Thread: Australian made moulds

Originally Posted by tdrumnut

silicon bought from ebay (Sounds Creative)

Rebecca's (Sounds Creative) silicone is a lot like the resin saver mould silicone.
She usually sells her silicone to soap makers for soap moulds.
The harder Duro silicone does split easier in the corners getting the mouldings out.
Both work out just as good .
I will say that the wall thickness needs to be thicker on the softer stuff.

Peter

Originally Posted by _fly_

Rebecca's (Sounds Creative) silicone is a lot like the resin saver mould silicone.
She usually sells her silicone to soap makers for soap moulds.
The harder Duro silicone does split easier in the corners getting the mouldings out.
Both work out just as good .
I will say that the wall thickness needs to be thicker on the softer stuff.

Peter

Yes I believe the silicone from Sounds Creative is fine to use and have no trouble and as i said earlier there is a big price difference. I have notice that there are 2 main sellers on ebay but i have spoken on the phone to the lady behind sounds creative (Rochelle) and yes her silicone is a little softer than some of the other stuff but after passing on my comments she has advised me that she will look at getting some firmer setting silicone when she next place an order so this could be good news for all concerned.

Cheers Ian

I was tempted to go thru my emails to check for her name but was pretty sure I had it right.
Never mind.
I should give her a ring and see if she has found harder stuff yet as I have used my last lots all up.

Originally Posted by _fly_

I was tempted to go thru my emails to check for her name but was pretty sure I had it right.
Never mind.
I should give her a ring and see if she has found harder stuff yet as I have used my last lots all up.

well i didn't mean to upset you fly by commenting on the ladies name I was just going on the name she signed her email with but feel free to give her a ring with regards to the firmer silicone she will not have it yet as it was only yesterday that we were speaking

Cheers Ian

Originally Posted by Dorno

this may be true but the silicone off ebay seems to work for a purpose. I have had moulds from others and there so called quality moulds have either broken or have split in many ways so I feel we have nothing to loose with the cheaper silicone. I cannot justify paying around $50 (a kilo or more not sure) to make a mold that seems to not last much longer than the so called good ones.

So time will tell

Cheers Ian

So are you saying the mold I gave you a few years ago is no good..? cause it was made from the UltraSil we sell.!! and has had over 30 Ltrs of resin in it before I passed it to you..

Some stuff works for some people and some stuff doesn't just like finishing of ur pens IMO

Ian

I have used many silicons to make molds over the years and they all have there place, from the very soft ones, up to the ones that are super hard (made for high heat applications). I did originally research hardnesses, but no longer have the info.

The Ebay cheaper silicon is fine but you do need to be careful with catalyst qty, and it is soft, so you need slightly thicker sides. As it is softer, actually the same as Resin Savers and others from US, it is easier to get the casts out but they tear easier. This softer silicon type is the only one to use when doing vertical round casts, with the very stiff silicon, it is almost impossible to get the product out.

With the block/slab type molds, the softer silicon works, but you must take care stripping the cast, otherwise you can split the sides easily. The softer ones can be fixed though, just add a bit more silicon to tear. One of the main disadvantages of the softer silicon in these circumstances is that the mold can deform when pressure casting, even with thicker walls, and I have had to build a timber box to help support the sides. For these molds, the stiffer silicon would therefore be better.

The resin saver type molds usually aren't used under pressure, so deformation isn't an issue, but getting the tube in and the cast out are. The soft resin is better to get the cast out, but tear more easily, so up in the air which would be best, but the really hard one silicon may be just too hard.

Hope this helps

Originally Posted by salty72

So are you saying the mold I gave you a few years ago is no good..? cause it was made from the UltraSil we sell.!! and has had over 30 Ltrs of resin in it before I passed it to you..

Mate don't get cranky with me I was mearly saying that if you look around alot of the suppliers of silicone the cost is quite expensive so to be able to get some alot cheaper is great for us poor people
With regards to your comment above I have not said that the mould I bought second hand off you was no good because i haven't even used it however some of the moulds that i have bought from overseas have either had the nipples break on them and also split and these mould have had very little use so I feel using the cheaper softer silicone will be at least worth the try

Cheers Ian

not cranky, I think there needs to be a distiction between cheep RTV used to make a mould and sold at High Prices and Quality RTV made into moulds at reasonable prices.

just to throw it out there 1Kg for $37+12 postage made into 2-Man sierra mould and sold for $25-30 each doesn't mean you bought good Quality mould..... However 1Kg of UltraSil at $47+8.50 , made into a Mould for $20-25 is still not cheep but it will last.... Personally If you buy a mould you should be told the Quality of the RTV used (just cause it's blue doesn't = Quality )

And by the same time just cause you paid $60/Kg for RTV doesn't mean you bought the 'good stuff' either. It all comes back to the shoreA Hardness ,the stretch, and the style of Activator used. how many guys use release agents in the RTV..? ( I know you don't have to as the silicon doesn't hold on tight) but the chemicals and the heat in the resin will destroy your moulds quick smart if you don't.. also UV is another killer it speeds up the hardning and cause them to tear very quickly..

One point I will make is if you buy your own RTV and make your own moulds - then you know what you paid for and you know what to expect..

so i am about to make a red and a yellow mould are they good one's or cheapies

just having some fun guys

Cheers Ian

I am looking at buying some moulds from tb can someone advise if these are suitable fof casting. I dont like the built in nipples its just that I feel that they may have a short lifespan, I haven't done much casting yet so its steady as she goes.JD

First may I say I did NOT buy my resin saver molds from Timberbits but from the manafacturer in the states but I do beleive they are the same ? somebody correct me if I am wrong ?

while the molds are a great idea i have had quite a lot of trouble with the nipples breaking of them and rendering them useless I have been told they can be stuck on but I have had no luck in doing this. So I ended up making my own some with the nipples and some without the nipples and have had great success.
I have also bought some of the type where there is a rubber plug in each end and they can be removed after the resin set for easy removal from the mold these blanks come from
http://www.luv2turn.com/siliconemold.html

and these turn out to be a great mold as far as I am concerned

Cheers Ian

I am still a little bit confused with this casting and stabilizing caper. Firstly some people seem to cast without pressurizing others seem to want to pressurize everything. It seems to me that it depends on the resin that is being used. ? Are there any hard and fast rules in relation to pressurising and cooking of the blanks. Obviously you cantcook in silicone moulds etc.. it seems to me that you have to do a few experiments and find out what suits you. Any comments or advice on these matters would be greatly appreciated. Cheers for now JD

Dam, I should have marked the the thread in which I answered this last time . Anyway

• Pure resin blanks - no pressure required
• worthless wood or other "things" in the resin - pressure preferred for PR resin, as it does not stick very well. If things are very rough you can often get away without pressure, just ensure you use plenty of thin CA as you turn, and give it time to set. No pressure required for epoxy resin or Alumilite resin as they stick well.
• Vacuum is used for stabilisation, so resins are drawn into internal voids.
• Vacuum can be used to remove air from pure resin blanks but care needs to be taken to avoid boiling resins.
• Under vacuum the temperature in the pot is effectively higher than outside pot, likewise the reverse is true for pressure where the temperature is effectively lower in the pot than outside.
• Vacuum does not normally work with casting timber in PR or Aluminlite, as the amount of air in timber is extensive, and the resin can go off whilst waiting for air to be removed.
• Vacuum can be used with epoxy resins as setting times are a lot longer, but care still needs to be taken to avoid boiling of the resin.
• If you are casting with PR and stabilising, cast first then stabilise, as PR does not stick to stabilising resins.
• If casting with epoxy or Alumilite and stabilising, the order doesn't matter, each sticks with the other.

Hope this helps