Crackled finish when painting blank interior?

[JimMc7]

I painted inside a blank using Model Master Acryl and had a crackled/alligator finish showing after turning the blank. Google search shows "alligator" effect is usually caused by applying the 2nd coat before the 1st coat dries. I let the 1st coat dry overnight before the 2nd and no problems with other colors done the same way but this one sure went wrong. Anyone else have this problem and know of a different cause/way to prevent? I'll try another bottle of paint and let it dry 2 days next time but asking the question in case there may be another cause. Thanks in advance!

Edit to add: I used 5 minute epoxy tinted with Mixol white as the tube adhesive (again, similar to other blanks but I don't always tint the epoxy).

 

[OKLAHOMAN]

Jim, did you clue the tubes with CA or epoxy and did both barrells crackel?

 

[JimMc7]

Roy, sorry for not saying the 1st time -- I used 5 minute epoxy tinted with Mixol white. I've used this same procedure with other colors and with the white on occasion but maybe this blank is more translucent than others I've done (could have it and not see it with other blanks).

And yes -- actually had the problem on all 3 blanks (both blanks of a workshop pencil and this Sierra blank).

 

[OKLAHOMAN]

Jim, that leaves out an reacting to CA. Did you clean the inside of the blanks with thiner before painting. I had a similar thing with clear cactus, the drill would leave a slight rough service inside the blank and if I didn't clean the inside of the blank a grayish spot would show at the nib and final where the blank was thinest.

 

[JimMc7]

I don't clean blanks before painting other than blowing out the debris. I'll try cleaning before painting next time. Thanks, Roy

 

[JimMc7]

To close this one...

I tried a different bottle of Testor's and cleaned the blank and still had the crackled interior finish. I switched to Apple Barrel brand acrylic paint for the blank interior and no problem. I've used other Testor colors and the white with other blanks without problems but for whatever reason the Testors didn't work well with the Mica Swirl AA blanks. The Apple Barrel is cheaper so at least something positive with this project.

 

[DurocShark]

Interesting that the enamel cracked but the acrylic didn't.

At least you solved the immediate problem!

 

[nava1uni]

I wonder if the Testor was reacting to heat build up during the sanding or polishing stage of completion. I have had problems with heat build up causing crackling or loosening of tubes, even with epoxy. Now I let the blank cool between different stages to prevent problems.

 

[JimMc7]

I wonder if the Testor was reacting to heat build up during the sanding or polishing stage of completion. I have had problems with heat build up causing crackling or loosening of tubes, even with epoxy. Now I let the blank cool between different stages to prevent problems.

I can be too heavy handed sanding or polishing but after the 1st occurrence, I tried to dial it down. I also examined this last problem blank before I started sanding (just after the skew) and still saw the crackling.

Not wanting to tempt fate, I'll stay with the Apple Barrel brand acrylic until I have a reason not to!

More facts in case this happens to someone else in the future:

These Mica Swirl AA blanks were glued with System 3 brand 5 minute epoxy. I normally use Manny's 5 minute epoxy but I ran out -- purchased the System 3 at Woodcraft. System 3 & Testor's combo hasn't resulted in crackling with other blank/color combinations. The Testor's paints were Model Master Acryl (flat white, 1/2 oz. bottle) in the 1st problem case and Acryl (gloss white brilliant, 1/4 oz. bottle) in the 2nd problem case.

I've used this blank a few other times and this is the 1st time I've painted the blank interior. I scrapped some of the others because glue voids were visible in the finished blank -- hence, the switch to painting the blank.