13 replies to this topic

[Paxamus]

Hey guys,

I have a jig that I am wanting to make and have had a RTV mold made for me in the past. I know that I can make one out of bondo, but what should I use to make one to last longer RTV? If so then which one and where to get it??

Thanks again

[mkvnmtr]

I make a lot of vertical jigs in bondo molds. I find that I can get about a hundred pours but heat is the problem. I use three molds. I pour each or the three molds three times rather slowly. Then I quit and go inside for a coffee or something. That is to let the molds cool. Then I do it again. I f I feel the molds are getting to hot I just quit for an hour or so. This morning I had an order for a jig and only had one mold. It was a rather large jig. I could only do 15 before I quit. The customer will have to bring me at least one more mold or we will quickly ruin the mold.
THe problem is inside the bondo there are bubbles. When you work to fast the air heats and expands thus cracking the mold. I would assume you will have the same problem with The RTV molds. We use bondo because it is much cheaper. Withe either one there is a learning curve before you can make molds that do not require a lot of hand filing of the product. That might not matter if you are making them for yourself but if you wish to sell them it makes a big difference.

[dlaery]

I think the RTV would last a lot longer. I have made several RTV molds but I don't use them very long. the most I would make is 50 pours. They don't show any wear at all. I use them to make models to make silicone spincast molds. the worst part of a RTV silicone mold is you have to wait to de-mold. On a 1oz jig after 10 pours and the mold gets warmed up you might have to wait 60 seconds before demolding.

[Paxamus]

dlaery, on 01 December 2011 - 12:59 PM, said:

I think the RTV would last a lot longer. I have made several RTV molds but I don't use them very long. the most I would make is 50 pours. They don't show any wear at all. I use them to make models to make silicone spincast molds. the worst part of a RTV silicone mold is you have to wait to de-mold. On a 1oz jig after 10 pours and the mold gets warmed up you might have to wait 60 seconds before demolding.

I have the same issue with my RTV mold that I had made. I was wondering where to get RTV for a mold, I have a design that I want just for personal use

[dlaery]

There are so many kinds of RTV it will make your head swim.
From Smooth-On they have Mold Max and I have used it, not for lead, and thought it was too hard, it was about 60 duro. I think if it is harder it tends to be brittle and could break off in places like deep eye socket. the kind I have used the most is Rhodasill v330. I'm sure Smooth-On has something just as good. It is a Duro 30. It is really soft but doesn't tear easy. I believe it is a Platinum cure which is suppose to be better than tin cure. It is more expensive. I would guess some of the less expensive stuff would be good enough for several hundred, maybe more, pours with lead.

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[tedg]

David, I tried to find Rhodasill V330 on internet search, comes up blank, any more info?
Thank you
Ted

[dlaery]

On Google I get 1 hit, and it is a PDF of what I use. The brand name is Rhodia. If you Google this
"rhodia rtv" The first hit I got is http://www.sunbeltma...om/rtv-1556.htm
they have it about half way down. I did not get this from them, so I don't know anything about this company.

[Paxamus]

I am having trouble finding a place to buy it, if you don't mind me asking where do you get it from?

[dlaery]

I traded for mine. My customer gave me the RTV to do a job for him. He doesn't remember where he got it.
Did the link I provided not pan out? The other I used was Mold Max from Smooth-On and my customer got it from Smooth-On. I didn't like the Mold Max but I didn't use it on lead, I used it polyurethane.
If you are looking for some, call Smooth-On's tech support, they have lots of choices, to see what they would recommend. On the Rhodasill, it is a 10 to 1 mix and it needs to be measured right and mixed good. Another thing will be keeping air bubbles down.

[Paxamus]

Thanks I will check with those guys first of the week

[Paxamus]

Does that v330 hold up fairly well? No one at Smoothon can help i talked to the guy at sunbelt and will probably order it, but he was concerned about the lead being too hot, it works fine for you?

[tedg]

The rhordorsil can be gotten rfrom bluestarsilicones. I am going to try aeromarine products, they list a pourable high temp silicone am160 which they say is good for lead temps.
Ted

[Paxamus]

I talked to the guy at sunbelt and he was VERY helpful, I am going to order some v 340 from him today, tedg let me know how you like that other silicone.

[Paxamus]

Hey guys got the v340 and made a two cavity jig mold. For a first homemade mold pours very well and only a few little imperfections that I can live with, once I refine my mold making some I will post some pics. After seeing all of the fantastic lures on this forum, I want to make sure mine looks REAL good before putting it up