Scratchbuilders!: Armor/AFV
This is a group for armor scratchbuilding questions, topics and projects.
This is a group for armor scratchbuilding questions, topics and projects.
Hosted by Mike Kirchoff
molding question
Abrams101
Member Since: July 18, 2002
entire network: 146 Posts
KitMaker Network: 0 Posts
Posted: Wednesday, July 31, 2002 - 08:39 AM UTC
Alright, I tried using mold builder liquid latex rubber and i poured it over the original and the top layer dried but under that will not it seems that when the top layer dried it created an air tight seal for the rest of it am i not doing somthig right I've looked around the forums and all types of websites but i cant find out how to dry it all evenly. ive tried a hairdryer and putting it under a lightbulb (100 watts) and nothing works HELP ME!!! #:-)
sgtreef
Member Since: March 01, 2002
entire network: 6,043 Posts
KitMaker Network: 1,603 Posts
Posted: Wednesday, July 31, 2002 - 10:42 AM UTC
Okay I use this stuff for making molds of fossils like Dino footprints. You must brush it on in thin coats,or it will not dry correct. When the outside sets up seals the inside and it won't dry. I would try again. But this is not the stuff for mold making. And it is Latex based. as the mold making rubber used is usually Silicon based. But if I remember if you put it in oven low heat,REAL LOW it will set but still will be MUSHY for a long time.
Abrams101
Member Since: July 18, 2002
entire network: 146 Posts
KitMaker Network: 0 Posts
Posted: Wednesday, July 31, 2002 - 04:06 PM UTC
So what exactly am i looking for, to mold prety basic stuff i guess figures ammo whatever
what is the best stuff out there and what exactly is it?
what is the best stuff out there and what exactly is it?
ukgeoff
Member Since: May 03, 2002
entire network: 1,007 Posts
KitMaker Network: 0 Posts
Posted: Wednesday, July 31, 2002 - 04:49 PM UTC
What you really need for making moulds is RTV silicone rubber. You can find some easy to use RTV at Micro-Mark.
http://www.dxmarket.com/micromark/products/82083.html
Latex rubber can be used to make moulds for simple things that have no deep undercuts. You need to build up the mould in thin layers, letting each one dry. Once you have a thick enough rubber layer, you need to fill the mould box with plaster/resin.... on the reverse side.....to support the mould when you start to make castings.
The RTV method is much, much quicker.....although it does tend to cost more.
http://www.dxmarket.com/micromark/products/82083.html
Latex rubber can be used to make moulds for simple things that have no deep undercuts. You need to build up the mould in thin layers, letting each one dry. Once you have a thick enough rubber layer, you need to fill the mould box with plaster/resin.... on the reverse side.....to support the mould when you start to make castings.
The RTV method is much, much quicker.....although it does tend to cost more.
sgtreef
Member Since: March 01, 2002
entire network: 6,043 Posts
KitMaker Network: 1,603 Posts
Posted: Wednesday, July 31, 2002 - 07:34 PM UTC
Quoted Text
So what exactly am i looking for, to mold prety basic stuff i guess figures ammo whatever
what is the best stuff out there and what exactly is it?
Look in phone book for a good hobby shop,they should sell the one made by Alumilite like $30.00 for 14 ozs of the stuff. Easy to use . Also you might try to find a Plastic dealer close by and get some Dow corning stuff $26.00 including harder for a pound of the stuff. But remember shelf life on this stuff is about 6 months after opening and about one year total from date of manufacturing. Hope this helped you
But if you need a couple of quick parts good ole Dow in the tube Silicion will work the same way for a couple of parts have used it in a pinch Look here
http://www.alumilite.com/
or here
http://www.dowcorning.com/FAQ/faq_search.asp?DCWS=Moldmaking&DCWSS=&ind=013&2ndlevel=
pictures are sometimes worth a thousand words
KFMagee
Member Since: January 08, 2002
entire network: 1,586 Posts
KitMaker Network: 302 Posts
Posted: Thursday, August 01, 2002 - 03:38 AM UTC
As many may know, I build profesionally - and therefor cast a LOT of RTV Silicon. I've tried them all, and while alumilite is good, by far the best thing on the market in terms of De-airing (getting rid of bubbles), tear strenght, and length of finished mold comes from Bare Metal Foils.
Unlike Alumilite, which uses a 10:1 ratio of Base to Hardening Catalyst, the BM/RTV is a 1:1 ratio (pink and blue). It sets up in about 3-4 hours, and is very easy to mix. i order the stuff in 16 lb increments (yeah - i use that much!), and it comes out to about $25 for the equivilent amount of alumilate.... about a 20% savings.
Also, unlike alumilite (which IS a fine product) you don't have to be nearly as precise in your ration measurements. Too much hardner with Alumilite and your mold will be overly stiff and hard to work with... use too little, and it will not retain strong mold strenght the longer you use it. With the BM stuff, i find I can just be "close" to 1-1 (visually measured) and get wonderful results.
The final clincher is ordering... i once bought a new Alumilite kit, and spilled my catalyst.... and they wouldn't sell me another tube! I had to go buy a whole additional new kit ($30!) just to get the catalyst. Which meant i still had a tub of base leftover! Over the course of time, I was able to ration out the base, using a 12:1 ratio instead of 10:1, but it was a real pain.
Unlike Alumilite, which uses a 10:1 ratio of Base to Hardening Catalyst, the BM/RTV is a 1:1 ratio (pink and blue). It sets up in about 3-4 hours, and is very easy to mix. i order the stuff in 16 lb increments (yeah - i use that much!), and it comes out to about $25 for the equivilent amount of alumilate.... about a 20% savings.
Also, unlike alumilite (which IS a fine product) you don't have to be nearly as precise in your ration measurements. Too much hardner with Alumilite and your mold will be overly stiff and hard to work with... use too little, and it will not retain strong mold strenght the longer you use it. With the BM stuff, i find I can just be "close" to 1-1 (visually measured) and get wonderful results.
The final clincher is ordering... i once bought a new Alumilite kit, and spilled my catalyst.... and they wouldn't sell me another tube! I had to go buy a whole additional new kit ($30!) just to get the catalyst. Which meant i still had a tub of base leftover! Over the course of time, I was able to ration out the base, using a 12:1 ratio instead of 10:1, but it was a real pain.
sgtreef
Member Since: March 01, 2002
entire network: 6,043 Posts
KitMaker Network: 1,603 Posts
Posted: Thursday, August 01, 2002 - 07:34 PM UTC
Quoted Text
As many may know, I build profesionally - and therefor cast a LOT of RTV Silicon. I've tried them all, and while alumilite is good, by far the best thing on the market in terms of De-airing (getting rid of bubbles), tear strenght, and length of finished mold comes from Bare Metal Foils.
Unlike Alumilite, which uses a 10:1 ratio of Base to Hardening Catalyst, the BM/RTV is a 1:1 ratio (pink and blue). It sets up in about 3-4 hours, and is very easy to mix. i order the stuff in 16 lb increments (yeah - i use that much!), and it comes out to about $25 for the equivilent amount of alumilate.... about a 20% savings.
Also, unlike alumilite (which IS a fine product) you don't have to be nearly as precise in your ration measurements. Too much hardner with Alumilite and your mold will be overly stiff and hard to work with... use too little, and it will not retain strong mold strenght the longer you use it. With the BM stuff, i find I can just be "close" to 1-1 (visually measured) and get wonderful results.
The final clincher is ordering... i once bought a new Alumilite kit, and spilled my catalyst.... and they wouldn't sell me another tube! I had to go buy a whole additional new kit ($30!) just to get the catalyst. Which meant i still had a tub of base leftover! Over the course of time, I was able to ration out the base, using a 12:1 ratio instead of 10:1, but it was a real pain.
I agree with you on the Rubber I use mostly Dow which have various different kinds of Silicon rubber. On the Resin itself is their anything really good that is easy to get ? Alumilite resin is local so don't have to wait 3 to 4 days to get it
GeneralFailure
Member Since: February 15, 2002
entire network: 2,289 Posts
KitMaker Network: 532 Posts
Posted: Friday, August 02, 2002 - 06:23 AM UTC
Thanks for all that info, guys.
Sully, you cannot use latex (rubber) in the same way as you would use a two-component silicone. What you could try to save your project, is to poor off all latex that is still liquid. When only a thin coat is left on your original, let it sit till it is completely dry. Then apply a next coating, let dry, apply a coating, let dry, etc... This is a possible alternative to using RTV, but you will never have the same qualtiy results as with RTV, it is more difficult and time consuming to use... and it smells !
But I hope you can save the project....
Jan
Sully, you cannot use latex (rubber) in the same way as you would use a two-component silicone. What you could try to save your project, is to poor off all latex that is still liquid. When only a thin coat is left on your original, let it sit till it is completely dry. Then apply a next coating, let dry, apply a coating, let dry, etc... This is a possible alternative to using RTV, but you will never have the same qualtiy results as with RTV, it is more difficult and time consuming to use... and it smells !
But I hope you can save the project....
Jan
matt
Campaigns AdministratorMember Since: February 28, 2002
entire network: 5,957 Posts
KitMaker Network: 2,626 Posts
Posted: Saturday, August 03, 2002 - 07:05 PM UTC
 |
WEB HOSTING BY
Copyright ©2021 KitMaker Network and Kitmaker Network, a subsidiary of Silver Star Enterprises
All Rights Reserved. Please read our Conditions of Use and Privacy Policy.
All Rights Reserved. Please read our Conditions of Use and Privacy Policy.