Make parts out of hot glue.

[OldMiner]

I have quite a few 1/35 paper models to build and a couple of scratch builds I want to do that need a ‘truck tire’.
I bought a German half track kit a while back and the front wheels are perfect for my needs. There are only 2 in the kit. Since I am cheap, I didn’t want to spend a bunch of money on extras, so I set about figuring out how to make my own.
Yes, I can make a silicone mold and cast them in resin. I will be doing that one of these days, but for simple, flat back parts and even some more complex things, I found a way to make a mold easily and cheaply.

I’ve started messing with ordinary air dry clay for the mold. I saw a guy make a part with the clay and hot glue on youtube and tried it. It works, although it is a bit fiddly. My first wheel came out OK, the third one was fubared (but still useable) by a glue gun burp and the second one is ugly, but still can be used.



Those are about 1” in diameter, or 35 inches or so to scale. The all black is the first one, the black tire is #3 and the glue one is #2.

You simply mash out a blob of air dry clay and press the part into it to form the mold. The fiddly part is getting it back out without ruining the mold. That is where I am now… experimenting with releasing the part. Remember, the clay is soft, you don’t let it dry.

When finished, you just wad up the clay and put it back in the bag with the rest of it.

This experiment was triggered by a little missile launcher thing (a HAWK) that came with a batch of army men off ebay. I had overlooked it as ‘silly’ originally but yesterday found out that it is actually a quite good, to scale, model of a Hawk launcher. All I have is the 3 missiles on their holder that pivots and is vertically adjustable.

The real Hawk setup looks like this:



I have the 3 missiles, tan like these, and the mount. I will need to build the trailer.



And the aiming/radar unit for this looks like this. It will have to be entirely scratch built. I think the bottoms of two soda cans will be perfect for forming the radar reflectors themselves.



My plan is to use the 1/25 trailer from the mobile kitchen unit in the resources section and re-scale it to 1/35. AND use hot glue wheels and tires.

 

[Rhaven Blaack]

Thank you for sharing this with us!

 

[mijob]

Awesome thank you.

 

[Revell-Fan]

Great tip! As for more flexible molds you could try "blue stuff". It comes in blocks which can be melt together in hot water IIRC. When they are soft enough you wrap it around the part you want to replicate. Wait till it has cooled down, take the original part out and fill it with your desired material. The best things of it are: it's cheap, fast, and you can re-use the blue stuff.

 

[zathros]

Paper wheels painted with "Liquid Electrical Tape", or with "Flex Seal" come out much better and look more realistic.

 

[OldMiner]

Great tip! As for more flexible molds you could try "blue stuff". It comes in blocks which can be melt together in hot water IIRC. When they are soft enough you wrap it around the part you want to replicate. Wait till it has cooled down, take the original part out and fill it with your desired material. The best things of it are: it's cheap, fast, and you can re-use the blue stuff.

Except, the hot glue melts the blue stuff. I will be using the blue stuff and some pellet type of similar stuff with clay and resin. I have that stuff.
Today I want to experiment with using a ‘disposable’ wad of clay. I am going to oil the pattern and the surface of the clay and press the pattern into the clay. This will probably ruin the clay eventually, but it is cheap. (I am using clay from long ago. It is Crayola brand and revived nicely by letting it ‘re-moisturize’ in plastic bags.) My guess is that the wad of clay will last for several molds at least. I’ll report back.

Oh, I almost ruined one part of the half track by ’testing’ it by surrounding it with hot glue. I made a major mistake by not lubricating the part and another by under estimating the heat/melt action of the hot glue. The part started to melt. I quickly put it in cold water and then spent a half hour digging the part out of the glue. It is useable still, but damaged. Failed experiment there.

 

[OldMiner]

Ok, this works fine. Greeblies, anything flat backed that is of reasonable size will cast OK.

I set up two wads of clay, one in a plastic form just for fun and started making wheels. I oiled the surface of the clay and the pattern wheel. Then the pattern was pressed into the clay and the mold manipulated until the wheel looked OK. I removed the pattern with a tiny pliers. Each mold was pumped full of hot glue, allowed to cool and removed by sticking the xacto knife in the back and pulling. Then I pressed the pattern in the hole again and repeated. Now I have a total of 10 wheels to play with.
I also cast one of the amputees from my army man limb transplants. I pushed him into the clay and cast a copy. That worked fine too. Now I need to remember to copy any cool greeblies I find. This only takes a few minutes to make multiples of anything small like that.

The assembly line:



And the results:



Those wheels aren’t perfect but it doesn’t matter. It is a WAR zone after all.

Those wheels could become part of a model or a junk pile or a spare on some equipment.
Having fun!

PS:
the clay seems to have survived the oil treatment just fine. I rolled up each piece and put them back in the bag with the rest. I will test them to see how long they last.

 

[zathros]

Those parts came out very clean and defined!

 

[mijob]

The wheels are looking great.

 

[Revell-Fan]

Great job, especially the driver!

And, yes, the blue stuff could melt..!

 

[OldMiner]

I’m going to add the Hawk missile outfit build to my Green Army Man thread.