Modern Epoxy instead of Welding?

[karls59tr]

Would it be feasible to use modern high strength Epoxy to bond an inner and outer sill to a floor pan if all three units were clean and new and thus avoid the necessity of welding?

 

[CJD]

Outer I would say possibly, as it is cosmetic. I would not consider the inner structural sill bondable. Remember, all epoxies are sensitive to heat. If it could be done, some car manufacturer would be doing it.

JMHO

John

 

[Brosky]

To be brutally honest, no. No matter what the packages say. Too much twist, flex and temp variation as said above for either application.

 

[tr8todd]

If you have enough overlap of the panels, you could probably get away with it along with a few rivets. Many of the new cars have more bonded panels than welded panels. Take the new Lotus for example.
I'm old school, so I'd weld it. In fact, I'd seam weld it, install mounting feet and fab up a roll cage while I was at it.

 

[George_H]

There are some hi-tech epoxys that can take very high heat. But to try and spec one out could be tricky. Some have good shear propertys but poor peel. They can be very costly as well and difficult to use.I use a high heat,high shear at work that costs over 200 a pound. You would need very clean surfaces as well. I would hate to find out a year later that flexing caused a peel issue. Just my 2 cents.

 

[Banjo]

Many body shops are now "gluing" panels instead of welding (Yes, rockers and quarters, not just trim). IMHO there are some really remarkable epoxies out there these days. I'm sure proper prep is key, but it's quite possible to end up with a stronger joint using structural epoxy than by spot welding.
Best thing is to talk to whatever local body shop is the most modern. The old school guys will never trust it. but the younger gen probably swear by it.
there are epoxies out there for body shops now that give the ability to bond together things that were previously impossible to bond. Glass, plastic, metals, rubber... Nothing is off limits anymore.

 

[Got_All_4]

I think all panel bonders require some welding for warrantee and the warrantee is only available to a professional technicians or body shops. Roof panels require plug welds in each corner. Also quarter panels, bed sides and rear pans all require plug or resistance welds in strategic places. That stops the possible pealing of the panel when the car body twists resulting in a repair failure. Peal strength is always the weakest aspect of gluing and I don't think any manufacture recommends gluing in structural areas. If your a good welder; weld it.

 

[GerryL]

The paragraph below is for a pannel adhesive called pligrip. I plan on using this for several patch pannels. The use of the pannel adhesive creates a water tight joint and eliminates the need for seam filling. I called a local auto body supply shop and this was the product that they sell. I googled the product and the link for the product is https://www.pliogripbyvalvoline.com/nr.php?id=7 The web site has several videos showing its use. Panel 60 adhesive also has passed both the FMVSS 208 frontal offset crash test and the FMVSS 301 rear-end crash test with adhesives-only repairs of the roof panel and rear quarter panel, respectively. This testing demonstrates that Panel 60 adhesive can stand alone without welds on secondary panel repairs. Panel 60 adhesive also is formulated to be spot-welded, so it may be used in repairs calling for weld-bonding and may be spot-welded wet.

 

[CJD]

Maybe I'm missing something, but when welding costs only $.50 per pound of welding rod...and adhesives cost, well, much more than that, I just don't get the advantage of using a high dollar epoxy on steel.

Now, that said, I do understand there there are advantages to bonding modern aluminum panels, because welding AL is more costly than welding steel. And, all of the modern plastic panels must, of course, be bonded. My 2005 Jag has many bonded panels, but the whole body is AL...apples to oranges comparison to our steel TR's.

Asside from the technical aspect, it just makes financial sense to weld a steel body.

John

 

[karls59tr]

Thanks for the info Gerry. What's your take on using this product for attaching an inner sill to an outer sill and attaching same to the floor pan? Too much flex as some say or not to be used here as it's a structural repair? I guess the bottom line is that some of the body weight would be supported by the inner sill to floor pan joint and would the epoxy be strong enough to take the weight there. I don't see where heat would be an issue in that location as has been mentioned.

 

[GerryL]

I am only a hobbyist and not a professional. You will have to decide yourself whether to use it for structural repairs. Below is a link showing how the pliogrip adhesive faired in crash testing.

https://www.youtube.com/watch?v=qSUOSWU99DI

 

[glemon]

Maybe I'm missing something, but when welding costs only $.50 per pound of welding rod...and adhesives cost, well, much more than that, I just don't get the advantage of using a high dollar epoxy on steel.

Now, that said, I do understand there there are advantages to bonding modern aluminum panels, because welding AL is more costly than welding steel. And, all of the modern plastic panels must, of course, be bonded. My 2005 Jag has many bonded panels, but the whole body is AL...apples to oranges comparison to our steel TR's.

Asside from the technical aspect, it just makes financial sense to weld a steel body.

John

It certainly makes sense if you have a welding unit and know how to weld.

 

[TR3driver]

It certainly makes sense if you have a welding unit and know how to weld.

And the joint is in an easily-welded location, and you're not worried about setting the car on fire, and ...

 

[tdskip]

It certainly makes sense if you have a welding unit and know how to weld.

And the joint is in an easily-welded location, and you're not worried about setting the car on fire, and ...

Welding in differential mounts with the body on the car requires laying on your back and welding over head. Now that is living...