Vulcanized vs. RTV

[Jwryrubber]

First, is that the responsibility of making the mold from a wax pattern or other non metallic part is the responsibility of the manufacturer... So .. what happens if the pattern is broken in the process? Oh well... another patern may need to be made... and at what expense !!!

Hi, Dan--sorry I was unable to present much depth in my effort to quickly pass on useful relating to the use of RTV

Silicones. You are correct, and many manufacturers still follow the route you outline. However, the original wax or SLA is at risk if you need to invest it in the model making process. Many original waxes are lost at this point. Many folks think that the original wax is at lower risk for loss if it breaks in the mold cutting process. Why? because you still have the mold from which to shoot copies. The shrink of platinum cure RTV is under 1/10 of 1% if cured at room temperature, so the dimensional change in the mold does not affect these applications. An 1/8" section will shrink less than .000125". Of course there are other shrink considerations down line, but I did not intend to address these as they do not relate directly to my original point.

Cheers!

Bill Mull

Zero-D Products, Inc.
38285 North Lane. #103
Willoughby, OH 44094 USA
800-382-3271
440-942-1150
fax 440 942 2130
WWW.ZERODPRODUCTS.COM

[Daniel3]

However, the original wax or SLA is at risk if you need to invest
it in the model making process. Many original waxes are lost at
this point. Many folks think that the original wax is at lower risk
for loss if it breaks in the mold cutting process. Why? because you
still have the mold from which to shoot copies.

Hi Bill, We do tend to agree with each other .. I just like to make sure that All people on orchid understand exactly what is invoved when manufacturing. Many are not aware of various processes. Many have dealt with casters and casting companies that don't give enough accurate ..Some of theses casters are not model makers

and don't do finished products... many don't do Hand polished high quality finished products which we do .

In my previous post, I did make mention to use RTV molds to make the production models... In otherwords... make an RTV of the wax or SLA pattern... cast a wax from the mold into metal and perfect that pattern. This perfected casting now becomes the production model that can be copied in any rubber and as many molds as you wish can be made from it without any problems. This also guarantees a better model since the cast model can be perfected beyond what is capable in wax or SLA. To do this, It is important to know the shrinkages of the molds, waxes and castings. I deal with these problems on a daily basis.... we get some 20 models a day sometimes and these come as carved waxes, SLA's ,metal models tree bark and what have you...often over 200 molds /week are made . 95 % of the models we get in wax are definitely not ready for production mold making and require extra work in the metal model to truly make a great casting. These are just some of the reasons why our customers like the casting and finishing work that we do for them... we try and cover every detail as best we can so that their finished product comes out the way they would like. That is also why , as a Manufacturer we would not recommend RTV 'ing a wax and using that mold for production ... only to create the production models in metal

I believe we both agree that making an RTV of the wax and producing a metal model is the best way to go...for production.

I would certainly like to try your platinum rubber as I'm sure we will have good uses for it.

Best Wishes,
Daniel Grandi
Racecar Jewelry Co. Inc.
52 Glen Rd. Cranston, RI 02920
contact: sales@racecarjewelry.com
Tel: 401-461-7803