Sanding blocks.

I'm pretty sure that SPI epoxy primer is stronger than the average filler. Using it during the straightening process is a different way of doing things that has many advantages. I would invite you to try at least one panel with the multiple epoxy application method to see how you like it, even if you do decide to skim the whole panel. In my experience it took me to the next level.

Epoxy can be recoated with filler with no sanding inside the recoat window. (Usually I scuff it after 72 hours though)
SPI epoxy has some film build, not as much as urethane but way more than other epoxy primers.
Epoxy seals the metal and filler against moisture intrusion.
SPI epoxy is semi-glossy. Blocking removes the gloss, revealing imperfections immediately.
Unlike urethane primer, SPI epoxy is designed to have filler applied over it. So no more sweating over putting glaze over 2K, which is kind of a "no-no."

There's more, I'll let others have a turn at listing the virtues of the epoxy...
 
But most of the skim coat should be sanded off down to your initial layer of epoxy primer. Only the lows should have filler when you are done. The same goes for polyester primer and high build urethane primer. Only the lows should have significant build. So long as you do that I don’t think there will be any long term issues.

Keep in mind that I’m not a pro. Guys like Chris, Crash, and Texasking do this for a living and have for many years.

Don

Thanks for the compliment but c'mon Don you are fooling no one.;) You know what you are doing. :) You do extremely nice work.

Crash mentioned one thing that gets overlooked, you can do some metalworking with epoxy already applied. Bumping up a low spot or working a small high down, because it's flexible and adheres, is no problem. Try that with poly or 2k urethane.

And epoxy builds more than people think. I would guess it's around 2/3 to 3/4 of what urethane builds per coat.

And BOP to give my opinion to your question I would also say epoxy is going to be more stable than filler long term.

And not that there's anything wrong with filler but I was surprised seeing how much filler was in some of those Name cars. I know for a fact how much Boyd used in some of those TV cars as a friend of a friend was involved in re-doing one. Much more than an 1/8 of an inch in many places. Up to 1/4" or more in places on that car. Lots of people got screwed by Boyd Coddington. (not trying to ruffle feathers but it's a fact)
 
Last edited:
The biggest problem I have with skimming a panel is getting it on smooth on a large area, before it sets up, unless Rage Ultra Extra is mixed with the Rage Ultra, to extend working time. As Crash said above, the advantages of using epoxy only are many. To add to what he said, the epoxy has less shrinkage than urethanes and more flexibility than polyesters. It will not chip off of edges near as easy, either. It is also the ultimate primer over many other substrates beside metal. Epoxy works better over fiberglass, urethane bumpers, and various plastics than any product I have ever used, and it likes the heat I have down here:)
 
This is our last major "restoration" we did, rust/dent repair, fabrications, straightened and polished all the stainless trim, paint and buffed.

Picture%202884.jpg



These are rather long quarters, and all the blocking here was done using the 36" AFS.


Picture300-1.jpg


Picture299-1.jpg



The quarter's have a lead seam at the rear deck just in from the front corners of the trunk lid. A few years have now passed, and I can faintly detect where this seam is. We had removed lead just to insure there were no lurking rust issues, and replaced the lead with Evercoat kitty hair and 416 glaze. Not sure if it's the torque this body sees or the filler used, but I can see it just the same.

So to try and prevent any such reoccurrence, when working on the wagon, all lead seams (and rust trapping pinch welds on the outer skin) were removed entirely with the sheet metal fully butt welded together. Any fill was kept to a minimum, and just as Crash described, after the initial blocking of SPI epoxy, more metal finishing was done, then minor skim coat in small isolated areas. For the most part, it was multiple evolutions of 3 coats of epoxy, blocking, 3 coats of epoxy, blocking, etc. I felt that the epoxy would be more stable than a long skim coat, given the experience of the quarter seams in the Fairlane. This is the result in the wagon (still needs cut and buff) also blocked using 36" AFS on the doors and quarters..


I'd have to agree with Crash, keep filler to a minimum, and for a restoration type project use the epoxy for build as it is more stable. The AFS I don't think are being produced anymore, but for long quarters and doors, 36 seemed to work well for us. Side note... also have the AFS in 27??" and this did not have enough overlap on the doors of the wagon, and was cutting a low in the middle of the doors. The 36 would span across the middle, cutting down the high spots and leaving the middle alone. So in blocking, especially long straight panels, make sure the sanding block is as long as you can stand.
 
Last edited:
Back
Top