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Extemporaneous · 29-07-2009, 19:18

I had a "Marine Engineer" (or that's what is on his card) weld some new bases on my Radar Arch as moved it off of a sloped combing.
The welded portion is now blue, like it was done with too much heat.
I don't know exactly what kind of Stainless Steel the original Arch was made of as it come on the boat when I bought it, perhaps 304 but can't say for sure.

Is this a problem?

Please let me know.

Thanks,
Extemp.

motion30 · 29-07-2009, 20:15

No problem To hot would be black. Pink or light blue is good If you wish you can clean that off with a ss wire brush

anjou · 30-07-2009, 01:25

With SS, any colour of the rainbow is fine. Too much heat will cause embrittlement. (HAZE)- heat affected zone embrittlement
The integrity of the steel hasnt been compromised.
More important is the quality of the weld. If there is porosity in the weld it signifies trapped impurities which will encourage rust.

**GordMay** · 30-07-2009, 03:10

Poor Colour on Stainless

Figure 7A shows discolouration on a stainless steel weld caused by overheating, which not only affects a material’s colour, but degrades its corrosion resistance and mechanical properties as well. Unfortunately, once this error is made, there is nothing that can be done to fix it except for scrapping the part and starting over. To prevent overheating, reduce amperage, slightly increase travel speed or shorten the arc length. If your welding equipment features pulsing capabilities, now is the time to learn how to use them. Pulsing reduces heat input, and it offers excellent control of the weld puddle. Figure 7B shows proper colouration of stainless.

Goto ➥ Miller - Ten Common TIG Problems: A Visual Guide

Also check out ➥ Welding: principles and applications - Google Books

Robertcateran · 30-07-2009, 03:42

One of the problems is that chromium carbide crystallises out of solution if the temperature is left high for too long. This leaves it susceptible to rusting and makes it brittle. I was taught to bring the temperature down as quickly as possible to avoid that crystallisation

imagine2frolic · 30-07-2009, 06:05

Has anyone polished the weld yet?......i2f

Extemporaneous · 30-07-2009, 09:30

Thanks all for your comments.

After doing some reading along with all of your comments, I'll have to look at this closer. I may not have a problem.
No it hasn't been polished yet. Any suggestions on the best/easiest way to do that?
I'll report back when I get back to the part to look at it again.

Extemp.

**sandy daugherty** · 30-07-2009, 10:16

Any good metal polish and a soft cloth will do. I personally like Flitz and its polishing ball that fits on a drill motor. Don't confuse the color cues for chrome plated steel motorcycle exhaust pipes with welded stainless.

Christian Van H · 30-07-2009, 10:20

Quote:

Originally Posted by anjou

With SS, any colour of the rainbow is fine. Too much heat will cause embrittlement. (HAZE)- heat affected zone embrittlement
The integrity of the steel hasnt been compromised.
More important is the quality of the weld. If there is porosity in the weld it signifies trapped impurities which will encourage rust.

Will you marry me?

imagine2frolic · 30-07-2009, 11:21

Quote:

Originally Posted by Christian Van H

Will you marry me?

ROFLMAO, That was kind of like my thought when I read her post. My problem being one is more than enough for me. 2 would be my DEATH!.........i2f

Brent Swain · 30-07-2009, 11:32

Quote:

Originally Posted by GordMay

Poor Colour on Stainless

Figure 7A shows discolouration on a stainless steel weld caused by overheating, which not only affects a material’s colour, but degrades its corrosion resistance and mechanical properties as well. Unfortunately, once this error is made, there is nothing that can be done to fix it except for scrapping the part and starting over. To prevent overheating, reduce amperage, slightly increase travel speed or shorten the arc length. If your welding equipment features pulsing capabilities, now is the time to learn how to use them. Pulsing reduces heat input, and it offers excellent control of the weld puddle. Figure 7B shows proper colouration of stainless.

Goto ➥ Miller - Ten Common TIG Problems: A Visual Guide

Also check out ➥ Welding: principles and applications - Google Books

This is total ********. Never had a problem with discoloured stainless in the 3 dozen steel boats I've built. It always discolours.
Brent

**s/v Jedi** · 30-07-2009, 14:20

What the welder skipped is that secret acid stuff to clean up and passivate the weld. I've seen them use powdery stuff (cleaning up (or activating?) with water) but understand there's also liquid versions. I never found it in a shop but every good welder I've used had it.

cheers,
Nick.

Extemporaneous · 30-07-2009, 16:46

Quote:

Originally Posted by sandy daugherty

Don't confuse the color cues for chrome plated steel motorcycle exhaust pipes with welded stainless.

Do you mean like these guys are?
Competition Chemicals, Inc. - BlueAway
Anyone ever used this product?

Extemp.

Extemporaneous · 30-07-2009, 16:51

Quote:

Originally Posted by s/v Jedi

What the welder skipped is that secret acid stuff to clean up and passivate the weld. I've seen them use powdery stuff (cleaning up (or activating?) with water) but understand there's also liquid versions. I never found it in a shop but every good welder I've used had it.

cheers,
Nick.

Could this be the "secret acid stuff"?
AvestaWelding Website - Pickling paste and pickling gel

Extemp.