HoK Paint cracking

[Burton]

HELP!

This last weekend I had done a pratice paint job on a Mail Box and the paint was cracking on me (While applying).

Here's what I did:

1st - painted the mailbox with the Silver Sealer, which went on great

2nd - Paint 3 coats of Oriental Blue KK (Inter Clear Mix), at this point looking great! Put one Medium coat of SG-100 Inner Klear over the top so I could sand off any overspray mystakes when I did the flames.(Waited over night)

3rd - Taped off my flames.

4th - Started to spray on a coat of BC-02 "Silver" and that's when the silver started to crack. It looked as if the BC(Sliver) was eating right through the Blue.

At this point I had ruined the job anyway so I had let the silver dry( 1 hour) and spray some Silver Sealer over the top
hoping that would clean it up. It actually covered very well and all of the cracked painted were smoothed out. Right when I tried to paint a couple of coats of organic green KK(SG - 100) it had cracked again. Am I not supposed to be putting BC over the KK's? Or visa versa?

I had tried a simular project on a sign blank not long ago and the same thing had happen, but I had chalked it up to not giving the base coats of KK/InnerKlear enough time to dry.
I'm just glad I didn't do it on my tank!

thanks,
Burton

 

[rex]

Scott and EZRIDER are the experts on this stuff but I'd say it's a system compatability problem,like lacquering over enamel.I haven't used HOK yet but that's my stab in the dark.

 

[ezrider]

Burton, i have used the KK in inter coat with the BC's and havent run in to this problem. How strong are you mixing the KK in the IC Clear. Also you didnt say any thing about scuffing the intercoat clear after letting it set over night before you tape the flames. Some times silvers will look strange if sprayed too heavy especialy if the base surface is not properly scuffed " preped", you only have 12 hours before it has to be scuffed or top coated. Sealer shouldnt burry any lifting or cracking, it may be you are spraying too heavy. Its realy hard for me to say with out really seeing the "cracking" another possibility is are you letting the coats flash properly? Give us a little more detail and may be we can get you straightened out.

 

[Burton]

I did scuff up the flames before painting. I'm not sure about the KK mix because I mixed such a small amount I just eye balled it. That could be it but I did spray a coat of inner clear over the top of it. Here is a pic of mailbox. Not sure if it will help, its not a great picture.

 

[rex]

Like I said,I'm not a HOK troubleshuter,but if it was a more consistent wrinkle and you knew it wouldn't delaminate you could probably get $100 for the custom effect.

 

[Burton]

I think I found why it was cracking. I know that I had a good flash coat and gave it enough time to dry or at least that what I thought. I used a slow reducer and the temp was in the low 70’s (Read the note at the bottom). Since then I have cleared it and it seems to be doing find. Hey Rex, maybe I should charge extra!

NOTE: Splitting or cracking is possible when using other companies' reducers or by using a reducer that is too slow for your shop conditions. Splitting or cracking may also occur when painting too fast without allowing proper dry time or by spraying on the base too wet and heavy.