Slug thrower (WIP)

[Bigglesworth]

A modelling store (plastic/resin tank kits) might have epoxy resin.

[Fortigurn]

I only wish I knew where to find the modeling stores. 

Finding places around Taipei means:

*  Asking your Taiwanese mates
*  Asking your expat mates
*  Asking on the most popular forum for expats in Taiwan

I can't say I've ever seen a modeling store in Taipei, though I'm sure they exist.  It's all a question of where to look.  But I really like the idea of fooling around with resin.

[Otto Von Pifka]

best way to work with it is to make it come off for sanding and fitting, much easier than trying to sand it in place and paint it in place.

when I want to make bondo release, I either use a bit of celophane plastic, clear case tape or aluminum foil to make a barrier.

foil works well but will probably stick the the epoxy like...well...glue!

tape works really well too but you may lose a bit of paint from the frame to the case tape.

I would wrap the handle in a layer of foil, carefully pressing it down along the back where you want the fit good. you can use the tape around the sides and the front to keep the foil in place.

like I said before, you want a pocket of some sorts over the CO2 screw clamp, so the epoxy wont form around it and be permanent. a small tapered cap of some sorts or even some modeling clay packed around it for now. just make sure its tapered so the epoxy will slip off. cover it with the foil too.

cut strips of plastic tape and add them over the foil where you will be building up the epoxy. keep the stuff as thin as possible as you lose detail and fit with a thicker barrier.

once you have the gun protected , mix your epoxy and build it up on the gun where you want it. don't overly fret about the outside finish at this point, you just want to get a good base started.

many of the putty epoxies can be smoothed fairly well with a wet finger, or a wet and slightly soapy finger.

you want the epoxy to firm up but not be fully hard to remove it. cut the foil tape condom from the frame and ease the   epoxy piece off and lay it to the side to firm up some more. once its firm, remove the foil and tape from inside it. it may or may not be an easy task. at the worst remove it from the edges where it will be visible.

don't worry if the fit is less than perfect right now. what you can do to fix it is redo the foil on the frame again and add a little bit of epoxy to the edges of the dried epoxy piece, then press it back into place over the new foil. the excess will ooze out of the way.  let it firm up a bit and pull it off again, removing the foil as soon as you can.  after it cures hard, you can sand off the excess oozes and square up the edges.

in place of the foil you can use plastic wrap but wrinkles on a complex shape are hard to deal with when using the plastic wrap.

here are two examples of how I used this method on a gun to make the barrel band and the loading gate. the gun itself is mostly one big piece of wood. the loading gate pocket is just dremeled into the wood and a bit of foil overlayed and some bondo pushed into it. once it set up the foil was peeled off and it was sanded and cleaned up, then a little more bondo buttered onto it and pressed into the pocket with plastic wrap as a barrier, to get the best fit. then it was sanded and painted then glued into the finished gun.

the barrel band was just bondo blobbed around the clear tape and foil, then the foil and bondo slid off and sanded to shape. the tape underneath was padded with paper to allow clearance to slide it on and off. more bondo was added to it to fill imperfections and the part trial fit from time to time while finish sanding it.

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the epoxy will work similar to the bondo, except you will have longer before it firms up and it will be much harder when fully cured.

I hope this has been helpful, let me know if you have any questions.

heres the finished gun, pictures are awfully dark.

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[Fortigurn]

Wow, this is fantastic advice, thanks!  And I can use this modeling resin like plaster, yes?  Make a cast of something and then pour it in or whatever, and then slap that to the gun somehow?

[Otto Von Pifka]

if your mold is pliable but firm enough to push in something thats about as firm as chewed up chewing gum, then yes you can mold epoxy putty to a certain extent.
a plaster mold probably wouldn't work so well, you would have to be able to pull out the putty but not deform it.

many hobby and craft stores sell a clear plastic resin for encapsulating stuff and casting in general. its fairly easy to use, just follow the directions religiously.
its a liquid so casting with it can be a little easier.

I'm not sure about over seas shipping but I use products from smooth on (smooth-on.com)
they sell a mold making RTV rubber called oomoo and they sell casting resins too. they have sampler /starter size kits that are great to learn with.
they also have tutorials online that are fantastic for learning the basics and a few helpful ways to do things.

[Fortigurn]

Wow, that smooth-on site looks good.  Would you recommend this kit to get started with?

[Otto Von Pifka]

that kit would be for casting things like hands and body parts. the plaster pieces would be only somewhat sturdy.

alginate is good for one use molds or just a very few castings, it's pretty much like a very sturdy jello! its water based and  the water in it begins to dry up so the mold you make doesn't have much of a shelf life.

[Fortigurn]

Ok, I'll have a look around and see what might be more useful.  Maybe the urethane plastic stuff?

[Otto Von Pifka]

it all depends what you are trying to do....

suppose you found a part and wanted multiple copies of it or wanted to make something and mold it.

then you would want the pourable molding kit. it has the oomoo RTV rubber to make the mold out of.
and it has plastic resin to pour into the mold and make parts out of.

usually if it says "rubber" it's what they expect you to make a mold out of, with some exceptions.
there is RTV which is silicone based, and there is urethane rubber. they both have pluses and minuses as far as performance and durability.

I like the oomoo line of RTV silicone because it's very easy to use, the end result isn't the strongest material for a mold but with care it can last for a good while.

the casting plastics or resins are for making the actual finished parts from the mold you made. they have different properties for different applications. the easiest to use are the ones you mix one to one by volume. demolding times and cure times are important too. if something is going to be time consuming to pour, a fast curing plastic may start to harden before you even finish filling the mold! on the other hand, why wait an hour to take something from the mold if you can get plastic you can take out of the mold after 15 minutes.

the best way to describe using oomoo to make a mold is like pouring cake batter into a fancy cake pan.
the oomoo is about as thick as cold maple syrup, and pours about the same. usually to mold something, you need to make a box around the item you want to make a mold of. some people make a box from lego blocks or just set the item inside a small plastic container. depending on the item you may need to stick it down or have it elevated in your casting box. with an item that you want to make a mold of so it has all sides molded (like a pistol) you will need a mold of at least two parts. it can get pretty complicated just figuring out how to shape the molds. just like a cake pan you need to lube it so the oomoo won't stick to everything once its firmed up, the kit comes with a spray release agent to coat everything with. it's especially important to use it if you use modelling clay for the box or to support the item molded or to make the item to mold. some clays contain sulfer which will retard the curing of the silicone and ruin the mold. (believe me, that REALLY sucks)

anyway, pour over the tutorials there at smooth-on.com and do searches on other tutorials and products.

I made a mold a little while back from a urethane type of rubber, to make zeppelin pins.

it mixed about as easy as the oomoo but it doesn't quite pick up as much detail as the oomoo, but the mold is a little tougher than the oomoo. the original was a lump of modeling clay I sculpted really fast, it was stuck down to a board and I used a glue gun to glue 4 pieces of plastic around the part to make a casting box. thats why the edges of the mold are so rough, the beads of hot glue left a negative impression in the edges.

[Fortigurn]

That's really terrifically useful advice, thanks.  Right now I'm not exactly sure what I'm going to be doing with this stuff, but I do know I'll probably be augmenting the handle of my gun (so I'll need something which molds like clay and then cures very hard), as well as probably making some things to stick on it.  I'm thinking of a curved side panel on which I can stick other things, without having to drill lots of holes in the gun itself, which would have to be made of something tough.  Which products would you recommend?

[Goggleyed]

Well, if you are looking for something to use that extra hammer for and some widget to randomly bolt onto your gun, I would take a look into making a type of breach loading shotgun. Also, to attach pipe and such to an airsoft gun without damaging it or permanantly affixing it to said gun I would use Scope Rings, such as these, http://redwolfairsoft.com/redwolf/airsoft/ProductDetail?prodID=21956 http://redwolfairsoft.com/redwolf/airsoft/ProductDetail?prodID=21434 or http://redwolfairsoft.com/redwolf/airsoft/ProductDetail?prodID=19739 , These would allow for you to simply put piping in for said widget and tighten the screws.

[Fortigurn]

Now there's an idea, thanks.  I'll have a look at scope rings when I go to my local airsoft store this afternoon.

[Goggleyed]

See, my personal idea on where the shotgun idea could go would be the basics of a break barrel mounted so that it swings down and there is no handle, just firing mechanism then barrel, with the barrel break between the rings of a joined scope mount. This however probably wouldnt work, or wouldnt work well.

[Fortigurn]

I have been wondering if I can find a bolt action in the spare parts bin or something, and strap that on.  That would work very well, and should be easy to mount.  I was thinking of something which would enable me to slide back the bolt, expose the breech, and insert a small battery or something for a flashlight or other electrical device on the gun.

[Fortigurn]

I picked up a scope ring and a small barrel with an open breech today.  I'll see what I can do with them tonight.

[Fortigurn]

New pistol above, first pistol below.  Now to start modifying the new pistol.  First a paint job. 

Spoiler (click to show/hide)

[Prof. Friedrich VonHart, PhD]

Well done Fortigurn! I just stumbled upon this this morning, looking good. I'm glad you're getting use from those parts (those are the chime counters BTW). Keep it up.

[Fortigurn]

Thanks mate.  That little bag of tricks you sent me has sparked my imagination considerably.  I'm tossing over a few ideas of exactly how and where to mount cogs at present.

[akumabito]

If I may offer a suggestion.. perhaps on the new gun you could keep the current wooden grips as they look quite nice. For the color, perhaps an even coat of beautiful red-golden copper? I think it would look quite smashing if you'd go down that route..

[Fortigurn]

It looks better in the photo than in real life.  Those grips aren't wood, they're unfortunately nasty plastic.  I do like the 'skeletal' look with the grip removed and the tank exposed, but today when I hefted the larger pistol the big grip did feel very comfortable, so I may try painting it a copper or brass.

[akumabito]

There are also paints available that give a VERY nice rosewood effect when applied correctly. Check your local hobby shop.. It's sometimes used to upgrade car interiors as well, so specialist garages/tuning shops may also stock it.

[Fortigurn]

Hmmm, rosewood sounds very attractive. 

[Goggleyed]

That scope ring bit looks rather dashing. Glade it worked out well!, now, if the second pistol is for say, more adventurous modification, I would go with a scope this time, Scope rings on that top rail and a long pipe optic device pulling back to the rear iron sight.

[Fortigurn]

Both pistols are going to end up with scope rings top and bottom.  All four scope rings will be occupied with optical devices.  The second pistol will also have a secondary hammer.

[Goggleyed]

Just wondering, are these retaining their Airsoft abilities or have some been removed for other purposes?