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Hi Art:
I just want to give you a cautionary note related to the Plastic cement & Styrene mixture for use as a filler…
I had been told that the expert modellers use it as a filler in place of putty. I had collected rotary cutter shavings from the last time I was cutting a curve in a thick sheet of polystyrene. I left them to dissolve in a well capped Tamiya paint bottle, half-filled with Testors plastic cement, and added small cut-off pieces from time to time. The mixture eventually became well dissolved into a consistent paste.
This is the first chance I have had to make use of the mix, to fill in the mounting-pin holes at the side of the Tamtech body. They are countersunk funnel shaped holes of 4 mm surface diameter and extending beyond the body inside surface. So they took a larger volume of the mix. I left the body overnight and found that only the surface of the fill was cured. I could press into it and make indentations. It became a bit harder after a couple more days. When I finally sanded it down, the centers of the fill was still pliable. The final stages of working it showed that the putty had in fact, not bonded to the plastic surface of the body and I was able to pop it out of the hole. I now realize that I should have tried an application of the straight liquid cement over the surface before applying the filler mix.
Also, if you are making use of this type of mixture, it may be best to apply it in thinner layers. Alternatively, you may want to test some additives. The formulation of the plastic cement is thrown out of balance with the addition of the styrene, so adding a bit of curing agent may help. However, we wouldn’t want a mix that is too thin to shape. Adding a bit of Acetone may be worth testing. Methyl Ethyl Ketone Peroxide is the hardener/curing component for most epoxies and is also involved in the plastic cement, as acetates of that compound, so it may be worth trying. So I think the technique needs a bit more testing. I’ve tried a few tests myself, but I don’t have enough volume of the mix to test different additives.
I’ve been preparing the body for painting and for cutting out the light lenses. It has a great number of mould seam lines, so a lot of sanding. That exposed more of the small imperfections in the surfaces. I thought I had caught everything then I found a seam across the whole width, under the front edge of the rear wing; it became very visible under oblique lighting. It was tricky smoothing it out under the wing, especially with the intake screen right at the edge. I have the body all sanded now, so I can try re-filling those mounting holes, then cut out the seven lens sections.
Sorry if this is more detail than you need Art! I didn’t want to leave you without complete info, and thought you may need the background if you try out the technique some time.
Thanks Art; good luck with the work. Hope to see you soon.
Austin.
The Happy Canadian Scale Modeler!
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I’ve used this technique in the past with varying results. Drying times are very long though. Almost prohibitively long.
The only case where I would use this method is on a plastic model where the model will be unpainted to match the colour of the plastic as closely as possible.
I prefer filling with plastic styrene panels or plastic dowels/sprue glued with super glue and sanded if I’m planning on painting the model anyway. (most cases)
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I completely agree Bill. One product I use especially if the model will be subject to pressure (ie. a prototype) is JB weld. Although it adds weight it does not collapse under pressure. Combined with styrene panels it can work well – and is easily painted. I’ve used this method on the Autobianchi(sp) I am making from a modified Honda ARII kit. Hopefully it will get to finally debut at the Targa III.
The Happy Canadian Scale Modeler!
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