by Art » Thu Oct 19, 2006 5:34 am
[quote="garyj36"]
I have a vacuum chamber to suck the bubbles out of the silicone after I mix it. You won't be able to use this wonderful device unless you invest a few hundred bucks. 'Til you do, all you have to do is pour real slow and puncture the bubbles out of the silicone as it covers the master/s. It's slow and tedious but you will be doing small items and taking your time anyway. Many, many modelers do it this way and get great parts.
Hi Gary,
I have been doing a variation of the technique for yonks. There is a procedure posted on the net somewhere, can't remember off-hand.
The point of this post is in answer to your statement about vucuum chambers and the few hundred bucks cost .
For nix you can build your own pump that will remove a cubic metre of air in 2 seconds flat ( or less ). I use a recycled domestic fridge/freezer pump, an old oxy bottle from a welding set as a vacuum storage unit and the piping and regulator from an old welding set that gives me the required 28 inches of mercury level.
True, the fridge pump will take forever to create a total vacuum in the oxy bottle, but once you have it, the top up time after each use is negligible.
The largest use to date has been a 7 foot DD hull that was vacuformed in one hit. Perfect results. ( the plastic bag was from some left-over (( n microns )) shade house sheeting. Too thick anyway. I have to get thinner sheet to enable it to conform better to undercuts.
Great fun and the items for moulding are limitless. I refined my technique after the details from Weta Workshop and LOTR production became available.
[quote="garyj36"]
I have a vacuum chamber to suck the bubbles out of the silicone after I mix it. You won't be able to use this wonderful device unless you invest a few hundred bucks. 'Til you do, all you have to do is pour real slow and puncture the bubbles out of the silicone as it covers the master/s. It's slow and tedious but you will be doing small items and taking your time anyway. Many, many modelers do it this way and get great parts.
Hi Gary,
I have been doing a variation of the technique for yonks. There is a procedure posted on the net somewhere, can't remember off-hand.
The point of this post is in answer to your statement about vucuum chambers and the few hundred bucks cost .
For nix you can build your own pump that will remove a cubic metre of air in 2 seconds flat ( or less ). I use a recycled domestic fridge/freezer pump, an old oxy bottle from a welding set as a vacuum storage unit and the piping and regulator from an old welding set that gives me the required 28 inches of mercury level.
True, the fridge pump will take forever to create a total vacuum in the oxy bottle, but once you have it, the top up time after each use is negligible.
The largest use to date has been a 7 foot DD hull that was vacuformed in one hit. Perfect results. ( the plastic bag was from some left-over (( n microns )) shade house sheeting. Too thick anyway. I have to get thinner sheet to enable it to conform better to undercuts.
Great fun and the items for moulding are limitless. I refined my technique after the details from Weta Workshop and LOTR production became available.