Am I using Tamiya lacquers right ?

[keveuh]

Hi everybody, I've made a few kits before using Tamiya spray lacquers "TS", and I've always used the same method, but since I'm far from being an expert in modeling and I know there are people on this forum who have incredible skills and knowledge about stuff, I need to ask something.

I've seen on this blog: http://italianhorses.net/Tutorials/P...aint/paint.htm
by Alex Kustov a tutorial how to paint using Tamiya spray cans. And he recommends this:

- first mist coat
- wait 20 minutes
- second mist coat
- wait 2-3 hours
- spray first wet coat
- wait 1 day
- spray second wet coat
- wait 4-5 days

So as you can see he recommends to wait quite a bit between each layer of paint or coats.
Now as for me I've always done like this:

- I spray as many mist coat as I judge needed to evenly cover the whole body, then I spray a final wet coat, and between each coat I wait 5 minutes. Why ? To let the paint dry a minimun on the surface so the upper coats don't drag the lower coats off the edges of the body.

So I wait way less long than what Alex recommends in his blog, and I read that paint should have time to gas out between coats but I'm not really sure how this works and if this is really accurate for Tamiya spray paint, knowing that I DO NOT USE ANY CLEAR COAT - EVER !


So my wondering is this: should I wait longer between coats or is my method just good enough ? For those who use Tamiya spray paint, how long do you wait between each coat ?


Thank you very much for helping and I hope my post makes sense.

[p9o1r1sche]

You didn't say if you are having problems or not.
If you are not getting runs or thick spots/thin spots and the paint is drying smoothly, then you are doing it right.

[kaisers_phoenix]

Hi, I'm no expert but I believe one should consider this factors when timing the waiting time between each coats:
1) temperature
2) humidity
3) stability of previous coat and thickness of coating applied

While we can't see or tell if your coat is ok or not (besides runny paints of course).. there are several signs that gas out is taking place..

1) If you polished a paint that has dried (ie. will not leave thumb prints when touch) but has not completely gas out.. you realized that the shine sometimes will turn dull after a few days later
2) It's always easier to achieve shine in a fully cured paint (coz it's harder)
3) try keep non fully cured painted parts in a tight container, you will still smell thinner accumulating in it a few days later when open it

While I can only guess that during post curing.. thinner/solvent molecules are slowly moving out from the paint matrix and this will make the paint layer harder and more compact.
If we allow enough drying time between each layer, it should dried faster (during the final layer) than to have short waiting between each layer and wait for all the thinner to evaporate all after the last thick wet coat.

[keveuh]

Thanks for the answers.

No, I have never had problems with paint, at leat most of the time, except once like a "drop" of paint, but I guess I had sprayed too much at that time.

I have just polished few days ago a kit I'm making, I painted it the same way I always do, and I didn't get any problem at all except for a bit af a "dull" look and orange pealm which were corrected by polishing.

Niw the problem is I live in Finland, and I spray on my balcony, and days where it's around 20C and low humidity are over. Nowadays it's rarely above 15C and humidity seems to be at 75-80%, and it's gonna get colder of course. I have painted in the past even when it was down to -10C. Thing to know of course is that I'm just out to paint then I rush back indoors where my box is and where I put my parts that I paint and where they'll dry. Unfortunately I don't see any other possibility for me.

Well, that was a little more info about how I usually spray paint.


EDIT: let me add something: I don't claim to make perfect paint job at all, as a matter of fact I'm sure I could do much better if only I knew what to do correctly that's why this thread. I cannot say my paints have always been perfect, and I don't know what to blame. The too cold/humid weather I paint in, the not enough drying time between coats, or even something else ? But at least for my latest finished model which is a Toyota GT-One I can honestly say that the paint was really shiny, a good shine enough that I didn't want to risk to destroy by polishing. Now the kit I'm making now a Honda s2000, the paint didn't look super shiny, I painted it with a TS-42 light gun metal, a tricky paint but I still got a very very very satisfying shine and surface after some polishing. And I'm also working on a Carrera GT which will go to paint hopefully someday next week, and maybe not long after that I'' try to get a Ferrari FXX and paint it as soon as I can so I don't have to paint when it's winter. And winters here are real winters....

[MerlinPro]

Since you have a fairly constant humidity and cool temp problem, consider a food dehydrator to cure the paint jobs.
You method is probably acceptable but just do not spray on very humid days and cure the paint no matter what.
A big cardboard box with a 60W bulb will do if you don't buy or make a dehydrator.

[keveuh]

I've seen a lot about food dehydrator here, I'm not sure how effective this is nor what's the purpose of it. I should have to take a deeper look into it.

but I don't think I have humidity problem indoors, I dry my kits in a box in a closet here which is alsways closed and is ventilated. the only time the appartment seems "humid" it's when a lot of laundry is drying, but then again that laundry dries fast.


Also, I've seen on at least one of my car, that several weeks maybe after painting it some strange paterns appeared on it. It's hard to describe, it looks like the scratches from sanding are visible through it, but I know it's not that because I always sand my cars with 2000grit at the end. Paint use was Tamiya without primer and I suspect that it might be because of either too thick coat at first or not enough drying time between coats, or even both... no idea.

[RonCla]

lacquers like Tamiya will always shrink back as they dry.

I perfect smooth paint job can easily start to show all the underlying scratches and blemishes weeks later as it dries out if the underlying surface wasn't perfect, particularly as you say you didn't use primer.

[keveuh]

So you think the cause of this is scratches due to sanding ? I'll try to take a pic but it's not easy to capture this on picture and I tried to polish it but it didn't help much.

There are pictures, on the last one you can see that I've polished.

[Stevie Disco]

I love the Tamiya TS synthetic lacquers. I wouldn't think of using anything else. Yes, they tend to be more expensive but once you perfect your technique you will see how easy they are to use a produce a great finish.

Obviously you need to start with a smooth finish. I prep my bodies by first sanding with very course 100 grit then follow with 320 wet-dry. I then follow with a couple of coats of Tamiya primer. I prefer the fine white. I then wet sand with 320 and wait for paint day.

I usually paint the colors coats in 3 sessions allowing one week between sessions.

The sessions are very similar in structure. Start with mist coats. Wait 2 hours and apply a little more of a mist coat. wait 1.5 hours and repeat. Continue making the time between coats less and less until you are down to about 15 minutes between the next to last and the last coat. The last coat should be as heavy as you can get it. If you do happen to get a run don't worry. The object is to slowly build up the layers.

Wait a week and wet sand with 320 and follow with 600. You can then start session #2. Same, start with mist and finish heavy - allowing at least 2 hours between coats to start and finishing heavy.

If you paint indoors, humidity should not be a problem. Temperature could be if you paint in a non-heated garage like I do. I make sure I let the cans sit in hot - non -boiling - water for about 10 minutes before using. Shake can real good. Warming the paint up makes the paint go on better and with less runs.

After you complete session #3 the paint job is done. If you have a run in session 3 you will have to wait a couple of days and sand it out, but if you're careful this shouldn't be a problem.

After waiting that final week you are ready to polish. I use Meguiar's Show Car Glaze #7. This stuff works great. Apply as directed and you will have a perfect mirror-like finish. Your paint job should be thick enough that you can even remove dust specks with the Car Glaze.

I know it sounds like a lot of work but I feel the end result justifies it. Please note that I don't sand with anything higger than 600 grit and I don't use any clear lacquers. Just the paint from the can.

Here are some pictures of cars I did using this method. I should point out that with the Camaro shots, it started rainingand I just went with it. Big drops maybe but looks real.

I hope this helps.
Steve

[keveuh]

Wow ! Your paint job is perfect ! I'm surprised how much paint you use and how rough sand paper you use !!!!

But I still don't know what happened to my paint job I posted pictures up.

[Stevie Disco]

It could have been the lack of primer or like you said - building the coats up too heavy and too fast. I used to be impatient and ruined many paint jobs by touching them too soon. Waiting a week between sessions might be excessive but you can be assured that the paint will be gassed out after a week.

It looks like you painted using TS-8, Italian Red. I painted a Porsche 934 in this color. The pictures might be a little blurry but you can see how smooth it is by the reflections of the trees. You can even see the green color of the trees in the reflection.

And remember, rattle can paint, no clear coat and nothing higher than 600 grit sandpaper.

[stevenoble]

Originally Posted by keveuh

So you think the cause of this is scratches due to sanding ? I'll try to take a pic but it's not easy to capture this on picture and I tried to polish it but it didn't help much.

Kevin you need to use a primer under the Tamiya TS. Those scratches you are getting are definitely a result of your sanding. The TS is sinking as it dries and etching into the sanding marks that are in the plastic. Using a good primer will eliminate your problem. Also make sure you use a very fine wet and dry on both the plastic, before you prime and on the primer itself, before you paint. If you're leaving scratches like that in the plastic they will show every time without fail...

Originally Posted by Stevie Disco

Obviously you need to start with a smooth finish. I prep my bodies by first sanding with very course 100 grit then follow with 320 wet-dry. I then follow with a couple of coats of Tamiya primer. I prefer the fine white. I then wet sand with 320 and wait for paint day.

I'm confused..?? 100 grit, 320 grit..?? If you're using the same grit grades that we have in the UK then they are extremely harsh. I never use less than 1000 grit wet and dry for general plastic preparation. Sometimes slightly rougher sanding sticks if I'm rubbing down filled areas..
I also use TS lacquers for certain projects but I don't understand all the mist coats, waiting, more mist coats, further waiting, first wet coat etc. I just spray (over prepared Tamiya primer) one tack coat, 5-10 mins to tack off, then 2-3 wet coats with 5 mins flash off in between. Bake in the Mr Dry Booth for 60 mins followed by overnight drying, polish the next day.

Lotus 97T (Tamiya TS)



If I'm in a rush it's Zero base coat colours over the same Tamiya primer. 2-3 light coats of colour with 5 mins flash off between, 20-30 mins in the Mr Dry Booth, followed by 1 light tack coat of Zero 2K clear, 5 mins flash off, then 2-3 wet coats of Zero 2K with 5 mins flash off between. Colour to clear, to finished, in under an hour. Baked for 60 mins, no polishing required, finish straight from the airbrush..

Suzuki Hayabusa (Zero stuff)

[Stevie Disco]

Beautiful work Steve. I use 100 grit to smooth out any dips or depressions in the plastic, sanding accross multiple panels whenever possible. I only go deep enough to make it smooth. I then use the 320 grit to prepare it for primer. After that I may use the 320 to smooth out a drip or remove a dust spot before final session but usually just 600 grit wet sanding. I've found that I don't need anything higher. It some ways my method may seem excessive and in others it may seem over simplified. I've gotten used to only using the 3 grits of sandpaper and it works. It keeps things simple and cheaper. Like I said before my concept is to slowly apply color until you get enough on that you can apply heavier coats without the fear of drips and runs. It takes one Saturday for one session and 3 sessions takes 2 weeks total. But I still think the Meguiar's really makes the paint job all come together - it's easy to apply and buff with a soft cloth. I only use this method on car bodies - not small parts.

[stevenoble]

Originally Posted by Stevie Disco

I only use this method on car bodies - not small parts.

Well from the pictures you posted of your models it works, so keep doing it that way. I always believe that no two people paint the same. Everyone has their own way of doing things and there isn't a right way or a wrong way to paint, just different ways. They are all correct if they work for that particular person. I like to stick to my tried and trusted methods, but also like to try new methods, new paints, different clear coats etc. I think it's one of the reasons why I build models, the painting process is what inspires me to build and the truth is you never stop learning

[SilverMk2]

What you show in your picture looks like paint checking. Its either what your are spraying over or big temperature swings. Generally speaking I finish all my work in the plastic up to 400 grit usually starting with 220 grit to do the actual work. Then I do a gray Duplicolor filler primer sanding that down with 3200 grit and generally follow with a white Krylon primer and going over with 3200 grit on the lighter colors. Tamiya white primer works to if you can find it. Generally I always clear coat these days. My rule of painting is a couple of light mist coats so that you are covering the primer up. Then thicker base coats until you get the paint coverage you need. These coats I do heavy enough to almost get runs. The heavier you lay it on generally the smoother it will dry. It takes some practice to get right. Same strategy on the clear except I'll generally make sure to do 3 layers of clear to have some thickness to polish on. Generally I'm waiting 15 minutes between coats.

I would make sure you're using a compatible primer beforehand, a clean surface, and try an spray in that 65-80F non-humid range that most paints are happy with.