I just remembered another great use for Kneadatite in model railroads.
.
I also use it to secure the ends of brake rods into the undersills of freight cars. this way it is impossible for the brake rod to come free and break off. Now it will never interfere with operation.
just bend the end of the brake rod so it ends in the sill center, and secure it in place with kneadatite. This is a permanent solution.
-Kevin
Living the dream.
I found pictures of something more relevent.
The Worthington feedwater heater on the Mikado did not fit the radius of the smokebox correctly. I filled the gap with Kneadatite. I think this is similar to what the original post was asking.
I could have done a better job smoothing the joint now that I see it blown up to 400% of life size. Believe me, at normal viewing distance it looks perfect.
I should go back to the cheaper camera for pictures like this.
OK, back at home for the weekend. I have time to post a more detailed response.
Kneadatite by Polymeric Systems Incorporated is a great product to use for any sculpting on any model. It comes in either a pair of tubes, or a strip. I prefer the 36 inch long strip. I strip like this will last a model railroader probably a lifetime.
These are some of the tools I use to work with Kneadatite. The three tools in the back are called "clay shapers", and they are necessary. The black ones are made by Royal Sovereign and are basically a stiff rubber nib on a handle. These tools let you blend the Kneadatite smoothly in between the surfaces. The metal tools are just basic sculpting tools available at many places. Squadron makes a great sculpting tool. There a many sculpting tools available through Micro-Mark.
When working with Kneadatite, cut off a small piece no more than 1/4" long. Pick out the hard part in the middle where the yellow and blue meet. Then knead the putty until it is a nice green color. Now it is ready to work with. It will stick to anything that is not wet, so keep your tools moist.
Do not carve the putty. All you can do is push it into the shape you want. If you have too much putty, scoop a bit away, and keep working it.
Mixed Kneadatite has a working time of over an hour.
I do not have very many in process pictures. I paint things pretty much as soon as they are ready, so there is not much lying around tha I could photograph.
I filled in the base of this figure with Kneadatite. You can see it can be worked into a very smooth and shiny surface. This base will be covered with flock when the figure is painted, so I did not make it perfectly smooth.
This Reaper figure had a head I did not like very much, so I replace it with a helmeted head from a different figure.
I sculpted the fill joint between the helmet and the torso with Kneadatite. I also added all of the hair and sculpted it. This hides the joint completely, and if you are not familiar with the original figure, you would never know.
This little Mini-Diorama of a gazing pool has the entire water surface sculpted from Kneadatite. This would be a great first project because it goes very quick and easy. There is also very llittle that can go wrong with water ripples. I will work this pool into my next layout.
Milliput is an epoxy putty that also has modeling uses. Tamiya also makes a similar, and excellent product.
Milliput has a grainy quality to it that Kneadatite does not. Kneadatite can be sculpted very smooth, but Milliput will always have a bit of a texture to it. There are actually different grades of Milliput that are more or less coarse.
The base on this figure was sculpted from Milliput. You can see a bit of the texture. This is kind of like the diferences in between Plaster and Sculptamold.
Aside from sculpting, another great use for Kneadatite is reenforcing detail parts. The feedwater pump on this locomotive had very little contact area with the boiler casting. I filled in the void with a chunk of Kneadatite. Here the adhesive properties of Kneadatite give an excellent benefit of both holding the detail in place and providing support to the piece.
This makes the model much more durable when it is put into service.
As I mentioned, the "street name" for Kneadatite is "green stuff". This causes a bit of confusion because Citadel makes a product called "liquid green stuff".
Liquid Green Stuff is not the product you want. This stuff is pretty much just the same thing as Squadron Green Putty, but in an open top pot that allows it to harden up too quickly. I recommend avoiding this product.
Kneadatite has many desirable properties. It does not shrink. It has amazing adhesive traits. It has a long working time.
PSI Website:
http://www.polymericsystems.com/
Blue/Yellow (green stuff) information page:
http://www.polymericsystems.com/epoxies-adhesives/epoxy-putty-tapes/kneadatite-blue-yellow.htm
Sculptor's information page from PSI site:
http://www.polymericsystems.com/technical-data/pdf/SculptorsInfo.pdf
Really good article about different mediums for sculpting. It mentions FIMO instead of Sculpey, but they are quite similar:
http://www.bananaking.net/cento/workshop/conv_green.htm
I hope this helped. Try it out. This is a great skill to add to your modeling arsenal.
And that my friends is why you ask questions.
Thanks Kevin!
DO NOT use sculpey on a locomotive shell modelling project! STOP!
If you are going to scuplt onto a shell, the BEST product to use is Yellow & Blue Kneadatite manufactured by Polymeric Systems Inc. (PSI). This is the standard product for nearly all the hand scuplted masters used in metal casting for everything from detail parts to metal army men.
There are plenty of YouTube videos on how to use it. The main rule is to keep your sculpting tools wet while working with it.
I sculpted the base of this flat fan to match the cruved roof of the Trainmaster with Kneadatite.
Most people in refer to it by its slang term "green stuff".
Sculpey has all kinds of uses in model railroading. I have used it for sidewalks, building foundations, cobblestone driveways, and so on. It is wonderful. It just is not as durable as you would want, and has no where near the adhesive or strength characteristics of Kneadatite.
dknelsonI can testify that a regular hair dryer can distort and somewhat melt plastic. Indeed that is one of the classic methods for dealing with warped plastic.
I should have noted that the advantage of using the hair dryer was I was able to modulate the heat applied to the plastic. When I felt like it was getting too hot, I removed the heat for a second or two to let it cool down. I also used our digital kitchen thermometer to keep track of how hot the air flow and surfaces were at the time of heating. Interestingly enough, the maximum temp that I recorded was only about 190-200 deg, significantly less than the 275 Deg stated on the package (and I heated it for less time too). I checked it again last night an the original patch was still very hard (hard enough for this application).
Your Mileage May Vary. :)
dknelsonDoes the polymer clay have to be baked with the plastic shell attached? That is, if it is shaped correctly why cannot it be baked separately and then glued or cemented?
No. But in the case above, I didn't think that I could sufficiently match the angles and contours and have everything come out smoothly. Again, ones mileage may vary.
I think that there are potentiality lots of uses for this stuff. I think there is a big potential for things like textured rock walls, small structures, etc.
I can testify that a regular hair dryer can distort and somewhat melt plastic. Indeed that is one of the classic methods for dealing with warped plastic.
And somehow I thought Detail Associates or someone like them made such a casting already, but cannot testify to it.
I have seen guys create their own second headlight opening with brass or plastic tube of the right diameter
Does the polymer clay have to be baked with the plastic shell attached? That is, if it is shaped correctly why cannot it be baked separately and then glued or cemented?
Another thought would be to try to obtain an old Varney F3 shell in metal, shape the part on it and bake it, then detach it from the metal shell and attach it to the plastic shell.
Dave Nelson
I'm sure somebody here uses/has used sculpey (or any other polymer modeling clay) for model railroading. I bought some a few weeks ago with the thoughts of adding a 2nd head light to a Santa Fe F-unit so we could run both a headlight and a mars light. I knew it had to be baked, and when I read the instructions the thought of leaving the shell in the oven for 15-20 mins at 275 deg F caused me pause. So put it ton the shelf and kind of dropped the project.
This past weekend one of my wife's plastic Christmas decorators took a nose dive and broke into several pieces. I managed to CA everything back together, but there was a small missing piece about 1/4" x 3/4". We had nothing to lose, so I figured I would give the sculpey a try. While I was molding and shaping it into place, I had a brain storm. So I got everything like I liked it, pulled out the hair dryer set it on high and proceeded to heat up the patch. After about 10 mins, the patch had hardened nicely. A few mins later I painted the patch and viola, good as new.
So I think I'm going to go ahead and try the Mars light project. I have an extra shell from that loco on a dummy that if I destroy, it won't be the end of the world.
Anyone else used this product? For what and how did you deal with the heating?