Sanding, the flawless finish

[Guest]

Hello fellow modellers.

I have been building WWII models for over 2 years. Over the years I have noticed in various internet forums and magazines that not much focus is paid to assembly or kits. It just all about airbrushing, weathering. I am always at the search of flawless sanding finish. I am not talking about resin but styrene plastic. Have you ever noticed that once you clip the piece off the spure, give it a nice sand, and once you polish the area where the spure gate was, there is ALWAYS a slight bump or inperfection remaining in the area. This imperfection only appears once you polish the surface and look at it from an angle, but sure enough its there. It is damn near impossible to get rid of this bump. I have tried many saning techniques to remove this "bump" and make the given part flawless. I have tried numerous tool also with no avail. So my question is this... What are your sanding techniques to get that flawless finish?

Thanks

[wonwinglo]

Martin,change your removal technique,instead of clipping it use a razor saw,by clipping you are in effect pulling part of the plastic away from the sprue,this scars the membrane of the plastic itself thus when sanding it it gets worse.

Also make sure that the file you use is wide enough,try a small warding file finishing off with abrasive paper attached to flat sticks,in other words file the entire area and not just the bump itself.

The problem is that so many different grades of plastic exist,each of which has its very own characteristics,plastic being so soft needs care in handling.

[Guest]

Hi Martin and a very warm welcome to the forum. I hope you benefit from our tutorials and enjoy reading some of our postings. Feel free to share your own experiences and let us see waht you have been making.

As for your sanding, the problem you describe is a classic example of using flexible sanding materials too early. You must remove the bulk of the material with a ridgid sanding tool such as a file or an emery board before finishing with something much finer.

Even then I usually tend to stay with a better supported sanding material than just wet and dry in your fingers.

Stick to this principle and your bumps will all be a thing of the past!!

[wonwinglo]

Bunkerbarge has hit the nail on the head,a bump will always remain a bump if a flat sanded surface is not applied,otherwise you are just sanding around the area and making things worse.

[Guest]

i have had this problem for a while now too, but one of the best remedies are often the simplest ones. I have found that usually the best thing to do is cut the piece so that you have a little bit more spar at the end. You can then go back and use a file tool on what is left. The only other thing you can do (but requires more time) is to cut the piece from the spar so that you are left with a small impression on the plastic piece, apply a small amount of body filler, and then lightly wet sand or file it down. If wet sanding, use nothing bigger than 600 grit on primary pieces, smaller pieces i tend to stick closer to 1500 grit. Good luck.