Cage Pad Question

[backformore]

Just want to clarify something I know I saw here somewhere. When welding the pads for the cage attachment points, I remember folks recommending not welding the entire perimeter, just "stitch" welding, inch long welds with an inch or two between them to prevent punch through from weakening of the sheet metal due to heat from welding. Is this true? If so, does that apply to element welded to the sills as well, or just to the pads on the floor?

Finally, for the folks who do annual tech for cars, is there any issue with this? Any guidance to insure trouble free tech?

Thanks for the feedback. I'm happy to say I am FINALLY at the point of my cage build to make this matter. I actually welded today. YEAH!!

Rory

[Flyinglizard]

Spotting to the floor pan is much stronger but may not pass tech. The floor pan is just there to keep water out.
Try to hit the sills and floor corners where multi pieces come together. Running a tube, sitting on the sill connecting the front and rear cage down tubes is the best way. Just on the driver side is fine.
When you fit the seat, allow the seat mount tube to lay on the floor and connect to the cage legs and or door bars or prior mentioned sill tube..
Ideally you want the driver box to push out of the floor taking the floor and cage assembly with it.
Modern cars have some strong points built in. Three layer areas, extra thic tin here and there. Play tappy tap with a small hammer to find them. weld to them.

As far as tubes joint and such, small angles are much stronger than 90* angles. triangiulate where you can and run straight tubes as opposed to bent tubes.
IE pass door bar can be straight and much stiffer than bent door bars. sameon the driver side, one straight angled tube is way stiffer than bent door bars, if you have room.
https://www.youtube.com/watch?v=1uJ9XCFZBvA This dash bar is angled across the car to help with stiffness.

[backformore]

I wanted to see if someone who does annual/initial tech could confirm that cage pads need to be welded around the entire perimeter and can not be "skip" welded.

Thanks.

[Greg Amy]

The GCR is mute on that point. It thus becomes a subjective opinion, primarily based on the inspector's experience and expectations.

If I see stitch welding, I would not automatically reject it, but I would give it more-detailed inspection. I recognize that those pads are there not for tension or shear but for compression, so my decision will be subjective based on if I think the pad would retain its attachment in an incident, compared to how strong I "think" the point is that it attaches to.

I would be far more hard-ass on stitch welding if that pad was in a lot of shear versus primarily in compression (e.g., most of its attachment was on a vertical rocker surface).

But in the end, there is no regulatory requirement...

GA

[backformore]

Thanks Greg. On the vertical attachments I have continuous welds. I really have just one spot where the floor is contoured in such a way that there is a large gap. I personally don't see a need to fill in the gap with a weld (and some additional material), but it would be easier to do it now than to have to "correct" it later.

[cschimmel]

It would be a lot easier to fill any gaps now ,than after the door bars are in .For sure!
One method I've used is that after the base plates are welded where its' tight ,use a floor jack with an old socket or something and push the floor up to meet your base plate. Floor pans seem to be the lightest gauge steel in the car. It's worked for me and I prefer to have them welded continuously, just like the bars. Hope this helps.
Chris