MoPac GP7 project

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mopacbuff

mopacbuff

Missori Pacific RR
Gents,

Anyone who has read my thread about a MoPac Geep RIP/Scrap track loco, located here;

http://www.modelrailroadforums.com/forum/showthread.php?p=212404#post212404

knows that I am in process of converting an Athearn blue box GP7 (in UP colors (YUCK, GAG, PUKE)), to a MoPac unit bound for the RIP/Scrap track.

I plan to make this my first loco detailing project by;

Removing the dynamic brake blister

Replacing the cast on grabs with wire units

Installing correctly located horns

and (maybe) doing some side sil surgery to more closely match an MP unit.

Depending on how good this project turns out, I'll either paint it rusty and weather the heck out of it and consign it to a RIP/Scrap track on my new layout (very probable). Or, if it turns out better than expected, I'll send it to the paint shop (custom painter) to have it painted for MoPac and then let it roam the rails of my layout (not likely).

Anywho, this thread will chronicle my trials and tribulations on this project, with pics and text. Here are the first pics of the unaltered shell;

View attachment 24165

View attachment 24166

View attachment 24167

View attachment 24168

Not sure if anyone will care, but it may help another noob with such a project.

MPB
 
A nice sharp chisel blade and a few sanding blocks should make ti disappear quick. Seems like a good project for a wide body BB GP9. Keep us posted on the project.
 


Step two

Ok,

Tonight I removed the fan on the dynamic brake, using an Xacto knife and an Xacto razor saw.

Gonna have to go to town for fresh blades, I need a new razor saw blade and I'm out of chisel blades, which I'll need later on in this project.

View attachment 24227

View attachment 24228

BTW, here are the tools I've used so far. All Xacto brand, got them all in a box at an auction, with quite a few blades and a bunch of other goodies, for $2

View attachment 24229

MPB
 
Good start. I'd cut those exhaust stacks off and replace them with more correct after market ones that Detail Associates makes.
 
Zactly my thoughts on the exhaust stacks TMLW. The stacks on MoPac units are taller on proto photos that I've looked at.

MPB
 
Personally, with all the work you're doing, I'd core out and replace the grill in the winterizeation hatch with a see-through one from Plano, but that would inspire you to want see-through fans throughout the model, and the appropriate 36" fans do not yet exist in good see-through replacement parts.

The exhaust stacks are going to be fun! Exact replicas are not yet available as a detail part. I'd suggest using strip styrene for the two side posts, and a strip of some etched mesh material folded into a "V" shape, with the point facing upwards (so the "V" is upside down), in between the styrene posts.
 
Details West makes these spark arrestors (#HO 124), Wite Metal. Just shave off yours with a Chisel blade knife
124.jpg
 
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I think those DW ones would be close enough, but making your own would be fun too.
 
I looked up those spark arrestors on Walthers.com, not in stock right now, added them to my wish list. As soon as they're available, I'll order them, I think they're close enough to the MoPac parts.

I'm waiting on my x-acto chisel blades and some other goodies from Walthers before I can update this thread. Should have the goods any day. I need the chisel blades to deal with the short hood before I go much further.

MPB
 
Back to work

Finally got my box of goodies from Walthers (shipping time seemed a bit long to me) and I'm back to work on this project.

Using an Xacto #17 chisel blade, the smokestacks disappeared.

View attachment 24372

View attachment 24373

Still need to sand that area smooth, but I'm going to fill in the hole left by the fan removal first.

So, 3 questions.

What's the best way to fill in the 3 holes on each side of the shell left from the blister removal?

Should I go ahead and replace the lift rings? I'll need advice on how to do this as I've never done it before.

Finally, what's the best way to deal with the short hood?

View attachment 24374

I need to remove everything but the rivets and lift rings and I need to fill in the holes (the horns on the MoPac unit are on the cab roof). Should I Should I carefully chisel away what I don't need or sand it flush and add a sheet of styrene with the rivets embossed on it?

Thanks for any input/advice.

MPB
 
mopacbuff said:
Finally got my box of goodies from Walthers (shipping time seemed a bit long to me) and I'm back to work on this project.

Using an Xacto #17 chisel blade, the smokestacks disappeared.





Still need to sand that area smooth, but I'm going to fill in the hole left by the fan removal first.

So, 3 questions.

What's the best way to fill in the 3 holes on each side of the shell left from the blister removal?

Should I go ahead and replace the lift rings? I'll need advice on how to do this as I've never done it before.

Finally, what's the best way to deal with the short hood?



I need to remove everything but the rivets and lift rings and I need to fill in the holes (the horns on the MoPac unit are on the cab roof). Should I Should I carefully chisel away what I don't need or sand it flush and add a sheet of styrene with the rivets embossed on it?

Thanks for any input/advice.

MPB
Click to expand...

Two ways to fill the side holes:

1) Take a sprue from a model kit, on a straight section heat with a lighter and stretch it out till it separates
Then stick the tappered end into a hole and super glue it in, after the glue dries, cut off the excess with your knife, then fill any cracks/gaps with super glue, sand smooth. This proceedure is the quickest and least work

2) Fill with automotive Spot Puddy and sand smooth, sounds easy but requires long dry times and several coats, sanding each time.
 
mopacbuff said:
Should I go ahead and replace the lift rings? I'll need advice on how to do this as I've never done it before.

Finally, what's the best way to deal with the short hood?

View attachment 24374

I need to remove everything but the rivets and lift rings and I need to fill in the holes (the horns on the MoPac unit are on the cab roof). Should I Should I carefully chisel away what I don't need or sand it flush and add a sheet of styrene with the rivets embossed on it?

Thanks for any input/advice.

MPB
Click to expand...
What happens if you try to only remove the Steam Generator Intake and Exhaust and leave the rest, you usually will destroy the rivet detail, one little slip and some are gone! So I just take it all off.
I make my own lift rings from fine copper wire, twist it around something the size you want the loop to be (making several twists to give the shank strength). I use strands from an old extention cord or similar size, drill your holes big enough for the twisted, wound part to go in the hole.
 
mopacbuff said:
flh80,

I have some Bondo automotive filler, is this what you're talking about?

MPB
Click to expand...
Not really, though it would work. Body guys use filler spot putty after the Bondo to fill in small scratches etc. Its an air dry puddy straight out of the tube. The Modelers world it was known as Squadron Green putty.
http://www.google.com/images?um=1&h...squadran+putty&btnG=Search&aq=f&aqi=&aql=&oq=

http://www.google.com/imgres?imgurl...page=1&ndsp=13&ved=1t:429,r:6,s:0&tx=93&ty=70
 
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flh80,

I think I'm gonna try the heated sprue idea. I'll putty everything later as part of the finishing process.

MPB
 


flh80 said:
I see Bondo does make a spot putty
Click to expand...

Better still, use some JB Weld for body filler. Automotive spot putties are laquer based, (really, all they are are paint solids in a paste) and can distort plastic body shells. Plus even though they are cured to the touch in a few hours, it actually takes 7 - 14 days to fully cure, in which time it can shrink!
Fully cured means you can no longer smell laquer when you hold it to your nose!

JB Weld is an epoxy based product (actually an adhesive) but it is fully cured and sandable in an hour, wont shrink, and actually strenghtens the surrounding material. I've used it with great success as a body filler material. I've even carved detail parts out of it! :D
jbweld_sml.jpg

or for really fast repairs
jbkwik_sml.jpg
 
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