Hello all. I'm still fairly new to the painting process, and I'd like to ask a few questions about the preparation of models for painting, and ultimately, the making a durable finish. I ask you to please bear with me and the long post that follows...

To start, I've heard/read numerous times that sanding a model in preparation for painting may not be necessary. Can durable finishes on a model really be made without sanding...? I would think that a micro-roughed up surface would be crucial in promoting better adhesion for the primer and/or base coat, right?

I've tried spraying Alclad and Vallejo primers (and regular Vallejo paints, too) onto the bare plastic of models without sanding, and they never seem to adhere very well at all, scratching easily with even the lightest scratch from my fingernail. However, if I sand with wet 500-600 grit sandpaper and prime, the finish is noticeably more durable, resisting the same scratches quite well. I'm not exactly looking for an-uber durable finish here, just one that can stand up to a light amount of abuse without any scratches or chipping. I should also mention that I've tried washing un-sanded models with dish soap + water, as well as Windex to get rid of any grime/mold release agents that may be on the plastic... no luck, the paint scratches off just as easy. Could I not be cleaning/prepping the plastic well enough?

Another thing I was thinking was, perhaps spraying Future ("Acrylic Protection" and all) would dramatically boost the durability of the base coat... but I also figured that if the base coat had poor adhesion with the plastic, the Future probably wouldn't be able to protect the base coat very well at all.

Am I missing something here? Please, tell me I am... I don't particularly enjoy the sanding process, especially the smaller, narrower parts of a kit... Thanks a lot for reading this novel of a post... I'm looking forward to any help I can get with this part of the model painting process.

These are the steps that I take when I am undertaking a project that want to stand the test of time (and toddlers):

1. Lightly sand all the pieces that I plan on painting.

2. With all parts still attached to the sprue, soak and lightly agitate (as in shake around in the solution) of lukewarm to slightly less than hot water and Dawn dish soap.

3. Rinse off the sprues, and set aside.

4. Empty container with soap solution and rinse it thourgholy (so to get all the sanding dust out of it)

5. Repeat the soapy solution process.

6. Rinse the sprues once again with warm water.

7. Set the sprues aside on some nice new paper towels and let them air dry.

8. After all nice and dry, I airbrush Vallejo primer straight from the bottle, and then proceed as per the instructions or what ever twisted image has appeared in my minds eye.

Again, this is how I do things, so you can give it a whirl and see how it works out.

Some 000 steel wool will do you well too. 500-600 grit sandpapers seem kind of rough to me, personally I use something around 1000 grit for paint adhesion. The wet/dry sandpaper is definitely a good way to go though. Definitely give your parts a good wash afterwards and you should be just fine. I prefer to apply primer, but you can skip it at this point if you really want to.

I usually wash my models, after the assembly is complete. However, I also use a lacquer primer. I have never had problems with adhesion. It takes a few hours to dry, depending on the environment. But, it is nearly indestructible once cured. The best primer I have found is Rust-o-Leum's self etching primer. It is rather pricey, at $9 a can. Well worth the money.

Vallejo doesn't have much bite to it. To the point that I rarely use it on vehicles except for detail painting.

I like Tamiya paints, thinned with a 'mild' lacquer thinner. No cleaning, no 'pre-sanding', nothing... just shoot and it sticks.

I'm too lazy(efficient? ) to waste hours between building and painting with prep work.

I have never sanded a model before painting except where filler is concerned. I have started using an acrylic car primer as a base coat, but that is used by me more to point out areas that need work. I like Jesse use Tamiya paint for the modt part with the Tamiya thinners and have yet to suffer the problem of poor adhesion except where some manufacturers products where the release agent sticks like S--t to a blanket despite a wash.

i have never sanded a kit on the sprue, off the sprue, or after the build is complete. i have never washed any of the parts either unless it was PE that i soldered. In fact, i have never even washed any resin kits either, which is said to be an absolute must because of the mold release that is used in the molds.

i have never had any problems paint adherence, ever, in any instance. this is under normal circumstances and doesnt mean i would be eating a juicy, greasy hamburger as i paint.

a good, well primed surface does the trick for me.

I haven't had many issues with Vallejo or AK primers. I thin them a bit and spray light coats. I find that primer and paint issues are usually my fault because I don't follow basic painting principles. Clean model, proper air pressure, paint viscosity, light coats,drying time between coats. I also use the same cleaning and thinning agents as the paint makers. Vallejo paint, primer and thinners. Tamiya paint, primer and thinner. Seems to work every time for me. I also had issues when mixing water base paints with water.