Undercoating

[JJSZABO]

Just undercoated the bottom of the cab.

I used Duplicolor roll on bed liner.  I know - it sucks as a bed liner, but wanted to try it as a undercoating - it was cheaper than Herculiner.

Prep:  I sand blasted the whole bottom, cleaned with laquere thinner, then wax and grease remover, then seam sealed the repair areas.  Then epoxy the whole bottom - let cure then applied the undercaoting.  Here is a picture:

[locdogg]

looks nice--I just put a new rust free bed on my truck and Herculiner-ed the underside as well as the inside of the bed and tailgate

[Blazin]

Looks good. I hope you sanded the epoxy primer first though.
 I did the same thing to my 86 cab but used SEM spray on bed liner. Used SEM self etching primer underneath it, and sprayed SEM acrylic black paint over it.

[87GMC2WD]

i used that SEM stuff in school on a utility trailer that we made with the same primer. CAme out pretty good. But on the underside of my bed and my frame i wirebrushed and used a 4in grinder than applied POR15. It works pretty good. i also painted my exhaust with it and it just baked right on and doesnt smell anymore.

[VileZambonie]

Looks good! I've used the duplicolor liner and I've had problems with it sticking well. One really cheap excellent product I've used with great results is Rustoleum Hammered black. It looks good and protects well. It does take a while to dry though. I would say wait at least 48 hours before really working with it.

[Captkaos]

I just put Durabak on my Crew Cab floor to seal it from any moisture before putting the carpet back in.  When I did the bottom of my cab in 2000 I painted it with POR15.

[Blazin]

I used to use the Hamerite but a few years back the Kilz company bought it. I think they changed to formula. It doesn't work as good or last like the stuff from 10 years ago. The old stuff worked awesome over Duponts Variprime or tightly adhered rust, it didn't work well over bare metal though.
 I use this stuff, its the same as POR 15 but about half the price. If you want to spray it they have reducer, cut it by 10%. I spray this right on a frame after needle scale and a little wire brush work. it works good over sandblasted metal also.
http://4wheeldrive.about.com/cs/classicrestoration/a/aa042003a.htm

[JJSZABO]

Well.......no, I didn't sand the epoxy before I applied the undercoating .  I am using Southernpolyurathene epoxy primer and the tech sheet says that the epoxy doesn't need to be sanded before applying body filler.... so .....I assumed that if the epoxy didn't need sanded before the body filler, then I didn't need it for the undercoating.  Time will tell.

[Blazin]

You said you let it cure is why I asked. Most epoxy primers are OK to recoat without sanding as long as they are not cured.

[locdogg]

I used to use the Hamerite but a few years back the Kilz company bought it. I think they changed to formula. It doesn't work as good or last like the stuff from 10 years ago. The old stuff worked awesome over Duponts Variprime or tightly adhered rust, it didn't work well over bare metal though.
 I use this stuff, its the same as POR 15 but about half the price. If you want to spray it they have reducer, cut it by 10%. I spray this right on a frame after needle scale and a little wire brush work. it works good over sandblasted metal also.
http://4wheeldrive.about.com/cs/classicrestoration/a/aa042003a.htm

Blazin---do you know of anyplace that sells this online?

[VileZambonie]

just google it

http://www.magnetpaints.com/underbody.asp

[Blazin]

I buy mine from one of the local auto parts chains. Don't know where you would get it online.

[JJSZABO]

Is there any one "right" way?   It's like fishing - as long as you catch fish who cares how it is done

As I observe, read  and learn new things, I have concluded that the path to the outcome may be different as long as the prep steps are done correctly.  Just my .02 worth.

The "you know what" is getting deep in here!!!!
Jeff

[Blazin]

If it works it works. I was just referencing in case there was more to be done or if someone else is thinking of doing the same thing.
 Basically if two components are compatible you can go over one with the other without sanding before the first is completely dry / cured.
 If the first is cured you should always have some sort of mechanical bond ( sanding ).

[JJSZABO]

It's all good   I was trying to be witty - didn't mean anything negitive.  Blazin - you have WAY more experience in this than I do and I really appreciate the help you give us all. 

Thanks again for your help

Jeff