TAMIYA MOTORCYCLE
Last modified: Saturday, January 6, 2001 6:20 PM

Tamiya's line of 1:6th scale motorcycle model kits has been out of production for a while, but you can probably still find them out there. (I was lucky enough to find this as a consignment sale for a good price.) The good news is that they've started the line up again, according to their web site. These are incredibly detailed and accurate replicas, with features like battery wires, spring suspension, spring-loaded kick stand, moving clutch & brake levers & rubber tires. And a lot more. Since it's a styrene model kit, it won't stand up to much rough-housing though. But it looks cool, and the parts fit together like a dream.

I haven't built models in a long time, and have never built vehicles, other than the 1/35th scale military armor. It's not the construction that's different or difficult, it's the painting. The military stuff and most of the stuff I've done have required a matte finish, so I'm pretty comfortable in my choice of paints & techniques. Trying to get a clean, glossy finish is a new thing for me, and as I've discovered, a huge challenge.

Occasionally, I give good advice and sometimes I even follow it. So the first thing I did was check out the rec.models.scale FAQ for tips on painting. It's a huge collection of tips, and gives you answers from a variety of perspectives. However, as a reflection of the way it is, ultimately you have to experiment and find out what works for you.

For this particular project, I want to paint the motorcycle different from what the manufacturer intended; not as a police motorcycle. I want to do the cowling in black, or possibly gold and maybe retrofit it with some rocket launching tubes. Yeah, maybe this is in bad taste, or heresy, but what the heck? It's paid for. What this means is that the large expanse of cowling, molded in white, will have to be painted with a smooth, candy-like finish.

My assumptions were that I would have to use an enamel paint for the sake of durability. According to the FAQ, enamels bond to styrene and gradually cure over a long period of time. I went with sprays since I hate messing with the airbrush, and the paint job seemed pretty straightforward. It's true-- you get a good glossy coat with enamel spray, especially if it's put on just thick enough so that it doesn't run. But I'd been warned-- they weren't kidding about the long cure time. Several days later and this stuff still seems tacky. A valuable lesson for me-- although others may be patient and willing to wait weeks for paint to cure, it drives me crazy and I need to find my own solution. I cannot see myself doing the basic on-the-sprue painting, waiting for it to cure, assembling it, patching the flaws, repainting it, and waiting for that paint to cure! Despite whatever subtle quality differences this may bring, it ain't worth it to me!

So my first attempt to turn this boat around is to Dullcote over all the pieces I'd coated with that nasty Buffing Metalizer that Testor's makes. Very nasty stuff that stays tacky & picks up fingerprints unless you seal it. Honestly, I didn't think it looked all that great, and I discovered that plastic polisher took it right off. Opinions may vary-- some people probably swear by it, but it's not for me.

As for the expanses of black, this is going to take some experimenting to come up with that candy-coat look in a fast-drying acrylic formulation. From experimentation so far, if you lay a thick coat of clear acrylic down on a polished smooth surface, it tends to bead up or pool. Spraying it on in mists leaves a mottled, flatter finish. And paints all act differently too, so you need to find the colors within a brand that work for you. Experiment, experiment, experiment. The Truth is out there...

-01/30/99


02/01/99 - Sanding, painting, sanding, painting... auuuuggggghhh! Are we having fun yet? There's something about this that I don't get: The manufacturer goes to a lot of trouble to cast the parts with a mirror-like finish. The hobbiest then coats them with a coarse coat of primer and applies paint to try to achieve the manufacturer's finish? I suppose that's the only way to fix some of the nitpicking details like mold & join lines between parts, and it's the only way to change the color the part was cast in. But it sure is a lot of work to go through!

I have received some good advice about refinishing from MERK, who knows his stuff from experience doing it on the 1:1 version professionally:

You`ll run into real trouble if you try to lay on too thick a coat. Several thin coats are best.... and don`t worry about a little roughness...after you get all your colour coats on you sand it (600 at least-1000 grit better) then rub it out with compound...and finish with toothpaste. Alternately...after the colour coats, sand, then shoot a coat of high gloss clear....then buff. I would recommend Acrylic enamel in the Airbrush but,If you don`t want the trouble...use Krylon Spray paint. But you need to shoot it all at once with that...or wait a week between coats (otherwise it may Craze or crackle) Not pretty...

Although I've yet to get to that point of having successful results, this jives with and fleshes out some of the advice given in the rec.models.scale FAQ.

In a nutshell, the procedure is to keep applying finer and finer grit abrasives to the surface, all the way up to things like polishes. And don't be driven crazy in the process.

I've experimented with several things: For small parts, you can get away with brushing on a thick coat of gloss acrylic. With luck, it won't run or pool, and the self-leveling action of properly-thinned paint gives a super smooth surface without any brush strokes. For larger areas, you can't get away with this because it will run. Shooting acrylic through an airbrush seems to be the best way, and I will probably go the full route which MERK suggested, once I round up an array of polishing compounds suggested here, and at the rec.model.scale FAQ. My feeling is that you can make it a bit easier for yourself by shooting the coats thick enough (with properly thinned paints) for the paint's self-leveling action to take care of some of the surface granularity, without it running. It's not easy, but it's easier to control that on an airbrush. The one absolute-for-sure-no-mistake-about-it lesson that I've learned so far is to avoid traditional enamel paints. Waiting a week for enamel to dry goes way beyond my tolerance level. Another thing I've learned is that Gunze Sangyo's Mr. Surfacer primer is fun stuff. If you shoot it through an airbrush from a distance, it makes spider webs! Cool, huh?

02/02/99- I can now say that I have explored a lot of the world of painting gloss finishes. One of the things which doesn't work is spraying Plasti-kote clear top coat lacquer over gloss acrylic! Wrinkle city! What does work is spraying a primer coat, airbrushing many thin coats of acrylic gloss paint, sanding the surface with a progression of very fine grit sandpaper (all the way up to 2000), buffing with plastic polisher (Bare Metal), buffing with a swirl remover (3M Finish Restorer), and polishing with Meguiar's Deep Crystal Carnauba wax. (kinda like what Master MERK said, huh?) Yes, it's a lot of work, and it takes a lot of time. You need to make sure that you have enough coats of paint on so that it's thick enough to stand up to all the sanding. You have to make sure that you sand very gently too, so as not to remove too much paint. If you do that, you're more-or-less, back to square one.

It should be apparent, but the prepainted surface needs to be free of obvious blemishes, since painting coats can only take care of minor blemishes and the sanding will only level the surface roughness caused by spraying paint. If the surface is lumpy, it won't look good polished to high gloss.

Oh yeah, I kinda "glossed over" the stuff you do before you're even in a position to begin to paint (especially high-visibility parts which are assembled from halves): gluing parts together with an aggressive plastic welding glue like Tenax, massive amounts of sanding to ensure that part joins are smooth and seamless, puttying over the minute seams that sanding won't take care of, sanding again and then applying a primer.

The finish isn't quite what I want yet. Now that I've tested the basic polishing procedure, I'm thinking of subjecting myself to some more abuse by spraying a bunch of coats of clear gloss acrylic, on the theory that this might make the finish deeper & more glasslike. I'm optimistic that I might have this project finished by the end of this century.

02/05/99- A project like this can bring out the obsessive-compulsive... What makes stuff appear glossy? I'm not a scientist, but I suspect that it has to do with the way the surface molecules lay down uniformly to reflect light directionally, rather than scattering it. You can see this if you look at different degrees of "glossiness". As you polish a surface, it reflects light like a mirror, and you can make out reflected shapes, like your work lampbulbs. In a poorly finished, matte, or oxidized surface, the image is out of focus. As you polish it, the focus improves.

It takes a lot of work to bring a finish to this state. It requires going though the full & gradual progression of fairly coarse abrasives to the finest. If you don't start with coarse abrasives, there will be small height differences between the higher areas which get polished, and these troughs, leading to a sort of shiny, pebbled or hazy finish. The purpose of going through the progression is to make the next step easier. Even 2000 grit sandpaper isn't enough to make the leap to polishing compound, IMO. You could spend hours using a very fine abrasive to level the surface to the point that a coarser abrasive could do in minutes. Fine abrasives aren't appropriate for removing large amounts of surface material. That's another reason why you should make sure that your paint coat is thick enough: In any area, the finishing operation should remove paint to the lowest area, where the paint is thinnest.

A couple of other related points: If you go this route, there isn't any difference between a gloss and a flat paint, since the gloss comes from the polishing work you put into it. A gloss paint is useful for small parts that don't need to be sanded, since the paint can be brushed on fairly thickly, and the self-leveling action of the paint will give you a very smooth surface. (Note that if the part is molded in the proper color, doesn't need to be sanded and can be clipped very cleanly from the sprue, you may not even need to paint it. You can polish the bare plastic to a very high gloss far more easily.) Spraying paint usually creates some surface unevenness, especially if you use fast drying acrylic mists-- the paint particles dry between passes, and don't really get a chance to level out. A thick coat takes care of this, but can create baaad problems with paint running or pooling.

Another sort of related tip is to make sure that your joined parts are very securely joined before you begin finishing & painting. Post-painting assembly can put some stresses on parts, and there's nothing worse than seeing a part you've carefully puttied over, sanded, painted a zillion times-- crack apart at the joint. There's no easy fix for this (that I know of) except starting from step 1 again. On the other hand, you could always ignore it...

02/08/99- Wait! Ignore everything I've written so far. ;^) I have discovered that if you need gloss black on a part that's molded in white, or a part that needs to be finished, use Krylon Ultra-Flat black. That stuff dries superfast, allowing you to put on a buncha coats within an hour! Versus the hassle of connecting & cleaning up an airbrush each time you want to add a coat of paint-- a process which can drag on for days. Chances are, you'll get pooped out and put one coat less than needed... you'll find that out when you polish down to the bare plastic! Ooops... Since it dries so quickly, you're not likely to get any dust in the paint either. And it bonds really well to Polystyrene, so there's none of that "scrape it off with your fingernail" stuff. Krylon UF black also goes down fairly smoothly, cutting down on one aspect the sanding & polishing time-- smoothing the surface paint granularity of the airbrush. (Instead, you're likely to get the tiny lumps that you see in most 1:1 automobile finishes). If it's put on thick enough, it obscures detail, which isn't always a bad thing. That can help hide seams or some surface imperfections. That's great if you want black, huh? I haven't experimented with other colors, but I suspect that gloss paints generally take longer to dry, and if you're going to be polishing the part anyway, you might as well use a flat paint that dries quickly.

I've refined my sanding & polishing routine somewhat. Now, I'll either start with 320 or 400 grit sandpaper (depending on the level of brutality that needs to be inflicted), go to 600, 1200, and finally 2000. Then I use Rubbing compound, followed by polishing compound. Then it's the swirl remover, and finally, Meguiar's Crystal Clear polish. The polishing compound could probably finish it up with enough effort, but I think that the last two steps produce the final gleam more readily. I've pretty much stopped using the plastic polish, since it's very similar to the swirl remover, and I don't know which is more abrasive. Either way, you can even use this basic progression to restore a scratched up piece of clear plastic to full clarity. For hard-to-get-to places, you can use rubbing compound followed by polishing compound on a cotton swab (Q-Tip). Rubbing compound is very abrasive, but being a liquid, allows you to go places where sandpaper has a hard time going. You just have to be careful though: raised areas and edges are most likely to get polished through to the bare plastic. Fortunately, you can respray just those areas and polish them to blend into the existing finish.

All this experience has left me feeling pretty cocky-- heck, I've used lacquer thinner to remove that horrible Testor's gloss enamel spray from parts-- there's no way to quickly get enamel off without marring the original polystyrene surface. (Unless you spent a couple months polishing it off!) No problem (just a hassle), because you can always refinish the melted-surface part close to its original state. I won't deny that it's a pretty scary thing when you wipe paint off and find out that you can mold your fingerprint in the plastic.

If you've read this far, congratulations!!! I assure you though, that your pain is nowhere near that which I've endured since this project began! Mind you, this doesn't mean that I've done a fantastic job on the model itself, har har har! This is a learning experience, and if I had a second one, (quick, somebody shoot me!) I'd do a better job. I've put some serious trial & error hours into this sucker so far, and in case you couldn't tell, it's boring me to tears and I wish it would just go away! Heck, I want to work on other fun projects! I want to clean up my work area! Unfortunately though, until all the sprues get picked clean, I can't do nuttin' but put up with the squalor. But as they say, "You will be rewarded for all your hard work..." As someone else said, "...when monkeys fly out of your butt..."

Coming up someday (maybe): A picture of the finished motorcycle???

Khadiya longs for the good old days when she danced "The Time Warp" back at the mansion...

Some pictures of the motorcycle??? (gasp!)