I’m just a hobbyist and these are my experiences…

Tamiya Metal Primer (87204) is a versatile tool. It comes in Tamiya’s classic square glass jar.  There is also a version of it that comes in a spray can.  I have tried both but prefer the liquid for airbrushing.

Here are the main points:

1. It is clear and dries to a gloss.

2. It can be airbrushed or brush applied (brush is included inside cap).

3. Clean-up with lacquer thinner.

4. It self-levels, dries quickly, and very thinly with a smooth finish.

5. Great for priming brass and other metals (and resin too).

6. Plastic safe – photo-etch can be attached to the model and sprayed/brushed without the need for masking non-metal areas.

The gloss, I think, is the key to its success.  It has a “grippy” nature to stick to surfaces, which is essential for a primer.  Paint applied on top “grips” well to it too.  It is also flexible – more on this below.

The only drawback I find is that it is sometimes difficult to see the coverage because it is clear.  Perhaps tinting it with a lacquer-based paint would help, but I have not tried this.

How I use it:

1. For locomotives and rolling stock, I airbrush it full strength (no thinning) at 40 psi (my airbrush has a .30mm[.012”] tip).  Yes, this is high, but the product goes on very wet and dries very thin – it can be applied it rather aggressively.  I always apply two coats (as recommended), leaving about ½ hour between coats.  Sometimes I apply three coats.  I wear a respirator when airbrushing TMP.

2. I also use the supplied brush for smaller items, mainly when priming resin automobiles and trucks.

3. If paint gets damaged showing bare metal on a model, I can airbrush this area locally by over spraying onto the painted areas without risk.  I use Tamiya XF (acrylic) and AK Real Colors (lacquer) on my models.

More than just a primer, I have discovered some other nice uses for TMP

The gloss is great for applying rivet decals on top of it, and then sealing them in.  As a test I applied rivet decals over TMP and then applied TMP on top about a ½ hour later.  Then after another half hour, I pressed very sticky masking tape on top of the rivets and tried to pull them off.  They stayed put even though I tried many times roughly to remove them.

This now allows for safe masking on top of decal rivets.  Using low-tack Tamiya Tape also reduces the risk of lifting paint when removing masks.

I also apply it on Delrin or flexible plastic parts like trucks and handrails prior to paint.  The flexible nature of this material is impressive.  As a test I brush applied two coats of TMP on a Tichy truck, then painted it with one good coat of Tamiya XF-69 NATO Black.  After leaving it for a day, I twisted one of the side frames back and forth – the paint did not flake off.

I primer all my resin freight car and vehicle builds with TMP.  I have also applied this onto a die cast locomotive chassis prior to spray painting it with Tamiya TS-6 Flat Black lacquer spray for a neat look.

Tamiya always puts out a quality product.