# casting of parts



## NTCGRR (Jan 2, 2008)

Yea, its me again.
After reading all of Master Burl's writings I stepped out on my own.









I'm shaing the photos but its best to read the articals in GRYs he wrote.









I had to use one of his as my masters and filled in some spots to make it easier to remove from the mold.
I broke it but later glued it.









the "pour"










The little one is a 100 ton hopper brake wheel which failed. I was tring to make them for Leons project.









I tried to pour slow to let bubbles out but I am still missing a part.


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## wildbill001 (Feb 28, 2008)

I'm no expert by any stretch of the imagination so take this for what it is worth: Maybe add some "vent" holes.

When the big boys are casting alum and such they will add vent holes, small channels that lead from casting to the outside of the mold, to allow gases to escape. Don't see why the same principle wouldn't work here. I'd use some 1/16" wire to make the holes.

Bill


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## rkapuaala (Jan 3, 2008)

Bill, 
Venting is the best suggestion. In addition, don't clamp like that. I prefer something lighter like rubberbands. The heavy clamps tend to distort the part. When you use the rubber bands on the backer, they distribute the pressure better. Also, you don't need a lot of pressure to keep the mold together, so don't double wrap the bands unless the mold is too thin for them to add pressure. Too much pressure will also close smaller vents.


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## NTCGRR (Jan 2, 2008)

Thanks 
I did not have any rubber bands , will go to town tomorrow to get my "forgotten items" 
my 3rd one I must have taken out too fast, its sad.... 
I even tried working on something else because I don't have patience. I don't like watching corn grow. hehehe 
My first mold was a hard one. I'm tring two windows now. photos later. 

I had to order more rubber just now. woow that stuff goes fast.


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## Jerry Barnes (Jan 2, 2008)

I use Smooth-on products Marty, just ordered some more. What are you using? Got a 1/16" thick 4x8 through Syl's old sign supplier, came from Regal Plastics in Nebraska. $45 with shipping.


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## Jerry Barnes (Jan 2, 2008)

Marty, use a syringe(I got one from my dentist) has a slightly curved plastic tip. That way you can jam it down inside and squirt the resin in the bottom some, so it wells back out the top. Then have a thin wire right there to poke down inside quickly to release any air bubbles. Works for me. I usually have carved an air vent also(the sprue on plastic kits is an air vent).


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## ConrailRay (Jan 2, 2008)

Hey Marty, 

Casting a brake wheel might be pretty hard without the correct vents and a pressure pot. You might be able to get away with a sort of open face mold of the brake wheel. Not really fully open face, but open enough where the rubber would still create the backside of the curved parts, but have a slight slit (as the open part) so that you can drag around a tooth pick to get the resin around and get bubbles out. Dont forget that the rubber is usually flexible enough to do tricks like this where the rubber mold slightly wraps around your part, but the part can still pop out ok. 



-Ray


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## ConrailRay (Jan 2, 2008)

Marty, 

Here's a drawing of how you might be able to fix the other mold the the trailer part: 









http://1stclass.mylargescale.com/conrailray/mold_pour.jpg You can use a sharp exacto knife to cut in some vents and such. In both phots, the blue line is a vent you must have. You can see the that part the trailer rests on, which is on the bottom of the mold, is already naturally slanted up and to the right, which is why you ended up with air trapped there as the air moved through the resin. So the left photo shows this cut, and you can pour the resin down only where the green arrow is. The air bubles should flow through the resin and up and out. Dont be afraid to use some vibration to get the b moving! 

Ideally, you may want to try the right photo. Pouring the resin down this new path should force almost all the air out, so you dont have to rely on the air bubles going throught the resin as much. If that bottom part were level, this would also be the way to go as you would probably have trapped air on both sides. 

-Ray


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## cudak888 (Mar 22, 2008)

Posted By ConrailRay on 12/21/2008 9:57 PM

Ideally, you may want to try the right photo. 



Your image was coming up as a link. Here it is:










-Kurt 

*EDIT: That didn't work, did it...?*


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## NTCGRR (Jan 2, 2008)

This one is called an OPPSSSS









I think I took it out too soon and forgot to shake the darker colored stuff before I mixed it.









I use styrene as forms then cut it away.


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## Jerry Barnes (Jan 2, 2008)

I think you are better off to STIR the resin than shake it. Don't be like James Bond! LEss air bubbles, I think.


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## NTCGRR (Jan 2, 2008)

I thought that at first, I don't shake the thick clear stuff, I now shake the thin dark stuff and very little if any bubbles stay in. This last pour I poured it in the thinner other side and it worked great. I am taking notes as I go and amounts per each item so i don't waste so much. 
I need to take a brake and get the end of my side dump car built so I can cast it. Hopefully many parts on it will be cast. I hope for 4 sidedumps to go with my section crew train.


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## rkapuaala (Jan 3, 2008)

Do not shake, stir. Also, if you make a mold that is all wrong, reuse it as filler on your next mold. That saves on rubber (rtv). Cut the old mold into tiny pieces with a pair of scissors. put no more than 3/4 of it in the new mold and that way you only use a 1/4 of the material. 
If you don't have a vacuum chamber to do this, you will have to do it slowly and in layers of cut material followed by the rtv. 
By the way, what is the gel time on your resin? 
Normally its 2 to 3 minutes. 
I set a timer for my castings, and to keep myself from getting antsy and pulling the part out before it hardens, I do other tasks like, clean up, sitting up another mold or working on another model. I let my castings set for at a minimum of 20 minutes on a warm day and 45 when it gets 60 F in my garage.


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## Jerry Barnes (Jan 2, 2008)

Larry Hergert sent me some pix of some cars he made. Molded each side and end piece and cast them. Then put them together. Worked out pretty good. Course he really knows his stuff!


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## rkapuaala (Jan 3, 2008)

Thats a cab I did with 6 molds and 11 parts.


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## NTCGRR (Jan 2, 2008)

good tip on RTV, I need to dig out the trash can now.


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## Kovacjr (Jan 2, 2008)

Hey Rich...A resin cab huh, I guess its not for your Ruby your workign on?? Looks like it should fit a similar loco though....How did you make the master for that?


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## rkapuaala (Jan 3, 2008)

Jason, 
No, not for the Ruby, it was for my 2 electric 4-4-0s. The master was made from styrene and wood veneers, and even a little clay here and there


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## NTCGRR (Jan 2, 2008)

JJ asked me to share more info and photos , so later I will up date some of the things I'm learning. 
Here is what I bought,
http://www.alumilite.com/ProdDetail.cfm?Category=Starter%20Kits&Name=Super%20Casting%20Kit
Keep in mind alot of folks have given me ideas over the years.








I cut the bases off very carefully.


I bought a new drawer thingy to store my molds and some parts.
I'm now doing easy stuff .












the chunks in the cup is to push in around the edges to raise the level around the people.

I buy these after Christmas people and repaint them , very reasonable prices.









The wire holds them down and in the center.
I'm casting them in rubber so I can have half people for the seats of my passenger cars.
Tomorrow morning I will be casting people. And yes I still have to paint them.


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## NTCGRR (Jan 2, 2008)

Last night I was working on my Duffus side dump car and today cast couple of the end panels. I'm waiting for more rubber to come in.









Also when I do a new pour and don't want to waste the extra have a small air tank or something to cast .


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## Jerry Barnes (Jan 2, 2008)

Marty, this morning I saw that Hobby Lobby now has casting materials, even the metal stuff. Plastic also and silicone molds and NO shipping! Might check it out. Jerry


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## wildbill001 (Feb 28, 2008)

Mine has it too.... Might ought to call it "AlumaGold" for what it is priced









Bill


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## Nicholas Savatgy (Dec 17, 2008)

Marty, great job with the casting but you might not want to show some of that stuff like the kadee boxs or the lexmark figures you molded,in this age of sue happy companys, you might get sued for coping there stuff....... just trying to help....
Nick...


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## NTCGRR (Jan 2, 2008)

Thanks Nick, noted. took awhile to figure out how to remove a photo in edit.


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## rwalker (May 22, 2008)

Just because you cast them, it doesn't make you liable. Trying to SELL said copies as your own is another matter. I've been casting parts for years to make multiples for large projects . Also if you'd like to refine your molding, here's my web pages on casting: 
http://fp1.antelecom.net/animeasy/casting1.htm


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## NTCGRR (Jan 2, 2008)

Posted By rwalker on 01/01/2009 9:58 AM
Just because you cast them, it doesn't make you liable. Trying to SELL said copies as your own is another matter. I've been casting parts for years to make multiples for large projects . Also if you'd like to refine your molding, here's my web pages on casting: 
http://fp1.antelecom.net/animeasy/casting1.htm

Thanks
http://fp1.antelecom.net/animeasy/casting1.htm
this should work.

Its getting past spending the $60 start up.
[But I found some wheel holders I tried making long time ago and gave up. today i have enough for my LGB 53' flat MOW car








 Max says HI..
I tell you, I love it.


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## Guest (Jan 1, 2009)

Marty,

I can't believe that you were hold up in the shop all day making train castings instead of watching the Huskers play in the Gator Bowl. What kind of Nebraskan are you anyway?









Ed


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## leonpete (Jan 4, 2008)

And Nebraska WON also!!


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## silverstatespecialties (Jan 2, 2008)

Marty, you can easily make a pressure pot to place the casting in after you pour it, to help remove the air bubbles. I just use paint pots (widely available on eBay & online) and pressurize to 35-45psi. I KNOW you HAVE to have an air compressor, so a modified paint pot should be a snap for you. It will help remove the air bubbles from your castings. After you pour resin in the mold, just put it in the pressure pot, secure the lid, and pressurize away. I have the best results around 35psi. It even works with some RTV/silicones. 

When you have your mold halves apart, look at each half and visualize that as the resin goes in, how will the air be displaced? Visualize the trapped air rising to escape the mold, and that should tell you where to cut/place your air vents. 

Keep up the good work & post your results please!!!


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## NTCGRR (Jan 2, 2008)

Thanks Warren 
But I have not really had problems, I allow it to flow into areas then fill up. I have done the wire thing someone said and popped the few bubbles before it set. 
I have black resin coming tomorrow. My next order of rubber will be PINK stuff. man this yellow stuff brakes easy. 
I missed that part in the Masters articals. 
I'm almost out of ides. I want to finish the side dump car and see how it fits together. 
cut the last tree down today . So now none of them hit each other in the wind and brake off sticks.


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## Burl (Jan 2, 2008)

Didn't someone make figurines of you & JJ? THAT's what you need to mold. 

Remember a few years ago in China when the archaeologists started digging up hundreds of clay soldiers? I've probably said too much...


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## NTCGRR (Jan 2, 2008)

Master 
Yes Chris Wallas made them and I keep it under lock and key with my one other valuable. I am very greatful for it.


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## NTCGRR (Jan 2, 2008)

Came home from work early today becuase of icy rain starting. so









My side dump car is coming together.
need to get the bottom figured out but.
This is FUN...


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## Jerry Barnes (Jan 2, 2008)

Yeah the making and figuring out how to do it is great fun.


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## Rod Fearnley (Jan 2, 2008)

I'm following this thread with great interest "Young" Marty. I'm not sure where to buy these kind of materials over here yet? But I'm beginning to feel the urge to cast and build.

HNY to you and Carrie
Rod


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## NTCGRR (Jan 2, 2008)

I did not get my corners right, but then I also needed a place to glue to. I bought black resin this time but its hard to see how its dring. 
These big mold s I had to practice before I poured to know where to lift to let the bubbles out of the lower side. 
I need to get going on my centerbeam ends becuase I know some are waiting for that. 
I will show a finished flat with wheels and I finally finished some other cars that I started but ran out of winter. 

Hers an up date.
I need to change out the cylinders because they are too small and I ususlly finish all the ends at the same time.








Once I place a washer under the car, the coupler will be right.









the molds.

heres the wheel car










73' bulkheads CSXT need weathering yet


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## NTCGRR (Jan 2, 2008)

I still have a lot to learn yet, the cars need decals and weathering.


















live and learn.


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## aceinspp (Jan 2, 2008)

Looking good Marty. You keep it up and you can quit your day job and start production of cars







. Later RJD


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## Santafe 2343 (Jan 2, 2008)

*Marty,*
* You have too much time on your hands. You need to get a job. Are you ever in the house relaxing ?







*
* They look great, are you going to make them operate ?







Remimber your quote, Is it real or 1/29th Thanks Rex*


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## John J (Dec 29, 2007)

Posted By NTCGRR on 01/02/2009 5:54 AM
Master 
Yes Chris Wallas made them and I keep it under lock and key with my one other valuable. I am very grateful for it.
I got a Mimie Me from Chris by way of Stan Ceaderleaf.

I also got a train car from Chris 

These are two of my most prized possessions 











I come unglued.


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## aceinspp (Jan 2, 2008)

He may have to change that qote







HeHe. Later RJD


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## NTCGRR (Jan 2, 2008)

Rex
This is how I get through the long winter dark nights. keeps me from being depressed.
This is also building up confidence so I can build Rex car I owe him, I owe Nick one, now I owe Kevin one.
I'm a slave to ya all!!!

Guys if I can do this so can you.
Its not that I'm tring to get "up" to Burls level, its that we are all in different pieces of the same pie.
There is NO levels.


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## wchasr (Jan 2, 2008)

Posted By NTCGRR on 01/06/2009 6:47 PM
Rex
This is how I get through the long winter dark nights. keeps me from being depressed.
This is also building up confidence so I can build Rex car I owe him, I owe Nick one, now I owe Kevin one.
I'm a slave to ya all!!!

Guys if I can do this so can you.
Its not that I'm tring to get "up" to Burls level, its that we are all in different pieces of the same pie.
There is NO levels.


Marty just a comment and slight correction.

Love the new adventure and someday I'll try it. Maybe sooner than later. 

As far as being level. There is but ONE level. We are all on it. Or rather we are ALL on the level. Sorry oblique Masonic reference. 

Seriously great work!

Chas


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## Matt Vogt (Jan 2, 2008)

Marty, 
Thanks for the thread - very helpful! Have you ever tried casting trucks? I have tried several times, and gotten close, but no cigar. I have always ended up with voids. I'll have to take another look at my vents. 

Matt


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## pimanjc (Jan 2, 2008)

Marty,
My observation is that most of your scratch built cars are non-production items so they are very special. That said, how do they compare to "store-bought" cars pricewise. On your side dump cars have you figured out what your second car materials cost would be?

JimC.


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## Kovacjr (Jan 2, 2008)

Looks really neat. Question on the mold, do you just pour into the mold and let it level itself or do you have a 2 part mold?


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## NTCGRR (Jan 2, 2008)

Matt have not tried trucks,,yet. 
Jim 
I tried to figure cost per oz $1.65 for 1 oz. 
the material in the cars is low, its the labor and high priced decals, plus trucks and couplers. 
Kitbashing is more costly but better out come over all. 
I build cars you can't get simple because very few folks have them, and I'm alittle different anyways... 
Most of them are simple boxes or flats with ends. 

Jason, so far I just level it. then belt sand it flat.


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## rpc7271 (Jan 2, 2008)

Marty, just what materials are you using and where are you getting it. I've been using OOMOO 25 from Smooth-On.com but that stuff has gotten expensive plus shipping!


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## NTCGRR (Jan 2, 2008)

I'm about to start buying smooth on rubber because this stuff rips too easy on hard molds. I listed it back in the thread where to get it. 

***I knew about this for years, but I let the cost stop me. now after the start up cost I'm off and rolling and making the stuff I have always wanted.
I can make it for others also.****


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## Jerry Barnes (Jan 2, 2008)

I use Smooth on also. Buddy told me that Micro Marks stuff is pretty good also. Seems all this stuff doubled in price in the last year.


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## rpc7271 (Jan 2, 2008)

Ya! The price of the stuff has about doubled plus shipping has almost doubled. To make matters worse, I don't make molds every week so the stuff sits on the shelf. I just threw out about 2/3rds of a gallon because Part A went solid on me! There are a couple of places in California I can order it from them but the shipping is usually the same.


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## yutzk (Jan 2, 2008)

Hey Marty...if ya ever need someone to check anything out on Smooth On, let me know. They are based in Easton, PA, about 20 mins from my place here in Eastern PA. 

Looks like good stuff....i should make an attempt on casting as some point as I have some ideas as well.


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## NTCGRR (Jan 2, 2008)

Kevin 
get your butt over there and ask them for free samples to be tested by a possible buyer. sweet talk them alittle and be sure to save your legs.


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## Guest (Jan 15, 2009)

been casting for 10 years & have used smooth-on & aluminite w/great results...molds made from smooth-on...box car doors..round covered hopper hatches[2 styles] 1/29 people[copies]side frames & lots of detail stuff


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## John J (Dec 29, 2007)

If you were going to cast a truck frames. So you make all the molds of all the parts. You pour the casting What do you use to glue the parts together? Does this casting resien requier a special glue?

Is it stronger than the plastic that the OM people use?

Will you have a stronger truck when your done?


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## John McGuyer (Jan 2, 2008)

When you cast truck frames, be sure to add some metal to the bolsters. We didn't and when I discovered my couplers no longer lined up, I checked and now have bow-sters. 

John


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## Jerry Barnes (Jan 2, 2008)

Larry Hergert(highpressure) sent me this pix of his truck casting setup, pretty neat, putting the bearings right in.


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## cprwatcher (Jan 2, 2008)

That is a great idea... I had to make up a drilling template which is not very accurate... especially when the part is still in the mold... 

Cheers, 

John.


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## Guest (Jan 17, 2009)

free doors ??/ i've got about 18 4-6 & 7 foot wide superior & plug doors that fit arsto that i've cast that are what i call seconds..not good enough for a model but paint em' & use em' for RR scrap...i ask for po$tage


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## silverstatespecialties (Jan 2, 2008)

NICE, Marty, NICE!!!! Thank you for the inspiration!!


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## John J (Dec 29, 2007)

Let me re phrase the question.









Is the casting resen when cured stronger than the plactic that Aristo or USA uses? What glue do you use to put the castings together?


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## Guest (Jan 18, 2009)

CA cement or 2 part epoxy works good- but make sure all the mold release is removed.& on a shinny surface i scuff the piece w/240 grit sandpaper b/4 gluing


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## NTCGRR (Jan 2, 2008)

JJ, I still use my 3M emblem adhesive. these car sides are stiffer feeling than some of my other cars.


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## Scott (Jan 29, 2008)

If you don't have a vaccuum pump, then vibrate the mold with a sander or similar to move the bubbles up and out of the mold. I used it for a recent casting with scultamold. Yeah I know it has slightly different properties, but this should work anyways. Placing the mold onto a piece of flat board helps to get the vibrations thru the mold. Scott


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## m ledley (Jan 18, 2009)

when i saw the article in garden rr mag. a few months ago i could see how that could scare alot of folks away from trying molds/casting...i've been casting 1 piece molds for years w/out a vacum or other devices..take your time, mix slowly , use 2or 3 cups for the mix..pour slowly..follow the manufactures guide line..if i had to have all those extra items i probably wouldn't do it !! i've lotsa fun over the years do'in castings the old fashion way..with excellant results


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## NTCGRR (Jan 2, 2008)

Its all in how you hold your tongue.. 
I to have very few if any bubbles and if I pour into a "cave" I tilt the mold till it fills first then lay it flat and continue. very thin wire helps hard spots.


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## Jerry Barnes (Jan 2, 2008)

CAsting when it's pretty humid can lead to air bubbles, I've found. Otherwise I seldom have any trouble.


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## NTCGRR (Jan 2, 2008)

This is an old thread.
I finally got the side dump cars loads made.









dang cat!!!!!










There we go, that looks better.


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## up9018 (Jan 4, 2008)

Those loads look great Marty 

Chris


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## Paulus (May 31, 2008)

It looked for a moment the cat was the new car load! 
Nice weathered cars. I love the rusty on white look.


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## DTI356 (Jan 3, 2008)

Marty, 

Those do look great. 

I'll bet your whole backyard looks like a kitty litter box to that cat  

Brian


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## Matt Vogt (Jan 2, 2008)

Nicely done, Marty Thanks for posting the end results. 

Matt


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