Finishing Methods

[rhitee93]

This question will probably provoke as many different responses as there are readers, but I'd like some opinions of finishing methods for cast parts.

I am getting close to starting the finishing steps on my PMR#1, and have been looking at a lot of the finished engines that you all have posted pics of. This has caused a major reversal in the way I was going to approach the process.

Way back when I did my #3, I left all non-machined surfaces as cast. The brass parts stayed brass, and all other non-machined surfaces received a carefully applied coat of paint. I was very disappointed in the results. It looked like a cheap toy rather than a model. I didn't want the same results this time.

Looking back on it, and some of your engines, I think I understand why. The the texture of the cast surface isn't to scale. It is just too rough for the size of the parts.

So, how many of your are smoothing the surfaces of your cast iron parts before paint? I assume some sort of body filler and/or high-build primer are in order?

What about the cast bronze parts? how on earth do you file/sand these smooth so they don't look wavy after they are polished?

I'd love to see pics of the processes and results.

Thanks!

 

[Jasonb]

I usually run a die grinder over them but a dremel will do using a mix of carbide burs and various shaped grinding stones. Teh aim being to knock off the high spots but not go so far as to loose the cast texture.

You can see the "bright" areas where the high spots have been removed from this head casting and thats about as far as I would take the part before painting, for a smaller scale I may work on it a bit more.

J

 

[gbritnell]

As you kind of stated it's a matter of personal taste as to how an engine is finished. I have some natural engines and I have some painted engines. As far as finishing a casting it depends on how smooth the part was cast. Some castings are made with smaller grains of sand and have less burn in than others so you can usually just prime and paint them while others have a very coarse texture to them and need a little cleaning up as Jason pointed out. I have seen engines painted black, blue, red, maroon, green, well just about every color imaginable and if done right all look very nice. One fellow even did a beam engine in white and it looked fantastic, so the choice is yours.
gbritnell

 

[Tin Falcon]

some depends on the engine and some depends on tast some depends on the part surface and what it is used for.
personalty I prefer not to paint brass and bronz. If I am going to pay the money for those metals I do not want to hide it. my pmr 2b I left the castings as is no paint. and I do a lot of work in corian and lucite . either would be sutable for painting . yes you can paint plastic and I have made professional models out of plastics inculing clear lucite that was painted.

somewhre along the line I saw a list of contrasting colors for stationary engines I wish I knew where.

I have done red and black. red and grey are good colors (my High shcool colors)
I found this list for old gas engines
http://www.oldengine.org/members/shpclub/tid002.htm
Tin