Natural Metal Finish on an Academy B-50 using Alclad: an experiment.

Years back I got a couple of mostly complete, unbuilt kits from a friend, a B-29 and a B-50, both Academy 1/72. I recently pulled them out for a change of pace, from SOS to Stash Reduction. Initially I was planning on an X-1 mother ship, until I realized the amount of research and modification I'd need to do. Both the -29 and -50 were used to drop X planes, but I decided at this point, an OOB build would be suit me just fine. So I sorted the bits for the B-50 and got started.

Early on, I knew I wanted to use the build as a testbed for a natural metal finish. My old go-to, Modelmaster buffing metalizer is long gone my supply used up. Bare metal foil has left me frustrated. So based on some recommendations from other builders, I would experiment with Alclad. The build started like any other, with lots of interior detail that would never be seen again ;-)

Surface prep would be key, so fit issues would need to be addressed. The fuselage halves needed work at least 75% of the way from nose to tail, top and bottom. The nacelles slipped over the wing rather than bring cast as part of them. They were assembled separately and their fit issues addressed, installed, and those fit issues addressed. High spots were filed down, and then hit with successive grits of wet sandpaper. Gaps were filled with Vallejo acrylic Putty. This was my first experience with this product. The promise of water smoothing and cleanup was appealing; additionally it is applied from a tube through a very narrow applicator, enabling a far more precise application than the "trowel it on now, sand it down later" of my old reliable Squadron Putty. I discovered that with its benefits,  Vallejo also required some technique changes. Squadron, being solvent based, bonded to the plastic, dried ~ quickly (depending on thickness), shrank, and sanded down well. Vallejo acrylic showed little shrinkage, but does not dry as hard, so careful light sanding of a fully dry patch, with a less aggressive grit and some water is recommended. Go at it too aggressively and you can peel it from the plastic. Fortunately due to its thin consistency and pinpoint applicator, you shouldn't need to sand as much. You can use a fresh exacto to carve off any protruding bits before sanding as well.

I learned a few things that I would do differently to get the best NMF from this product. If you want a polished-looking finish:

Don't fully assemble your kit (yet). You need an exceptionally smooth gloss finish for best results. Leave off anything that protrudes and wet sand and base paint (more on that in a minute), dry, and wet sand again. Use gloss base paints. What do I mean by base paints? Alcad goes on Very Thin. It is translucent, and the shade used to prime underneath it will show through. To get a sense of this, I prepared a test styrene surface, and applied white, two grays, and black. I wet sanded across half of these.

Test bands

Alclad Polished Aluminum overspray

Light angle makes a huge difference 

I decided that the black was too dark: I would use white and two grays for this project. The sanded surface did give a superior finish, as predicted. 

The good news is that you needn't prime with an Alclad product.  It worked just as well over Tamiya acrylics.

The Alclad really is unforgiving. Any scratches, cross hatching, or irregularities won't just show, they will be highlighted. All the work is in prep - spraying it on is easy. No thinning required, it goes right from bottle to color cup and soray at a comparatively low pressure. Note: it is very thin. I used almost a full bottle (at nearly $10 a bottle) to cover 1 plane this size. I can't imagine what it will take to cover the 1/48 Liberator in my stash...

In order to get some natural variation in metal shades, I primed the entire plane light gray,  then used successive masks for white on the control surfaces and nacelles, and dark gray on selected body panels as shown below.

White applied,dark  gray masking begun

Underside, shades completed.

Just to reinforce,  I recommend leaving off all protruding bits until after this is completed, and prepping them separately or after attachment. It's not just going to complicate the multiple masks, you Will break things off...

Also, I went through a full roll of Tamiya tape in the process, along with sheets of newsprint and a few post-its. Be prepared.

The good news is that the finish looks great. Even with my lack of adequate surface prep it displays well.

Variation in shades looks natural 

Different light angles make the shade differences more apparent.

I was warned that using decal setting solutions can affect the finish, so I didn't use any. What you see is raw Alclad and decals, no finish coat.  That experiment will have to take place on another kit, another day.

To sum up, this was a great learning experience leading to a good result which could have been great.  I can recommend both the Vallejo Putty and Alclad for your next NMF project. Take your time and you can create something great!