Spot welding vs seam welding ---> chassi

[cannabolic]

I thought I start a topic about welding.

I see there are different views about the matter.

Some say spot welding (me) while others do seam welding.

I'll put my pros and cons, but I am very interested to hear your opinion.

[u:c440e4a63d]Seam welding[/u:c440e4a63d]
Pros
* less time consuming

Cons
* more heat to the metal

[u:c440e4a63d]Spot[/u:c440e4a63d]
Pros
* easier
* less heat

Cons
* take more time

That's about my adds

I see a lot of seam welding, but I also see spot welding (Japan, even N2 TRD).

Please put your experience here.

I am not writing about stiffness cause I've heard/read that both are stiffer than the other.

[[Walaki]D`Lair]

I'm ahead of the chassis work, so im just seeking information Good topic

[MartinS]

yeah, sounds interessting.
I'd like to know how you guys are spot welding? Do you have a special tool or do you have a home-made technique?

[doggy]

Spot welding all the way - BUT - you have to have apropriate equipment for this - and this costs a FORTUNE... A spot welding machines - that car weld 3 - 4 1mm sheet metals sandwitches - cost a fortune....

Also - if you have a good TIG - you can do a nice spot welding too - but this will take more time... especialy - in preparation of the metal before welding.

[Aram]

Great topic!
Just in time too.

BTW, does anybody have the TRD bible AE86 in PDF file?

[dazed_driver]

I did both. I seam welded MOST of my rally car, but I took a mini hole saw kit and bored holes through the top layers in the door openings, 1/4 windows, and a few other layered areas and "spot" welded them with my MIG. But for the most part, if you run an inch on, inch off (2.5cm), you'll be good. It's kinda hard to do, though... you kinda wanna keep going. It takes a bit of practice to restrain the bead down to an inch, as its way shorter then you'd think, while welding, haha.

[Ivan141]

@Aram: Lennert and I both have the trd bible in pdf.. but you'll probably still find it on the internet as well as it is pretty popular.

About the seamweld vs spotweld discussion:
Spotwelding to me seems the obvious better choice. It adds strength, but has less negative sideeffects on the metal.
But for most of us the choice is not really there.. Good spotwelding equipment is expensive, and you're not likely to use it often so the return on investment is not there.
Also, spotwelding equipment that can reach the floorpan or any other part of platework that is not near an edge is totally out of reach for us amateurs, and most professional garage's too. So you'll need to seamweld there anyway.

If I had the choice I'd spotweld around the doors and window pillars, and seam weld the rest. But since I dont want to fork out cash to get spotwelding done I would rather just drill and weld in the manner that dazed driver described.

[HybriD07]

Great discussion this, as i'm preparing to spot/seam weld my 86 this winter.

I also found this video of keiichi's ae86 build which might be interesting.