Undercarriage process

Dis00

New Member
Hi

First time poster here and have just received my first SPI products for my restoration of a 1982 vw pickup truck. I currently have the truck on a tip over jig and have been working on replacing the floor pans and stripping down the undercarriage to bare metal.

My plan is to spray SPI epoxy primer as the base coat for protection and then cover with another product. I am considering the using either:
Upol raptor bed liner
Upol gravitex
Wurth underbody sealer
I think 3M has a body Schutz

My questions

Any recommendations on the above products?

Do I need to apply seem sealer? And if I do, would that be after the epoxy primer, before the undercarriage coating product?

I have some surface rust between pinchwelds and some other places I cannot cut and replace. How to a treat these areas before I lay down the epoxy?

There are some crevices that I cannot get to to completely remove the factory undercoating/seam sealer. Is this an issue or will the epoxy adhere to this as long as it’s clean?

Thanks
Dean
 
Cool project. Can you post picture of the tip over jig? I almost went that way but finally decided on rotisserie

SPI Epoxy works great for final coat on undercarriage. Just make sure 4 hour induction and 3 coats. Don't need anything else.

But, if you are set on another final coat, Upol Raptor is great stuff.
If you order some, make sure the kit includes the Upol Shutz type gun. Some suppliers like TCP Global include a crappy Chinese gun that will be a headache.

If you removed seam sealer or your repairs were on a lap joint you will need to apply seam sealer.
Epoxy first, then seam sealer, then epoxy over the seam sealer.
FYI, 2 part seam sealer cures fast. 1 part cures very slow (days or weeks) and can slow down your project. Ask me how I know...

As for the rust, others here have better info than me and I'm sure they will jump in with helpful tips.
 
Last edited:
I've used raptor on underside of floor pans 3 times. I like it. It sure does stink though. I used to pour it into a pitcher to mix the color in but now I just drop an old nut in the bottle and shake it up like a rattle can. The product calls for scuffing prior but I really don't think that makes a difference. That stuff isn't coming off. If u spray it within the epoxy recoat window then it REALLY isn't coming off.
 
Do three or four coats of epoxy for the underneath and leave it.
When fully cured in 90 days, it will give you a lot better protection and STRENGHT than a bed liner or any paint.
Plus, down the road, if you go to sell the truck, the bed liner will scare people off as they think you are hiding something.
I've seen many nice cars at auction, and as soon as most buyers see undercoating, they get up and walk away.
The exception is if it came from a factory with a shultz coating like old Mercedes and some BMWs.
 
Welcome from a fellow VW enthusiast. Post pictures or start a build thread; we love shiny, techy things :cool:
I have more questions than answers in this forum so I will just listen in.

-----
Emil
 
Back
Top