# Gemini Gemcoat Precat Cracking



## [email protected] (Jun 29, 2016)

Hey ya'll..anybody had any problems with Gemini Precat cracking? I'm not a professional wood finisher..but been painting in pretty much every other industry the last five years(automotive, marine, truck) so I got called upon to respray 15 sets of dressers and bedside cabinets that the gemini gem coat precat lacquer had cracked. We bought these sets new from a furniture manufacturer in canada..the wood was hickory btw..long story short they got cooled down to 20 degrees fahrentheit during transport. had various degrees of lacquer cracking..gemini guys came and found dft of 2.5 to 7.5! anything under 3 dft had not cracked. I just finished respraying them (after tons of elbow grease varnish removing them) with various stains and topcoats..everything looks good..basically I'm wondering if anybody has had any problems like this? Do you think it was caused by excessive dft or cooling or both? 

ps. in another forum I saw a guy ask about what to do about sw precat cracking..somebody responded he's using a **** product and should switch to gemini precat just found it funny.


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## Jmayspaint (Mar 26, 2013)

Most likely the DFT was too high. Every pre-cat lacquer I’m familiar with has a max DTF of around 3-4 mil. The Gemini at a max of 3 mil is no exception. 

I’ve seen plenty of cracked lacquer. Mostly on white or off white cabinets. It is kind of a pain to deal with as you have to sand almost all of it off. 

I doubt it’s a result of low temperature. Dried lacquer is pretty resilient to cold in my experience. 


Sent from my iPhone using Tapatalk


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## dwallon60 (Apr 22, 2018)

Jmayspaint said:


> Most likely the DFT was too high. Every pre-cat lacquer I’m familiar with has a max DTF of around 3-4 mil. The Gemini at a max of 3 mil is no exception.
> 
> I’ve seen plenty of cracked lacquer. Mostly on white or off white cabinets. It is kind of a pain to deal with as you have to sand almost all of it off.
> 
> ...


I concur. Better to have multiple mist coats also. It is hard to control if you hurry.


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## [email protected] (Jun 29, 2016)

I used an airless with a 410FF Lp tip. I put on as light a coat as I could while still getting even coverage. I put on two coats about one hour apart with light sanding in between. I have no way of measuring dft. Like I said..i have no previous experience spraying lacquer. I sprayed it in a paint booth with pretty good airflow..no reducer and no retarder. Around 72 degrees. Sometimes it looked really wet in strips and right next to it looked too dry(I'm assuming because of difference in porosity) so I have no idea of even guessing my film build. With it being only 20% solids do you think there's a chance it'll crack again?


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## stelzerpaintinginc. (May 9, 2012)

*Wet Film Thickness Gauge*



[email protected] said:


> I used an airless with a 410FF Lp tip. I put on as light a coat as I could while still getting even coverage. I put on two coats about one hour apart with light sanding in between. I have no way of measuring dft. Like I said..i have no previous experience spraying lacquer. I sprayed it in a paint booth with pretty good airflow..no reducer and no retarder. Around 72 degrees. Sometimes it looked really wet in strips and right next to it looked too dry(I'm assuming because of difference in porosity) so I have no idea of even guessing my film build. With it being only 20% solids do you think there's a chance it'll crack again?


 Out of the thousands of members on PaintTalk, I bet very few actually have the proper equipment to test DFT, (I know I don't). What we DO have are WFT gauges. Go to a paint store and get a WFT gauge so you will know for certain you're applying to proper mil spec. I haven't read Gemini's data sheets, but my guess is you'll be looking for around 3-4 mils of WFT per coat to achieve approx 1 mil DFT. Confirm with Gemini though. 

As far as having issues with dry spray, you'd have to post a pic and get pretty detailed about your setup & application procedures in order to get an exact answer. Could be from your spray speed, angle, distance, overlap, could even be from excessive humidity causing blushing. But if you're confident that your technique is solid & atmospheric conditions are favorable, then I'd suggest using a retarder, which helps keep the product wet enough when spraying to avoid dry spray.


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## PACman (Oct 24, 2014)

I can measure dry film thickness. And yes, it is either to thick of a coat OR using it over a stearated stain or sanding sealer.


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## Woodco (Nov 19, 2016)

I have a great technique for getting even coverage with lacquer. Firstly, I reduce it about 10% I use a 410 , and I use super quick passes with the spray, and moving over just a tiny bit with each pass, as opposed to paint, where you move at a slow to medium rate, and overlap by half your spray. Its a lot more movement, and a workout if you spray doors upright, but it gets it nice and even. sometimes I will do a doublewet coat, with the second one being more of a fogger coat. I probably do about twice times as many up and downs with the spray as a normal paint, but moving twice as fast, and moving over half as much each time.


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## mug (Dec 22, 2010)

Can you paint over an old cracked laquer if it is below the surface? I recently did a set of Cabs and one of the drawers looked like broken glass but smooth on top.


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## Krittterkare (Jul 12, 2013)

Jmayspaint said:


> Most likely the DFT was too high. Every pre-cat lacquer I’m familiar with has a max DTF of around 3-4 mil. The Gemini at a max of 3 mil is no exception.
> 
> I’ve seen plenty of cracked lacquer. Mostly on white or off white cabinets. It is kind of a pain to deal with as you have to sand almost all of it off.
> 
> ...


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## [email protected] (Jun 29, 2016)

PACman said:


> I can measure dry film thickness. And yes, it is either to thick of a coat OR using it over a stearated stain or sanding sealer.


Are you saying the Gem COat might have cracked because it of a sanding sealer? They did use a Gemini sanding sealer when it cracked. I however did not use one now that I refinished them.


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