I'm repairing the passenger long. I've removed the rust and welded in two patches that comprise the bottom 2/3 of the long. To strengthen the long due to the welding I've made a sleeve out of 18 gauge cold rolled (same material as the patches) that is 36" long as pictured below.

Click to view attachment

The problem is that the 90 degree bend in the sleeve has made it tough to bend to the exact shape of the long for a tight fit. I put clamps on it and then with a hammer and punch beat it at the back (as shown by all of the pock marks). I think if I start welding it at the front and then do the hammer and punch thing as I go along it will probably conform to the long. But, I'm not 100% sure and would hate to have it half welded in and realize that the last 1/3 will not fit tightly. I could also make an 18" relief cut along the bend, bend it to conform, and then weld the sleeve to that shape prior to welding it to the long.

I was going to run a bead on the black lines to make it more stiff, but figured that would make it even harder to make conform to the shape of the long when welding it in. So, I guess another advantage to the relief cut method might be that I could put a couple of beads in the sleeve (though perhaps that might also throw the fitment out of whack and put me back to square one with welding it in being more difficult).

So, my question is, which is the best way to proceed. Take a chance on being able to bend it as I weld, or make the relief cut to fit it prior to welding it in? And, if the latter, should I put a couple of beads on the sleeve?

I would toss that, fix the long with new panels from Restoration Design and then add a reinforcement from Maddog that's made to fit out of the box and is proven to work well.

Definitely don't run that long seam on the black line. Long welding runs are how you warp/twist cars.

Oh, and while I'm being negative (sorry ) hammering while welding is a terrible technique. Everyone who's learning tries it at one point or another, and most people learn their lesson. If it doesn't fit perfectly, don't start welding.

Why not drill and screw in several locations ti pull it tight? Yup would not weld the total length unless you do 1inch beads let cool and skip to a new spot. Its the best way to do it without to much damage.

Thanks for the feedback. I'm pretty happy with the patches under the pictured sleeve, but not so much with the sleeve. If the Maddog is like the Engman that goes on the outside I'm wanting to stick to the inside. This car is going to be stock so no need for chassis stiffening from a performance perspective.

I'm not planning to run any beads, just plugs and some seam sealer.

Yeah, I'd rather not hammer but, with what I have on hand, I don't see a viable alternative. So, any issue with the relief cut method?

Addendum: just realized the bead comment.....in my first post I meant a bead from a bead roller. I should have been more explicit.

@mb911: good idea but my sense is that the 90 degree bend has made it so stiff the screws wouldn't bend the metal.

Just my opinion but I would make smaller reinforcement sections.
Biggest problem here is the top must be flush with the bottom.
If both panels aren't in contact, air gaps will cause the plug welds to be weak.
Smaller sections can be manipulated to fit better and than welded together.
Use vice grips clecos and sheetmetal screws to hold the panels for welding.

@ mgphoto: If I can't make the single large piece fit correctly, I think that is a good solution.

Sleeving with smaller patches will be less problematic, add the needed strength, and will solve the fit problem.

The area around that oval access hole is very easy to deform with heat/hammer, so be especially careful with heat there (ask me how I know)...

A fellow who saw my handiwork in that region offered that I could have tack welded some square box lengths along the "cabin" side of the longs to prevent warping. Everything turned out OK, but it was good advice.

Click to view attachment

Extremely busy right now. Haven't been around lately. I wouldn't worry about making it tight on the radius. For what your attempting to achieve you could use a break and form it like this. I'm no artist so... But you should get the picture.

As long as the flats are well fit you will be ok. Spot in a random pattern and let things cool before moving on.

I'd clean up the inside and seal it with a proper rust-preventative coating. Then put it back together and use the Engman style kit to reinforce, which fits proper and is proven to be the most effective way to strengthen the longs (better than the outer clamshell versions).
Just another $.02 worth.

Thanks, Rick! Not having to worry about the radius will make it a lot easier. Given that, I might be able to salvage the existing 36" piece. Is there an advantage to having it all one piece or, if need be, is it just as good to have say 3 x 12" pieces?
P.S. I have a brake rated for 18 gauge, but when they did the rating they must have been using a 4" piece, because it won't even touch a large piece. So, I'm relegated to bending in small sections with a little vise...

You will get more strength if you just add material along the top flange and along the bottom glange. The material on the side isn't all that important. If you please a piece of 3 " x 1/8 flat bar along the top and along the bottom it will give you incredible strength by a square. It's not even a doubling its a square. I'd have to calculate it but let me tell you it's way better than welding a sleeve.

I'll do hand calculations and show you the stiffness of a sleeve Vs just adding material along the top and bottom flange. I'm BBQin right now so calca will have to wait. Trust me it's the way to go.

Would that apply in this scenario where my concern is the butt weld seams on the vertical plane of the long? What I'm really trying to achieve is strengthening of the planes that have the weld seems (mostly on the vertical plane and also one on the bottom in the middle where the two pieces meet).

P.S., just finished gorging myself on BBQ chips and didn't think I could feel hungry again but your BBQ talk has me thinking BBQ again

I think that what you have there is good to transfer the load to the top and bottom flanges of the long. Then weld an additional 1/8" plate along the top and bottom flange and it will be stiffer in bending than any engman kit. I'll calculate it for you and show you by the numbers.

You can't reinforce across the flanges while it's apart. Clean it up and have absolute control with longitudnal pieces on the outside after it's back together. There's no need for 1/8" anything along the longs! That's heavy puke, not engineering.

I did/am doing the same thing. I am using 18ga.
I am not going up as quite as high, but basically the same thing. I probably wouldn't have gone up as high, but I wanted to get the emergency brake recess kinda high up 'cuz that area is prone to cracking. It gets lower going back.
I built mine in sections because my break has difficulty with 18ga that long. I think I did it in 3 pieces, including the part that went up behind the rear heater tube.
Doing it in sections allowed me to get it pretty tight. I didn't weld it into the long in pieces, I formed it in pieces, then once I had them good, I welded the pieces together, then welded the whole thing in.
Doing it in pieces also allowed me to form the grooves easier on the bottom

Not a lot of welding in any one spot to allow areas to cool. No long beads.
Oh, and on the the side I am about to do I will probably make the cutouts for the heater tube dimples round. I figured the stress would be better distributed.

Here is the driver’s side before I welded it and coated with Eastwood frame coating:

Click to view attachment

This is after:

Click to view attachment


This is the passenger’s side patch to repair the rusted area. I will then make another layer similar to the driver's side:

Click to view attachment

Show me with a calculation that what I'm proposing is not engineering then I'll believe you. Otherwise you are flat wrong.

I don't want to get into calculation games. You'd have to show yours too. If you want to add excess weight, no doubt your answer will be strong. I do know that 1/8" is not necessary. Eighteen gauge with a proper fit, welded properly, is hella strong. If you need something beyond that, then you need a cage.

It certainly is an interesting idea for stiffening the chassis, assuming the calculations pan out.

In my case, given that I'm not looking to stiffen the car, but certainly wouldn't mind having it stiffer while I'm at it, I do wonder about the extra weight vs. the stiffening if I really don't need it.

@ amfab: very nice work! I particularly like how you are replicating the beads in the bottom of the long. I should have taken the time to do that, but no going back now.

You're on.

Fair enough. All this aside, I am really enjoying your build. Could be lighter if you are using 1/8" in the longs... but it's truly a standout. I saw someone call you out on FB "it will never see the road." I beg to differ: Watching your work, I know you'll get it done and I can't wait to see it driving.

Thanks, I bought a $130 harbor freight bead roller and reinforced it and it works pretty good.
Click to view attachment

double post

Use sheet metal screws where you will later do your plug welds to hold the pieces tight together. With all the plug welds or rosettes, the two layers will share the load. Make sure your door gaps are good as you progress, move around with your welding locations. Eventually you remove the screws and finish up welding those locations.
Click to view attachment

A small relief cut on the horizontal plane seems to have taken care of it.

Click to view attachment

Click to view attachment

Sweet

(DISCLAIMER ALERT do this at your own risk. This may or maynot work)

OK I did some calculations based on a 6x4 section .09" thick. This is a close approximation to what we have. I compared apple to apples and was somewhat surprised with how well the current method of strengthening works. i.e., outside reinforcing or inside reinforcing. Since the long is opened up I thought that it would be easy to weld a 4", 1/8" thick flange on the inside of the long at the top and bottom flanges. Well the calculations show that this would be 86% stiffer than an unreinforced long and a long reinforced with a plate welded to the side is 71% stiffer than an unreinforced long. Bottom line the current method of stiffening is really really good! Either Engman or Maddog However, since you have the longs opened up, it would be simple to weld a top and bottom plate 1/8" thick and make as wide as possible. I would also make sure that the vertical section of the long is a continuous piece. For everyone else, if you use the Engman style along with the Maddog......damn that will be really stiff.

Thanks Rand ....man there are a lot of haters on Facebook. I mean really why would anyone want to say something like that?

Very interesting, wish i could follow all of the math. But wouldn't it be better to use the usual Engman type stiffener (or similar to what OP is using) to hopefully more evenly distribute the flexing of the chassis as a whole? Like too much rigidity in one area causing weekness some where else? Debating doing something similar to my own car.

PS the Facebook hater is probably incapable of doing such complicated work so they pin their inadequacies on you. Hate people like that.

Brett

Bretth after doing the math, the Engmann or Maddog area really good alternatives. Since the OP has the long opened up, I though it would be easy to reinforce it with a bottom and top flange.

I think what Brett is saying is that the sleeve I have is kind of like a reverse Engmann (because it's on the inside), and so might be sufficient. But, if I understand correctly, you were suggesting to install my sleeve and then add one strip of 1/8" plate on both horizontal planes. I'm installing the sleeve to strengthen the long because I've welded in patches such that the bottom 2/3 are new metal, so I don't know where that puts me with respect to chassis stiffness as a starting point relative to a new long that has never been cut.

The maximum length of a single piece of plate could only be the distance between the locations where the heater tubes are welded to the long (I'm keeping the heater tubes) on the top side. So, that would be about 25" give or take an inch. Probably 2" wide would be the widest it could be. On the bottom it could run from the heater tube at the front to the back of long (about 35").

I'm still left wondering whether or not it's something I should do. If my sleeve is kind of like an Engmann, even given that it's there to compensate for the welds, perhaps that's strong enough for my needs.... I'm not an engineer and not really sure how to weigh the costs-benefits of adding the plates vs. the downsides (e.g., extra weight).

One long piece like the Engman kit, that fits precisely and tightly against the longs is so much more efficient than hacking 1/8" patches on the inside, which will be way heavier than necessary. But it will be stealthy, I'll give you that. It's a helluva lot more work for less benefit IMHO. Then you have to close it back up. I'm glad your welding skills are solid, because most would twist their chassis out of whack with all of that excess welding.

Ya, 1/8 is not the answer regardless of the math. When you add heat to the equation you introduce a whole new problem. We have had countless guys posting on here with cries of help after they warped the longs to the point where the doors and top no longer function.

The type of heat that would be required to properly bond 1/8" to 18 GA. is a recipe for disaster. The holes in the 1/8 would need an increased size in order to allow the wire to generate enough puddle heat to melt into the 1/8. At that point if your not blowing holes through the factory sheet metal you introducing heat into the 1/8 that expands out further from the spot weld and stays hot longer. allowing the metal to warp.

Doug, Use 18 GA. move the spots around while working and cool the panel as you work. Check the car as you you go to be sure you are not moving the metal. Don't worry about stitch welding the edge of the sleeve.

Long reinforcement is a good Idea where from the inside or the outside. But I can not express enough how important it is to work slowly here. There is always time to do it right the second time.

Fortunately its summer in LA and with my welding jacket I get too hot before the metal gets too hot, so I can't help but work slowly.

Good advice, Rick. I spent all day yesterday welding in the sleeve, so that's pretty slow. I waited for the metal to cool to where it barely felt the slightest bit warm anywhere on the panel before doing another weld (only a few degrees Celsius warmer than the rest if the car). The long still pulled up a bit on the bottom! Door measurements are unchanged but I'll put the door back on the next time I'm at the farm just to make sure. Since yesterday, I've been thinking exactly what Rick is saying... The heat from welding 1/8 to 18g would be really dicey... certainly outside my current welding ability.

Back when I learned to weld, we all wore flannel. Hot, but not as hot as leather.