72 Bedside Repair & General Rust Advice

[ItWillBeSlow]

Hello everyone,

72 long bed in average southeast condition, truck has been in the family since new. I have owned for several years and am contemplating really digging into the truck and doing an average-joe restoration. The overall goal would be to have a decent cruiser and also save a family heirloom. Truck has been repainted once and has another topcoat of primer. I know it needs cab corners, rockers, and some floorpan/kick panel repair based on what I can already see, I haven't sanded everything down to fully assess the condition.

Starting with the passenger bed side, we clearly need a big wheel arch patch on one side. Also have a decent patch of pinholes in the side behind the rear wheel. Two large dents have a large float of bondo on the back near the lights. Best guess is other side is equivalent at the moment. The bed floor has some general rust along the floor supports an I would replace the floor with new if starting this project.

Is this a repairable bedside? I prefer not to buy everything as replacement. I have not done auto body /metal work before but have access and funds for a welder and tools to do the job, and generally have the aptitude to learn these things myself.

Looking for general advice, starting with the bed, about whether this type of metal rot is a major or minor concern. I've already done some poor mans resto work, including POR15 the frame, cleaning up the engine, new inner fenders, etc.

[Pro299]

I can understand wanting to keep as much as possible on a truck handed down in the family. That said, if it were mine I'd look for another bed. In my experience, any rust through like that is just the beginning of the rot you'll find. A new floor, supports, patches, etc. will cost a bunch and you'll still have spots that will rust through before long.

[67swb72klb]

The floor could be ok to use but I would not try to fix the bed side.
Look over the bed cross members good and the floor itself.. good luck!

[sick472]

I have brought back two projects from MUCH MUCH worse shape than your bed, but to do it with any hope of it lasting your lifetime (or close given that it's loved and kept garaged) you will have to get to the back side of those bed panels. I drilled all the spot welds on my bedsides to separate the inner panel from the outer, and used electrolysis and sandblasting to remove all the rust that can not be reached while still factory assembled. One could use an acid dip, but then painting those areas becomes difficult to imposssible. Looking back, I wish I had the funds to just buy new bedsides, but money cries when you don't have much. And, I had the time to rebuild them. Your pin holes are showing up due to the rust that is coming on from the inside. One could weld those holes up, putty, prime and paint, but they will be back or at least ones right next to them.

Now, With all that said...replacing those areas with patch panels really buys it some time assuming that the patch panels extend out past the pock-marked hidden rust. Surface rust up-in-there is just that, but pitting rust is trying to get to the outer surface. I have found that putting in patch panels on a truck bed to be the most difficult of patch panel tasks...they are long and straight which contibutes to warpage. They are not terrrible, you just need to be on your game. Cab corners and rockers and small fender bottoms are a cake walk compared to keeping bedsides striaght. Do the floors first, then the cab, and by the time you get to the bed you are practiced at sheet metal work.

The PO of my 85 K20 put a paint job on it and within 5 years there was a hole the size of a lemon above the rear wheel well...one year later, the hole was the size of my arm (lengthwise). It was puttied, primed, painted, and sold (to me). No inner rust remediation! I use the truck as a daily driver, especially in the winter, so I knew it was coming.

My 2 cents scattered here and there.

[mrein3]

Regarding the question of the bedside being repairable, anything is repairable. However, if the outside looks like that, you don't want to see the inside.

I filleted a bedside on my truck. The bedside came from out west and had no rust on the outside. The inside however...

Remember when these trucks were built, they didn't use galvanized steel then dipped them in epoxy primer like they do today. The inside of the bedside has NO paint or primer. ALL trucks from this era, including the survivors in the desert, will eventually rust from the inside out. That is why our rockers go so fast.

I filleted one bedside on my project. Stripped all the rust off, did the acid wash to convert the rust in the pores that survived the rust removal, sprayed epoxy, then re-assembled the two sides. That bedside will the the last remaining 67-72 bedside on this planet.

When it came time to do the other side I bought a re-pop. Best $400 or $500 I ever spent on the truck.

Originally Posted by ItWillBeSlow

snip

Is this a repairable bedside? I prefer not to buy everything as replacement. I have not done auto body /metal work before but have access and funds for a welder and tools to do the job, and generally have the aptitude to learn these things myself.

Looking for general advice, starting with the bed, about whether this type of metal rot is a major or minor concern. I've already done some poor mans resto work, including POR15 the frame, cleaning up the engine, new inner fenders, etc.

[69Tom]

I'm not sure why it's being stated to not fix the bedside. What you uncovered is not all that difficult of a repair. However, the question is, what other issues might you uncover.

Personally, since the truck has been in the family since new, I'd try to keep/save as much original metal as possible. With that in mind, I'd do the following:

• Purchase some good tools to do the job. I know this from experience. You can do the work with less, but this makes it so much easier. A good compressor, a 100 lb pressure blaster like this one to get rid of rust, paint, etc (https://www.eastwood.com/ew-100lb-pr...e-blaster.html), and a good welder. From there you're ready to start.
• Then I'd use the blaster to remove all filler, paint and rust.
• After that, determine whether parts of the bed need repairing or replacing. If you have holes all over the bed sides like that, then you're better off replacing. But you won't know until you remove that paint.

[ItWillBeSlow]

Really appreciate the comments guys. Any others?

I should also add, I plan to replace the floor since it is well dented and has some rust lines along the supports (not reasonably salvageable). I also have a new tailgate and planned to do the front panel. I really wanted to save the bedsides to maintain the heart of the original bed instead of having all repop.

Not everything is as I wanted to hear but I can understand the viewpoints. It does seem worst case I can give it a try, especially if I split open the inner and outer bedsides. If its over my head or just not worth it, I could go to plan B and replace.

Is splitting the inner and outer a major task?

I hadn't considered starting with the cab and rocker work, then going to the bed. I intended to start with the bed since it would need to come off first anyway to do the cab corner work. Anyone else share this same opinion?

Id like to do this myself to salvage the original parts, as well as learn the skillset. I will also gladly purchase/collect tools to do the work vs. spend less to go replacement. With that being said I dont want to spend 3 months doing it so there is a balance somewhere. I think ill sand the other side this weekend and get a feel for whether its in the same condition. Its its significantly better or worse it could sway a decision.

Thanks again please keep any comments / opinions or similar experiences coming.

[sick472]

Originally Posted by ItWillBeSlow

Is splitting the inner and outer a major task?

Anytime your drill out spot welds turns into a task. It's kinda like taking your gas pole saw out into the yard to trim trees...within 45 minutes of trimming trees, you have created a days worth of picking up brush.

I few tips:

Be maticulous drilling out the spot welds along the upper bed rails. They can be difficult and there are alot of them. I got frustrated and, being naive, ended up doing alot of cutting with a cut-off wheel which left about half of the lip when I was done so it does not look original. I will be adding aluminum 2x3 angle along the tops and insides of the rails to cover it up...kinda like the treadplate bed rails you can get aftetrmarket. The other spot welds are mostly hidden and can be bugger welded up, ground down, and painted without much visual defect concerns.

Once the panels are separeted, they will do some bowing as the stresses are relived from the removal of the spot welds. This bowing is mostly unnoticable, but it's there. You will want to make a piece of angle iron (or maybe a good straight 2x4) that bolts/screws to the inner panel where the bed will eventually bolt in to put it back straight. This needs to be done before welding it back together, otherwise, it may get welded back together bowed and that could make it not want to bolt back up to the straight bed floor panels. This phenomenon can aslo effect the outer panel, but it's just a matter of looks for the most part. You don't want the outer to buldge in or out beyond what your eye can perceive.

Buy a few spot weld cutter bits and some good drill bits. Spot weld cutters make the work much nicer/easier. You will want to concentrate on establishing a good centered pilot divit at the spot welds otherwise the bits may wonder of center and you end up wollering holes more than necessary. Spot welds are harder than the surrounding metal due to the heat introduced during the welding process and the bits will want to wonder off to the softer surrounding material. This will leave you with a spot weld only partially drilled out and then require a carbide die grinding bit to get the rest of it removed. Often times the hole is centered well and the whole weld is not removed. A screw driver or chisel can be used delicately to work the two panel edges back and forth, in and out, so that the remaining weld fatigues and breaks loose. If you find yourself wanting to beat on the chisel with a hammer...you should consider a larger drill bit or the die grinder. The uglier the holes...the more time you will spend welding them back up. If you get real good at removing spot welds, you should end up with a hole in the upper panel (the one you put the drill on to start the hole) and NO hole in the second. This is not an easy thing to accomplish, but it really makes it easier to weld back together. When you have holes in both panels...you have to fill an open hole. When the second panel does not have a hole in it, it welds up much easier, MUCH and it looks better too.

Practice welding up holes on the same thickness of sheet metal. Welding on sheet metal is tricky, more difficult than thicker steel. The heat involved tends to blow out the thin panels causing more welding to be required. You don't always get the spot weld complete before it starts to melt out and you have to stop and start another hole to allow the previous one to cool before going back and finishing it up. This is why having a solid second panel is good. That solid backing requires lease weld which means less heat which means less blow-through which means less welding.

I welding the patch panels back in while the bed panels were separated. This makes it easier to get to the back side for clean-up grinding, priming, and painting. Welding patch panels back in is a different topic...you don't just start at one end and start welding. It is a long series of spot welds. A few to get it held in place and then alot of skipping around to avoid heat build up and warping. And when I say spot welds, I mean "spots". Anything longer than a spot and the panels take too much heat and will warp beyond what you care to beat on with a hammer and dolly.

I hope this does not scare you off. I did my sheet metal work on my truck 20 years ago with no experience and without youtube for guidance. Even did it with a flux core welder...not the best choice, but it worked. It just requires more clean-up grinding.

[mrein3]

Originally Posted by ItWillBeSlow

Is splitting the inner and outer a major task?

I'm glad I did the one I did. That said, I'll never do another. I know, never say never.

sick472 made some pretty good comments about drilling spot welds and patching panels while they are separated. I didn't have any patches to do other than fill in a travel tanks door hole a previous owner made. Maybe it was even the dealer that made that hole.

One other thing I would recommend is once you do all your rust removal and have all your patching done, but before you weld the two sides back together, spray epoxy primer on the inside.

The problem with epoxy or any paint for that matter is you can't then weld the piece where you painted/epoxied. To get around that I masked off all the spot weld holes and places on the wheel arch where you need to reweld. And the back and front. After your epoxy is cured, remove the masks and then spray weld-through primer. That you can weld as the name implies.

Those are the only things I can think to add.

sick472 - good tree trimming/brush analogy.