Correct undercoating steps

[Iron Ranger]

On one of my vehicles, I undercoated the rocker panel and the lower lip of the door.

I first went over the areas to be painted with a 180G sanding sponge, wiped the area clean with acetone, put 3 coats of self-etch primer, 3 coats of automotive primer, and 4 coats of Rustolium Bed Liner. It held up until halfway into winter. All were aerosol cans.

Now, some parts are peeling off the edges and some parts come right off with my fingernail. After every car wash, a little more disappears.

Now, my question to you guys out there, could I have done something different with my steps? Maybe use a different type of cleaner or use sealer primer after the self etch? Or is the bedliner no good and I should upgrade to herculiner or something similar?

Help!!

 

[strvger]

only thing i see is that you used the spray on bedliner. the roll on is much better and the professional sprayed on is better still. i've used the spray on with similar results. won't make that mistake again.

 

[adsm08]

Did you sand in-between primer coats? Gotta sand in between primer coats. Even with the self-etch, still gotta sand it. 800G is better than 180. For automotive painting i like to use between 600 and 800 grit, I'll use 1000 if it's all I can find.

When I did the nose cone for my olds I took the old paint off with 180 then sanded it down with 800, laid primer, sanded with 800, laid primer, 800, primer, 800, green, 800 green, 800, clear, 800 flames, pin-stripes, 800, clear, 1000, buffer and wax.

 

[Sasquatch_Ryda]

I did the lower part of the rockers on my 91 6 years ago and they are still like new. I scuffed the paint up with some 200 grip, wiped it all down with wax and grease remover and sprayed it with Rust Check Hi-Build rock guard (think i did 3 coats). Never had it peal yet and it hold up to the abuse my truck gets put through very well.

http://www.rustcheck.com/products.asp

This is about a year after I did it

Here is it not that long ago

 

[strvger]

guess i might try to give that Rustcheck stuff a try as there is a dealer here in Duluth, Mn. all the rest are in Indiana and Ohio here in the US.

 

[Iron Ranger]

Did you sand in-between primer coats? Gotta sand in between primer coats. Even with the self-etch, still gotta sand it. 800G is better than 180. For automotive painting i like to use between 600 and 800 grit, I'll use 1000 if it's all I can find.

When I did the nose cone for my olds I took the old paint off with 180 then sanded it down with 800, laid primer, sanded with 800, laid primer, 800, primer, 800, green, 800 green, 800, clear, 800 flames, pin-stripes, 800, clear, 1000, buffer and wax.

Ok. No, I didn't sand inbetween primer coats. It's on my Cobalt of all vehicles and it looks like water somehow got inbetween the self etch primer and the car factory clear and started to separate it. I painted it on a dry week in the middle of summer, so I'm a little confused as to how this happened.

What's that high build rust guard stuff, is it like thick, hard chip resistant stuff? Because that's what I'm shooting for.

 

[Iron Ranger]

Oh, do you wipe the area clean with cleaner after sanding it each time, or just a microfiber rag?

 

[Sasquatch_Ryda]

It is about a 1/16" thick on my truck. It does not chip or gouge off (it dries hard not soft like undercoat/rubberized bed liner) Haven't had problems with it fading either.

Like I said, I scuffed the original paint, cleaned it with wax and grease remover, sprayed a coat, let it tack, sprayed another coat, let it tack and sprayed it a final time. Didn't prime or anything like that, no need to when you are going over factory paint.

 

[Iron Ranger]

It is about a 1/16" thick on my truck. It does not chip or gouge off (it dries hard not soft like undercoat/rubberized bed liner) Haven't had problems with it fading either.

Like I said, I scuffed the original paint, cleaned it with wax and grease remover, sprayed a coat, let it tack, sprayed another coat, let it tack and sprayed it a final time. Didn't prime or anything like that, no need to when you are going over factory paint.

OK. What's that wax and grease remover stuff? Is it in aerosol form and can I find it at NAPA or something? I used acetone, but I'm not sure if that's good stuff to use or not. If I'm going to redo this, I'm going to do it right.

 

[superdave1984]

OK. What's that wax and grease remover stuff? Is it in aerosol form and can I find it at NAPA or something? I used acetone, but I'm not sure if that's good stuff to use or not. If I'm going to redo this, I'm going to do it right.

Prepsol. Get it at an auto paint dealer. Use that first before you sand to get any wax or grease off. Self etching primer works better on bare metal than over paint. Get everything clean, then clean again.

 

[Iron Ranger]

Prepsol. Get it at an auto paint dealer. Use that first before you sand to get any wax or grease off. Self etching primer works better on bare metal than over paint. Get everything clean, then clean again.

Huh. So, it can be used over sanded primer too before the paint or whatever goes on it?

 

[adsm08]

Oh, do you wipe the area clean with cleaner after sanding it each time, or just a microfiber rag?

I hosed it down with water, blew it dry with an air gun, and then wiped it clean with DX330 degreaser.