Scale model building

[wallfish 19,276]

20 hours ago, ebinmaine said:

I've been mulling how to create a rounded look at the rear and haven't come up with a method that's within my current skill set. So, flat backed it is. 

Just spit balling again

Is the rest of that tank sealed except the front? As in, heat that flat piece you made and blow pressure into the tank. Maybe a damp rag /paper towel wrapped on the tank edge near it to keep that from heating and expanding too

[ebinmaine 77,322]

15 minutes ago, wallfish said:

Just spit balling again

Is the rest of that tank sealed except the front? As in, heat that flat piece you made and blow pressure into the tank. Maybe a damp rag /paper towel wrapped on the tank edge near it to keep that from heating and expanding too

 

 

Decent idea but no... the tank is far from sealed. It is, in fact, not at all joined well. 

To some extent that's the fault of the kit(s) but also, I'm doing a combo that the manufacturer wouldn't have planned.  

 

[wallfish 19,276]

1 hour ago, ebinmaine said:

 

 

Decent idea but no... the tank is far from sealed. It is, in fact, not at all joined well. 

To some extent that's the fault of the kit(s) but also, I'm doing a combo that the manufacturer wouldn't have planned.  

 

How a bout, Make a thin metal cylinder just a bit larger than what the final cut out shape is, glue a piece to it and do the heat air pressure thing. Then cut out the smaller correct size out of that?

Thin aluminum flashing is pretty easy to shape.

[ebinmaine 77,322]

2 minutes ago, wallfish said:

How a bout, Make a thin metal cylinder just a bit larger than what the final cut out shape is, glue a piece to it and do the heat air pressure thing. Then cut out the smaller correct size out of that?

Thin aluminum flashing is pretty easy to shape.

 

This may be combined with carving from wood/clay or bondo.  

[wallfish 19,276]

39 minutes ago, ebinmaine said:

 

This may be combined with carving from wood/clay or bondo.  

What about just making a small metal ring the shape and size it needs to be, thickness would depend how deep you want the concave to be. Lay the plastic material over it and heat the center. Push down if necessary.

 

Or heat the material, lay it right on the actual piece and push to concave it. Once cool and hard flip it over and cut out the shape 

 

I don't know how soft that material will get

Edited 5 hours ago by wallfish

[Achto 30,980]

One idea that may be adaptable on a smaller scale.

 

[ebinmaine 77,322]

30 minutes ago, wallfish said:

making a

 

It's the crafting of the mold that's exactly the challenge for me. 

 

The tank end is wider than tall.

The middle of the crown needs to be maybe a 1/4" out?

I don't have the artistic skills or tools to make a concave or bowl with the two different angles - much less literal dozens of angles from top to side. 

 

That's why I like the idea of using clay or bondo. 

Perhaps cut out another flat oval. Lay/glue a 1/4" stub in the center. Use that to line up to the edges by molding a softer material. 

Sand/shape from there.  

 

 

 

[ebinmaine 77,322]

34 minutes ago, Achto said:

idea

Very cool! 

[ebinmaine 77,322]

The rear third didn't set just right yesterday so I did some readjusting to the seam. A little more grinding on the plastic at the top. 

Stuck it back together and let it rest for a while. When it felt strong enough I started laying down/in/on/out some filler.  

 

 

 

[8ntruck 8,599]

I'm guessing that you don't need very much dome contour in your tank end.

 

You might be able to use some #8 or #10 solid copper wire formed to the desired oval outline of the tank end, then using a heat gun to heat your plastic sheet sitting on top of the formed wire until soft enough to sag into a shallow dome shape.  Thin sheet .010" or .020" thick should work for this.  Some encouragement may be necessary, though.