Jump to content
Model Cars Magazine Forum

Lacquer over enamel - possibility?


Recommended Posts

I have an idea for a two-tone paint job that will entail using lacquer (Tamiya) over enamel (Model Master) because each offers a specific shade I want to use that's not available in another formulation.

Here's what I want answered:  If I shoot the enamel first (lighter accent color) and cover that with a coat of Testors Wet Look (lacquer?) can I mask the cleared enamel design and shoot Tamiya lacquer over it without making the enamel wrinkle up?  

Link to comment
Share on other sites

Why not do the lacquer first ? 

When doing big rig motors I use enamel paint and then spray lacquer dull coat on it, had never seemed to cause an issue, but then again it’s not a part that I want looking shiny like a body .

Link to comment
Share on other sites

2 hours ago, tbill said:

Why not do the lacquer first ? 

When doing big rig motors I use enamel paint and then spray lacquer dull coat on it, had never seemed to cause an issue, but then again it’s not a part that I want looking shiny like a body .

The lacquer will be the darker of the two colors, and it seems like it would take a lot more effort to mask and paint a lighter color on top of it.

Link to comment
Share on other sites

Something that may work would be to brush a coat of future over your enamel primer before shooting the lacquer paint over it. The future should seal your primer and allow you to spray lacquer over it. Still, I would do a test before committing to the body.

Link to comment
Share on other sites

1 hour ago, Monty said:

The lacquer will be the darker of the two colors, and it seems like it would take a lot more effort to mask and paint a lighter color on top of it.

I hear ya, but, you’re masking anyway , so do darker lacquer color, mask, coat of light color primer , then your light color enamel, clear with enamel, and done.  I get the light/dark issue, but to get the colors we want, sometimes we gotta go the extra mile to pull it off ( including some trips to the pond, been there, done it).

Link to comment
Share on other sites

I painted this Mercury with Duplicolor primer, two different colors of Tamiya spray can paint, and TESTORS Wet Look Clear:

DSC03013-vi.jpg

The odd thing about this build....the clear was smooth as glass on the green, but came out grainy on the blue....even tho I sprayed the clear over both colors at the same time. Wet sanding got it to this point. Not perfect, but it's in my display case!! LOL

If you have a natural break point between colors, such as the chrome trim shown on this Mercury, careful masking gives you a choice of which color to shoot first. I was able to not overlap the colors on this build.

Time will tell if the clear cracks, but for now, it looks very good. There are about three coats of clear on this build.

Link to comment
Share on other sites

Hi Monty,

As most have said lacquer over enamel is not the common practice.  That said, I have made this exact situation work doing essentially what you said you are planning to do with the Testors Wet Look.  Only difference for me was I was using all Testors paints.  This is what worked for me:

1. Prep and primer

2. Testors enamel, allowed to dry for about a week.

3.  Testors Wet Look allowed to dry for a couple of days.

4. Taped off desired pattern.

5. Testors Lacquer allowed to dry a couple of days.

6. Several coats more of Wet Look 

I thinks as long as you give the enamel enough time to dry the Wet Look is safe to use and should seal the enamel from the next coat of color lacquer. (At least that was what I was assuming would happen when I did it.).  For my build there were actually 2 enamel coats prior to the lacquer color with each color coat separated by a coat of Wet Look. No problems at the time of spraying or during polishing.  I can't speak to longevity as I did this less than a year ago. Not sure if the tamiya will play nice with the Testors but if it were me I would go for it and if it doesn't work sent the body into the vat of stripper of your choosing ( I like Simple Green, but that is a whole other discussion).

Have fun

Theo

Link to comment
Share on other sites

Let me applaud everyone in this thread, at least so far, for the civil answers and help being given.  I asked the same question in two groups on Facebook not too long ago.  To be more specific, I asked if I could shoot Tamiya TS over Krylon.  I had my reasons for this situation.  Pretty simple question requiring a pretty simple answer.  I did get some helpful answers but I got just as many "what the heck are you thinking" type answers.  Had my skills as a modeler even being questioned, (please feel free to look at my models in the Workbench and Under Glass sections).    One Admin took a cheap shot at me and then turned off responses to my post so I couldn't even explain why I was asking the question in the first place.  I don't, and never will, understand why people have to put down someone else in that manner.  Just answer the question, add some explanation if needed and move on.  No need to denigrate anyone.  I do see it happen here on MCM too but not like it is on FB.

 

Anyhow, I just thought I would share that with you all.  Thanks!  (BTW, I am going to finish that model, two-tone, in Krylon just to prove it can be done and it can be done well.)

Link to comment
Share on other sites

Problem here is that things aren't as simple as a token "enamel over lacquer is ok" statement.  There are many different pain formulations (both lacquers and enamels) and different solvents used in all those paints.  In some cases, you can get away with breaking the rules, and in other paint combinations you will not be so lucky.  Then how do you know for sure whether certain paint type or brand is enamel or lacquer?  Often that fact is not mentiones anywhere on the can or bottle.  If you ask the "expert", they might not be correct either.

 

Bottom line is that the best way to check compatibility of all the paint layers you will apply to your model is to do a test spraying on something like plastic (polystyrene) spoon or soft drink bottle.  Spoon is the same, or similar plastic used in a model's body - plastic soda bottle is not quite the same. 

Link to comment
Share on other sites

8 hours ago, peteski said:

Problem here is that things aren't as simple as a token "enamel over lacquer is ok" statement.  There are many different pain formulations (both lacquers and enamels) and different solvents used in all those paints.  In some cases, you can get away with breaking the rules, and in other paint combinations you will not be so lucky.  Then how do you know for sure whether certain paint type or brand is enamel or lacquer?  Often that fact is not mentiones anywhere on the can or bottle.  If you ask the "expert", they might not be correct either.

 

Bottom line is that the best way to check compatibility of all the paint layers you will apply to your model is to do a test spraying on something like plastic (polystyrene) spoon or soft drink bottle.  Spoon is the same, or similar plastic used in a model's body - plastic soda bottle is not quite the same. 

Spot on with some additions.  All paints are made of three basic components.  Pigments, binders and solvents. The binders and solvents interact differently with classes of paints.  The main reaction has to do with the solvents.  This means that when you spray one type of paint over the other, the solvent in the new coat will interact with the binders in the substrate. That interaction is one reason for problems.  "Hotter" solvents such as lacquer thinner, are designed to be much more reactive with substrates because that is how lacquers are intended to work.  Each new layer slightly dissolves the prior and binds it together making a single layer.  Other paints such as water based acrylics(which are actually alcohol based but that is another discussion) do not do this and actually have distinct layers with surface binding only.  This can be seen when stripping paint.  Lacquers will come off in a single sheet whereas others will come of in multiple layers.  Thus lacquer will tend to try and attack the surface of the enamel to bind.  You can get away with that by creating a situation where the exposure of the substrate to the top coat of lacquer thinner is significantly reduces.  Several very light coats with sufficient curing time will build up a protective coat of lacquer binder over the enamel and allow you to paint one over the other. 

The other issue is contraction rates.  All paints shrink as they cure.  Some more than others.  They also take different times to reach stability and the shrinking stops. The classic case of shrinking issues is the "alligator skin" effect where the top coat lifts and wrinkles the substrate. You can also have cracks in the topcoat that show up days or even month after the paint sprayed. There are no hard and fast rules regarding this.  I have experienced shrinking issues with the same type of paint from differant manufactures or even with the same brand.  Tamiya clear was notorious for this when it was first introduced.  It took a delft hand to make it work and I had my shares of disasters with it.  I believe they changed the formula and it is now much better. 

In short when mixing paint classes the only way to make it work is to experiment on an sacrificial body and pay close attention to what you did.  When you get it to work, then follow that process exactly. Anything else is a roll of the dice with craps as the most likely outcome. 

Edited by Pete J.
Link to comment
Share on other sites

12 hours ago, Pete J. said:

Spot on with some additions. 

. . .

Lacquers will come off in a single sheet whereas others will come of in multiple layers.  Thus lacquer will tend to try and attack the surface of the enamel to bind.  You can get away with that by creating a situation where the exposure of the substrate to the top coat of lacquer thinner is significantly reduces.  Several very light coats with sufficient curing time will build up a protective coat of lacquer binder over the enamel and allow you to paint one over the other. . 

I thought it was just the opposite.  Lacquers are the ones which can be dissolved after they dry, and enamels (after they harden)  cannot ever be redissolved, as their chemical properties change. So they come off in sheets.

 

Example:  if the solvent mostly evaporates from a bottle of lacquer, adding more solvent (thinner) will revive it, so it can be used again.  But if the solvent mostly evaporated form a bottle of enamel, the remaining binder/pigment  turns into a rubbery "goo". Adding more thinner will not reconstitute that "goo" it cannot be redissolved. Even if you mechanically breake it up and stirr it, it will still be floating in chinks in the thinner, not a homogenous paint that can be used.

 

BTW, thanks for expanding on what I mentioned - not many modelers understand the ins and outs of paint chemistry.  But they should, since they use paints all the time.  Understanding paint chemistry (even if just the basics) makes them better modelers.

Link to comment
Share on other sites

15 hours ago, peteski said:

I thought it was just the opposite.  Lacquers are the ones which can be dissolved after they dry, and enamels (after they harden)  cannot ever be redissolved, as their chemical properties change. So they come off in sheets.

Example:  if the solvent mostly evaporates from a bottle of lacquer, adding more solvent (thinner) will revive it, so it can be used again.  But if the solvent mostly evaporated form a bottle of enamel, the remaining binder/pigment  turns into a rubbery "goo". Adding more thinner will not reconstitute that "goo" it cannot be redissolved. Even if you mechanically breake it up and stirr it, it will still be floating in chinks in the thinner, not a homogenous paint that can be used.

Looks like I didn't explain this properly.  You are right, lacquers can be reconstituted with more thinner.  I was talking about lacquer over lacquer and not lacquer over enamel.  When you spray multiple coats of lacquer each new layer dissolves into the surface substrate and becomes a single homogeneous coat. If you use a paint stripper like super klean, the lacquer comes off all at once and you don't see the individual layers.  My experience with enamels in the same situation has been each coat will come off separately.  Once again, there are exceptions.  For some reason I have had Tamiya white primer dissolve in the purple pond faster than the top coat and the whole top coat comes off at once.  Kind of weird, but is could be easily explained as a differant formulations.  With paint, if you vary anything, brand, thinner,  heavy vs. light coat, differant temperature or humidity level, you are conducting an unintended science experiment with unknown or and unknown combination of chemicals.  Sometimes it works, other times not so much!  What you can count on is if you use the same paints and thinners exactly the same every time, the result will always be the same. 

BTW, thanks for expanding on what I mentioned - not many modelers understand the ins and outs of paint chemistry.  But they should, since they use paints all the time.  Understanding paint chemistry (even if just the basics) makes them better modelers. Agreed!!

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...