Using Panel Bonding Adhesive for Floor and Rocker Repair

[JerseyHarold]

 My four-door '52 Cambridge has rust in the rockers but not that bad; the trunk floor is rusted out completely around the body mount by the spare tire well.  My '51 business coupe has a solid trunk, but nearly non-existent rockers and a weak floor.  

 

I'm thinking about taking a no-welding approach to repairing the floors and rockers.  I'm looking for 'driver quality' not necessarily show-car perfection.   Will metal attached with panel-bonding adhesive, supplemented by rivets, work on these areas?

 

Thanks for any ideas.

 

Harold

[casper50]

do you wish to ride on seats attached to a floor held in by glue?  Just a thought.

[Bingster]

Ouch!!

[jrhoads]

 My four-door '52 Cambridge has rust in the rockers but not that bad; the trunk floor is rusted out completely around the body mount by the spare tire well.  My '51 business coupe has a solid trunk, but nearly non-existent rockers and a weak floor.  

 

I'm thinking about taking a no-welding approach to repairing the floors and rockers.  I'm looking for 'driver quality' not necessarily show-car perfection.   Will metal attached with panel-bonding adhesive, supplemented by rivets, work on these areas?

 

Thanks for any ideas.

 

Harold

 

 

 

I think you know the answer here?  Seriously... there is no easy way that is "quality"  I could offer some ideas better than proposed, but it still just wouldn't be right...

[Plymouthy Adams]

there is a tutorial on panel bonding sponsored by 3M that provides a bit of an outline as to what can or cannot be panel bonded...some panels require X welding in conjunction with panel bonding.  I would not know where to advise you to draw the line based on the design of the body on these old cars...perhaps a review of these films would give you better insight to what depth of repairs you can get by with.

[55 Fargo]

Read this, if you think a panel bonded with adhesive is weak, think again...

http://wardsauto.com/news-analysis/use-bonding-sticky-question

[Frank Elder]

Every hole you drill to accommodate a rivet has the potential to crack after the rivet is installed...doesn't matter if it is solid or a pop rivet or a cherry max. Then you also are exposed to galvanic and dissimilar metal corrosion...steel eats aluminum like candy unless you use Monel rivets which corrode at a slower rate.

I would use the modern adhesive before using rivets.....on my own car I would use neither of these methods, but it's not my car.

[Young Ed]

do you wish to ride on seats attached to a floor held in by glue?  Just a thought.

 

Hauled anything in a truck built in the last few decades? The boxes are held together with this same stuff.

[50fordtruck]

My passenger side lower half door skin was epoxied with an automotive epoxy 15 years ago and is still good.

[jrhoads]

Read this, if you think a panel bonded with adhesive is weak, think again...

http://wardsauto.com/news-analysis/use-bonding-sticky-question

 

Well there you go... learn something new everyday if you are paying attention   I guess I just have done it old school and not looked outside the box.

I still think doing it old school (welding) is the more trusted approach when it comes to floor pans and structural components. My opinion. Yours may vary...

Edited February 1, 2016 by jrhoads

[Theturtle]

I'm facing the same question.  I am using West System epoxy bonded to steel supplemented with steel pop rivets for some of the rusted floor and rocker areas of my 1950 P19 project.  I have done some tests and it certainly seems to stick to both steel and Rustoleum Rusty Metal Primer.  Also, my experience with this has been positive.  

 

I have built two airplanes that included West System Epoxy bonded to aluminum.  The first was finished in 1999 and the second in 2012.  I have been flying both regularly and have experienced no issues.  On the airplanes we bond thick plexiglass windshields to sheet aluminum, using an epoxy/fiberglass fairing about 2 inches wide.  We also bond it to aluminum for fairings in several other areas.  So far (16 years) it has held firmly, looks perfect and shows no signs of cracking dispute experiencing a lot of stress, temperature changes, etc.

 

Based on the airplane experience I used the West System epoxy in parts of a 1958 Volvo (PV444) project five to ten years ago (I am slow at these).  There I used MIG welding in some places (mostly floor and part of the trunk) and the epoxy in others (mostly fender lips and flanges).  Both have held up well.  But the Volvo is not a real test because I have not driven it on salty roads and only a few times in the rain.

 

I do pay attention to shielding the repaired areas using paint, seam sealer and undercoating.  Driving modern cars and seeing how well they protect the fragile underparts makes  me want to do more shielding for these two old cars.  Both have their clutch linkages exposed to everything that comes their way.  On the Plymouth, 30 years of driving on gravel roads (driven 30 and parked 35) caused part of the clutch linkage to be almost worn away at the pivot point.

 

As the previous posters point out, this is not a "quality" repair for resale purposes.  But that is not a factor for me.  I have no intention to sell the cars.  I just like to work on them, drive them and share them with the grandkids.

 

Please do not take this as a recommendation - it is just a data point.  I have no idea if this is actually a good idea for car repair.  But it really works on airplanes!

 

Keith Williams

1950 Plymouth P19 Fastback

Milan, IL

[jeffsunzeri]

 My four-door '52 Cambridge has rust in the rockers but not that bad; the trunk floor is rusted out completely around the body mount by the spare tire well.  My '51 business coupe has a solid trunk, but nearly non-existent rockers and a weak floor.  

 

I'm thinking about taking a no-welding approach to repairing the floors and rockers.  I'm looking for 'driver quality' not necessarily show-car perfection.   Will metal attached with panel-bonding adhesive, supplemented by rivets, work on these areas?

 

Thanks for any ideas.

 

Harold

"Will it work" and "Will it work safely" are two different questions.

 

A no-weld, modern adhesive seam can be as safe and as show-perfect as a welded seam if properly applied. A welded seam can be inferior in many cases if unprofessionally done.

 

Are you going to employ professional-level skills and materials for the repairs? If so, the choice is probably going to end with the welding process as it's likely to be the most cost and time efficient.

 

If you're thinking that since you don't have welding skills or equipment available, can you make-do with adhesive and rivets, then no, you will likely not get a safe repair because using the adhesives systems requires a high level of fit and finish preparation as well as some technique, and the adhesives are significantly more expensive than welding supplies.

 

Too often "driver quality" ends up meaning "cheap and shoddy" and often unsafe quality. Bad floors and rockers run the risk of carbon monoxide poisoning, and crash-worthiness safety concerns as well as other issues such as body integrity down the line.