Kitchen seam repair -- fiberglass/filler/sealer

[randalieren]

TL/DR: Will fiberglass and/or filler crack if it is sealing the side/rocker seam behind the kitchen and repairing max 1" gaps along that seam left after after rust removal/treatment?

Longer version:

I had what seemed to be pretty standard rust on the side/rocker seam behind the kitchen. I'm upgrading to a Truckfridge and rewiring a bunch of the kitchen stuff, so I decided it was time to pull the cabinets and address the seam.

I'd love to learn to weld, but now is not the time for various reasons. So after reviewing all of the kitchen seam threads that I could find on here, I decided to:

1) Grind and sand out all of the rusted metal
2) Ospho inside and outside
3) Por15 the interior
4) lay down fiberglass cloth to close the gap on the inside and provide a surface for filler on the outside
5) Epoxy primer on outside
6) Fill the gap with Rage Gold
7) epoxy primer again
8 ) paint

It seems to have gone pretty well so far. Today I put the Rage Gold on and sanded the body down smooth. Everything feels pretty good, but with the fiberglass on the inside and the filler on the outside I've pretty much erased the seam. Now I'm worried that the seam is going to flex and crack the filler.

At this point would it be better to (1) finish the job and hope it lasts for a few years until I can get the body work done right or (2) slice a narrow gap into the new surface from one side or the other and apply some kind of seam sealer that is made to flex? (I'm worried that most seam sealer won't bond right to the fiberglass).

I understand that this is a temporary fix, but I want to make sure the whole repair isn't going to just crack and fall off once I start driving.

Thanks!

[dobryan]

If the fiberglass and epoxy was applied to a properly prepped surface (well scuffed with 80 grit so a good mechanical bond can be created) then it is not going anywhere. If it was applied directly onto por-15 with no sanding then you may have an adhesion problem later.

If the filler was a thin skim coat that should be OK too in my book. Thick filler would be no bueno.

I have done similar (except no por-15, I hate that stuff) and see no issue.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

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[4Gears4Tires]

IMO, the only acceptable use of POR15 is for bumpers, trailing arms, frame rails, etc. Anything that you want to give a bit of protection, but you won't cry when a something hits it and it starts flaking off. I would not use it under paint and I would not use it anywhere you care. And even then, there are better products and methods to use for the above items.
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'87 Syncro
Ferric Oxyhydroxide Superleggera Edition

[clift_d]

I'd recommend you strip out your kitchen and interior panelling along that whole side, do a bit of poking around and wire brushing, and then put some pictures of what you find on the forum before you make a decision. If your sill seam is badly corroded then you can pretty much count on the whole edge of the floor on that side being corroded as well, which may require there to be some degree of welding/bodywork.
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1988 LHD T25 1.6TD Westfalia Club Joker syncro

[VicVan]

I went through this a month or two ago. Here's the thread with lots of pics:
https://www.thesamba.com/vw/forum/viewtopic.php?t=752104
In retrospect the mediablasting bart was overkill. Wirewheel with a drill, and ospho, should be enough.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[randalieren]

Thanks everyone. To clarify:

- I only used POR-15 on the inside, on treated bare metal that will not receive a top-coat. I scuffed the parts that would be in contact with the fiberglass. My plan was to put another layer of the POR-15 over the fiberglass before I reinsulate. I know there are lots of mixed opinions about POR-15.

- I have completely disassembled the kitchen cabinetry, and fully treated/repaired the small amount of rust on the floor panel beyond the seam.

- The fiberglass is already down on the inside and the filler is already on the outside.

- Let's assume that all of that was done reasonably carefully without skipping any steps or putting the filler on too thick, and there was no rust left in the seams.

- My actual question: if I've erased the seam by sealing over it with fiberglass on the outside and filler inside, is that seam going to flex and crack my fill?