How to scratchbuild a crate of bottles?

Another moldmaking material is cheap and available at any hardware store. Clear silicone caulk (must be 100% silicone) can be used to make a decent mold. There are some tricks to it and it needs some getting used to, but it works in a pinch or on a budget.

Silicones bond to glass and sand (same base ingredient - silica), so if you are molding a glass object, seal it first with a coat of crystal clear acrylic spray. You can use a spray mold release as long as it's not silicone based on top of the crystal clear.

Silicone caulk needs air/moisture to cure, so it can't just be poured in a big thickness and expected to set. Since it is a condensation cure elastomer, you can force it to set in almost any thickness if you stir water into it. I use water based paints to activate it in thick layers since i can see when it's stirred through. You need VERY LITTLE water or paint. It should still be translucent when you're done mixing it.

I suggest that you always do a couple of test runs before you commit to a new technique or material, so please practice on something that is made of the same material as your intended model, but something that won't matter if you mess it up.

Mix a small batch and use a disposable brush to carefully (and quickly) get the silicone into all of the details. Keep it thin at this point. Quickly add more silicone/paint mixture to add thickness. You can let the silicone set up and add more layers until you have the thickness you want. The silicone will set in very thick sections since you've added moisture to it.

Let it cure for 24 hours before you open it. Use a spray mold release whenever you cast into this mold.

Doug

This information is given in good faith and no warranty is expressed or implied. Please take appropriate safety precautions.

i've done this a couple times and used clear sprue, stretched it a little bit (to make short stubby bottles like Mickey's) but instead of shaping then cutting it off the rest of the sprue, i just shaped it then pressed it into some sculpey a couple times to make a mold. the short stubby shape almost completely eliminates the problem of getting the resin to fill the mold. after casting what i needed i used a butter knife (a bad one, not one of my moms) and a propane torch to make the lip on the ends of the necks. if the resin you use is clear use a mixture of tamiya clear paints to color the bottles. hopefully this will help out someone out there. it took me a few tries to get the resin all the way into the mold but once i had it figured out i was good to go. Tip: tip the molds at about a 45 degree angle when first pouring the resin in, pour it in veeeeerrrrrrrrrrryyyyyyy slowly and you should be good to go.

Thanks, srspicer! I'll be looking for the Knead-a-mold to try that method.   I appreciate the tip!

Hello senojrn,

 There is an easier way to rubber mold those bottles for the next time. There is a product called 'knead-a-mold'.

 It is an RTV that is two parts, mixed together like epoxy puddy. NO pressure equipment needed. Knead the material together and insert your bottle so the base is the only thing showing. You may get some air bubbles, but you will at least have a good starting point for you bottles. Also, the dremel lathe is best if you do not have a real lathe.

I actually lucked out and found a somewhat easy way to make crates and bottles for relatively cheap.  I bought some 1:24 scale Coca-Cola bottles in crates on eBay.  I disassembled the crates and removed the bottles.  The Coke crates were 6x4, and I was needing 3x4, so I cut the crates down and scratchbuilt/reassembled the crates the new size.  The bottles themselves were a little chunky, so I did use my drill and a sliver of sand paper to neck down the bottles. 

1:24 scale bottles are a little too small for wine bottles, but they worked for what I needed! 

Thanks to everyone for the tips, hints and ideas!

depending on the scale you're working in, you could chock some sprue of the appropriate length into a power drill, then duct tape the trigget down to keep it running. get some sand paper of various grades and just sand the sprue down tothe shape/style you want! then just paint it. im shure that not all the bottles would be all identical, so if you're going for accuracy,...just an idea. sam

ski4jeepin wrote:

Hey Nate,      I've got some RTV you're more than welcome to. If you want to have a go at it, give me a call, I'll be on cell phone today. I've also got some other molding media that might work for your bottles. Even if it doesn't work you can still have some fun trying at someone else's expense!

Thanks, Ski...I gotta work a 48 (Tues/Wed), but I'll catch ya after that.  Talk to you then!

I forgot one thing.  The alumalite kit has good RTV but the resin lacks somthing.  I still buy Their RTV but I look to others for Resin.

Grizz

Hey Nate,

     I've got some RTV you're more than welcome to. If you want to have a go at it, give me a call, I'll be on cell phone today. I've also got some other molding media that might work for your bottles. Even if it doesn't work you can still have some fun trying at someone else's expense!

HeavyArty and Grizz...thanks A LOT for the info, I really appreciate it!! 

Sorry it took me so long to get back.  Heavy Art is right it is not that hard or costly, unless you don't have an air compressor.  All I did was buy a pressure pot form Harbor Frieght, if you wait they have them on sale for US $40 to 50.  I got a couple of fittings one to plug a hole one to release air and one that has a valve stem that was treaded to put air in.  Pressure Casting is different than Vacum casting.  I went with pressure because I thought it might be easier, I know it was easier to get set up.  I want to post some pictures sometime in the next week to show my set up.  As I said before you do need an aircompressor.  I don't think a hobby one would do.  I use around 50 Psi in the paint pot (the one I got came with a pressure gauge which is nice). 

What I do is fill up an air caddy at the barn and then use it to pressurize the pot.  You do all the same things that you would do with regular casting.  Use a mold box etc..  The only thing I have found that is different is hollow pieces (I wasted some RTV learning this).  I put the mold in the bottom.  If you have a paint pot it most likely will have a rounded bottom.  I just used a pastice sign that I cut out to fit in the bottom to make it flat.  Then sercure the lid.  Then fill with air using the valve stem and air caddy (it's just like on a car).  I leave it over night under pressure.  When using the resin I leave it under pressure for a couple of hours.  Actually I leave a little resin in the mixing cup and when it is good and hard I let the air out.  I am not very fast so I got a resin that has a longer pot life.  I got some off the internet but Micro Mark has some with like a 7 or 15 min pot life.  It will make the process go slower but I like the longer working time and I usually go and do somthing else while it is curing. 

REMEMBER:  This process uses some high pressure and could lead to some severe damage to people, pets, or your house.  The paint pot I got states not to use more than 80 psi. that's one reason I only use 50 psi (and the air caddy I use is twice the size of the paint pot so when I fill it to 100 psi I get 5 to 6 fills on it).

I hope this answers some of you questions.  If you want to look at a paint pot got to

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93119

this is the one I have.  I most also say I got the info for doing this off of another web site (don't ask me where I don't remember)

Grizz

I am still VERY MUCH interested in pressure casting...what type of equipment is required?

It really isn't that much different.  Basically, you need some type of pressure vessel.  Some people use a converted pressure cooker pot.  You can also use an old paint pot from a spray gun system.  All you do is pour the mold, then place it in the pressure pot and pressurize it, forcing the resin into all the nooks and crannies of the mold.

Good luck.

I have the Alumilite starter kit already, but just waiting to get a little more info before starting to mix and pour. 

 

Heavy Arty, thanks for the link to the previous thread on casting...that will help a bunch!  It has already.

 

I am still VERY MUCH interested in pressure casting...what type of equipment is required? 

The best mold material is RTV rubber.  It hardens enough to hold the details and is still soft and pliable enough to bend and pop out the cast items.  It comes in two parts that are mixed together and cures in about 4-6 hours. 

Also, two-part casting resin is preferred.  Hot glue is not a good material since it is so thick and has a high surface tension, plus the heat. 

You can get a starter set of RTV rubber and casting resin at Hobby Lobby by Alumalite for about $30.  The Alumalite resin is a cream color though, not clear, so you will have to get some clear casting resin for the bottles.  You can also tint the clear with green food color to make tinted bottles as well.  Or you can just paint the cream bottles as you want them.

Check out this tread for more info on making molds and casting resin parts.

Using the RTV and resin isn't hard once you try it out.  It gives great results too.  I have been casting parts for years.  As I said above though, for thin/small parts, pressure casting is needed to get complete castings w/o air bubbles.

Grizz, I'd like to know how to do some pressure casting--what all is involved?  Does it require a large $ piece of equipment? 

Thanks for the good ideas--I've used hot glue before to make a bottle and formed it around a straight pin.  It was a very slow process (about an hour) to make one (successful) bottle--most of the time was trial and a LOT of error.  But I am making about 100 bottles for this project. 

I've tried to make a mold of the injection molded plastic kit bottles I currently have and then inject hot glue into the mold.  I tried Poster Putty (aka Sticky-Tack), modeling clay, Play-Doh and Silly Putty.  But all these melt when the hot glue hits them.  Any suggestions for a substance that is pliable enough to make a mold, but then hardens to be able to withstand the temperature of the hot glue???  (I have also tried plaster and drywall compound, but they took a week to dry, and when they did dry, either: 1) the mold had to be broken away from the master thereby ruining it, or 2) the mold warped and cracked and did not produce a good mold. AAAAARRRRGGGGHHH!!!) 

So all that to say, any more thoughts on mass producing bottles?  Thanks again. 

If you take some sprue, heat it and stretch you are well on the way to making a nice Burgundy bottle. If you heat up the thin end it will ball back and you can make the lip. You can also tidy it up by putting it in a drill press and gently sanding it to the shape you want (poor man's lathe). One you get the shape you want,  cast away with a tinted clear resin. If you want it to go more quickly do as is suggested above and make half a dozen. Don't forget that the bases of wine bottles are often hollowed out.

I wonder if you might consider using something like sculpey, or some other modeling clay to create the bottles.

Here's another option: what if you were to create a master out of a hard substance, and then use that to cast a mold (better yet, more than one). You could then use that mold to create bottle halves that could then be glued togther and sanded.

I don't know if that might work for you. 

I have done really fine detail with pressure casting.  I am considering doing a little tutorial about how I do it. 

The other thing it is to make some "good" crates (open with the bottles) and then some "ok" ones like having a lid on it and cover the "ok" ones with the "good" ones.

I thing I am using to many quotes.

Grizz

Hi Senojrn,

I feel for ya, my measuring skills lack the precision to do something that small and inticate, and it would take me about 5 hours to figure that out as well.

Let me take a look in my LHS after work today. I seem to recall a selection of styrene that had a sort of honeycomb style to it, not quite. I remember thinking, "now what the heck could that be used for?". I'll let you know what I find out. Any reason to go to the hobby shop is a good reason.

As far as a wealth of bottles, I don't know how you plan to make 'em. If everyone on the scratchbuilding forum kicked in $5, we could buy a lathe and go the time-share route. But you could make a few good ones out of styrene rod and then cast them. 

Steve

 

 

Sounds like you are on the right path with the crates.  It just takes time to get all the pieces and angles right.  Sorry, no special trick to it.  You could try making a jig for the sizes to cut.  That may help.

You could make a mold of it when you get it right, the bottles too.  The RVT will hold the fine detail without problem.  The issue comes when pouring the resin into them.  For molds with small, thin parts, it is hard to get all the air out and the thick resin in.  To do it effectively, you have to use a pressure chamber to force the resin into the molds. 

Good luck.