RADBMX.CO.UK

BMX General => BMX Chat => Topic started by: oldschoolace on August 11, 2011, 02:22 AM

Title: mig welding vs brazing?
Post by: oldschoolace on August 11, 2011, 02:22 AM

Ok, go easy on me as i know fook all about either.

Lets just say i decided to chop shop a cheap steel frame and cut new tubes to a nice tidy joint. Could i fillet braze the joints with map gas and brass/silver rods or would a mig welder be better?

P.S I'm a cheap bstard and am only having a go so i dont want to spend hundreds on the right gear  :-[

Title: Re: mig welding vs brazing?
Post by: Peter J on August 11, 2011, 07:41 AM

Both are good methods but............................its all down to the skill of the welder

Welding is a skill or even an art and its a bloody hard one to get right  :daumenhoch:

Title: Re: mig welding vs brazing?
Post by: animal on August 11, 2011, 09:19 PM

Braizing is stronger if done correctly as it does not melt the parent metal so doesn't build in added stress that needs 2 b anealed  ;) MIG is nice and strong but not as neat as TIG on thin tubing  :daumenhoch:

Title: Re: mig welding vs brazing?
Post by: lk_97 on August 11, 2011, 09:42 PM

So what exactly is a bubblegum weld? I've saw one but I don't really know what they are...

Title: Re: mig welding vs brazing?
Post by: Peter J on August 11, 2011, 09:44 PM

Quote from: lk_97 on August 11, 2011, 09:42 PM

So what exactly is a bubblegum weld? I've saw one but I don't really know what they are...

Crap welding

http://www.jalopyjournal.com/forum/showthread.php?p=2748674

Title: Re: mig welding vs brazing?
Post by: oldschoolace on August 11, 2011, 09:54 PM

i'm thinking more brazing at the moment, looking to have a go making my own frame over the christmas hols.  :Great_Britain:  :daumenhoch:
Anyone got any tips? 

Title: Re: mig welding vs brazing?
Post by: mattfx81 on August 11, 2011, 10:30 PM

Brazing will be cheaper and more practical, mig isnt so good on thinner gauge materials. With brazing its all about the gap or rather creating the right conditions for the filler material to flow into the joint via surface tension to create a strong joint. Tig is even better as you have more control of the heat input in the joint and amout of filler material deposited but a  decent machine is expensive and requires practice.

Title: Re: mig welding vs brazing?
Post by: oldschoolace on August 12, 2011, 01:23 AM

Quote from: mattfx81 on August 11, 2011, 10:30 PM

Brazing will be cheaper and more practical, mig isnt so good on thinner gauge materials. With brazing its all about the gap or rather creating the right conditions for the filler material to flow into the joint via surface tension to create a strong joint. Tig is even better as you have more control of the heat input in the joint and amout of filler material deposited but a  decent machine is expensive and requires practice.

Cheers. If i was looking to fillet braze a joint (i think thats what they call it) where you use more of the rod, like a mig weld i guess, do i still use flux or is that mainly to help the brazing material to flow into snug joints such as lugs?

Title: Re: mig welding vs brazing?
Post by: mattfx81 on August 24, 2011, 01:49 AM

Yes, you can use the flux to help wet the surface to let the braze flow more easily.