What are these called and where do I get them?

Dazed_Driver Wrote:
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I just thought it would
> make it not so stainless anymore? Can you explain
> whats going on?
>

Okay, this is a bit simplified but what's going on is dilution of the constituents at the weld interface. There will be a gradient of Nickel and Chromium diffusing out of the stainless into the mild steel and vice versa. The insert is still stainless and the body shell is still steel except for the mix in and around the weld itself.

The carbon content from the mild steel moving into the stainless is normally bad. At high temperature it precipitates out at the grain boundaries and the material micro cracks/falls apart. That's why when you see markings on 304 stainless you will sometimes see it dual marked as 304L. The "L" stands for low carbon. The low carbon contend protects it at high temperatures (by high I mean glowing turbo down-pipe temperatures). That's also why 321 stainless exists. The addition of a little Ti to the stainless mix basically locks up the carbon preventing it from causing cracking.

The safest procedure is to MIG or TIG the stainless insert to the mild steel body with steel wire or filler rod.

-Tim

ahh, that makes more sense. I guess I always new just at and around the weld it would be contaminated... but it never really clicked. Thanks!

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Welcome to the cult of JVL drink the koolaid or be banned.

Grant, we think alike on McMaster.

Only thing I did different was order a box of stainless hex head caps screws instead of button heads. If the head gets buggered by rox and it's a button head, yer screwed. If it gets buggered and it's a hex, you just file it til the wrench fits or grab vise grips.

But stainless is the key. I made the mistake of using cad plated bolts under there. Once.

I also tried rivnuts on one car. By the second year, all of them were ripped out and replaced with weldnuts.

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Lurch
Eric Burmeister
The west coast...of Michigan

Lurch,

How many of these do you need for the underbody? Any chance you could post a pic?

Thx
Brad

Yeah, I could probly post a pic. Enough.

I just space them between 12-18 inches apart. We welded a piece of square tubing down the inside of the pinch seam and put them in there, then other places under the body. If you do this, you may extend the plastic out like running boards and it does a very good job of protecting your rockers...something that's important on FWD cars.

I did this with the PRotege, but the 3 has plastic rocker covers that just get replaced every couple rallies instead, so I don't have to have running boards.

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Lurch
Eric Burmeister
The west coast...of Michigan

For the more or less perminate plastic under car armor these are good ideas but for the skid plate I always design to have a very quick remove and install system, I like to have a bar near the back of the motor that my plate hooks onto and then have only two bolts up near the bumper so I do not need to get under the car to undo or install the plate.

Tom B where do you live I wish to make the long trek (10 blocks or so) to come over so I can laugh and point at all your hard work. I will bring beer - or even better Aquavit.

I am at 107th and Densmore in North Seattle...

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In the long run reality always wins.

Derek,

I live just north of Seattle, the shop is in Shoreline, I'm in Lynnwood.

My brother Don lives right by you just off of Greenwood and 85th.

I'm up at the shop on the weekends from time to time staring at the amount of crap I still need to do.

give me a ring one of these weekends, ya might even be able to lend a hand!

206422-268-0

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-Tom
DemonRallyTeam | Fine Tuning | CTS Turbo & RP Turbos | RalleyTuned | JRM | Meister Autowerks
Spitfire EFI | Product Apparel | JVAB Imports | NLS | AP Tuning | USRT

Add us on Facebook | Next Event: 2013 Olympus Rally June 22-23 Olympia, WA

Derek does most work that takes people like 3 weeks in only one night in rain in the dark in a 12 sq ft parking space. If you can get him to work on your car it'll be driving months sooner than you expected.

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Grant Hughes

Jon Burke Wrote:
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> thx....yeah, haven't decided exactly what size
> I'll get...whatever is appropriate for the grade8
> hardware I currently have.
>
> that one is also mounted on the outside, which is
> fine/necessary if its welded to the frame...but if
> its to the sheetmetal on the floor (which on a
> suby is pretty thin), i'm thinking it'd be better
> to go on the inside.

Are you using the grade 8 hardware simply because you have it already? From my understanding it's likely not the best grade for the job/won't have any benefits.

Of course I stand to be corrected, but I'm thinking why do you need such strong brittle hardware there.

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Andrew M
Onterrible
30ish

Or weld the 300 series stainless steel to steel using the following process

1. Make sure the steel surface you are welding to is clean of rust, scale or paint and is above 50 deg F.

2. TIG or MIG using E309 welding wire.

3. After the completion of welding, perform a Liquid Penetrant inspection of weld and surrounding base metal.

hudson Wrote:
-------------------------------------------------------
> Jon Burke Wrote:
> --------------------------------------------------
> -----
> > thx....yeah, haven't decided exactly what
> size
> > I'll get...whatever is appropriate for the
> grade8
> > hardware I currently have.
> >
> > that one is also mounted on the outside,
> which is
> > fine/necessary if its welded to the
> frame...but if
> > its to the sheetmetal on the floor (which on
> a
> > suby is pretty thin), i'm thinking it'd be
> better
> > to go on the inside.
>
> Are you using the grade 8 hardware simply because
> you have it already? From my understanding it's
> likely not the best grade for the job/won't have
> any benefits.
>
> Of course I stand to be corrected, but I'm
> thinking why do you need such strong brittle
> hardware there.
>
>
>
> Andrew McNally
> Hamilton ON
> 28


yeah, its just what I have (grade 8.8, to be precise)....need to replenish my supply though, I'm certainly open to suggestions. In fact, I was thinking of doing a thread on where to buy a decent 'bulk selection' like this, but w/o the price tag:
http://www.pegasusautoracing.com/productdetails.asp?RecID=1353

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Jon Burke - KI6LSW
Blog: http://psgrallywrx.blogspot.com/

jameseshepherd Wrote:
-------------------------------------------------------
> Or weld the 300 series stainless steel to steel
> using the following process
>
> 1. Make sure the steel surface you are welding to
> is clean of rust, scale or paint and is above 50
> deg F.
>
> 2. TIG or MIG using E309 welding wire.
>
> 3. After the completion of welding, perform a
> Liquid Penetrant inspection of weld and
> surrounding base metal.
>

so, I'm going to apologize in advance...I just ordered my mig welder, I'm on a waiting list for a class, but I'm probably still going to bug the shit out of you guys with noob welder questions for the next 60-90 days

I bought some E70S-6 wire for mild steel (for basic projects and stitch welding....0.023)

How is that different from what you just said, and can it get the job done?

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Jon Burke - KI6LSW
Blog: http://psgrallywrx.blogspot.com/



Edited 1 time(s). Last edit at 11/07/2008 12:06AM by Jon Burke.

nevermind, I found it.....309 is specifically for stainless steel....but what I found is 309L.....what's the 'L'?

Also....308L? that much different?


hijacking my own thread....oh yeah....

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Jon Burke - KI6LSW
Blog: http://psgrallywrx.blogspot.com/

Too much thinking not enough riv-nutting going on around here. The force on underbody plastics should not be pulling DOWN so the attachment point doesn't need to be TOO sturdy. If your underbody is getting ripped off you've got other problems.

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Gone fishing

metric 8.8 = sae grade 5