Panel bonding?
- Thread starter heddrik
- Start date
That's what I did on the Salt Shaker to install the half quarter.
We put quarter skins on a 70 Nova using adhesive. The structural panel bonding adhesive joint is supposed to be stronger than the sheet metal panel. A long seam is the best place to use the adhesive, you don’t have to worry about warpage from welding. And the adhesive acts as a rust proofing on the lap joint.
I've used the 3M panel bonding stuff. Strong stuff, with the added benefit that you can attach dissimilar materials together with it (e.g., stainless to steel, aluminum to steel, steel to fiberglass, etc) as well as it's intended use for patch panels. The instructions say not to use it for structural stuff that is load bearing, etc. Also, you cannot weld through it (it's flammable). It's a great problem solver for building my hot rods.
Fusor has multiple types of panel bond including structural bonding adhesives. Some of their testing includes bonding on a roof and roll over crash testing if I remember correctly. None of the joints failed, only the roof panel metal.
Yes, you can use it on lap joints and I like to over lap 3/4" to 1". I don't use panel bond on the perimeter of panels where they were originally spot welded. I like to spot or plug weld there.
fourzeronine
Well Known Member
Collisions most certainly impart tension, shear, and bending stresses upon parts. Tension and shear are what rips welds and panels apart.
There are varying types / strengths of panel adhesives. With some the steel will rip apart before the adhesive joint fails.
Mr. Chev
Well Known Member
Im a red seal body and painter since 1983. Ive seen many demos from slickster selling their glue. I have seen two pieces of metal glued together then put on the frame rack and pulled untill the metal ripped and the glue held, Ive seen the same piece of glued metal picked up off the floor after the demo and watched as they are peeled apart with bare hands, you can glue, Ill weld.
Mr. Chev
Well Known Member
If you read all of this ot goes into detail about adhesive construction and what the manufacturer suggests Yes there is some adhesive in new cars but none for structural unless supplemented by welding. If i repair a vehicle I use panel bond where it originally was like a door skin ect but not going to glue a quarter panel or boxside on unless thats the way oem did it. To each his own.
fourzeronine
Well Known Member
Panels, frame members, and other parts do get pulled on. What do you think causes panels to stretch when they're dented and require shrinking to pull the dent out? Every dent and ding has a tensile stress component. Tension and shear are what pull spot welds out of panels and cause them to rip or tear.
The forces and stresses that parts experience in a collision are are a lot more complex than simply being compressive.
Companies such as Lord, Sika and 3M manufacture structural adhesives that can replace the need for welding in a properly designed assembly. And as you've found, OEMs are using adhesives to replace welds or join dissimilar materials and they are commonly used in the aerospace industry. Their success is going to be dependent upon prep and application.
Do note that the linked article is 24 years old. Technologies have changed and improved over the past two decades.
Mr. Chev
Well Known Member
And yet 24 years later they still dont glue on quarter panels and boxsides and again for the most parts a crash is energy absorption designed in thats why the call the different parts of the vehicle crumple zones and crush points. Yes there is some stretching and shear but usually after massive crushing and deformation, a few reasons domestic oem dont ise it is because they have designed the vehicle to absorb energy in a controlled manner where temperature and other influences that can change the glues properties and make the crash not repeatable, when I do any panel I use a piece of masking tape and before I remove the panel I mark every spot weld with a sharpie and transfer the tape to the new panel so I have the exact amount of spot welds exacty where the manufacturer wants them, one thing I was taught over the years was to “not kill the baby” wether in you vehicle or the one next to you , glueing a panel on is not making it pre accident condition it alters it and it may not crash exactly the way the manufacturer wants, it has its place for composites and places that have been tested and approved by the oem, not by the glue manufacturing, again use it for cab corners use it to glue on you patch panels, Ill stick to what I know works, and half the time someone is shrinking a panel is because they beat the shit out of it with their hammer on dolly smashing technique. Anyways Ill weld and use adhesives where the oem does but I will use the proven method the oem uses. Im not going to be responsible for killing anyone because I want to save time or cut a corner.
Last edited: