Author Topic: Use of panel bonding adhesive: my experience  (Read 2912 times)

Tom in seattle

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Use of panel bonding adhesive: my experience
« on: May 08, 2019, 01:00:33 »
Back in January I posted a query regarding replacement of my rusted trunk section.  There were those that suggested that this process may not result in structural strength equal to welding, others thought it would be OK.  So I did quite a bit of research.  I dropped the fuel tank and set the fuel pump aside before cutting the offending section out with a 4 1/2 inch cut off wheel.  I ordered a replacement floor panel from K&k Manufacturing and it was a perfect fit but I did not replace the front 10" or so as there was no rust there and would have been a more difficult fit.  My research yielded the fact that panel bonding adhesives are now widely used in most if not all new cars. M Benz yes.  A new Cadillac has 50 feet of 2 part epoxy from 3M holding its sheet metal in place.  I selected 3M 08116 and followed its directions.  I used self tapping sheet metal screws to "clamp" the floor panel for a day and then removed the screws and filled the holes.  It looks great.  As for strength, the tech sheet says a 1/8" bead applied to both pieces of Sheet steel after 7 days has a strength of 4000 psi! I remember welding new floor sections in a 356 years ago, it took me weeks of work.  The bonding method could have been done in a weekend.
Tom Averill
1967 250 SL Auto Euro Spec

Jordan

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Re: Use of panel bonding adhesive: my experience
« Reply #1 on: May 08, 2019, 01:33:25 »
Tom, great to hear it worked out.  Do you have any pictures?  How much did you overlap the sheet metal around the edges and what did you use to fill the sheet metal screw holes?
Marcus
66 230SL  Euro 4 speed

WRe

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Re: Use of panel bonding adhesive: my experience
« Reply #2 on: May 08, 2019, 09:32:01 »
Hi,
there are some videos on youtube about panel bonding: https://www.youtube.com/watch?v=oxHActyy9Ds.
...WRe

specracer

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Re: Use of panel bonding adhesive: my experience
« Reply #3 on: May 08, 2019, 10:03:56 »
I used the same method to close up some floor rust on the inner floor (I think from an unsealed condensate AC line from the Frigiking), and to eliminate speaker holes in the rear bulkhead. Both instances the heat of welding would have not been desirable.

Tom in seattle

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Re: Use of panel bonding adhesive: my experience
« Reply #4 on: May 09, 2019, 01:18:55 »
I waited until the next day to remove the screws and filled the holes with the 3M bonding glue.  There is no metal distortion.  It is easy to find the right areas to cut by roughly removing the center of the old floor.  Then you can easily measure to the areas you want to bond to and make your final cuts because you can feel and see the limits of the original edges.
Tom Averill
1967 250 SL Auto Euro Spec

swood1

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Re: Use of panel bonding adhesive: my experience
« Reply #5 on: July 08, 2019, 08:09:48 »
Interesting idea.  I am just removing my floor panel at the moment.   To remove my old panel I have been drilling out all the old spot welds, wont these all need to be refilled again and then ground back prior to gluing in this panel?  Interesting repair route to take, I shall do some more research.

Thanks
250 SL (early), in bits. Triumph TR4a