My entry door's skin had de-laminated which caused the door to drag on the sill. It was twisted enough that the top aft corner stuck out past the drip rail.....approximately an inch. I had been putting it off as I dreaded the VHB tape removal process.
I picked up some 3M spray adhesive remover and a 3M adhesive eraser wheel. Removed the door and set it up on the work bench....known to be flat and level. After getting the outer skin removed from the door I cut down the thickness of the VHB as much as I could with a razor window scraper (the wide bladed, long handle variety). Using the wheel (in an electric drill) and adhesive remover I was able to clean the VHB from the door and skin at at rate of 12 linear inches per minute....yeah!
The interior skin is still intact so I left it alone, but did check squareness and twist. Corrected a slight warp with a shim under the low corner. Roughed up the bond line with a coarse grit sanding disc cleaned with solvent. Used Sika 252 as I had on hand and the specs (shear, tensil and elongation) are better than the VHB. Clamped the skin with light pressure and caul blocks so as not to squeeze out to much adhesive.
Happy to report the door is hung is square in the opening and pretty much fits flush all the way around. Closes with a thunk and opens so easy.....wife is happy life is good:-)
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very nice work. i like the look of your shop too
tom
Thanks Tom, when you meet my Wife you will know that there is a DMZ line between her parking spot and my shop. Never cross the DMZ with anything shop related....except the broom:-)
This is a good opportunity to add a bit of insight to this process. Having been in the Newell bidness for over 10 years, I have had plenty of opportunity to rebond doors and bay doors. The earlier attempts using different adhesives, different clamping strategies, and different surface preparations all eventually started to delam again. Another guru, unnamed, had mixed results also.
The breakthrough in thinking was that we were overclamping the bonds and squeezing out the adhesive. After all, in wood working more clamping is always better. In the early days, I used more and more clamps.
The technique I have used for bay doors that seems to work very well is very similar to what Steve did. Clean up the old bond with 3M adhesive remover, and then scuff the surfaces with a wire wheel or coarse grit disc. I then used small spacers of 3M double sided adhesive tape located around the bond line every three inches or so. The purpose of the spacers is to keep from squeezing out the adhesive. Wet out the adhesive on both surfaces and then assemble. Lightly clamp.
I found an added benefit of using the double sided tape was that once I lined up the two pieces on the assembly marks, they did not move around relative to one another while I fiddled with the clamps.
On the bay doors, I also added a radiused fillet of epoxy at the skin frame juncture all the way around.
My thinking from looking the failed doors, was that the crack or separation always started at the upper corner. The stress is concentrated there when the door is closed. The purpose of the fillet is to distribute the stress.
I have used urethane adhesives, epoxies, and two part acrylics in the past. My favorite, and easiest to use is Jamestown Distributor’s Thixo in the caulk gun cartridge. It’s a two part flexible epoxy that uses a static mixer tip on the end of the cartridge so that you simply squeeze it onto your workpiece. It’s thick enough that it doesn’t run.
Just my .02
In the aviation sheet-metal world we used some serious bonding products that are not cheap but really worked great. I like and will be using Richard's bonding method on my next door(s) project. It seems to be a cost effective way to fix a de-bonded door If I have to rework the entry door that to will get the same treatment.
Steve
Newell removed and rebonded my entry door a number of years ago. Their procedure was similar to yours Steve. They also put rivets around the door panel. Not sure if that is good or bad. Looks better without them but no question it keeps it from moving. Newell recommended adding the rivets on my 1992 model even through it didn't have them originally. Certainly has helped with the door sticking issue which was totally resolved.
I haven't had to rebond anything yet but the automotive industry has moved into adhesives and aluminum repair . The panel bond 8115 is the bonding agent that I will use for delam problems it has glass beads that prevent over squeezing the addhesive out. 3M instructions are to clean back to bare metal wipe with alpurpose adhesive remover coat both sides with a thin layer attach both move it in place apply as Manny clamps as possible let sed for 4 to 6 hrs remove clamps and install 12 to 15 hrs later. you can't squeeze it to much the glass beads in the mix prevent that. This product has been used for years on steel and now on aluminum and sometimes used instead of welding certain pinch welds .Although you can't weld thru it but next to it .
Good info !!! Thanks for posting.
On my 93 coach, a contributing factor to the delamination of the door was that the foam inside the door was oversized and attempting to push the door apart which after 20 some years of persistence it was finally succeeding. Prior to rebounding the skins I shaved the foam back to flush with the internal door structure.