Pinholes in 2K clearcoat

[Hagwood]

Well, my first attempt at using Spraymax 2K didn't go too well. It looked great going on, but after the final coat set up for a few minutes, it started developing bubbles in the finish in a few areas. After it cured for a couple of days I tried to see if they would sand out, but they turned into pinholes that are too deep to keep sanding. I started with 600 and the rest of the finish is smooth except for the few spots that had the bubbles. Not sure If I can just spray a few more coats over it to fill it in or if they will still be visible. I'm not sure if the new layers 'melt' into the previous ones like Nitro or if it's just going to lay on top of the imperfections. Any advice would be appreciated.

 

[Hodgo]

No, you need to sand them out, 2K is not soluble in its original solvents like nitro or shellac.

 

[Hagwood]

No, you need to sand them out, 2K is not soluble in its original solvents like nitro or shellac.

Damn, probably gonna have to start over then, I think they're to deep to sand out without getting into the color. Any idea what would have caused that ? I'm not new to spraying and have never seen that. It's over the top of Aniline Dye and Solarez grain filler, which looked great after applying and sanding.

 

[Hodgo]

Damn, probably gonna have to start over then, I think they're to deep to sand out without getting into the color. Any idea what would have caused that ? I'm not new to spraying and have never seen that. It's over the top of Aniline Dye and Solarez grain filler, which looked great after applying and sanding.

I hope you don’t end up cutting into color, I’d start with some really mild sanding.

As to why it happened, I can only guess… either the surface wasn’t cleaned, or flash coats weren’t given enough time and some solvent got trapped, or humidity was a factor. Hard to say. Initially I thought you had skipped the grain fill but that doesn’t seem to be the case.

 

[Hagwood]

I hope you don’t end up cutting into color, I’d start with some really mild sanding.

As to why it happened, I can only guess… either the surface wasn’t cleaned, or flash coats weren’t given enough time and some solvent got trapped, or humidity was a factor. Hard to say. Initially I thought you had skipped the grain fill but that doesn’t seem to be the case.

Thanks for the help, I'll work on it some more tonight. How long do you go between coats ? Humidity has been really low here, about 25%, and I spray inside a temp booth (tent) with ventilation.

 

[Hodgo]

Thanks for the help, I'll work on it some more tonight. How long do you go between coats ? Humidity has been really low here, about 25%, and I spray inside a temp booth (tent) with ventilation.

Whatever the manufacturer recommends is your best bet. I don’t have enough experience with 2k to give you better pointers, but witness marks are a function of catalyzed finishes in general.

 

[Byron]

I watched a few u-tube videos on recoat times etc. I am planning on a similar project...now I'm scared. Best to sand out the spots and not sand off to the color or it may show witness lines. Maybe talk to an autobody person for more info. Good luck and keep us informed

 

[teleme01]

I watched a few u-tube videos on recoat times etc. I am planning on a similar project...now I'm scared. Best to sand out the spots and not sand off to the color or it may show witness lines. Maybe talk to an autobody person for more info. Good luck and keep us informed

Don't fear the imperfect, you won't get everything perfect the 1st time, at the end of the day its a piece of wood, replaceable, you can build a nother one.

 

[Byron]

Don't fear the imperfect, you won't get everything perfect the 1st time, at the end of the day its a piece of wood, replaceable, you can build a nother one.

That's what she said. I have a few horror stories/ learning experiences with finishing. Even a hat trick on the same body. But you are correct.

 

[Hagwood]

Don't fear the imperfect, you won't get everything perfect the 1st time, at the end of the day its a piece of wood, replaceable, you can build a nother one.

That's what she said. I have a few horror stories/ learning experiences with finishing. Even a hat trick on the same body. But you are correct.

Exactly right, When trying to sand it out last night I hit the color, so just kept on going to bare wood again. Not life or death, and only took about 30 mins with 400 grit on the Random Orbital. Just be careful with the lam top, left a little color on it. Gonna try again this weekend with some info I have learned. This was one planned to learn on anyway, and at least I'll be really good at dying......

 

[Spud]

Exactly right, When trying to sand it out last night I hit the color, so just kept on going to bare wood again. Not life or death, and only took about 30 mins with 400 grit on the Random Orbital. Just be careful with the lam top, left a little color on it. Gonna try again this weekend with some info I have learned. This was one planned to learn on anyway, and at least I'll be really good at dying......

View attachment 64428

Be careful as there is only so much depth on that top to work with.

 

[Hagwood]

Be careful as there is only so much depth on that top to work with.

Exactly, that's why I left some color on it, just barely took the dye off. Hopefully 3rd time is a charm, it may not have enough left for a fourth.......

 

[Hodgo]

I saw your original finish post… my goodness man, you have high standards!

 

[Hagwood]

I saw your original finish post… my goodness man, you have high standards!

LOL, I do have a touch of OCD to be sure, but I would have been happy with the first nitro finish if wouldn't have kept shrinking up and 'wrinkling', even after months. I re-sanded and buffed like 3 times and it would keep happening, and as much of a PITA as it was to apply I said I'm done with Nitro. 20 coats over a week and then 3 weeks to cure and still issues. I'm not into relics and don't care about the 'vintage' finish or checking of Nitro, so figured the 2K would be better for me. Oh well, at least I'll have all the processes worked out before my next build, I'll chalk it up to a learning experience.....

 

[Spud]

LOL, I do have a touch of OCD to be sure, but I would have been happy with the first nitro finish if wouldn't have kept shrinking up and 'wrinkling', even after months. I re-sanded and buffed like 3 times and it would keep happening, and as much of a PITA as it was to apply I said I'm done with Nitro. 20 coats over a week and then 3 weeks to cure and still issues. I'm not into relics and don't care about the 'vintage' finish or checking of Nitro, so figured the 2K would be better for me. Oh well, at least I'll have all the processes worked out before my next build, I'll chalk it up to a learning experience.....

I hope you are aware that this is all due to your failure to watch the second movie I recommended right?

 

[Hagwood]

I hope you are aware that this is all due to your failure to watch the second movie I recommended right?

Dang it, that must be it....... It's still on my list, but been doing a lot of camping while the weather is tolerable in TX.

 

[Hagwood]

Well as a plus side I am getting plenty of practice in on dying….. a little more refining the burst, then ready for round 3 of finishing…..

 

[Byron]

Looking good. I looked at your first try. Seems like the 2K did not flow together. How did you clean the body before spraying/ Did it cure properly? In one of the Utube vids I watched, the guy was no shy and put down many coats, waiting for each to flash off. he then rolled the body to prevent runs and sags

 

[Hagwood]

Looking good. I looked at your first try. Seems like the 2K did not flow together. How did you clean the body before spraying/ Did it cure properly? In one of the Utube vids I watched, the guy was no shy and put down many coats, waiting for each to flash off. he then rolled the body to prevent runs and sags

Thanks. On the first try I did Solarez grain filler on the mahogany back after the dye. Then after cured good and sanded back, gently cleaned everything up with a slightly damp rag so as not to remove any color. This time I’m putting some de-waxed shellac down first before the 2k. I’ve been practicing in some scrap maple and if brushed on lightly it won’t disturb the dye.

 

[Byron]

Thanks. On the first try I did Solarez grain filler on the mahogany back after the dye. Then after cured good and sanded back, gently cleaned everything up with a slightly damp rag so as not to remove any color. This time I’m putting some de-waxed shellac down first before the 2k. I’ve been practicing in some scrap maple and if brushed on lightly it won’t disturb the dye.

Did the grain filler need more than one coat? I may be wrong thinking of the Solarez as a filler and seal coat that would lock the color down after level sanding for the clear coat???