Resin Casting, First Attempt.

[StevenGuthmiller]

I decided it was high time I started doing a little parts casting being as I continue to build old annual kits with no interior detail. Pretty simple operation actually. I started out by casting a couple of window cranks from a '59 Chevy kit. Now I just need to put together a mold so I can cast a whole set at a time, & I'll be in business. Now I'll be set for small detail parts like window cranks, door handles, wipers & possibly some outside mirrors if I can get a molding system that works well for them.

Anyway, I'm happy with my first attempt.

Steve

[atomicholiday]

Pretty cool! I was just looking at a casting kit in Hobby Lobby yersterday.

How do you make the molds?

[rsxse240]

casting parts so as to have exact duplicates or multiple pieces of exact detail is an essential part of custom modeling. I've been casting parts of my own for years now. In fact, it's actually almost as addicting as building and customizing models. I find myself, at times, making molds of parts that I don't have any intention of using right away so I can later cut them up and use them as parts for other builds.

Simple castings such as window cranks and door handles, I find, are more difficult to cast because you need to be so much more precise in measuring out your resin since you're mixing such small quantities. To alleviate that, I tend to make tons of extra parts all at once and either give, trade or sell the extra parts and get more resin.

The Alumilite kit at hobby lobby is a great starter as it is readily available but don't get your hopes up for the longevity of the molds, it shrinks rapidly and your parts will distort and not fit after a short while.

I have been using SmoothOn brand silicone and resin for some time and have some molds that are several years old and still cast as good as they did new.

Edited March 29, 2015 by rsxse240

[Roadrunner]

Nice going, Steve. They look great. I'm considering casting up some clear 70 Challenger headlights as replacements on future Challenger kits I'll be doing.

[StevenGuthmiller]

Pretty cool! I was just looking at a casting kit in Hobby Lobby yersterday.

How do you make the molds?

The kit has all the materials you need to make the molds. As far as the cranks themselves, I just cut a couple off of a Revell '59 Impala kit & used them for making the mold. Now, I just need to cast a whole set so I can use them to make a mold so I can cast a set of six at a time.

Steve

[vintagercr]

Steve, nice work!

[StevenGuthmiller]

casting parts so as to have exact duplicates or multiple pieces of exact detail is an essential part of custom modeling. I've been casting parts of my own for years now. In fact, it's actually almost as addicting as building and customizing models. I find myself, at times, making molds of parts that I don't have any intention of using right away so I can later cut them up and use them as parts for other builds.

Simple castings such as window cranks and door handles, I find, are more difficult to cast because you need to be so much more precise in measuring out your resin since you're mixing such small quantities. To alleviate that, I tend to make tons of extra parts all at once and either give, trade or sell the extra parts and get more resin.

The Alumilite kit at hobby lobby is a great starter as it is readily available but don't get your hopes up for the longevity of the molds, it shrinks rapidly and your parts will distort and not fit after a short while.

I have been using SmoothOn brand silicone and resin for some time and have some molds that are several years old and still cast as good as they did new.

I'll most likely not get into casting a lot of parts Ken. But there are a few parts that I find to be lacking in availability to the "factory stock" modeler like me. Parts that I find myself "raiding" from other kits constantly. Parts that I need for almost every build, like mirrors, are my main objective. Measuring small amounts of resin has not been an issue for me yet. Making a small mold, on the other hand is diffucult as the silicon molds require a 10 to 1 material ratio.

I had another member tell me he's used the Hobby Lobby "mini-kit" for many years & has molds that are years old & still work well. I'm guessing the molds for most of the tiny parts I'll be casting should hold up for a while. If not, I'm saving my original parts so I can make new molds down the road.

Steve

Edited March 29, 2015 by StevenGuthmiller

[Harry P.]

Steve, those cranks look great.

[MGL]

I was thinking about casting a few parts for myself and was wondering if putting a sander (like a mouse sander, not a da) against the mold right after pouring the resin would help the resin settle into the mold and reduce air bubbles. I have cast small cement pieces in the past and this works well for that but maybe resin sets up to fast?

[DumpyDan]

Nice work, look really good

[disabled modeler]

They look good to me Steve... . Been wanting to cast some stuff myself someday but need to learn how to do bigger parts...bodies,hoods,etc. I have made small item before with use-able results but did not use resin.

[Kit Basher]

Steve, I understand the problem of mixing small quantities of Alumilite rubber. If the kit you are using has the "2 oz. rubber, 1 scoop catalyst" method, it works well, but that can be too much rubber for small molds. I have had some success using 1 oz. rubber and eyeballing 1/2 scoop catalyst. Two oz. of rubber will make a mold about 2" x 3" x 3/8"-1/2" thick. If you can find enough parts to fill that area, or have more than one mold ready to pour at one time, you can avoid wasting too much rubber.

I agree with Ken that casting can be addictive. I often copy parts from one kit to use on another model. That way the donor kit is still complete. Or I may make multiples of parts that kits should have but don't. The current example is brake drums for 60-70s American cars. Hope that is helpful, have fun!

[StevenGuthmiller]

I was thinking about casting a few parts for myself and was wondering if putting a sander (like a mouse sander, not a da) against the mold right after pouring the resin would help the resin settle into the mold and reduce air bubbles. I have cast small cement pieces in the past and this works well for that but maybe resin sets up to fast?

You have to work pretty fast Mark. With these very small pieces, air bubbles weren't too much of an issue. I could just sort of "pick" the bubbles out with the tip of a toothpick while the resin is still liquid. While I was doing that on one casting, the resin had already set up in the cup!

Steve

[StevenGuthmiller]

Well, at least I have a set now for my '59 Bonneville project.

Steve

[krow113]

Parts are looking good!

If you get more into the casting thing try and find a vacuum pump if possible.

I used one from my neon manufacturing days to make this for our IPMS club's use. That and an old pressure cooker work great for small runs:

This opens up the opportunity to upgrade the whole works , as it will allow the vacuuming of air from the mould silicone prior to pouring , the resin prior to pouring and the final pour in the mould as well. The window allows viewing the de-guassing of all the materials involved.

[robertw]

You've picked some excellent and very much needed items to cast. Many of us build those old flat interior door kits and its surprising the number of kits that don't have exterior mirrors. I'm always scrounging for these kinds of items.

[Bob Ellis]

Don't you need vacuum for the mold and pressure for the curing of the resin?

[krow113]

Don't you need vacuum for the mold and pressure for the curing of the resin?

If ya look at the top of the pressure cooker , you will see a DeVilbis air valve. I found that after vacuuming the poured resin, I can open that and air rushing in creates the pressure needed to push resin into the mould. A benefit I found out by accident!

Vacuum is a cool 'condition' , you would be surprised how much air will come out of a glass of water!

Edited March 30, 2015 by krow113

[StevenGuthmiller]

If ya look at the top of the pressure cooker , you will see a DeVilbis air valve. I found that after vacuuming the poured resin, I can open that and air rushing in creates the pressure needed to push resin into the mould. A benefit I found out by accident!

Vacuum is a cool 'condition' , you would be surprised how much air will come out of a glass of water!

Thanks Steve, but I'll mostly be casting very small Items. I don't do a lot of custom building/ parts swapping, etc. on my stuff. I'm mostly into stock builds. The only reason I decided to try it at all was because it's very hard to find some of these simple parts that I mentioned for that type of build. I have a feeling I'll probably never go any larger than possibly a set of wheels or the like. I really don't have much of an interest in resin casting as a hobby in itself & absolutely do not need anymore expense when it comes to building. I'm mostly trying it out of necessity because I know of nowhere else to obtain these simple resin parts. But thank you for your suggestions.

Steve

[Snake45]

For parts as small as those in the OP, and even a bit bigger, you don't even need any expensive, complicated "resin casting" stuff. You can make molds from common silicone caulk (I like the Permatex brand, but have also used GE Silicone II), and fill them with inexpensive J-B Weld or 12 or 24 hour epoxy. If the part isn't too thick, you can even "cast" it from carpenter's yellow wood glue (the sandable kind).

[BirdWatcher]

I can't believe the first time i tried to cast was using the foil method. I should have had some practice using molds and casting resin before i tried foil casting, but it pushed me to evolve. Casting your own parts is fun!

[StevenGuthmiller]

For parts as small as those in the OP, and even a bit bigger, you don't even need any expensive, complicated "resin casting" stuff. You can make molds from common silicone caulk (I like the Permatex brand, but have also used GE Silicone II), and fill them with inexpensive J-B Weld or 12 or 24 hour epoxy. If the part isn't too thick, you can even "cast" it from carpenter's yellow wood glue (the sandable kind).

That was my original intention when I went Hobby Lobby. I was going to just get some modeling clay or something & just try casting these small parts using Testors window maker or something. When I started looking at the resin kits, I thought, if I make some "good" molds that will last a while, I could just quickly cast them as I needed them. That was my motivation for buying the kit, & aside from needing to purchase more mold making material of some sort, I have enough resin with the kit to make 50 sets of window cranks.

Steve

[gtx6970]

To make copies of something thats say,, less than an 1/8" long and MAYBE .010 to 020" thick ,,whats a good material to use.

many years ago I tried the deglued BMF trick , then fill the mold with baking soda and super glue,,it didnt work out so well

Its the 3 little star emlbems on the side of the club de mer I want to copy.

I was thinking of pulling a mold off them with home depot silicone ,,anything I need to do to the body first to insure the silicone comesoff cleanly,,yet not effect paint coats later on ?

[krow113]

To make copies of something thats say,, less than an 1/8" long and MAYBE .010 to 020" thick ,,whats a good material to use.

many years ago I tried the deglued BMF trick , then fill the mold with baking soda and super glue,,it didnt work out so well

Its the 3 little star emlbems on the side of the club de mer I want to copy.

I was thinking of pulling a mold off them with home depot silicone ,,anything I need to do to the body first to insure the silicone comesoff cleanly,,yet not effect paint coats later on ?

Always taking a chance putting silicone and plastic together when painting will be done. Not something I would recommend.

You could use Parafilm between the two ,stretched tight over the emblems. Or a mould release agent , usually sprayed on. Try the film and press clay on the emblems, then use the clay form to cast your emblems. Many ways to get to the desired result.

Yaya there is no pressing need to fully equip a casting scenario , 'push moulds' as described here will work for the single sided window cranks desired.

I found that after some simple casting excursions I wanted more!

Edited March 31, 2015 by krow113

[Foxer]

For parts as small as those in the OP, and even a bit bigger, you don't even need any expensive, complicated "resin casting" stuff. You can make molds from common silicone caulk (I like the Permatex brand, but have also used GE Silicone II), and fill them with inexpensive J-B Weld or 12 or 24 hour epoxy. If the part isn't too thick, you can even "cast" it from carpenter's yellow wood glue (the sandable kind).

I have some two-part RTV silicone molding compound that has lasted 20 years and makes great small molds like we're talking about. I needed door handles for a van build and just filled the molds with melted sprue ... sprue I left in a jar of Ambroid. I also cast the GMC logo off the grill to use on the rear door.

My latest material for these small jobs is Bondic light cured plastic This has worked better than expected .. it's fast and simple and yields a part a good as resin. The clear part in middle is Bondic. White one is the original part.

Edited March 31, 2015 by Foxer