I picked up an old Matel Vacuform machine last summer, and was thinking about using it to make some of the bulged out windows used on many fire & rescue helicopters.
I’ve never used one of these before so I was wondering, could I use modeling clay on the kit window to make the master for a bulged out version of the window? I’m a little concerned the clay may deform or the plastic could bond to the kit window.
Thanks
Some modeling clays can permanently affect a canopy’s clarity. Ask me how I know[D)]! So, you may be resigned to sacrificing the original in using it as a “master” (or “buck”, as they also call it). Clay is not a good buck material, as it is rather soft and cannot always stand up to the rigors of the forming process. If you want to do something relatively quick, your best bet is to modify your original canopy with the clay, then make a silicone mold of it, then cast a resin buck from that.
The heated plastic sheet will not usually stick to your plastic master, since it cools rapidly after forming. However, the plastic canopy master may be affected by heat if it is let to sit on the Vac-U-Form forming table for too long. Place it there right before forming is to take place.
Here’s another tip: Do not heat your plastic (styrene is best to use) sheet on the hot plate for more than 90 or so seconds. That’s all you’ll need. Any longer and the plastic loses its elasticity and will not form well over the master.
If you dip the window in Future Floor wax first, that should keep the clay from interacting with the plastic itself.
But unless you plan on using hardening clay (like air-dry clay), I don’t think it’ll stand up to the rigors of vacforming.
Your best bet is to sculpt a master from balsa wood. It shapes easily and cane be used multiple times as a buck.
-Fred
Thanks, both options sound like something I can manage.
While I agree for the most part with the Clay, if you use Super Sculpey or one of the other sculpeys, bake it, and then make sure to sand it smooth, it will work fine. Using a soft clay without hardening seems ludicrous to me. Alot of people use Super Sculpey then bake it to make canopy bucks for vac-forming.
Another possibility, is using milliput for a buck.