Bolted on body panels

Hi, I am in one of them quandaries about wanting to change things around without welding, as in test fitting.

Assuming all fasteners are used in replacing most all spot welds as strength testing and ridgitity are a concern.

Outside of looks, i assume it can be done and allows further mods if needed without having to cut out the panel being tested.

Any bad points in doing so. Yep, I know it's going to look like bad surgery, but I assume the holes can be welded closed after everything is proper.

tyrodtom wrote:  Do you mean replace each spot weld with a self tapping screw, or something similiar to hold the panels together? Unless you use some awfully big bolts, the strength at each point isn't going to equal the strength of a spot weld, and then you'll be left with some big holes to weld up in both panels. I don't see the point in this, unless you're just wanting to test fit it. Older cars that were spot welded by men don't have the welds in perfect placement,  when you compare two of the same car, you'll see a variance .  Newer robot welded cars do have exact spot weld placement, the spot welds will be close together in high stress areas, and have wider spacing in low stress areas. I try to duplicate exactly as I can the spots welds on street driven cars,  but on race cars I spot weld the heck out of them, and solid weld some panels. I usually use a lot of C-clamp vise grips to hold the panels together,  or if it's a area that I can't use a C-clamp,  I'll use small self tapping screws, that I take out one at a time as I weld up the spot welds.   But I did once race a car for about a half season with the quarter panel held on with self tapping screws, because I wanted to able to take it off later and beat it out better.   But that car had a full roll cage,  the qtr. panel contributed very little strength to the chassis.

Thanks for the great info.

Well understood, and realise the bolt size and how many spot welds must be done. I have thought a bit about placement of factory spot welds, and the lack proper spacing was noted with the modified factory panels I have, both replacement and on the car.

Won't be using screws as this is load bearing and to be ridged. Thinking of making backing plates to hold and clamp the panels together, and distribute stress evenly. Though it won't be stress tested on the road, just vehicle weight.

I guess I am talking my self into doing at least one side to see how fitment and all works before final fit and weld.

If it were not for the fact things will not be in relation to stock fit. This would not be my concern, as it would be just like any other patch panel replacement.

So that is why I must allow for the bolt on approach. It is the only way to do it and feel confident before welding. In my head it sound so backwards, but I have no other car body or template to go by. So my car is a test model of sorts on this.

A full weld will be considered as there are just to many questionable areas to just use spot welds to mount like stock.

Welding in holes will be one more thing to add, at least they are easy to get to.

Ah, even factory spot welds are not that strong. Had popped off a good section of the splash shield / air vent defector at the cowl. Made me think twice about some factory welds not holding well. Though they were lighter than structural spot welds to begin with, just some would pop others would tare the metal around the weld.

I plan on doing my shock humps. I made a comment a while back on my modding of the front, and felt the best way for a first time change up, was to think about how everything works in final form than to be left having to cut welds to make a change.

Unclejohn, did a full weld on exchanging out trunnion to 70 on up suspension. So I know it can be done, but I have a bit more than just factory setup. So just the changing out the panels is more than just using alignment from factory positions with components.

It will not be on the road, just needed for measurements and adjustments with car on the ground. I think it is my only sane option. One thing I hate most is getting something done and finding I must do more work to get it right. Even though welding up holes will be adding work, it is in a positive direction not backwards. Maybe the time between the good side and the bad side of things will be a wash, who knows what trouble I can bring. That is why I think about things, knowing what seems so easy in all the previous mods, have not backfired as of yet, knock on wood. That's why it takes me a bit of time before I make big changes.

For the most part, the stuff I have completed is 1st time on my own with a bit of info from various posts through the years, and made it all work for my ideas. Second, I have no shop, and limited tools. But looking at how much I have done, makes me wonder how much I could have done long ago when all I needed was to put my mind to it. Ha! I guess I needed to kick myself in the arse, to get a move on, more or less.

Ok, thanks! Yeah it makes sense to get the welds done as best as possible even if redundant doing both types of welds.

I don't plan on redoing the area once things are in place. It will be a permanent change as far as I am concerned.

At least I can have peace of mind in how I start on it. Nothing like telling yourself it's easy enough, and wonder after the fact, why did I do it? Ha!