Questioning my mil thickness on universal clear

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I have been working on my TR7 project, and have some pics posted in the Restorations section. Now, I'm wondering about my mil thickness and whether to sand and add more clear.

The main shell shown below took around a quart per coat (maybe 30 oz) sprayable, in universal clear. No reducer. I asked a very experienced guy to help me with the clear because I didn't want to screw it up. He was there, and I decided to let him spray it and I'd watch. (my first big clear spray job and I had too much time into it to want to screw it up).

He wasn't on board with spraying more than 3 coats. Each coat was really wet and glossy, and we had a few small runs. I don't think we could have sprayed much more per coat.

I was curious about mil thickenss, so I took off a few pieces of masking that were in areas that should have been painted just like the rest of the car. I cut them and looked at them under a microscope at work. Seems to be right around 3.5 mils for those 3 wet coats. Is that right? I was hoping to see more thickness.
Here is a cool picture from the lab at work. The blurry yellow stuff is masking tape, then there is black epoxy, then red base, then clear (the part with dimensions on it).
Paint - 2.jpg

I sprayed the trunk, doors, and hood myself in subsequent weekends. I decided I was going to do 5 coats (expecting to not spray as consistently or as wet as he did).
I also set up 5 panels of aluminum flashing (the brown and white painted stuff) and pulled one out after every coat, figuring I could easily measure paint thickness with a micrometer after it dried. I was spraying right around 0.6mils per coat. 3 mils total for 5 barely wet coats. These were puposefully sprayed as light as I thought I might have went anywhere.

I ended up needing to order a 2nd gallon of clear and more activator to finish my doors. I used a little spraying test panels, etc, so I figure I have about 2 gallons sprayable universal clear on the project. Does that sound right?

All was sprayed with my LPH400LV, 1.4.

The body was sprayed at around 34PSI, 5 turns out (OMG!) He was moving fast! I sprayed at 28PSI, and 2.75 turns out (moving a bit slower LOL). Maybe all my paint went into overspray.

I have almost a full gallon of clear left, so I could certainly spray more clear.

 
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2-3 mils from 3 coats sounds pretty low, but then spraying at 34psi is real high. I used to use an LPH400 at 27-28 psi, but tried it at 22 psi to get less overspray. UC layed down just as nice at 22 as it did at 28 and much less overspray (fog) in the booth.
 
I hate posting my screwup, but I agree. Seems thin. i don’t think I’ll be satisfied unless I put more clear on. Glad I have that option.
 
My brain aches thinking conversion lol.
If 0.100 mil is roughly 4 thousandths (paper money approx) then it's thin i say.
Edit- 0.100 mm not mil i mean
Edit again- my head hurts it's friday lol. Stick with thousandths.
 
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My brain aches thinking conversion lol.
If 0.100 mil is roughly 4 thousandths (paper money approx) then it's thin i say.
Edit- 0.100 mm not mil i mean
Edit again- my head hurts it's friday lol. Stick with thousandths.
Lol. I just deleted my last post because my head hurts thinking about it. I have 3.5 mils (thousandths) on that masking.
 
I’m going to take some better masking samples to disect at work. Stay tuned. I can’t believe i only have 3.5 mils.
 
On an average one mill per coat is normal; every painter is going to be different BUT, if you are sure the tap has the same amount of clear as the rest of the car and it was nice and wet with some sages in it, 3 mills is plenty! I take it that it is a high solids clear? unless you are going to sand and buff aggressively you are fine. Also reminder the top/flat panels will have more clear than a side panels.
 
Barry would be the guy to give a "definitive" answer but most premium clears are going to be around 1.1-1.3 mils per coat if sprayed correctly. 3.5 mils puts you right where you should be. Minimum mil thickness should be around 2.0-2.2. Too little millage is not good but too much millage isn't good either. If you are not cutting and buffing then 3.5 is perfect. If you are going to cut and buff I'd recommend actually sanding after 3 coats and then spraying three more coats then cut and buff. That would be the best way to make sure you have enough clear on the body. Doing it that way will give you around 4.0-4.5 (assuming everything done correctly) which is about the maximum millage you want on a car. Spraying more than 3 coats at one time is not ideal, you'll get millage buildup in places you don't want it (edges of panels etc)
 
Thanks guys. All good info. I am going to check clear thinkness on a few more masking peices and make up my mind what to do.

As the finish sits right now, I have already surpassed my goal for how it looks. So far, there is nothing that I wish I had done better on or spent more time on. In the end, this car will primarily get driven to work and WalMart as I have done with it for the past 30 years. I did the car show thing with an AC cobra replica I built 15 years ago. After a few trophies, I lost interest and just enjoyed driving the car. I’d rather sit in my garage and admire my work in solitude with a beer. LOL. I have a 54 Chevy driver that I love. 6 volt, 3 on the tree. It looks nice at a cruise in, but it is no where near show paint. I have absolutely no desire to have perfect paint on it.
 
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Thanks guys. All good info. I am going to check clear thinkness on a few more masking peices and make up my mind what to do.

As the finish sits right now, I have already surpassed my goal for how it looks. So far, there is nothing that I wish I had done better on or spent more time on. In the end, this car will primarily get driven to work and WalMart as I have done with it for the past 30 years. I did the car show thing with an AC cobra replica I built 15 years ago. After a few trophies, I lost interest and just enjoyed driving the car. I’d rather sit in my garage and admire my work in solitude with a beer. LOL. I have a 54 Chevy driver that I love. 6 volt, 3 on the tree. It looks nice at a cruise in, but it is no where near show paint. I have absolutely no desire to have perfect paint on it.
How about a picture so we can admire your work !!?
 
A bill is 4.5 mil using my cheap caliper. Cool if you can measure one with your very cool high tech scope.
I must've put the clear on my cars 2 or 3x that. I like extra to go through the grits afterwards.
Yes we can't wait to see your child :)
IMG_5387.JPG
 
How about a picture so we can admire your work !!?
Assuming you are talking about the other cars I mentioned,.... This required me digging out old CD backups of pictures. I made this collage to have printed and it hangs in my garage. The bottom right corner has the cobra and the 54 chevy in it. My crazy attention to detail on the cobra build is what everyone recognized. Most of them have short cuts here or there.

Cobra8x10Logo.jpg
 
A bill is 4.5 mil using my cheap caliper. Cool if you can measure one with your very cool high tech scope.
I must've put the clear on my cars 2 or 3x that. I like extra to go through the grits afterwards.
Yes we can't wait to see your child :)
View attachment 6325
We are indeed talking about small dimensinos. Scary small. I thought I must have sprayed thicker clear too, but that wasn't reality. It does seem to line up with the dimensions Chris mentioned though.

In all seriousness, if anyone wants to mail me a sample of clear on something (scrap of patch metal, masking, etc), I can section it and measure it in the microscope at work. I really want to know what is achievable on a vertical panel.
 
I should have specifically mentioned the TR7 "as the finish sits right now", but all of this is very cool! Both of these are super neat. I always wanted to do a Cobra replica, but it never happened (yet).
 
I should have specifically mentioned the TR7 "as the finish sits right now", but all of this is very cool! Both of these are super neat. I always wanted to do a Cobra replica, but it never happened (yet).
The cobra was a blast. I built it for a friend of my dad’s who lived in California and had a summer lake home near me (western NY). Part of my payment was that I got to have the car for about 3 yrs after it was finished. The car went to Cali for a few years and then it was sold to someone in Germany.
 
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