Engine assembly and painting

[kmc3420]

I have been looking at many build threads and can't help but notice the clean paint on each engine. I want to make sure I am assembling my engines correctly. I am using tamiya thin cement for assembly and have been assembling the two block halves, painting the block and then painting all other engine pieces, stripping the paint off at meeting points and attempting to carefully glue. Is it easier/better results to glue the motor all together first and then paint after assembled? My current issue is I'm removing some of the paint at times trying to glue after paint. Thanks. 

[Ace-Garageguy]

I usually assemble everything that's the same color on an engine and paint it all as a unit...just like on a real engine.

You'll also get better results usually if you carefully file the mating surfaces flat prior to gluing things together.

Very often, for instance, the front of the engine (after you've glued the block halves together) won't be square and flat. If you just glue the timing cover / water pump on without getting the surface flat first, you may find you have a large unsightly gap on one side. Same goes with the bellhousing in the back if it's a separate part. The cylinder head mating surfaces also often need a little truing up too.

[kmc3420]

I usually assemble everything that's the same color on an engine and paint it all as a unit...just like on a real engine.

You'll also get better results usually if you carefully file the mating surfaces flat prior to gluing things together.

Very often, for instance, the front of the engine (after you've glued the block halves together) won't be square and flat. If you just glue the timing cover / water pump on without getting the surface flat first, you may find you have a large unsightly gap on one side. Same goes with the bellhousing in the back if it's a separate part. The cylinder head mating surfaces also often need a little truing up too.

Thanks Ace. I think I will give it a go as you have suggested. My current issue is putting the water pump and pullys followed by the fan. They didn't line up perfect and gluing them on after painting is when I got a few paint smears. I should have pre assembled the motor as well as you have suggested and filed down the high spots. 

[Snake45]

I usually assemble everything that's the same color on an engine and paint it all as a unit...just like on a real engine.

You'll also get better results usually if you carefully file the mating surfaces flat prior to gluing things together.

Very often, for instance, the front of the engine (after you've glued the block halves together) won't be square and flat. If you just glue the timing cover / water pump on without getting the surface flat first, you may find you have a large unsightly gap on one side. Same goes with the bellhousing in the back if it's a separate part. The cylinder head mating surfaces also often need a little truing up too.

Ace just saved me a bunch of typing. That's exactly what I do, too.

Also, I make sure the intake manifold and the heads meet tightly with no gaps. And if the intake manifold is the same color as the block/heads, it gets glued on before painting, too. (I'd be willing to bet that Ace does these things as well.)

Don't forget that you want to remove the glue seam on the block halves, and usually on the bellhousing, but some (manual) transmission cases will actually have a "mold line" running down their centerline, so you don't necessarily want to remove that seam completely. (Check pics of the real transmission you're modeling.)

[Art Anderson]

I have been looking at many build threads and can't help but notice the clean paint on each engine. I want to make sure I am assembling my engines correctly. I am using tamiya thin cement for assembly and have been assembling the two block halves, painting the block and then painting all other engine pieces, stripping the paint off at meeting points and attempting to carefully glue. Is it easier/better results to glue the motor all together first and then paint after assembled? My current issue is I'm removing some of the paint at times trying to glue after paint. Thanks. 

Actually, automakers have been assembling engines before painting them since at least the mid-1930's, so almost everything that is the basic, overall engine color gets painted at the same time (inluding any bolt heads or nuts used in the assembly process to that point..  Ford was perhaps the last "holdout"  when it came to painting engines:  From their beginnings in 1903 until  the shutdown of civilian car production in early 1942, Ford's practice was to paint each casting prior to assembly, then paint overspray was removed during the final assembly of engines (blocks in the machining process, heads as they had their mating surface milled and polished.  This made for a fairly "dressy" engine when new---the cadmium-plated bolts and screws really stood out.  

Art

[kmc3420]

Thanks Art and Snake. I have a 68 c10 model truck I am going to try and incorporate your suggestions above on, and more than anything take my time and prefit the pieces together. 

[randyc]

Yup.  Pre assemble all you can.  Remove as many parting lines as possible before gluing.   File or sand flat the mating surfaces so they fit tightly.  AFTER you do all that, BEFORE you paint, go back and inspect the block/trans or whatever parts (seats, differentials come to mind as well) and sand/file the seam between the pieces.  You can also thin out the flanges on oil pans and valve covers to a more realistic thickness.  As molded, usually way too thick.  

When applying glue to things after paint, use a slim metal pick or similar.  I use a set of dental picks or an old airbrush needle.  If I'm using CA, I have a piece of masking tape on workbench for paint or glue blobs.  Put a drop of CA on that, pick up a bit of glue with the metal pick, apply carefully to surfaces being mated.  I use the metal devices because they are metal, sharp, and long.  After the glue/paint dries, I can scrape them clean and they are new again.  Toothpicks never work well for me.  I have an aversion to wood for some reason.  When the tape gets too messy, I peel it up, throw away, and put down a new piece.

The best modeling is done slowly and carefully.  You can put some parts together quickly, but you still have to slow down and clean up the parts.  I will usually spend at least an hour with a new kit just scraping parting lines when I first start working on it.  Or do that while waiting for paint to dry on another kit.  Attached is my currnet build and I'm not as good as many on here, but you can see the top of trans is sanded to look smooth.  I assembled everything except intake and painted red at one time.  Then painted bottom of intake, glued on, and painted the top and adjacent areas to make sure it all matched up.  Tried to get all the parting lines off exhaust manifolds as well.  The engine block was probably glued up a couple years ago in a slow moment.  

[Brutalform]

I don't remember the last time I scraped a plated, or painted part. I use top coat clear in the Model Master glass jar for engine assembly, or CA glue, with accelerator. I even use 5 min epoxy. As long as you are careful with the epoxy, it is undetected and speeds up the building without waiting for parts to dry. I always use regular liquid cement for block halves, oil pans and water pumps if they will be the same color.

Edited October 6, 2017 by Brutalform
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[kmc3420]

Thanks all, for sure some great options to try here. The quick drying super glue, as well as using the pick to apply. I will most likely give both of those a try. I think my issue was getting glue on my fingers and handling the motor which caused the paint to be thinned. I then had tracks of paint all over the engine.