Panel Bonding?

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CrustyJunker

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Always was curious how well this kind of 3M stuff would hold up. Even with weldable primer, OE seam sealer, and all that expensive stuff, I always feared that poor weather would rust above and below my repair welds.

Last time I did an OEM door skin, it held up surprisingly well - but I wasted more than a month of spare time with prep work, finishing, sealing, painting. Not very productive or cost effective for those working at a shop. :buffer:
 

AK 99

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I'm with Hipster on this 1...it'll work, but not the way I'd go about it. I'm on the other end of the spectrum. Deal mostly with higher end street rod/custom stuff. With as much time put into some of these builds an extra few hours with a welder/grinder makes for a better longer lasting fix. With the cost of materials (primers, basecoats, & clears) only going up I don't want 2 take the chance.

It's not really about a time savings. You can weld it all up quicker than using adhesive and waiting for it to cure, so there's no time saved at all and it's also not the point. With 3m panel bond, rust prevention is an extremely big benefit. It holds off moisture and the elements better than any weld through primer and the like. That's not something that you would normally be concerned with on a garage queen.
 
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TechNova

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I have been out of the professional business for 7 or 8 years now. I guess that I shouldn't be surprised regulations are still tightening due to all the lawsuit happy folks that want anyone but themselves to be responsible. But as far as the insurance companies go, most of them I had to fight with because they wanted to go the cheap route with improper repairs.

But anyway, it seems we've went down a rabbit hole, lol. We can all agree that installing cab corner patch panels with panel bond and proper prep work is a fine way to go, correct?

No offense, but honestly if you have not been in the business and kept up on training for a year or 2 you are left behind. It is changing so rapidly even with usages of existing products. I laugh at our required minimum 20 hours of training a year. I-CAR says "you don't know what you don't know". I have to go searching for things I am not aware of and find the training to deal with those items. What was an SOP or UPCR(universal procedure for collision repair) is no longer valid. Even a panel bond is not used the same for every vehicle.

no, I will not agree to panel bond on patch panels, it MAY and often will ghost. Hipster is correct about thermal expansion differences. I have used forms of panel adhesive since the early 90's, great products but they have specific uses. I do not consider patches one of those uses because of failures I have seen.
 

Kustombuilt1911

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Some of the "garage queens" your referring to have 100's of hours into them. Not to mention thousands of dollars worth of materials, paints, pearls, or kandy's as topcoat. I'm not going to put my reputation on the line to save what comes down to a few hours of work. Trying to blend a custom mixed kandy job is not fun. Even having to completely repaint a kandy/pearl car when your dealing with a small repair can & has happened to me. Just not worth it.
 

Hipster

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No offense, but honestly if you have not been in the business and kept up on training for a year or 2 you are left behind. It is changing so rapidly even with usages of existing products. I laugh at our required minimum 20 hours of training a year. I-CAR says "you don't know what you don't know". I have to go searching for things I am not aware of and find the training to deal with those items. What was an SOP or UPCR(universal procedure for collision repair) is no longer valid. Even a panel bond is not used the same for every vehicle.

no, I will not agree to panel bond on patch panels, it MAY and often will ghost. Hipster is correct about thermal expansion differences. I have used forms of panel adhesive since the early 90's, great products but they have specific uses. I do not consider patches one of those uses because of failures I have seen.

Yes, It's changing rapidly and you have to pay attention to the oem repair guidelines. I-car is not what it used to be but better then nothing I guess. We get the oem repair procedures printed out on every job that needs panel replacement.

Two from today, Subaru center outer door post skin. You can't Pro Spot it. Your back to prepping for Mig plugs. Ford F150 electronic steering rack. We couldn't get it set up with what we have, our mobile ABS/airbag guy couldn't get it done either. The alignment shop didn't get it done. It's being towed to the dealer to get the new rack re-progammed or whatever it takes. A lot of the oem's are keeping a lid on the new systems by keeping the info proprietary.

Guys forget vehicles are designed to collapse at a controlled rate and everything on a unibody including the quarters and glass are considered structural so when you use the wrong repair methods you alter those dynamics. If you don't restore strength the car collapses faster then the airbag deployment. Too much strength and the damage travels further into the cabin and why sleeves/backer plates and sectioning rails is no longer acceptable.

I don't know about you but I have pulled many an oem quarter off, The adhesives used there are also more of a urethane like substance. Somewhat pliable. This is true for different oems. When you get the quarter off and the adhesive is hanging loose you can see the e-coat is still under it. Panel bond is a totally different product and the application method of grinding all the e coat off both panels is different. Yeah brush it out over any bare metal on both sides and hope we don't disturb that while installing. Kinda crazy when you think about it.

Before the advent of panel bond we used to use 1k seam sealers over the wheel arch along with some welding. Urethane 1k seam sealers when they came out even better adhesion. It worked then, still does, leaves the e-coat in tact, and you don't have to slop it on everywhere. Quite a few of the 1k urethane seam sealers are also spec'd as adhesives but the jobbers running around with factory reps doing demo's pushing $60 dollar tubes of panel bond are not going to tell you a $25 tube of urethane seam sealer or even window-weld for that matter will do the same job.

I still prefer to use urethanes but I'm not in charge of material requisitions and have to use what's provided.
 

AK 99

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Some of the "garage queens" your referring to have 100's of hours into them. Not to mention thousands of dollars worth of materials, paints, pearls, or kandy's as topcoat. I'm not going to put my reputation on the line to save what comes down to a few hours of work. Trying to blend a custom mixed kandy job is not fun. Even having to completely repaint a kandy/pearl car when your dealing with a small repair can & has happened to me. Just not worth it.

That was my point. It's apples to oranges. The original post was not about a high dollar show car that spends all its time in a dry climate. I don't know where the OP lives, but judging from the fact that the cab corners needed replaced, they live in an area with inclimate weather and the vehicle is driven in it. Even if there was a minor issue with the paint finish due to different expansion rates (again, that has NEVER been an issue for me and no, I'm not just ignorant and yes, I have built show quality cars) it is still much better than having to replace the cab corners again in a few years due to rust where they were welded in.
 

Hipster

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, I have built show quality cars) it is still much better than having to replace the cab corners again in a few years due to rust where they were welded in.

Not really following your comment . Whether you cut it out and glue or weld a patch on you need to do something to address corrosion protection on the inside. Where there's rust there's usually more and if the glue is applied over anything other then rust and rust pit free metal the repair is going to be short lived.

The list of cons to using the panel bond are longer than the pro's. Sure I've seen it painted over with little issue, but I've also seen filler, primer, and paint blister up off it when the bake cycle is turned on.

After seeing and witnessing multiple failures the product comes into question. You've been lucky, not all of us have.

Consistent and repeatable results is one of the main issues.
 

AK 99

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Not really following your comment . Whether you cut it out and glue or weld a patch on you need to do something to address corrosion protection on the inside. Where there's rust there's usually more and if the glue is applied over anything other then rust and rust pit free metal the repair is going to be short lived.

The list of cons to using the panel bond are longer than the pro's. Sure I've seen it painted over with little issue, but I've also seen filler, primer, and paint blister up off it when the bake cycle is turned on.

After seeing and witnessing multiple failures the product comes into question. You've been lucky, not all of us have.

Consistent and repeatable results is one of the main issues.

The panel bond seals off the area where the two panels meet. Where with welding, you're going to have one heck of a time getting the bare metal sealed off as well.

I'm not trying to say that it is the end all, beat all method of bonding two pieces of metal. But there are scenarios where it can produce better and longer lasting results than welding.

And again, I'm really only sticking up for the 3m 8115 adhesive. It has worked well for me and has provided repeatable, reliable results. For 20 years. Other brands and types, I have little to no experience with due to the fact that the 3m product has always worked for me and there has been no need to experiment with anything else.
 

letitsnow

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I am really enjoying reading the input that ya'll have added. Thank you.

Talk about being behind the technology - my 1st career was autobody tech. That started in 1990 and ended in 1998. I have done my own stuff forever, but those are the only years that I was paid by a shop to do it.

The trucks that I keep running are solid runners. I won't own a car/truck that is nice enough to wax, and I basically don't like anything newer than 2000. My trucks are (some of my favorite) tools. I am only trying to keep them alive in this harsh MN environment.
 

thinger2

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Panel bonding has been used in the aviation industry for decades.
But only in certain pre engineered and highly tested and inspected situations.
Everybody needs to know what they are doing and be trained to do it and everybody gets to sign for it.
If that bond fails and causes a crash?
They will find you and charge you.
Just a part of the industry.
But, when they sell "miracle glue" to the general public or to a less regulated industry like auto body,
That paper trail of liability doesnt exist.
Any type of adhesive or resin or any chemical mix can only be used within its very specific set of parameters.
If you go outside of those parameters,
You end up with catalyize failures, bond failures, slow cure, no cure and on and on and on
All of this also applies to fiberglass, carbon fiber settup epoxy bolts ....
A cab corner patch?
Okay maybe. You wont kill anyone but I still hate the whole idea.
Rocker? No
And you still have to follow the instructions exactly.
I know this doesnt really have a whole lot to say that is really relevant to a cab corner,
But I'll leave you with a couple of glue failures.
1. The "BigDig" in Boston.
They used epoxy anchors in a verticle application and a huge and entirely decorative slab of concrete dropped on some poor womans car and killed her.
Why? you cant use epoxy anchors in verticle application.
If you are stupid enough to try it, you need to use undercut wedge anchors which is stiill a bad ******* idea.
She got crushed by a slab of stone just to satisfy some egotistical architect.
#2
The Americas Cup carbon fiber multi million boat that snapped in half and sank.
Some moron didnt understand how carbon fibte works.
Hole sawed through the deck to install compasses.
You tube it, its pretty awesome failure.
#3 personal experiance.
Had a sub install 2000 friggen concrete bolts and they all failed.
And this, if you are still reading is the very important part.
He got a "great deal" on epoxy tubes.
They were 5 years expired.
Whatever you decide to do, pay really close attention to the batch date and expiration date.
Dont pay for **** thats been on the shelf for years.
Old goop of any type reacts and sets in a different way than new goop.
And it might not react at all.
It may "fake bond" and shrink back.
The moral of the story?
Just ******* buy a cheapass decent mig with dual sheid and practice on some scrap and watch some vids and learn how to weld and how to shrink welds for ***** sake.
Its art. Learn how to be an artist.
And thats my rant.
Stay safe, stay warm my friends
 
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