FW Lynx Conversion

Follow up on a previous post where I repaired some minor issues.

After looking at how the cannon assembly works on the standard Lynx I realized that a hull brace like the FW Cobra would be a great modification.

Stock photo from FW's site, showing mount style I am hoping to build.

Here you can see where I have ground down the existing hull and added in a piece of plastic card to form the mount.

Here the Gun has bee glued into place and is resting on the mount strut.

Here the mount has been melted with a heat gun and wrapped up around the barrel.

Here the mount ring has been completed 100% around the barrel using Pro-Create.
















Now the cannon barrel will stay secure in while transporting the model, and the barrel wont droop under its own weight.

Some final sanding and details will follow shortly.

Resin Model Repair

So I have been working on a few ForgeWorld or possibly FW knockoffs in an attempt to catch up on my backlog of unassembled models.

Eldar Lynx partially assembled












Repair needed

Here you can see the white area just lower and left of the cockpit.











There was a small break here and I did not have the piece that broke off.  I used a very thin piece of plastic card (from a yardsale sign) I glued it to the underside and trimmed it to fit the old curve of the piece.

I then dropped a few drops of superglue onto the piece, followed up with sprinkling baking soda on the glue.  The baking soda makes the glue cure almost instantly, and when it dries you can sand it.  It it much harder than GreenStuff.  Making it ideal for this fix.

Other fixes needed too.

3 different areas needed repairs here.












1 The engine cover got snapped off, I reinforced it from below with thin plasticard.
2 The engine cover and stabilizer seen far right had broken in transit.  I rebuilt the cowl using thin plasticard from underneath and using ProCreate grey putty on the visible side of the model.
3 The white half of the stabilizer mount is thick plasticard cut and sanded to fit the original missing piece.

Warpage

The barrel of the gun was significantly warped.

I glues a magnet to the mounting end and hung it from my work bench.  Then I used the heat gun to soften the resin and bend it back into shape.  Because it was hanging gravity helped keep it straight while the resin cooled.

Resin Casting Tutorial

Now that a mold is finished we need to pour some resin.

Lets make these.

Smooth-Cast 305

Once again this product is mixed at a 1:1 ratio by volume and has little or no odor.

It has a 7 minute pot life and a 30 minute demold time.

I recommend getting some squeeze bottles like restaurants use for condiments to make it easier to pour.





I use Alumilite's Black dye to get a gray resin.  305 is usually bright white.  A few drops in the A side jug and shake till blended. Go slow with this and test until you get a shade you are happy with.


Tools and work area

I use a marble cutting board for any of my messy work.  Hot metal, super glue and resins scrape right off with the razor scraper.

• Syringe for injecting resin into the mold, or pulling resin through a vent gate.
• Graduated mixing cups, labeled in CC
• Mixing Stix
• Rubber bands to keep molds together
• Clamp(s) for molds
• Hard board or plastic card used when clamping the molds.

Clamped Molds

Using a hardboard or thicker plastic card line up the halves and hold them together.  Use rubber bands or clamps.  You have to figure out the right amount of pressure for your mold. Too little and the resin will seep out of the bottom, too much and you will warp and deform the cast.

Mixing and pouring tips

• Shake both sides of the product to ensure they are fully mixed, especially is you are using a resin dye.
• Stir the A&B sides well, make sure it is completely mixed.
• With this mold I was able to pour directly into the main gate, I used the syringe slowly pull resin & air pockets up through the vent channel.
• Rotate and shake the mold to help free any trapped air pockets.
• Wear gloves you don't want mixed resin on your hands.

First Cast from these molds

On this pull (that's what a casting is called) you can see the middle claw did not form because there was a small amount of silicon that needed to be removed from the vent.  A few small air bubbles but over all a very nice first pull, means this should be a very good mold.

On this pull we see a few air bubbles and the toe had a trapped air bubble.  Still better than most packaged and sold Finecast.  The toe bubble was solved in future pulls by rotating the mold while the resin was liquid, to allow the air to escape.

The vents on this mold did work right the first time.


With a little work these legs will be usable, a small amount of green stuff and less time than I have spent on most ForgeWorld I have gets a very good set of bug legs.

Two part mold making tutorial - Resin Casting

Making the 2 part mold.

Lets make these.
























Smooth-On Oomoo 25.

This product is mixed by volume at a 1:1 ratio.  It does not have an foul odor, in my opinion.  It has a 15 minute pot life and sets up in 75 minutes.

This product does not need to be degassed or weighed, it is mixed by volume.

Making it much more user friendly.






Clay.

Bad Photos, blame the plastic wrapper that I was trying to photograph.  On the second frame the label says no sulfur, your gonna have to trust me on that.  I would recommend if possible by a natural colored clay instead of blue or whatever.  The color is a pain in the ass to clean out of skin, tools, and clothing.

You have to use sulfur free clay so that it does not mess up your mixed silicon.














Mold boxes.

This step will take longer than it most would people think it would, take your time and do it right.  Using a sulfur free clay, build up a layer of clay to around half way up the original.  Make sure to leave no gaps and not get the clay on the top half of the original.  Build your mold on a flat portable surface, I used a piece of 1/8 inch thick plastic card.  I also Use Legos for the walls of the mold box.  Where you stop with the clay will be the mold line, you want to be aware of this so that you can minimize mold lines in you detailed areas.  Leave plenty of room on all sides of the original, so that the mold halves maintains strength.

Adding vent channels.

At the bottom of the photo you can see the end of a syringe that I use as a pour gate for resin, the white plastic rods were added to make channels for air to escape when pouring the resin.

The holes in the clay will form registry keys that will help to keep the halves lined up properly.













Math Hell.
If you are still with me this far along, then I am going to assume that you can read and have a basic understanding of the MATHs.  At this point you need to figure out how much silicon to make.  So some basic calculations of volume are going to be needed, along with at least one graduated container.  So my two boxes had interior measurements of 6.5 cm 9.5cm x 1.5cm  &  6.5 cm 11.25cm x 1.5cm, giving me two volumes 92.625cc & 110cc.  Total volume needed approximately 202.3cc minus the filler(scroll down) and volume of the original to be cast.
This is America here but metric is so much better for things like this (everything really).


Two Compounds One Cup.

I use clear throw away drink cups, using the graduated container measure out 100cc of water and pour into the cup.  Mark a line with a sharpie  at the water line.  Now pour another 100cc of water in and mark the next line.  Make sure the cup is completely dry  I put tape over my lines so that the mark would not rub off.







Mix it up.
Follow the manufacturers instructions on mixing the A&B sides of the silicon.  I keep two labeled large paint stir sticks like from Lowe's and two measuring cups one for each bucket with my gear. After stirring I add the thinner of the two to the cup up to the first mark, then add the other side up to the second mark.

Stir with a third stick until the color is even, you need to stir this and pour the silicon in around 5 or so minutes you have a work time of 15 minutes total.

Left over silicon.

Left over silicon can be cut into small bits and added to a new mold pour. Keep it to small amounts added after the first part of the pour.  When the resin has coated the clay floor and original.

Keep and failed molds and left overs for this reason.








Poured Silicon.

Start pouring in the most empty corner of the mold box and allow the silicon to flow by itself throughout the mold box.  That will help to ensure complete detail capture.




In this photo you can see the air bubbles caused by mixing and pouring rising up and popping leave them alone and let the silicon do its thing.  Gently shaking, tapping, or even vibrating the mold will make this go faster.


(You can buy a professional vibrator for this, please post pics of it delivered to your door step if you do.)
The manufacturer says 75 minutes to cure, I recommend pouring the first half and between 2-4 hours.  Let it really set up and cure well before the next steps.

Remove the walls.

Remove the walls of the mold.













Remove the clay

Remove the clay, notice how the blue stains the plastic card.  Buy a natural unstained shade if possible.


Make sure to get all the little flecks and pieces.  Try not to remove the master from the mold silicon.



Prep for 2nd pour

You must apply a rubber to rubber mold release agent to all of the silicon, be extra careful not to get any on the master being copied.  Use a old paint brush for this.

Ready to pour the other side.

Rebuild the mold box, mix & pour your silicon.

2-4 hours later.

Gently pry the 2 halves apart.  You will have to clean out the pour channels and venting sprue gates.  Use a very sharp knife and possibly a good quality sprue cutter.

Give the mold at least 8 more hours to fully cure before you start pouring resin in it, yeah the manufacturer says its ready but do your self a favor and wait.

Green Stuff Basics

So I have been getting some questions on forums about how to sculpt with GreenStuff  (henceforth GS).  So here goes my amateur tips and techniques.

GREENSTUFF

Buy this size, and keep a dish of water handy when working

First don't buy the strips, buy the big tubes for around $13 for 100grams from the warstore.  The same weight of GS from GW would be $50.00 in strips and the strips do not store well.









Basic Tools

Tools most GW hobbyists are familiar with.

No matter what sculpting tools you use or make keep water handy to keep your fingertips and tools wet, to keep the GS from sticking to you as much.  I know some sculptors make their own tool ends for specific effects or their own preferences.  I am not that far along yet or more correctly I have not found the need create a tool tip.



Clay Shapers

Clay shapers size Zero 

If you want good looking sculpts, buy good tools like these.  GS rarely sticks to these and they are great for smoothing our fingerprints and blending/feathering GS edges.














Digital Scale

I bet most of you did not see that one coming.  Get a jewelers scale from eBay that can handle around 500g to 1000g.  You can weigh out the blue and yellow portions individually to be sure you are close to equal.  I have found that I am rarely able to use more than 1.5g in a single session before it starts to set up and get more difficult to use.  Remember that is about .750g of each color.  Some sculptors like to vary the amounts of each color or even add different putties like milliput or Brown Stuff.  this lets you make sure your ratios are right.  Like painting and trying to match a blended color, a scale can make it easier to match a special ratio keep a note book handy for these sort of things.









Now Get Sculpting
Here are some techniques and tricks I have picked up:

• Use an armature or skeleton to build up you sculpture on, GS is flexible and will not support much weight without bending.  Use brass wire or plastic card, remember that if you are going to cast the model later in metal that you will want to use metal supports because of the heat and pressure many mold making processes generate (most resin techniques avoid this problem)
• Sometimes you may be sculpting two parts that will join up to each other but need to remain apart, like a ball and socket joint. In the case of a ball & socket joint once the socket is formed and cured a good tip is to lightly apply petroleum jelly (vasaline) to the inside of the socket and the press a wad of GS into it to take the ball shape.  Petroleum Jelly will not stop GS from curing but it will keep the two pieces from sticking together.  Once cured clean up the goo with regular dish soap.
• Press Mold, read this post to get a better insight on press molding.
• Work in thin layers, build the model slowly.
• On this torso I extended the backbone in around 3 sessions.  The first was to build a plastic card skeleton joining the ball back to the waist and then covering it with GS.  Once cured I blended the vertical strips of GS onto the torso.  Next after that had cured I packed a small amount of GS at the bottom of each U shaped valley and using a Clay Shaper made the cross members by working the excess up the groove until I reached the top of the torso.  It took days to complete and probably could not have been in one session.

White Metal Casting Tutorial

A step by step walk through on how to cast you own small figures in white metal aka pewter.

Items needed

From this retailer:

miniaturemolds.com/pricelist

List of materials needed:

A heat resistant work area (I use the slab of green marble shown in this pic)

Mold Rubber                                          $20.00

Mold Vulcanizer Tool                             $95.00

HDF or Masonite mold clamp boards       $0.50

Heavy Duty spring clamps                        $4.00 (local DiY store)

Melting Pot                                             $72.00

Pouring Ladle                                           $6.00

10oz Ingot                                                $7.50

Talc powder / baby powder                      $2.00 (wal-mart)

Heavy Duty gloves                                    $4.00

Shipping                                                 $17.00

Total around $230 shipped to a US address

So understand its a hefty investment to be able to make 1 mold and cast 10oz worth of metal figures.  

1. If you mess up the mold making step you just cost yourself around $20.00. They have a bulk deal for 5 or more blanks each one is reduced to $15 each.
2. To make 2 metal figures like the 2 small ones I used in this example uses 0.84oz of material, so you will get approximately 11.9 figures (obviously YMMV depending on what is cast).  Good news is you can remelt miscasts.
3. So to break even; assuming you buy one mold blank and 5 ingots ($260) you would need to cast 59 figures (barely possible) @ $5.00 retail ($295).  However with all the reliable discount web stores offering %20 discounts and cheap/free shipping you are still in the hole in money spent and time used.
4. So If you are thinking gee I wanna be a recaster and flood eBay and trading boards with high quality metal recasts of some other companies IP understand its probably not worth the effort and cost.  
5. If you want to make casts of your own creations that are worth selling at a premium price, this is probably a decent option for you.

I purchased my setup around mid 2001 and spent considerably less that the current costs. I wanted to finish out a very large army of high cost metal models that at the time were hard to get in the specific pose I wanted (random blister packs), and there was not reliable discounters.  My break even point back then was around 45 models I wanted 60ish. 

First Steps

1. Place a new blank in the vulcanizer tool dust both sides of the tool with Talcum (or Baby powder), the uncured slabs are smaller than the cavity and will expand when heated causing rubber to squirt out of the tool like a hard toothpaste.  Remember this when later when baking it, you will want a catch tray underneath the tool.
2. Lightly place the original to be cast on one slab of the rubber, you may be able to place 2 small models on the slab leave around 1/4 inch of room to any edge and any other model.
3. Because you obviously plan on casting you own designs know the following.  A green stuff master can withstand 3 vulcanizations (per the kneadatite website).  Also your GS master must not have a plastic core because of the time at the required heat and pressure.
4. Once you have lain out where you think you want the models to go remove a small amount of the mold rubber making a cavity smaller than the master (around 1/3 of the volume of the original), you will repeat this on the other half of the mold rubber.
5. Place 4 of the register keys into one side of the mold, all four facing the same way.  The flat edge of these should be flush with the top of the slab of rubber that you push them into.
6. You may also want to use a metal pour gate, instead of cutting it your self later from the cured mold.
7. Now that the original(s) is on one slab lightly dust the slabs with Talcum powder.
8. Close the tool, tighten the hex screws, and remove the wooden handles.
9. Place in the oven at 400 degrees for an hour.

Mold Vulcanizer & mold blank

register key nuts and pour gate

Mold blank & Vulcanized finished mold (top)

Open Vulcanizer with an uncured mold blank

Cured Mold Prep

1. Let the sucker cool down, be patient
2. Remove the mold from the tool, this will be easier if you have a wooden stir stick / Popsicle stick.  The mold has expanded to fit the cavity of the tool and will require some wrangling.
3. Pry the halves apart and remove the masters.
4. Cut your pour gates (how the molten metal gets into the cavity)
5. Cut vents if this is your first mold try a casting or two and see if any area is not getting metal into it.  This will usually be the ends of gun barrels or horns etc

Completed mold with pour gates and vents cut

Cutting tool, used to remove cured rubber

Hot Metal Time

1. Have a heat resistant work surface and gloves, molten metal will eat your face/skin right off (Like the Honey Badger (Honey Badger doesn't give shit)
2. Your mold needs to be hot, a cold mold will cause the molten metal to setup too fast and your pour won't fill in all the detail.
3. Once you mold is hot if you are having miscasts then you might need to cut vents see photo above.

4lb capacity melting pot, ladle, and pewter ingot