Gonna dive in and try making my own resin stuff

.

Gonna dive in and try making my own resin stuff

Joined: July 8th, 2005, 12:41 am

March 22nd, 2012, 6:08 pm #1

given that half the stuff I need is now OOP. Questions for those that already do it - what type of vacuum pump and jars do you use to degas your mold rubber? I read great articles about mold making and resin casting...

http://www.b9robotresource.com/molding1.htm
http://www.b9robotresource.com/plastic_casting1.htm

...but wanted a few other opinions.

Also, why do you have to pressurize the mold when you cast your resin? I would have thought that the vacuum technique would remove the resin bubbles the same way they do for mold making.

Last question: I'm going to try to mold a 1/24 tailwheel borrowed from another, finished kit. Will I ruin the paint when I cast the mold?

Thanks folks!

James
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Joined: November 17th, 2006, 1:18 pm

March 22nd, 2012, 6:39 pm #2

Mold release, store bought or home brew (turp and Vasoline), should save the paint job. nt
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Joined: February 27th, 2006, 6:25 pm

March 22nd, 2012, 7:47 pm #3

given that half the stuff I need is now OOP. Questions for those that already do it - what type of vacuum pump and jars do you use to degas your mold rubber? I read great articles about mold making and resin casting...

http://www.b9robotresource.com/molding1.htm
http://www.b9robotresource.com/plastic_casting1.htm

...but wanted a few other opinions.

Also, why do you have to pressurize the mold when you cast your resin? I would have thought that the vacuum technique would remove the resin bubbles the same way they do for mold making.

Last question: I'm going to try to mold a 1/24 tailwheel borrowed from another, finished kit. Will I ruin the paint when I cast the mold?

Thanks folks!

James
For both my vacuum and preasure pots I use modified Siphon paint spraying pots. Sears has them, Harbor freight and Northern tool probably do too.
Both have quick open/shut ball valves with quick connect hose connections. One has a pressure gauge the other a vacuum gauge. I have a 300 gallon capacity air compressure/tank combo for pressure and a small vacuum pump for the vacuum.

All the above cost around $1500.00 You can go cheaper by looking at swap meets,garage sales, pawn shops for some of teh pots, compressor ,hoses etc.

HTH, Mike
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Joined: January 23rd, 2006, 7:52 pm

March 22nd, 2012, 8:40 pm #4

How large a vacuum pump do you need to vacuum casting using a pressure pot for your vacuum chamber?

I am in the process of setting up a paint pot for pressure casting, but would like to be able to do vacuum degassing of clear resin and molds in the future. I see all kinds of vacuum pumps out there but I have no idea what capacity of pump is sufficient to do this type of work in a typical paint pot sized chamber.

What would you recommend?
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Joined: July 8th, 2005, 12:41 am

March 22nd, 2012, 8:57 pm #5

Great question. One of mine too.nt
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Joined: February 27th, 2005, 4:14 am

March 22nd, 2012, 9:12 pm #6

How large a vacuum pump do you need to vacuum casting using a pressure pot for your vacuum chamber?

I am in the process of setting up a paint pot for pressure casting, but would like to be able to do vacuum degassing of clear resin and molds in the future. I see all kinds of vacuum pumps out there but I have no idea what capacity of pump is sufficient to do this type of work in a typical paint pot sized chamber.

What would you recommend?
Airconditioning pump. It's a 6cfm pump. I got mine used from another caster, but it works great. A seller on Amazon has one for $285.

http://www.amazon.com/Robinair-15600-CF ... 364&sr=8-9

You want to be able to move the air out of the pot as fast as possible. It's not such a big deal with rubber which has about a 45 minute pot life, but with resin, unless you want to wait forever for the casting to cure, you're only gonna have about 3-6 minutes to go from mixed to pour. With the 6 cfm pump, I can empty a 2 gallon pot in under a minute. I give the resin 2 minutes in the pot and still have plenty of time to get it in the mold. A slower pump may give you some challenges racing the resin.

Mike
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Joined: January 23rd, 2006, 7:52 pm

March 22nd, 2012, 9:26 pm #7

Do you need to use special non collapsible hose lines and fittings for vacuum work, or just regular airlines and fittings?

I'm wondering if the vacuum will require something special here?
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Joined: April 26th, 2006, 10:40 pm

March 22nd, 2012, 10:53 pm #8

given that half the stuff I need is now OOP. Questions for those that already do it - what type of vacuum pump and jars do you use to degas your mold rubber? I read great articles about mold making and resin casting...

http://www.b9robotresource.com/molding1.htm
http://www.b9robotresource.com/plastic_casting1.htm

...but wanted a few other opinions.

Also, why do you have to pressurize the mold when you cast your resin? I would have thought that the vacuum technique would remove the resin bubbles the same way they do for mold making.

Last question: I'm going to try to mold a 1/24 tailwheel borrowed from another, finished kit. Will I ruin the paint when I cast the mold?

Thanks folks!

James
..for decades I 've gotten by with out all the pumps and things.
In the early 90's I was building 1/24 scale race cars and NO good tires were available except for a set of excellent race rubber in the Fujimi GT-40. When I bought my third kit just to get the tires I figured there had to be a better way. Micro-Mart had the RTV/Resin as a kit so I started with that and have been duplicating my own rubber for years.
I have about 20 race cars with resin tires. Just be careful pouring the resin, tap the mold to get out the trapped bubbles and BaDaBing...

These are my own resin tires on this Heller Lotus49...



And on this......



Poke air bubbles out with tooth pick before it hardens...







A little practice is all it takes, I keep it simple. I had a 1/24 scale Messerschmitt wheel, I needed four...







Plugged into the same race tires as the Lotus for my Volkswaffe...





Start off slow and cheap, a lot can be done very simply.

HTH.....

Thanks,
Allan

Youth, talent, hard work, and enthusiasm are no match for old age and treachery.

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Joined: February 27th, 2006, 6:25 pm

March 22nd, 2012, 11:38 pm #9

How large a vacuum pump do you need to vacuum casting using a pressure pot for your vacuum chamber?

I am in the process of setting up a paint pot for pressure casting, but would like to be able to do vacuum degassing of clear resin and molds in the future. I see all kinds of vacuum pumps out there but I have no idea what capacity of pump is sufficient to do this type of work in a typical paint pot sized chamber.

What would you recommend?
from Grainger Been a while and I no longer have the papers on it. It will pull the gauge down to 25 inches of mercury according to the needle.

Paid $300.00 for mine.
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Joined: February 27th, 2006, 6:25 pm

March 22nd, 2012, 11:41 pm #10

Do you need to use special non collapsible hose lines and fittings for vacuum work, or just regular airlines and fittings?

I'm wondering if the vacuum will require something special here?
I vacuum the rubber down to 25 inch/ merc. close the valve and let the rubber set for 10 minutes. Then open the valve and let them finish over night.

Mike
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