OT plastic kit car

[Dave72dt]

You seem to go through a lot of argon.  Small bottle?  Option to go to a larger, maybe more economical size possible?

[Ulu]

I was thinking, “I must modify two of the rails as necessary to fit the floor.”

 

That was me trying to think too far out of the box again.

What I needed to do was simply reshape the floor pan a little bit with a ball peen hammer. One side is done and the seat rail now sits down quite nicely.

The original builder just ignored this and mislocated the seats all crooked.

Anyhow you can see where I hammered by the missing paint.

Also you can see one of the seat bolts attached through the crossmember with the temporary bolt.

[Ulu]

I got the seat risers installed and the seats fitted. Then the seats came back off during welding & paint.

 

The back of the seats bolt through the steel crossmember, but the fronts just bolt to the pan. This was flimsy & always needed its own crossmember.

This new crossmember tube is only 16ga so just enough to stiffen the floor.

 

 

Tomorrow I will get this tube and the risers welded down.

[Ulu]

On 12/3/2024 at 9:33 AM, Dave72dt said:

You seem to go through a lot of argon.  Small bottle?  Option to go to a larger, maybe more economical size possible?

I weld outdoors. I want extra argon because of air motion. Also I do lots of tiny welds, so that takes extra too.

 

A larger bottle will cost the same, as I pay for cuft used. Not the bottle itself.

 

l bought lifetime 126 cuft bottle exchange rights for $300. If I want a bigger bottle it would be like $500**, but nothing bigger than a 156 sits on my cart.

 

So it’s not worth the cost to enlarge
 

**unless I found a used tank cheaper. That rarely happens with argon, but is how I got my oxy/acetylene tanks.

[Dave72dt]

I knew they provided argon in much smaller sizes than the 126 and as often as you run out, I thought for sure you had a smaller tank but if you have the pressure turned up and hold the gas on longer at the end of the weld, you'll use it much faster.  Next step up from a 126 isn't practical for a DIY.  Mobility goes away in a hurry.

[Ulu]

I got all the rust and dirt out of that tube and coped it a bit more. Then I drilled the holes and the access holes.

 

It needs a bit more trimming but it is almost ready to weld.

[Ulu]

Well today was a challenge. I tried to weld that crossmember in, and started masking a real mess.

 

When TIG welding steel you see the blue-white plasma flame of the electric arc, and you see the glowing puddle of hot liquid metal.

 

When you TIG weld over dirty or painted steel you will also see miniature fireworks. Tiny little orange sparks fly from the puddle. This is carbon atoms as they burn up and die.

 

But my metal was clean. Burnished and acid dipped, then sanded. I had a new electrode.

 

What the devil?

 

You will also see those sparks when you are welding and run out of argon. But I had a fresh bottle. I had just turned it on.

 

I checked the flow, and gas was flowing normally. I even added more gas. The sparks actually increased a bit. My weld looked like porous crap. I did a test weld on different steel. Same issue…

 

Finally, you will see those little sparks when someone has put MIG welding gas in an argon bottle: 75% argon and 25% CO2.

 

The carbon sparks come from the  CO2.

 

So after I figured this out, I had to take the gas back to the welding shop and exchange it. This whole exercise blew most of my energy today and I didn’t get as much done as I expected.

 

I did however get 24 little welds tying that crossmember to the floor pan, and the whole car just got much quieter and stiffer.

[Ulu]

This will support the fuel tank cradle.

 

I need to strip it and weld it in.

 

Also the ends of the new underseat crossmember aren’t welded yet.

 

This really stiffens up the floor. I may have to “adjust” the seat risers if the seats won’t drop right on the risers.

[Ulu]

Today I got my new gas tank support stripped, sanded, and ready to weld in place.
 

Then I made a couple 1/8” frame gussets that notch in under the new crossmember, right where the frame kinks in on each side.

I prepped the floor and crossmembers for more sheet metal welding.

I’ll get all that stuff welded in place tomorrow.

 

[Ulu]

I got these little gussets welded on today.


I think that tank of “bad gas” was actually wet gas.

The new gas worked crappy, then ok, then crappy, then ok.

I laid our all the gas hose to slope downhill, then purged the hose 15 seconds. Problem solved

I would have done more, but today was Christmas tree shopping day. I got a lovely tree but the trunk was 1” too thin to bolt into my stand.

I ended up making 5 little “shoes” for the clamping bolts from scrap tubing.

Problem solved.

[DonaldSmith]

Where's the fifth shoe?  The bottom?  Inquiring minds need to know.

[Ulu]

7 hours ago, DonaldSmith said:

Where's the fifth shoe?  The bottom?  Inquiring minds need to know.

There’s a trick of perspective that makes it all look so “square”.

 

(It’s right behind the trunk in my photo.)

[Ulu]

I was calling these gussets because they also connect to the crossmember, but they are really splice plates, where the bottom cord of the frame has been severed and then welded.

Anyhow I made two more today and got them welded in. The welding went pretty well considering but I was careful to purge my hoses so that I didn’t have any water. When it is cold I can see moisture condense on the outside of my flow meter after a few minutes of welding.

[Ulu]

I got most of the floor welding done now. I also got the fuel tank support welded on.

I need to roll the chassis to finish up a few more pan welds. Also I still have a few welds to repair.

[Ulu]

I got the last 24 crossmember to floor pan welds on the bottom, fixed a couple bad welds, and started stripping off the bad paint. It sounds solid with no rattles.
 

[Ulu]

By the way, when I finished welding, the oil-canning stopped. The distortion wasn’t removed.

 

It increased enough to stop popping under light pressure. It will still pop up if you smack it with a mallet.

 

Perhaps the sheet metal will flex just enough to not crack at the welds from entrained stresses.

[Ulu]

Rain rain rain!

 

It rained four times in the past day and this has kept me out of the boat yard and in the house messing with my aquariums.

 

It also got much warmer, up into the 60s, but now it’s cooled down into the 50s again.

 

But today appears that it’s dried up enough that I will be able to get out and continue knocking the rust and bad paint off of my chassis.

 

 

[Ulu]

Who remembers when Frank Zappa played the bicycle?

 

Ulu plays the Volkswagen pan:

 

https://youtube.com/shorts/DV5exhhWIsM?feature=shared