Plastic parts

[Jimmy Blazes]

Currently working on a Corsair and I'm trying to get the plastic parts to work out. I am Having trouble getting them right. An hints or suggestions would be appreciated.

[Bill Gaylord]

What problems are you having with them?

For seaming, I use CA and activator, for instant curing. Hats off to people who have the patience to use regular glues. After seaming parts, running a bit of glue along the inner seam will give you some sanding latitude to eliminate the seam appearance on the outside of the joined parts. For people who like to glue the parts together with a bit of a flange left after trimming away from the parts sheets, the inside glue buildup is the only way to provide material inside the part, so that you can sand away the flanges after joining the parts. I prefer to get them to mate as well as possible for gluing, to eliminate that issue.

[WIDDOG]

I do all my repairs with a hot glue gun. I don't know how it would work out for a display model. I have gotten fairly good with the hot glue gun. Maybe you might have some comments on it.

[Jimmy Blazes]

I am typically having trouble getting the two halves to fit together correctly and without too many gaps. I think there must be an easier way to get them right than what i am doing. Thanks for the comments

[heywooood]

Best to remove the parts from the plasic sheet by sanding.
Place a sheet of sandpaper - 220 grit - on a workbench and then sand the back of the
plastic sheet with the part on it until the part just peels off.
Sometimes you have to cut the part free from the sheet when there are multiple parts on it.
Just cut around the part leaving about 1/4" of excess material all the way around the part - then sand the back of the part until that scrap falls away.
If you remove parts this way you always have a nice flat mating surface all the way around

[Bill Gaylord]

If you can accurately cut them right at the parts sheet with an exacto, where the radius joins the sheet, you will have a pretty decent seam. Of course that means not cutting much into the radius and staying on the sheet. Once getting the hang of it, it's relatively easy to guide the knife, as the radius at the beginning of the parts helps guide it. I use a sanding block with around 150-220 grit to deck the parts after removing, which takes a while as they are fragile. For parts such as cowlings, I'll actually spin them on the sanding block, as they are too fragile to sand across.

I use CA and instant cure activator to join the part halves, and couldn't live without it. If you leave a bit of a "flange", it makes it easier to join them, but will need to be sanded down afterward for good appearance. I run medium to thick CA along the inside of the seams, building up a few layers and curing with activator. This works really well for parts such as wheel pants, as the glue will run right down the inside seam, since the flange leaves a bit of a "gulley" for the glue to flow along. You now have material behind the seam, so that you won't sand through when sanding the seam flush.

Guillows is pretty good about making the parting line right where the radius begins for the molded parts, which is just a hair above the flat sheet, so it will need to be sanded away for parts such like pilots and pilot heads, or the parts will be just a hair large in size after joining. In other words their molds are perfect halves, versus being a bit more than half on each of the joining parts. Still not a major issue though to leave a bit of a flange and then join, if the seam is sanded away afterward. Leaving a flange for joining and then sanding it away afterward is obviously easier, as it simplifies alignment.

[Chris A.]

I sure didn't look like that when I flew a Stearman. but it was summer in Virginia. You can buy 1/2 hour of passenger time in the Virginia Military Museum's PT-17 Navy Trainer. Also good for close up detail shots for finishing the model.