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PostPosted: Mon Aug 22, 2011 4:07 pm 
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I picked up a stick of 1-1/4 x .040" 304 stainless square tubing last week. Today I took a piece of it and welded on some 1/8x1 1018 cold-rolled steel tabs.

Oh, my.

I laid about eight inches of shiny-like-chrome weld with the box cranked up to "nuclear attack" from the last thing I welded. No sags, no blow-throughs. Nice fat puddle - a PUDDLE on .040" sheet metal!

I've read that stainless has less heat conductivity than regular steel, which might account for some of it... but if this stuff is *this* easy to weld, I might use it anyway...


Meanwhile, I'm going to have some really snazzy tornado anchors made of brushed stainless steel tubing. Too bad the next step is to bolt them up to the weldments on the floor joists and pour concrete around the part that goes below the ground...

Hey, I needed something to make the anchors from anyway, what better place to experiment?


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PostPosted: Mon Aug 22, 2011 4:44 pm 
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Too bad the next step is to bolt them up to the weldments on the floor joists and pour concrete around the part that goes below the ground...


Will that prevent oxygen getting to the stainless? I don't know... There have been some failures when stainless was used for keel bolts on sailboats...

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PostPosted: Mon Aug 22, 2011 5:16 pm 
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Also check to see if the lime in the cement will be an issue with the stainless.

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PostPosted: Mon Aug 22, 2011 7:48 pm 
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horizenjob wrote:
Will that prevent oxygen getting to the stainless?


Dipping the welded ends in Rust-Oleum and a good coat of enamel will have to do.


KB58 wrote:
Also check to see if the lime in the cement will be an issue with the stainless.


Hmm... I just went through an interesting trip down the rabbit hole. Lots of warnings, but not much in the way of real data. The general concensus seems to be that 304 would be okay for direct ground contact. I might just paint the whole area to be sure, though.


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PostPosted: Mon Aug 22, 2011 11:04 pm 
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You might find this link http://www2.ku.edu/~iri/publications/SM65.PDF interesting. As I have heard here before, Google Is Your Friend. I searched this ** 304 stainless in concrete ** and came up with a whole herd of info. :wink:

Walt


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PostPosted: Tue Aug 23, 2011 1:40 am 
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Sorry I didn't give much info. THe papaer in the link above seems to say it is a good idea, but I only read the first page or two. Considering how much it must cost to replace things like the pillers that hold up bridges over highways, I'm surprised you don't see rebar made from stainless.

Stainless resists corrosion as long as it is exposed to oxygen. It requires this to maintain a layer of oxide that resists other forms of corrosion. If it is used to bolt a keel onto a sailboat it can corrode because it's under water. Maybe there are galvanic issues too, but i think lack of oxygen can be a big issue.

It's nice your finding it easy to weld.

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PostPosted: Mon Feb 13, 2012 3:10 am 
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Digging this up a bit I guess to help sort out some stuff...
Stainless is ferrous, meaning Iron, Fe on the periodic table of elements, is a major constituent of the material.
200 and 300 series stainless steels are non-magnetic because of the Austenitic grain structure. 200 series is not as common, but was brought about by the war. It uses manganese as a major element, instead of the nickel used in 300 series.
300 series is by far the most commonly used stainless as it has great properties. It welds quite well, can deep drawn in forming, and has good general corrosion resistance.
The welds done with proper filler rods and cleaned of contaminants before and after welding will not exhibit any less corrosion resistance in air. Carbide precipitation can influence corrosion resistance in the heat affected zone surrounding the weld in aggressive environments as the chromium is not removed or burned out, but bunched in clumps with carbon, leaving areas void of the minimum 10.5% to be considered stainless.
Shielding gas is crucial when welding it. You must protect all areas that will reach a molten state. If you do not, a chromium oxide will form. It has a gray, very coarse appearance,a nd is often referred to as "sugaring".
Here are some TIG welding pics to show various points...
Proper welding done on 304 with good shielding gas coverage inside and out...
Outside
Image
Inside
Image
Now, that will certainly suffice, but better purging can result in interior welds that actually appear better than the outside ones due to the fact that once it's been purged properly, there is much less oxygen around after the weld cools.
Image
Just the same as using a big gas lens and cranking up the gas flow can yield nice results on the outside also..
Image
Image
The closer to silver, the better.
If your weld has a grey appearance, it needs more gas. MIG tends to look this way since there is no post-flow after the weld is completed.
I would mostly worry about the inside though.
Practice, destroy and check some welds, take a course. It only takes one bad accident to appreciate good workmanship. What is your life worth?

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PostPosted: Mon Feb 27, 2012 12:02 pm 
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For those who don't know Chris, when he speaks, everyone should listen.

He's very knowledgeable and very skilled in this field.

Glad to see you made it over here. The headers on the 'yota powered 7 are gorgeous!


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PostPosted: Mon Feb 27, 2012 1:27 pm 
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Boy howdy, talk about stacked dimes! Beautiful work dude :cheers: Were you backflushing with Argon or Nitrogen? Never been able to get that pretty of a seam myself. ..

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PostPosted: Tue Feb 28, 2012 1:43 pm 
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PinkNinja wrote:
For those who don't know Chris, when he speaks, everyone should listen.

He's very knowledgeable and very skilled in this field.

Glad to see you made it over here. The headers on the 'yota powered 7 are gorgeous!



Thanks. I really try to do my best and stay well-read, but their is always room for improvement, and more learning.
I really want to build one of these. I like the idea of the freedom, and how easy it is to put aside to do paying work.
The stainless chassis would be a nice challenge, with neat results.

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PostPosted: Tue Feb 28, 2012 1:52 pm 
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oldejack wrote:
Boy howdy, talk about stacked dimes! Beautiful work dude :cheers: Were you backflushing with Argon or Nitrogen? Never been able to get that pretty of a seam myself. ..


Thanks. Yes, I use Argon. Nitrogen is hard on the tungsten if you run any kind of a gap, but can be used on 300 series stainless as a rule on closed joints. The nitrogen can be broken down in the weld arc and enter the molten puddle with ill effects on certain alloys. It's one of those situations where if you aren't sure, don't try it. If the gas just sees a molten puddle, then all is fine. It's dirt cheap, but can be costly if you know what I mean.

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PostPosted: Wed Feb 29, 2012 6:30 pm 
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unobtainium wrote:
PinkNinja wrote:
For those who don't know Chris, when he speaks, everyone should listen.

He's very knowledgeable and very skilled in this field.

Glad to see you made it over here. The headers on the 'yota powered 7 are gorgeous!



Thanks. I really try to do my best and stay well-read, but their is always room for improvement, and more learning.
I really want to build one of these. I like the idea of the freedom, and how easy it is to put aside to do paying work.
The stainless chassis would be a nice challenge, with neat results.


I won't disagree. Everyone can improve somewhere, somehow, to some degree. No one can ever be perfect. That said, no one can discount the time and effort you've put into your skills.

I want to build one of these as well. I've been heavily contemplating tearing S14 #2 apart and making a "locost", but new careers are costly...

I think a stainless frame would be awesome, but I think the overall cost factor would just be to much to justify. However, I think 4130 would make for a really nice frame.


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