Welders (or 'Those in the Know') Please

[geraldbasford]

You got me on that one. few know what a reducing flame is or what to do with it.You know what the difference is between a newborn baby and a welder is---answer is sooner or later the baby will stop crying.

[anjou]

Originally Posted by geraldbasford

Hey lady thats a big oxidizing flame you got there.I think you need a little more oxygen there.With a smile like that who cares.

Ive heard some brilliant chat up lines in my time, but that sure is different and original

[geraldbasford]

That is humor designed for welders. You know how many welders it takes to screw in a light bulb?Answer---One they hold the bulb in one hand and the whole universe rotates around them.Can you tell I have way to much time on my hands?

[anjou]

old welding joke:Little boy is walking down the road and sees a pair of welders overalls, so he puts it on, rolls up the sleeves and legs. Walks a little more and finds some rods, so he slides them in the leg pocket.A little further on he finds a pair of gloves and puts them onNext he finds a mask and puts it on his head. Hes realy excited cos he looks just like a welder.Then a car pulls up and a creepy guy asks him if he likes to have kinky sex.Little kid says, Nah, I found all this gear laying in the road, im not realy a welder.

[geraldbasford]

you scared me I thought the creepy old guy was going to be the welder.I heard a story about a body they found floating in the river out here in California. They pulled him or it may have been a women to be politically correct. Anyway thay checked for identification and found absoleutly no money a few IOU's at local bars. Afew old love letters,some free coupons for hamburger stands but no identification as to whom this person is or should I say was. So they took the poor soul to the morgue.They did a through autopsy and discribed the person as wearing really tattered clothes with strange burn holes and metal slag embedded in the clothes and some wire wheel bristles stuck in them with a chemical test showing some grinder dust embedded in the clothes.They still couldn't identify the person. So they decided to xray the body and what a suprise. They still couldn't tell the persons name but did find out the occupation of this person. Why lo and behold it was a welder can you believe that. Was it from the clothes and slag and grinder dust NO. they could see from the xray the person has hugh quantaties of coffee in the stomach they were amazed at how much coffee was in the stomach and also they observed very very thick calouses on the butt area thus the conclusion it must have been a welder.I don't know why they didn't mention the black lung,thick reading glasses,Wrinkled complexion, hugh brain cavity and small gray matter.

[um saudade]

Passivation of all stainless is primarily by nitric acid to remove the iron(which rusts) from the surface leaving a thin veneer of chrome that does not rust. This is why if you scratch stainless it bleeds as you have removed the protective chome from the alloy below.

all stainles should be passivated after fabrication.

Jerry

[geraldbasford]

I really hesitate doing something I can't spell.And as you can see my spelling is not so good. I wished they had spell check on this forum.I have been around stainless work and have never seen anyone use this process. I don't question your accuracy. But in the Oil refinerys they never go beyond heliarch and wire brush.The refinerys do alot of exotic stainless alloys for different processes and high temps and extreme pressures but don't passivate any of their welds.Tell me more.I know in the welding field you can learn something new every day.Where have you seen this done? What alloy stainless are you refering too.Or should I ask what product or system requires this. do know caution is needed not to contaminate stainless with carbon steel. Not even storing on a rack together for fear of cross contamination.A you a real welder or an arm chair welder.You do know welders do have a right of passage.I remember some welds made on stainless 347 alloy that were quenched with regular water and not distilled and contaminated the heat zone. It seems the minerals in the water embedded in the grainstructure of the stainless and caused a flaw. The results were a person was killed when bringing a hydrostatic test up to pressure and a resultant rupture of the vessel.

[um saudade]

As to the welding and passivation of ss alloys: When I say all should be passivated I do refer to marine use where the appearance is generally considered as important as the part itself.
Many of the newer welding electrodes are self-passivating to a certain extent and show no major oxidation over the years even in highly corrosive environments. This is not to say that the weld is totally protected because the steel in the original component gets re-melted and re-deposited, thus the edge of the weld often shows oxidation.
Look at the alloy content of most stainless and you will see that the chromium content is quite low, thus the 18-8 designation. Cut the end of a piece of 304 or 316 and watch it rust without passivation. This rust will also be superficial, as this is not the corrosion that destroys stainless but that discussion is not the purpose of this thread.
As to not storing of mild steel next to stainless I don’t buy it. I won’t buff stainless on buffing wheels that have mild steel on them but I don’t think that contact with a piece of mild steel while out on the rack will cause anything to happen to the stainless other than as I said before: If you scratch it, it will bleed unless you remove the surface iron with an acid.
As to my abilities, welding or otherwise, I don’t blow my own horn but let the facts speak for themselves.

I don't have a lot of time on my hands so good luck to you.
Jerry

[geraldbasford]

Great info.I think if you persue the storing of diffrent alloys together it will be rejected on some project because of cross contamination.I don't think most marine applications are not as stringent as other applications.Like I said you learn something new every day.You didn't blow your horn but you didn't answer thr question.Sorry if I sound horn blowish but I'm proud of being a welder and don't care what anyone thinks about it.Get me a soap box and I will declare to the now existing world how we have basicly built this country.Ok how's that sound.I get dramatic and cry alot

[s/v Jedi]

Gerald,

See Passivation - Wikipedia, the free encyclopedia for a complete description, but this one sentence on that wiki explains it all:

Another typical passivation process of cleaning stainless steel tanks involves cleaning with sodium hydroxide and citric acid followed by nitric acid (up to 20% at 120 °F) and a complete water rinse. This process will restore the film, remove metal particles, dirt, and welding-generated compounds (e.g. oxides).

cheers,
Nick.

[geraldbasford]

I think maybe winerys use this process in order to make it fit for food grade service.Thanks for that.The only thing I knew about passivation is how much time slips by when your having fun.That's called passing time. I guess not the same.