Roostre's 1967 C20

[Roostre]

89 spotwelds later, my outer roof skin is off. Hopefully this week the new skin will be glued on.

[lil hoodlum]

Originally Posted by Roostre

89 spotwelds later, my outer roof skin is off. Hopefully this week the new skin will be glued on.

I would be interested in seeing your process for gluing the outer roof skin back on. My outer roof skin has hail damage on it, so I'm thinking of replacing it at some point.

[BigBird05]

Can you weld on the Rust inhibiter that you used?

[Roostre]

Originally Posted by BigBird05

Can you weld on the Rust inhibiter that you used?

I don't know. I plan on cleaning down to bare metal anywhere that I need to weld. The 3M adhesive I plan to use says that it needs to bond bare metal, so that will need to be cleaned up also.

[Roostre]

Originally Posted by lil hoodlum

I would be interested in seeing your process for gluing the outer roof skin back on. My outer roof skin has hail damage on it, so I'm thinking of replacing it at some point.

Stay tuned. I did an initial fit up of my new roof skin last night. Like most aftermarket panels, it doesn't fit as well as the OEM, but I think I can get it to fit well enough for my purposes.

[Roostre]

Dupli-Color's version of Por-15. It was the best I could find without having to order it. I figured I'm pretty safe with it being inside the roof.
Also figured out how to hold the new phone to get the pictures right! It's a right handed world!

[Boog]

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[Roostre]

Originally Posted by Boog

top

Thanks!

[Ol Blue K20]

Originally Posted by Roostre

Dupli-Color's version of Por-15. It was the best I could find without having to order it. I figured I'm pretty safe with it being inside the roof.
Also figured out how to hold the new phone to get the pictures right! It's a right handed world!

Yep, I've had to learn how to so many things with the wrong hand(right). LOL

[Roostre]

Originally Posted by Ol Blue K20

Yep, I've had to learn how to so many things with the wrong hand(right). LOL

It's the things one would never think of that really make the difference. I'm looking for a good left-handed digital caliper. It's really annoying to have to flip a normal one over to read the measurement.

[Ol Blue K20]

Originally Posted by Roostre

It's the things one would never think of that really make the difference. I'm looking for a good left-handed digital caliper. It's really annoying to have to flip a normal one over to read the measurement.

I know the feeling well...

[Boog]

You fellas could come over to the right side.

[Roostre]

Haha, OK, back to the truck, temporarily.

I was waiting for the oil to drain out of my daily driver, so I figured I would work on my truck for a while. I'm still waiting on the adhesive to show up so I can stick the roof skin back on, so I decided to tackle more of the right fender. After I replaced the front cup, I found a suspicious amount of bondo behind the wheel well. It looks like it was hit on the body line. Someone pulled it back out and carved the body line out of bondo. I swear a previous owner of this thing must be the Michelangelo of bondo, there's so much on this truck and intricate carvings. It would be impressive if it wasn't coming loose and rusting the metal under it. So I lined up the patch panel and cut off the skin. I found a small rust hole in the inner structure, so I cut that out and welded in a piece of the old outer roof skin. Then, since the can was sitting there, I painted the inner part of the structure with the Dupli-Color rust inhibitor.
Enough typing, on to the pictures!

[Roostre]

A friend came over last night and we glued the new roof skin on. Because it is an aftermarket panel, it didn't fit perfectly, but that was expected. I also suspect that the rear panel of my cab has been tweeked in the 50+ years of the truck's existance. It went together well enough in the end for my driver quality truck. Here's an overview of what I did.

I used 3M 08115 structural adhesive. It comes in 200mL tubes, and one tube was enough to do 1/4" bead all around the skin with enough left over to kind of fill the rear gap. It has a 90 minute work time, a 4 hour clamp time, and a 24 hour cure time. The instructions say to scuff down to bare metal with 50 grit sandpaper. I could only find 60 grit, so I went to town to remove the e-coat on the panel and the surface rust on the truck. I then wiped everything down with some 3M surface prep that I had. We then test fitted the panel and got our clamps set up. After that, we applied a 1/4" bead of adhesive to the truck and carefully set the outer skin in place, front first. We clamped down the front and sides, then squeezed the rest of the adhesive tube into the gap at the back. We rachet strapped a 4x4 to the back of the roof to press that joint down a little bit. We then walked away and it currently is sitting with the clamps still on it.

I will have to put a little more filler in the rear seam, but I think it will be good enough. I could probably have worked with the replacement panel and gotten the back to fit better, but with the twist it had, I'm definitely time ahead just getting it to bond to the cab and then filling in the seam wherever there is a little more of a gap. This is definitely not going to be a show truck.

Here are the pictures!

[ItWillBeSlow]

Originally Posted by Roostre

A friend came over last night and we glued the new roof skin on. Because it is an aftermarket panel, it didn't fit perfectly, but that was expected. I also suspect that the rear panel of my cab has been tweeked in the 50+ years of the truck's existance. It went together well enough in the end for my driver quality truck. Here's an overview of what I did.

I used 3M 08115 structural adhesive. It comes in 200mL tubes, and one tube was enough to do 1/4" bead all around the skin with enough left over to kind of fill the rear gap. It has a 90 minute work time, a 4 hour clamp time, and a 24 hour cure time. The instructions say to scuff down to bare metal with 50 grit sandpaper. I could only find 60 grit, so I went to town to remove the e-coat on the panel and the surface rust on the truck. I then wiped everything down with some 3M surface prep that I had. We then test fitted the panel and got our clamps set up. After that, we applied a 1/4" bead of adhesive to the truck and carefully set the outer skin in place, front first. We clamped down the front and sides, then squeezed the rest of the adhesive tube into the gap at the back. We rachet strapped a 4x4 to the back of the roof to press that joint down a little bit. We then walked away and it currently is sitting with the clamps still on it.

I will have to put a little more filler in the rear seam, but I think it will be good enough. I could probably have worked with the replacement panel and gotten the back to fit better, but with the twist it had, I'm definitely time ahead just getting it to bond to the cab and then filling in the seam wherever there is a little more of a gap. This is definitely not going to be a show truck.

Here are the pictures!

Can you share more info about your removal of the roof skin, and how you clamped the new one in?

How did you get the rear seam cut out without damaging the lower cab skin? Did you find a way to cut the spot welds on the "lips" that hold these 2 skins together?

I am guessing you were not able to clamp the "lips" the hold the new skin and old rear skin together. You used the wood block to hold some pressure on it, and the clamps around the rest of the perimeter to keep a healthy pressure on this joint while the sealer set up?

[Roostre]

Originally Posted by ItWillBeSlow

Can you share more info about your removal of the roof skin, and how you clamped the new one in?

How did you get the rear seam cut out without damaging the lower cab skin? Did you find a way to cut the spot welds on the "lips" that hold these 2 skins together?

I am guessing you were not able to clamp the "lips" the hold the new skin and old rear skin together. You used the wood block to hold some pressure on it, and the clamps around the rest of the perimeter to keep a healthy pressure on this joint while the sealer set up?

Sure, I took my angle grinder with a cutoff wheel and cut the outer roof panel about 1/2 inch away from the seam. My old panel was trash, so I didn't care about ruining it. I then took the same cutoff wheel and grinder and used that to cut out the spot welds and carefully pulled and pried the thin strip of roof panel off the rear panel.

I had to think for a while about how to clamp the rear seam because I couldn't get to it. I ended up using 2 ratchet straps secured to the firewall and bed over the roof with a 4x4 board under them to put a little clamp load on the rear seam from the outside. I then squeezed a little more adhesive into anywhere I felt the seam wasn't filled adequately. This should work just fine. Remember that this is structural adhesive, so it's really strong. The outer roof skin just needs to be held in place and the seams sealed from water. If the rear seam isn't 100% strength of the seam sealer due to not being fully clamped, I really don't think it's a big deal. I used a bunch of vise grips with dowels in the drip rails around the sides and front of the panel. I'm sure these had enough clamping force to give the adhesive plenty of strength to hold the roof skin on.

Another thing that is helpful is that the rear panel of the cab has kind of a double bend on the lip that helps align the roof skin and hold it in place.

There was about an 1/8 inch gap between the roof and rear panel. I filled and sealed it with the adhesive, and will have to fill some voids with body filler. I could have probably worked with the two panels and made the seam much tighter, but didn't feel that it was worth it for the scope of this project.

Sorry, I see you asked how to not damage the inner roof panel. If you cut about 1/2 inch away from the rear seam, there's about a 2 inch void between the roof panels, so my 3 inch cutoff wheel did just fine. You can kind of see it in the pictures of treating the rust on the inner panel. I also like using the same wheel to cut spot welds because you can see when you are getting close to the lower panel and can stop before cutting into it.

[ItWillBeSlow]

Originally Posted by Roostre

Sure, I took my angle grinder with a cutoff wheel and cut the outer roof panel about 1/2 inch away from the seam. My old panel was trash, so I didn't care about ruining it. I then took the same cutoff wheel and grinder and used that to cut out the spot welds and carefully pulled and pried the thin strip of roof panel off the rear panel.

I had to think for a while about how to clamp the rear seam because I couldn't get to it. I ended up using 2 ratchet straps secured to the firewall and bed over the roof with a 4x4 board under them to put a little clamp load on the rear seam from the outside. I then squeezed a little more adhesive into anywhere I felt the seam wasn't filled adequately. This should work just fine. Remember that this is structural adhesive, so it's really strong. The outer roof skin just needs to be held in place and the seams sealed from water. If the rear seam isn't 100% strength of the seam sealer due to not being fully clamped, I really don't think it's a big deal. I used a bunch of vise grips with dowels in the drip rails around the sides and front of the panel. I'm sure these had enough clamping force to give the adhesive plenty of strength to hold the roof skin on.

Another thing that is helpful is that the rear panel of the cab has kind of a double bend on the lip that helps align the roof skin and hold it in place.

There was about an 1/8 inch gap between the roof and rear panel. I filled and sealed it with the adhesive, and will have to fill some voids with body filler. I could have probably worked with the two panels and made the seam much tighter, but didn't feel that it was worth it for the scope of this project.

Sorry, I see you asked how to not damage the inner roof panel. If you cut about 1/2 inch away from the rear seam, there's about a 2 inch void between the roof panels, so my 3 inch cutoff wheel did just fine. You can kind of see it in the pictures of treating the rust on the inner panel. I also like using the same wheel to cut spot welds because you can see when you are getting close to the lower panel and can stop before cutting into it.

Thank you, great info. You also mentioned in your earlier post there were a couple minor fitment issues with the new panel. Can you elaborate on those? This panel makes me more nervous than some repops in that it could only be “adjusted or modified” so much.

[Roostre]

Originally Posted by ItWillBeSlow

Thank you, great info. You also mentioned in your earlier post there were a couple minor fitment issues with the new panel. Can you elaborate on those? This panel makes me more nervous than some repops in that it could only be “adjusted or modified” so much.

I may get a little long-winded with this, so I'll give you the Cliff's notes version first so you don't have to read the story if you don't want to.

Cliff's notes: The replacement roof panel had a slight twist to it. When I test-fitted it to the cab, if one corner was clamped down, the opposite corner would pop up a little. This wasn't a big deal and may well have been caused by the shipping damage, or even the cab being 50+ years old and not completely square. The rear seam gap wasn't consistent and anywhere from 0 to +3/16 inch wide. This could probably have been fixed through spot welding sequence while installing, but I didn't want to tear into the cab to spot weld that seam.
All in all, this panel actually fit much better than the fender patch panels I've been using.

Settle in, here's the whole story and my opinions:
My truck is not going to be a show truck. It is going to be a driver that I use as a truck and have fun with. It is also a learning platform to figure out how to do rust repair. The end goal of it is to be something I pull up at the local trap range and the old farmers say that looks like a decent truck. From that standpoint, I don't need it perfect. I want the rust fixed, and understand that it will get dented and chipped up. That's OK, I'll just fix it again.

I was replacing the seam sealer in the drip rails on my cab roof. Like many have had issue with, my sealer was dry and cracked and started to allow moisture under it. I caught it before it damaged the inner roof. As I was cleaning the rust out of the drip rails, I found some body filler above the passenger's side windshield. As I got into it, I realized it was 1/4+ inch thick, about 8 to 10 inches back from the windshield, and about half way across the roof, something must have hit it at some point. I didn't want to replace all of the body filler and risk it coming loose in the future, so I started thinking about a patch panel. I didn't really want to do the whole roof to begin with because I didn't want to deal with the rear seam. I called the local shop that specializes in these trucks and parts, Bowtie Truck Stop. I get everything from them. Kevin and Lisa are wonderful people and I trust them completely to shoot straight and help me out. Come to find out, no one makes patch panels for the roof. But they had a roof panel that was damaged in shipping and they were willing to give me a smoking deal on it. I picked it up, and there were three small dents in the center of the roof where it looks like someone set something on it and maybe slid it a little.

I got the roof panel home and started playing with my hammer and dolly. I am not a body man. I just have a few tools, patience, and want to learn how to do this stuff. I managed to get the dents out to the point where no one would notice them unless they are doing a concourse level inspection. This may be where the slight twist of the panel came from.

After taking the old roof panel off, I started test fitting the new one. Aside from the slight twist, it fit really well through the drip rails. The rear gap wasn't very consistent. It didn't fit snuggly against the cab rear panel anywhere, but it could be pulled into place in most places, if I had access to the pinch welds. I decided that the good fitment in the drip rails was good for me, and since I was going to use adhesive anyway, I could get the rear seam close and fill any voids with body filler, again this isn't a show truck. The adhesive I used has some gap-filling capability, so I used it to fill the thicker gap spots. I used the lumber and ratchet straps to put a little pressure on the rear seam, so that some of the product did squeeze out.

There is also nothing saying that my rear cab panel is straight and correct. The rear of my cab has some dents that I'm really not doing anything about. This is a 50+ year old vehicle that has been used hard and put away wet more times than I care to speculate on. Personally, I don't think it would be realistic to expect a replacement panel of this size to fit 100% correct even if it came from the original tooling.

So the panel ended up working for what I'm hoping to achieve and for what I'm willing to spend on it. I've got pretty limited bodywork skills and so don't really have the knowledge to get it to fit better than adequately. I do have people I could have had help massage the panel and cab to get the rear gap better, but when it came right down to it, I didn't have the ambition to get it to fit better either. I'm happy with how it turned out, and I don't have to worry about a large chunk of body filler blowing off of my roof in the future, or worse trapping moisture against the steel and rotting it out prematurely.

Sorry for the long winded post, but I did warn you at the beginning!

[BigBird05]

Just for my education, is that how the factory installed the roof panel?

[Roostre]

Originally Posted by BigBird05

Just for my education, is that how the factory installed the roof panel?

No. Mine had 89 spotwelds in the drip rails and rear seam where it met the back of the cab. I figured this would be easier and more than strong enough to hold the outer roof skin on.

[Roostre]

Clamps are off, and I have to say that I think the structural adhesive is the way to go here. Roof skin is nice and tight and I didn't have to drill any holes to spot weld it or worry about too much heat or burn through. I will replace the seam sealer, but that would have been done if I had welded it as well. I also didn't have to figure out how to spot weld the rear seam, or clean it up to weld it solid and again worry about too much heat or burn through. I'll have to put a little filler in there to even it out, but no big deal.

Long story short, I'm a fan of the adhesive for this part.

[54blackhornet]

Congratulations ! I admire your abilities...

[Roostre]

Originally Posted by 54blackhornet

Congratulations ! I admire your abilities...

Thank you! I'm certainly not very good yet, just learning as I go. There are some truly talented people on this site that I take a ton of inspiration from!

[Roostre]

I resealed my drip rail tonight. Overall it went pretty well. I used 3M 08307. It has an 8 minute work time, 15 minute paint time, and 1 hour cure time. It's like squeezing syrup from a caulk gun into your drip rail. It comes in a 200mL 2 part tube, and i was able to do my entire rail with just a little left over.

First, I taped the body below my drip rails behind the doors on either side of the cab because I figured this stuff would run down the vertical part of the rails, and i suspected it would be a pain to try to clean up. I was right on both counts!

I then cleaned the rail with some 3M cleaner I had. After that, I went to town squeezing the sealer into the rail. I started in the center of the windshield and worked my way out until I was about 3/4 of the way down the vertical part. I then went to the other side and repeated. I worked in kind of a small Z pattern that seemed to work well. The instructions say to keep the application tip submerged in the sealer to limit the amount of air bubbles in the final product. This is a very important tidbit.

As it cured, I watched for any thicker gaps due to the after market roof skin, and filled them in with a little more sealer as they opened up.

As it got sticky and stopped flowing (about 6-7 minutes), I used a utility knife and cut it where it ran out of the bottom of the vertical part of the rail and pulled my tape. I don't think it would be a good idea to leave the tape on until it cures completely.

All in all, it came out well. Enough story, on to the pictures!

[68isgreat]

Originally Posted by Roostre

I resealed my drip rail tonight. Overall it went pretty well. I used 3M 08307. It has an 8 minute work time, 15 minute paint time, and 1 hour cure time. It's like squeezing syrup from a caulk gun into your drip rail. It comes in a 200mL 2 part tube, and i was able to do my entire rail with just a little left over.

First, I taped the body below my drip rails behind the doors on either side of the cab because I figured this stuff would run down the vertical part of the rails, and i suspected it would be a pain to try to clean up. I was right on both counts!

I then cleaned the rail with some 3M cleaner I had. After that, I went to town squeezing the sealer into the rail. I started in the center of the windshield and worked my way out until I was about 3/4 of the way down the vertical part. I then went to the other side and repeated. I worked in kind of a small Z pattern that seemed to work well. The instructions say to keep the application tip submerged in the sealer to limit the amount of air bubbles in the final product. This is a very important tidbit.

As it cured, I watched for any thicker gaps due to the after market roof skin, and filled them in with a little more sealer as they opened up.

As it got sticky and stopped flowing (about 6-7 minutes), I used a utility knife and cut it where it ran out of the bottom of the vertical part of the rail and pulled my tape. I don't think it would be a good idea to leave the tape on until it cures completely.

All in all, it came out well. Enough story, on to the pictures!

I just ordered a new roof skin for my 68, and will be using the 3M adhesive you showed in the previous post. Regarding this drip rail sealer 08307, would regular (thicker) seam sealer also work, or is this more liquid version preferable?