LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently March 28, 2024, 3:55 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 42 posts ]  Go to page Previous  1, 2, 3
Author Message
PostPosted: August 22, 2011, 4:07 pm 
Offline
User avatar

Joined: March 30, 2011, 7:18 am
Posts: 1615
Location: central Arkansas
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?


Top
 Profile  
Reply with quote  
PostPosted: August 22, 2011, 4:44 pm 
Offline
The voice of reason
User avatar

Joined: January 10, 2008, 4:47 pm
Posts: 7652
Location: Massachusetts
Quote:
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...

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.


Top
 Profile  
Reply with quote  
PostPosted: August 22, 2011, 5:16 pm 
Offline
Mid-Engined Maniac

Joined: April 23, 2006, 8:26 pm
Posts: 6410
Location: SoCal
Also check to see if the lime in the cement will be an issue with the stainless.

_________________
Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/


Top
 Profile  
Reply with quote  
PostPosted: August 22, 2011, 7:48 pm 
Offline
User avatar

Joined: March 30, 2011, 7:18 am
Posts: 1615
Location: central Arkansas
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.


Top
 Profile  
Reply with quote  
PostPosted: August 22, 2011, 11:04 pm 
Offline

Joined: April 17, 2009, 1:28 am
Posts: 212
Location: San Tan Valley, Arizona
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


Top
 Profile  
Reply with quote  
PostPosted: August 23, 2011, 1:40 am 
Offline
The voice of reason
User avatar

Joined: January 10, 2008, 4:47 pm
Posts: 7652
Location: Massachusetts
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.

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.


Top
 Profile  
Reply with quote  
PostPosted: February 13, 2012, 3:10 am 
Offline

Joined: February 8, 2012, 12:35 am
Posts: 53
Location: Langdon,AB
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?

_________________
Lurking and leering...


Top
 Profile  
Reply with quote  
PostPosted: February 27, 2012, 12:02 pm 
Offline

Joined: July 26, 2010, 10:12 pm
Posts: 25
Location: Barrie, Ont, Canada
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!


Top
 Profile  
Reply with quote  
PostPosted: February 27, 2012, 1:27 pm 
Offline
User avatar

Joined: April 12, 2010, 5:40 pm
Posts: 2081
Location: san francisco bay area
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. ..

_________________
"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett


Top
 Profile  
Reply with quote  
PostPosted: February 28, 2012, 1:43 pm 
Offline

Joined: February 8, 2012, 12:35 am
Posts: 53
Location: Langdon,AB
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.

_________________
Lurking and leering...


Top
 Profile  
Reply with quote  
PostPosted: February 28, 2012, 1:52 pm 
Offline

Joined: February 8, 2012, 12:35 am
Posts: 53
Location: Langdon,AB
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.

_________________
Lurking and leering...


Top
 Profile  
Reply with quote  
PostPosted: February 29, 2012, 6:30 pm 
Offline

Joined: July 26, 2010, 10:12 pm
Posts: 25
Location: Barrie, Ont, Canada
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.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 42 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 8 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
POWERED_BY