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Old 11-04-2018, 11:23 PM   #1
BaroneDog
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Rusty Roof Best Approach?

My 67 stepside does not have much rust, but it does have it BAD in the drip rail and adjacent roof area (see pics below). I think it is because it spent much of its life in foggy SF and that salty fog accumulated on top. Anyway, I have done a little reading and there seems to be three approaches that I have seen:
  1. Shave drip rails and cut out roof and replace with new sheetmetal (roof top appears to be available through LMC)
  2. Chop off entire top (through pillars) and weld on new top
  3. Find a new cab

My preference would be to do #1, but it appears that the rust is also under the drip rail and into the top of the door frame on the driver side (last picture below) which might require some more detailed custom sheetmetal fab to fill in. I have never done this type of body work and I only have a MIG welder. Trying to decide if this is something I want to tackle. Seems like something in the realm of my skillset if I take my time with it.

Would appreciate some input from those of you who have done something like this before. Be honest...I can take it. Thanks!
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Old 11-05-2018, 12:17 AM   #2
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Re: Rusty Roof Best Approach?

Bad thing is thats just the rust you can see...when you start cutting there's no telling what you'll find...you could do your options in the order you listed...if it's to bad I'd be looking for another cab...I would also weigh how much time and money you'll have in invested fixing your cab vs. buying another one in better shape...

You could try cleaning up the drip rail with a sand blaster first just to see how bad it really is
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Old 11-05-2018, 09:03 AM   #3
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Re: Rusty Roof Best Approach?

The trouble with the rust you're showing is that many times the issues start from inside the roof from condensation and not from water laying in the drip rail. You may not fully see the damage until the roof is opened up. Try an inspection mirror from the inside and perhaps you can determine where the rust originated.

As far as shaving the drip rail, you have at least three layers coming together in some fashion, and likely an inner panel that blocks any hammer and dolly work from the inside. Meaning, any shrinkage that naturally occurs from welding will be there for good. Any additional blow outs from metal still rusty on the inside, and any further weld attempts to fill such blowouts, will cause additional shrinking from the additional heat, likely causing puckers in the roof. If you can't get to the weld seams to planish the welds to stretch out the shrinking effect, it's going to be a mess, no two ways about it.

If repop replacement parts are available and you have no other damage in the cab (crash damage) then perhaps repairing with new parts is a good option. Not likely that new England area has any rust free parts left in a junkyard, but if you're leaning toward cab replacement, I'd look for as rust free as possible in the dry areas of the country. May be some cabs in the classifieds here. See if anything is available, that may help to steer your decision.
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Old 11-07-2018, 10:21 PM   #4
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Re: Rusty Roof Best Approach?

Thanks guys. Good advice. A friend has an inspection camera I can try to stick in the hole on the inside of the cab where the visor mounts. Might be able to survey the depth of the situation before cutting anything.
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Old 11-08-2018, 09:17 AM   #5
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Re: Rusty Roof Best Approach?

There is certainly evidence of rust trough. I'd grind out all the seam sealer. Possibly cut out a couple of the worst spots and take a look. It may not require the entire roof to be replaced.
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Old 11-08-2018, 12:43 PM   #6
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Re: Rusty Roof Best Approach?

Thanks Bigdav160. Would be great not to have to replace the entire roof. I have a feeling most of the roof is in good condition. But, as you can see in a few of the photos, there is definitely some rust that has migrated into the very front portion of the roof. I could sand it down and treat it with something, but my guess it that it would come back. I was thinking that cutting and welding several small spots on that curved surface might actually be more work than just cutting the entire top off and replacing. But maybe that is not true. Have you ever done a roof repair? If so, I would like to hear about your experience. Thanks.
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Old 11-08-2018, 06:33 PM   #7
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Re: Rusty Roof Best Approach?

In the middle of it now. I think it's easier to replace the entire roof panel than repair. I didn't buy a new panel, sourced it off of a donor truck. It is labor intensive.

The good news is if you cut the roof off & find too much damage under it you can still section the top half & you're not out anything except your time & labor.

The original panel had over 60 dents. Worked on it until I gave up! Pretty sure someone was dancing on that roof. With the roof off it allowed me to easily repair some dents on the inner panel too.

I haven't bonded the new roof on yet but there are a couple of threads on here that show you how.
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Old 11-10-2018, 10:56 PM   #8
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Re: Rusty Roof Best Approach?

Great pics B.W.! Great to see someone else working to save a cab! Would love to see more pics as your work through and finish. Any chance you can send some links to the threads you say have the steps? I have seen a few threads about the topic but did not see a step-by-step yet.

I bought a little endoscope that was able to fit in between the two roofs (fished it up through the hole for the visor) and was able to snap a few pictures of the inside. Great little gadget. Only $35 on Amazon. Hooks to your phone wirelesssly. Very easy to use. In case you are interested: https://www.amazon.com/Depstech-Endo...era+with+light

Anyway, Looks like the top (outer roof) is worse than the inner roof. First shot is the entry point then next two shots are on the drivers side looking down towards rear along the seem. Other two shots are the front. Blueish tint is the top (outer) roof. Doesn't look too bad at the seem, but would be interested to see what you and others think.
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Old 11-11-2018, 12:59 AM   #9
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Re: Rusty Roof Best Approach?

Yeah, I was amazed at how little rust was under my roof - bare metal with almost no rust! Progress is slow right now, I still have to epoxy prime the inner panels and spray cavity wax down the A & B pillars before I bond the roof.

Still not sure what I'm going to use as a sound insulator, of the two roofs I cut, one of the insulators is in good shape, could re-use it but I think I'm going to try "Peel & Seal". Thought about closed cell foam also.

To bond the roof I'm going to use Evercoat Large Panel Adhesive (P/N 100816) and lots of clamps!

Here's two:
http://67-72chevytrucks.com/vboard/s...d.php?t=462888

http://67-72chevytrucks.com/vboard/s...ight=roof+skin
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Old 11-26-2018, 08:20 PM   #10
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Re: Rusty Roof Best Approach?

Baronedog are you doing a full restoration on her? Doesn’t look that bad from here but if your going to put a lot of time and money in paint I understand you wanting to be sure
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Old 12-04-2018, 02:38 AM   #11
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Re: Rusty Roof Best Approach?

Baronedog,
I have the same problem as you. My problem was the heat here in Cali baked the seam sealer away and allowed rain to get between the pinch welds. So now I have rust on the inside above the window frame. So as you I asked myself repair or just cut the complete top off and replace with good donor. I am going to cut the top and replace. Going to make original opening panels out of plywood. These will get put in to replace the doors and front and rear windows so when I put donor top should be easy to size up and then start welding.
Good luck and please take pictures as you go..
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Old 01-13-2019, 10:02 PM   #12
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Re: Rusty Roof Best Approach?

Is there any difference between the replacement panels sold by the various vendors? I usually get stuff from LMC but never bought sheet metal from them. I need drip rails and the outer roof skin at least. LMC has all except for the front drip rail. Brothers and GMCPauls have the front dril, but GMCPaul website says they do not sell the side drip rails now due to poor quality. Any advice on where to buy and whether anyone has had good luck with the side drip rails and outer roof sold by LMC? Thanks.
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Old 01-14-2019, 09:24 AM   #13
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Re: Rusty Roof Best Approach?

It's my understanding from reading stuff on here that most all panels are made by one manufacturer and then rebranded by whoever sells them....seems like a crap shoot as to how they fit....
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Old 01-31-2019, 11:08 PM   #14
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Re: Rusty Roof Best Approach?

OK, so getting ready to cut roof skin off and start exploring. However, not sure about best cut locations. Part of the issue is that I don’t entirely understand how the top roof, drip rail, and door frame come together. To help with my questions, I added a few cross-section hand drawings below.

So, related to the first drawing, I could probably cut at #1 and then grind out #2. Or, I could cut further back around #3 and then peel back roof and delaminate #4 (but not sure if stock assembly is welded or adhesive bonded). Also, is the drip rail butt welded at #5 or does it overlap more like the second hand sketch below?

Hoping that a better understanding of the construction will help me avoid mistakes.

Thanks!
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Old 02-01-2019, 05:50 PM   #15
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Re: Rusty Roof Best Approach?

I took my outer skin off. It's still off now I guess. It was time consuming to do, but I got it off nicely and fixed it up pretty good.
If it was me I would take it off as if you were planning on reusing it. Even though you stated in earlier posts you are going to buy a repop. Just in case the new roof doesn't fit exactly like you want - which is a common issue with repop items.
How I removed mine was by first sanding all the paint off around the whole roof where you have #2 on your drawing. You wouldn't go down the back of cab beyond the roof seam I guess. Then you will see or feel a bunch of spot welds. Take punch and punch the center. Drill them out with spot weld drill bit. There will be a ton of them! Then I cut directly in the back seam across the whole cab above the back window. I then took a flat screwdriver and dug under #2 in your drawing and started prying little by little until it popped off.
To answer your other question #5 isn't butt welded. The drip rail is spot welded. From your picture the spot welds are all about under the "R" where in your picture you wrote "drip rail". I also removed them to clean up those areas and put them back on.
Take a look at my build thread if you want to see some pics. I might even have some more that I didn't post if you want to see more of what I am talking about.
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Old 02-01-2019, 05:57 PM   #16
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Re: Rusty Roof Best Approach?

Good info Ryan. Thank you. A suggestion???? You should put a link to your build in your signature?
Quote:
Originally Posted by ryans69chevy View Post
I took my outer skin off. It's still off now I guess. It was time consuming to do, but I got it off nicely and fixed it up pretty good.
If it was me I would take it off as if you were planning on reusing it. Even though you stated in earlier posts you are going to buy a repop. Just in case the new roof doesn't fit exactly like you want - which is a common issue with repop items.
How I removed mine was by first sanding all the paint off around the whole roof where you have #2 on your drawing. You wouldn't go down the back of cab beyond the roof seam I guess. Then you will see or feel a bunch of spot welds. Take punch and punch the center. Drill them out with spot weld drill bit. There will be a ton of them! Then I cut directly in the back seam across the whole cab above the back window. I then took a flat screwdriver and dug under #2 in your drawing and started prying little by little until it popped off.
To answer your other question #5 isn't butt welded. The drip rail is spot welded. From your picture the spot welds are all about under the "R" where in your picture you wrote "drip rail". I also removed them to clean up those areas and put them back on.
Take a look at my build thread if you want to see some pics. I might even have some more that I didn't post if you want to see more of what I am talking about.
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Old 02-02-2019, 12:53 PM   #17
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Re: Rusty Roof Best Approach?

Quote:
Originally Posted by First c10 View Post
Good info Ryan. Thank you. A suggestion???? You should put a link to your build in your signature?
I have no clue how :/
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Old 02-02-2019, 01:58 PM   #18
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Re: Rusty Roof Best Approach?

OK hope this helps!

Top left of the page in the blue bar you will see the words "USER CP"
click on it.
On the left hand side of the page you will see "SETTING & OPTIONS"
Under setting & options you will see "EDIT AVATAR" Click on this to add/change the picture to the left under your user name. (like my skull diff cover)
Next is "EDIT SIGNATURE"
Click on this to add things like Links/comments/ Ancient Chinese secret's etc" This will show up on the bottom of everyone of your posts.
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Old 02-03-2019, 05:33 PM   #19
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Re: Rusty Roof Best Approach?

Thanks a lot for your reply ryans69chevy! Very helpful. Great suggestion about trying to maintain the integrity of the original piece as much as possible. I will try and follow the same method. Just one more question:

For the rear seam, I thought another thread stated that the rear roof section is welded underneath the roof (C to D in diagram below). If so, I am a little worried about getting the cut at the seam just right. For example, if I cut the path of A then I am good, but if I cut too vertical, like B, I might accidentally cut off the underlying lip. In order to keep the original roof skin whole, I would need to cut into the back seam without damaging C or D, right?

Also, I would happily view some pics of your build. Thanks!

Quote:
Originally Posted by ryans69chevy View Post
I took my outer skin off. It's still off now I guess. It was time consuming to do, but I got it off nicely and fixed it up pretty good.
If it was me I would take it off as if you were planning on reusing it. Even though you stated in earlier posts you are going to buy a repop. Just in case the new roof doesn't fit exactly like you want - which is a common issue with repop items.
How I removed mine was by first sanding all the paint off around the whole roof where you have #2 on your drawing. You wouldn't go down the back of cab beyond the roof seam I guess. Then you will see or feel a bunch of spot welds. Take punch and punch the center. Drill them out with spot weld drill bit. There will be a ton of them! Then I cut directly in the back seam across the whole cab above the back window. I then took a flat screwdriver and dug under #2 in your drawing and started prying little by little until it popped off.
To answer your other question #5 isn't butt welded. The drip rail is spot welded. From your picture the spot welds are all about under the "R" where in your picture you wrote "drip rail". I also removed them to clean up those areas and put them back on.
Take a look at my build thread if you want to see some pics. I might even have some more that I didn't post if you want to see more of what I am talking about.
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Old 02-04-2019, 11:25 PM   #20
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Re: Rusty Roof Best Approach?

OK, so I started doing some exploratory sanding and was able to find the roof spot welds. Also, used a Dremel wire wheel to remove the filler between the roof lid and the back cab (see photo below). I was surprised how far down it went. Felt like I might have been able to get all the way through if I had a larger diameter wheel.

Can someone clarify for me how the rear roof lid is attached to the rear cab? Is the sealer/filler that I removed with the wire Dremel wheel all that holds it on back there? Or is it also spot welded from underneath? Thanks!
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Old 02-06-2019, 10:30 PM   #21
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Re: Rusty Roof Best Approach?

Sorry I haven't checked this thread in awhile! I snapped a couple pics of the back cab seam. They both have lips on it like what I show on the roof skin. Then they are spot welded together from the inside.
How I cut mine off was taking a cut off wheel and laying it in right on that seam. I tried to cut the lip off the back of cab instead of the roof skin if that makes sense? I just took my time and it went really good. Then when I go to reinstall I will just weld that seam shut. I just left the lip on the roof skin for integrity basically.
If you have any more questions or need any more pics just PM me and I'll post them back on this thread!
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Old 02-06-2019, 10:31 PM   #22
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Re: Rusty Roof Best Approach?

Shoot sorry... new phone forgot to turn it sideways.... at least I can post multiple pics in one post now!
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Old 02-25-2019, 02:11 PM   #23
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Re: Rusty Roof Best Approach?

Made some progress. Got the lid off and did a little wire wheel de-rusting. Looking for some feedback on which path I should follow next.

I added some pics below to illustrate the current condition and how the surfaces looked before/after a wire wheel hit. They are pitted but structurally sound. So, now I face the dilemma of how far I take this:

1) Do not dismantle anything further: Continue using abrasives (wire wheel, sanding, blasting) to clean off all surface rust, metal patch/weld any spots where rusted through, and treat everything with POR-15

OR

2) Further Dismantle: Try to remove inner roof sheet metal as well, leaving just the top cab frame structure, metal patch any spots needed, abrasively clean everything thoroughly and treat each piece with POR-15

#2 would certainly be more thorough, but just not sure if worth it. The only fear I have with #1 is that I cannot get into the cracks/seems of the various pieces and they may rust through later. However, if that ever happens in the lifetime I have the truck, I could probably just address it from the inside at that point.

Note: In both cases above I will put on a new outer roof and side gutters.

Thoughts?
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Old 02-25-2019, 02:13 PM   #24
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Re: Rusty Roof Best Approach?

And a few extra pics of the nasty side that will need welded patches. No cleaning done on this side yet.
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Old 02-25-2019, 02:28 PM   #25
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Re: Rusty Roof Best Approach?

At this point you are showing further rust repairs needed. Cut out those sections, clean any rust found under that, replace with new metal (or solid donor pieces).


For your "surface rust" I would abrade the area using media blasting (garnet), or wire wheel (crud thug?) or similar that will turn area into a bright metal finish. I'm not a fan of POR type products as their success rate is sketchy at best. Any rust left will still be prone to further rusting under the POR covering. While you have it apart, if it were me it would be media blasted and painted with SPI epoxy primer. Fix it right, fix it once.
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