing of the frame, I'm using a large (stationary?) buffing wheel, not a handheld sort (except I will for tight places) so I should get a very uniform polish))

Thanks all,
Henry
(I hope this is the right category to post this in)
 

CrabJoe StretchPants

Reincarnated Crab Walking Head Spinning Bruce Dick
Nov 30, 2003
11,568
427
Groton, MA
Why you did that is beyond me. Thread 2 screws in the bosses and be done with it. Is it really worth chancing a perfectly good frame for the sake of having a "cleaner" looking bike? Even if you did weld plugs and grind/polish flush, it will still look horrible compared to 2 screw heads.
 

Henry

Chimp
Jul 19, 2008
5
0
Why you did that is beyond me. Thread 2 screws in the bosses and be done with it. Is it really worth chancing a perfectly good frame for the sake of having a "cleaner" looking bike? Even if you did weld plugs and grind/polish flush, it will still look horrible compared to 2 screw heads.
If I were to not do anything with it, it would end up just collecting dust or getting trashed. The whole reason for this project for me is to just experiment and see what I can do in a budget.

I don't have to weld plugs in the holes either, I could put in a screw or just plug it with something else. Cork anyone? :P
 

Henry

Chimp
Jul 19, 2008
5
0
I wouldn't worry about plugging the holes. They are pretty benign.

The drop-outs on the other hand...not sure that would be a good idea.
With the drop outs I'll probably leave them alone and just keep the tensioner, but it was just a thought.

I'll look into it some more.
 

Stray_cat

Monkey
Nov 13, 2007
460
0
Providence
For filling holes I'd look at using a flux, as opposed to welding in a plug of the same alloy. I'd try and find a low temp flux, that's approprate as an aluminum filler (possibly Flux10 or 14, but the numbers I can never remember as I don't deal with it too much). I'm not sure at what temperature you effect the aluminum comp. which would resulting in needing to heat treat the frame. Ask your friend with the torch.
 

H8R

Cranky Pants
Nov 10, 2004
13,965
35
If he knows how top weld ask him if he knows how to braze.

Fill the holes with brazing and sand smooth.
 

Timekiller

Monkey
Oct 9, 2006
697
0
NJ
If it was my frame, I'd go for the whole shebang... But then again, I have a TIG welder, and Ive been welding a long time.

In fact Im building a bike soon from double/triple butted 4130Ch-Molly. Just gotta figure out all the geometry/math first.

But yes, if he is a good welder, you should end up with a flawless job that you would never know where the braze-ons were. If he is a REALLY good welder, he can work around the heat treating problem.

Also if you go for it, search framebuilding. When I did, I came across a real trick site that a guy runs his shifter/brake cables through the frame, its neat!
 

Henry

Chimp
Jul 19, 2008
5
0
Thanks to everyone for their replies. I'll talk with my friend some more and research this well..
 

yamaguy01

Chimp
Jun 2, 2008
23
0
Fussa, Japan
If it was my frame, I'd go for the whole shebang... But then again, I have a TIG welder, and Ive been welding a long time.

In fact Im building a bike soon from double/triple butted 4130Ch-Molly. Just gotta figure out all the geometry/math first.

But yes, if he is a good welder, you should end up with a flawless job that you would never know where the braze-ons were. If he is a REALLY good welder, he can work around the heat treating problem.

Also if you go for it, search framebuilding. When I did, I came across a real trick site that a guy runs his shifter/brake cables through the frame, its neat!

Klein bikes also run their cables inside the frame, I think this looks sweet and makes sense. My cables on my Trek have scratched the heck out of my top tube and all the mud/dirt stays in the scratches. On a white bike it really is an eye sore. Plus it would probably keep alot of debris out of the cable housings.

Good luck with your project!

Dave
 

Henry

Chimp
Jul 19, 2008
5
0
After some consideration, I'm most likely going to either put a rivet in the hole or carve up an aluminum plug on the laithe. I'll most likely go with the latter as rivets don't always look perfect :) (Atleast for me, sometimes I get nice looking ones but other times.. bleh).

(My friend is an alright welder, but we're both iffy about him doing it so.. maybe next time)

I know it's not a big project compared to some of the other awesome bikes up here, but I'll have some photos posted later on when I'm 100% finished.

Thanks for everyone's feedback!