welded seams?

[CamaroAJ]

was watching some video of subaru building their race cars and they stich weld all of the seams on the car to stiffen up the uni-body. they were doing about 1.5-2 inch welds every 6 inchs or so.

i do for sure need to do this to the torque boxes for the spring mounts on the aftermarket floorpans, the spot welds broke when i put a screw driver between the two panels. they didn't look very good to start with and i'm glad i checked it.

is this something that anyone here has done or is going to do? i am thinking about doing it to mine and the only downfall i see is if any part needs replaced down the road it would be a major pain.

[Bow Tie 67]

I did the seams under the roof when it was off. The vehicle will transmit road noise / vibrations much better..... ie: louder inside, its a trade off but I think worth it.

[Rhino]

I did the seams under the roof when it was off.

I wish I would have thought of that when my roof skin was off. It's a great idea.

[John Wright]

Behind the rear seat is a place that I always thought needed some help....in my car I could see the factory paint lines and where the car has moved over the years.

[CamaroAJ]

looking through pictures of mini tub installs on DSE's web site some of the tubs have full welds on the inside and some only have stich welds.

i think i'll go ahead and stich weld the whole car while i got it tore down. i'll bet it will also help with squeeks and rattles caused by the body flex.

[Kenova]

was watching some video of subaru building their race cars and they stich weld all of the seams on the car to stiffen up the uni-body......
......is this something that anyone here has done or is going to do? i am thinking about doing it to mine.....
This is a popular practice among the H-body fans (Vega, Monza, etc.). A lot of guys will stitch or fully weld the seams in the engine compartment, while a few have done the whole car.
If you have the car apart, plan on repainting it, have a mig welder and some spare time, I would say do it. I'm sure there is a point of diminishing returns as far as how much you do, but who pays attention to that sort of thing?

Ken

[CamaroAJ]

spare time is something i am short of. but if its going to help make a better car in the end then its worth the extra time now.

I'm not going to weld the whole thing just stich weld it. now maybe the firewall i'll fully weld since i'm smoothing it and this will help doing some of that. other than that i'll just do the rockers to floor pan and any other real structure that will help tie everything together. more than likely won't waste too much time on small things like the trunk drops and such.

[Jim Nilsen]

I welded the seams at the pinch weld on the rocker and the wheel wells to avoid having to use seam sealer. It makes for a cleaner look and it is more rigid. I don't like welding the area between the rear panel and rear qtr or the rear qtr and the panel below the rear window because the welding will make it brittle and can crack under stress, seam sealer can be used there and look good to make it all smooth and not crack.
I also added a whole bunch more spot welds everywhere I could to help out the whole stiffness of the car.

[Scott Hightower]

I welded the frames on old sportsman and hobby stock cars years ago. It definitely made them more rigid, stronger, and they handled better.

Scott
Fab Manager
Welders360 (http://www.welders360.com/)

[CamaroAJ]

i went ahead and welded the seams on the floor pan last week. what other seams should i weld? the floor pan and tubs are done so whats next?

[novaderrik]

i don't think you can over weld the car- the seams more you weld together, the more solid the car is.

[High Plains Mopars]

Look around and search for for the thread on uni-body stiffening by member SN95. He measured the results of seam welding a mustang and they were pretty impressive.

[Jim Nilsen]

Sounds like you getting there !

[Jim Nilsen]

i went ahead and welded the seams on the floor pan last week. what other seams should i weld? the floor pan and tubs are done so whats next?

Add more spot welds in the door frame,cowl, and everywhere else you can. It will take quite awhile to get them all.

[CamaroAJ]

i've been welding seams here and there when waiting for some other things to cool down. i have the frame rails done along with the floor pan.

the door frame, when i replaced the inner rockers and firewall i added extra spot welds to it. i'm just going to add a few seem welds to what i already did.

the cowl area has been fully welded on the inside and outside at the firewall. had too when i cut it to move the engine back, kinda like 2 birds one stone. i still need to add some welds to the sides of the cowl.

also i am going to weld the seams on the torque boxes. the aftermarket floor pan came with them installed and it looks like 1/8" pinch welds and they didn't look good. i stuck a flat blade screw driver between the torque box and the floor pan and twisted and all of the spot welds came apart like a zipper!

[paul67]

If seam welding go so far then stop ie about 6" then gap 6" then go back and in fill , if the weld start to split it will stop at the break and go no further.

[CamaroAJ]

not fully welding the seams just 1.5" welds every 6" or so.

[paul67]

I mean fully welded,they do that on a lot of rally cars ,and there also now requiring it on our UK MOT repairs on structure.

[CamaroAJ]

is that so if they are wrecked again they just total them out?

[cpd004]

So are there any downsides to doing this?

[GTOtzel]

Seam welding is great for stiffening up the entire car, anytime you can take out body flex, you can better tune the suspension for the load being put into the car. I would limit seam welding behind the rear axle and in front of the front wheels. Make the car as rigid as possible but in the unfortunate event of a crash the area in the front the front wheels and behind the rear axle will be your crush zones so as not to transfer the energy through the car to you. As long as the car is stiff between the front and rear wheels, where suspension loads take place you achieve performance and safety.

[F-Body International]

Interesting thread. Welding a shell seems like a good idea but would make it hard to disassemble it were ever needed.

Solid body mounts, subframe connectors and firewall braces are the main go-to mods for an F-Body. Reinforcing the areas surrounding those mounting points would probably be of great benefit.

[Zachalanche]

I did most of my car between the front and rear axle. sandblasting the body first made it much easier.

in my experience disassembling spot welds isn't all that easy. you get the occasional bad one that pops with a screwdriver, but the rest are kind of a pain in my opinion. I don't see seem welding increasing the difficulty of disassembly all that much in the event you need to go back in and replace a piece. But I am practically a surgeon with an angle grinder.