Anyone got any "bump welding" skills for anodized?

[jakedaawg]

Looking for some pointers...I got it down pretty okay but always room for improvement...

 

[Scott Danforth]

grind off the anodizing where you are welding since welding destroys the anodizing anyway

 

[dingbat]

What is “bump” welding?

Professional trained and certified in MIG, TIG and SMAW. Never heard the term.

Anodize isn’t an issue. It’s less than 0.0005” thick. Arc burns right thru it

 

[dwco5051]

What is “bump” welding?

Professional trained and certified in MIG, TIG and SMAW. Never heard the term.

Same here, 23 years Navy as a shipfitter/hull tech but since that must of been about when they quit making ships from wood and starting using iron I looked up the term. I guess I learn something new every day.

"Anodized aluminum requires a technique known as bumping, which is a way to remove the thick oxide layer without putting too much heat into the weld pool. Because it uses a fingertip control switch, a foot pedal is unnecessary for this technique.

Bumping involves very briefly starting an arc using the finger control switch, adding the filler metal, extinguishing the arc, moving down the weld joint about 1⁄16 in., and repeating the process. Turning the fingertip switch off gives the weld pool a moment to cool and solidify before you reintroduce the heat with a new arc.

Although easily described, bumping is one of the more difficult GTAW techniques to master. A proficient operator typically can reach a travel speed of about an inch every 30 to 40 seconds."

 

[Scott Danforth]

and we simply run a 4-1/5" with 36 grit down the face where the weld goes, lay in the weld, dress off, and send back our for re-anodizing

 

[dingbat]

Same here, 23 years Navy as a shipfitter/hull tech but since that must of been about when they quit making ships from wood and starting using iron I looked up the term. I guess I learn something new every day.

"Anodized aluminum requires a technique known as bumping, which is a way to remove the thick oxide layer without putting too much heat into the weld pool. Because it uses a fingertip control switch, a foot pedal is unnecessary for this technique.

Bumping involves very briefly starting an arc using the finger control switch, adding the filler metal, extinguishing the arc, moving down the weld joint about 1⁄16 in., and repeating the process. Turning the fingertip switch off gives the weld pool a moment to cool and solidify before you reintroduce the heat with a new arc.

Although easily described, bumping is one of the more difficult GTAW techniques to master. A proficient operator typically can reach a travel speed of about an inch every 30 to 40 seconds."

Sounds similar to a technique used as a first pass in an overly wide butt joint.

Not sure what the technique brings to the table. Never had an issue welding to anodized material.

 

[jakedaawg]

By using the bump method it's less about the heat and more the high frequency arc start that removes the anodizing. Good welders can use that instant initial high amp high frequency arc start to push the anodizing to the sides and add filler. On a typical pontoon rail repair, which is pretty thin,~85 thou , I use upwards of 195A ac.

in a production environment time to grind is too much and many pieces are too large too anodized, tuna towers and such. It's a method originally pioneered by pipewelding,inc. The largest manufacturer of marine towers for big boats. It's also used on many pontoon railings. When done right re anodizing is not necessary, a little silver paint is all many use and is industry standard.

 

[jakedaawg]

I was hoping that with the newer inverter technologies and the ability to define the arc on either side of Ac that some new methods may be out there...