Hi,

I had a few gutter rashes on my rocker panel so I did some research and tried to repair it myself. This is my first time but I'm pretty sure I've done the steps right but for some reason after applying the 2nd base coat I started to see white cracks in some places.

https://www.dropbox.com/s/3wb65obq4vqvp ... 6.jpg?dl=0

https://www.dropbox.com/s/n43iud7i3woeu ... 6.jpg?dl=0

Here are the steps from the beginning:

1. Sand area with 80 Grit sand paper
2. Clean area with wax and grease remover and dry it
3. Apply Filler Primer: Apply 3 coats of Filler Primer (10 mins between each coat)
4. Sand with 120g then 240g
5. Apply 3 coats of Adhesion Primer (10 mins between each coat)
6. Wait 1 hour
7. Sand with 800 wet sand
8. Apply base coat (2 light + 1 heavy coats, 10 mins between each coat)
9. Wait 10 minutes
10. Scuff down any other area that needs clear coat
11. Apply clear coat (3 coats, 10 mins between each coat)

Where did I go wrong?

what is the adhesion primer #5 your problem is the base coat didn't like something that was under it, most likely the old color coat. were the materials shaker cans?
Jay D.

badsix wrote:what is the adhesion primer #5 your problem is the base coat didn't like something that was under it, most likely the old color coat. were the materials shaker cans?
Jay D.

Yes everything was in aerosol cans. the adhesion primer was septone
https://vgautopaints.com.au/products/se ... tocomplete

that's where you went wrong. something you sprayed over wasn't compatible and caused lifting. this happens a lot when using a lacquer material over an un catalyzed enamel based product.
Jay D.

badsix wrote:that's where you went wrong. something you sprayed over wasn't compatible and caused lifting. this happens a lot when using a lacquer material over an un catalyzed enamel based product.
Jay D.

I'm a newbie... can you explain that in English please

These guys used the same combination of products in their tutorial and that's what I followed

https://www.youtube.com/watch?v=LHA0jhp3CSM

Also, I just remembered that when I was wet sanding using 800 grit before applying the base coat, I noticed the primer was kind of fading in the areas that I sanded so I stopped sanding half way. Could that be the problem?

NEWBIE, good video a little deceiving. I have no idea what your material is or what was on the car, but something reacted to one of your products. it could be one of your primers or something that was on the car to start with. for a test spray a couple good heavy wet coats of the base on somewhere with no primer just on the original color and see what happens. if it lifts you might need to change your materials.
Jay D.

From the troubleshooting manual:

LIFTING
(Wrinkling, Raising, Alligatoring, Shriveling, Swelling)
The existing paint film shrivels, wrinkles or swells during new finish application or drying.

CAUSE
(A) Solvents in a newly applied product attack the previous finish causing wrinkling, raising, or puckering of the paint film due to:
(1) Recoating enamels or urethanes that are not fully cured;
(2) Exceeding maximum flash or recoat times during application;
(3) Recoating a basecoat/clearcoat finish, where existing clearcoat has insufficient film
build.

REPAIR_
(1) Remove lifted areas and refinish.

PREVENTION
Check questionable finishes by rubbing a small inconspicuous area with a shop towel saturated with lacquer thinner. Finishes susceptible to lifting will soften, swell or shrivel as lacquer thinner is applied. If any of these reactions occur, the following recommendations should be considered.
(A) Do not exceed a product's maximum recoat time during or after application.
(B) Allow enamels or urethanes to thoroughly cure before recoating or attempting a repair.
(C) Avoid applying undercoats or topcoats excessively wet.
(D) Avoid the use of lacquer products over an air dried enamel finish.

I did the job in my apartments underground parking which has little ventilation but no outside air. Could this have caused the crazing?

I understand from everyone's suggestions that I have to redo the whole thing but at the moment I just need to somehow cover up those defects and I don't really care if it's not showroom quality.

Multiple problems here.

3 coats of filler/primer. Even with 10 minutes between coats, if you left it for a day that probably wouldn't be enough.

3 coats of adhesion promoter? 3 COATS!!!!!??? One mate, just one, thin coat is all that should be used and it should not really be used over painted surfaces. It's for unpainted plastic. Being 1K it's also mostly thinners so even after an hour you had heaps of unevaporated solvent sitting there just waiting to get out.

So then a coat of base. By now you had a ticking time bomb just waiting to explode and the second coat of base was the straw that broke the camel's back. That it didn't fry up even worse surprises me.

Take it all off and start again. This time repair the scratches either with filler or by sanding down and feathering the edges. Then prime, sand and apply base. Wait minimum 15 minutes if you're up north, maybe an hour if in the southern states. Longer is better, remembering that you're using acrylic products and the solvent will activate the prior coat and soften to achieve adhesion. Clear with 1 light tack coat then 2 coats medium wet, not heavy.

Oh, and don't scuff after your base coat. Scuffing should be done either before or after primer. Scuffing base will scratch it and the scratches will be visible through the clear.