ORIGINAL: Timthetoolman1
Very good read, I must get away from the Classic Pattern pages more often. Thanks for sharing.
I read you had problems with the Mylar. It's possible the Klasskote is the problem. I've used Mylar without anything on it for my wings in a vacuum (I think this idea came from Phil Barnes video on glider wings, I suggest it to anyone that wants to see this technique) and I've never had a problem. I do get some residual epoxy outside the wing area that is a bit stuborn so if it's a wing I plan on making a lot of I'll use wax only. Klasskote on the other hand eats through most plastic unless it's specially designed for use on these harsh liquids. I've got some pictures of my results under my Dirty Birdy Build in the Classic forum.
There's a couple things that I want to learn for this forum. Sealing the wood and making landing gear.
I've read where some guys are treating their balsa first so it doesn't soak up too much epoxy. I place my glass and epoxy on the mylar and squeegie out the extra epoxy but it may still be soaking up too much.
I'll have to look up some of your other posts for the gear. I've been wanting to make some for my pattern planes. I figured I'd make a mold and lay them up but I like the way you fixed them in the fuselage.
Tim
Thank you Tim,
I think my material has fallen on deaf ears for the most part, in this regular Pattern forum. Nobody builds anything anymore in regular Pattern. Guys just assemble stuff that someone else created.But of course, in the classic forum, everyone builds and creates.That's where I'll start to post stuff of general interest from now on.
Klass Kote was not the problem so much. Mylar prep was. Besides waxing, it also needed a coating of PVA. Moldsfor the various parts I make which areprimered first, always are PVA'd before the primer step. These have never failed to release the primer perfectly. If I didn't use any primer though, I agree the mylar would have released fine as is. Point is if one needs to bring a molding out of the mold fully primed or painted, best to PVA the mold first to produce a proper barrier between the surfaces.
Sheeting sealing is a good practice to get into. I use hair spray much of the time but also use nitrate dope occasionally (but never use butyrate). Weight gain is a couple grams for 500 square inch sheets. But that savesat least a half ounce of epoxy per sheet (a couple ounces at least, per wing)in the end
Squeegie use is a must. But even 1/2 ounce glass cloth is thicker than silkspan and will hold more epoxy than necessary. Plus there's weave to deal with if you remove too much epoxy. Let me suggest that you use silkspan next time. It will be lighter and of course thinner but more prone to hanger rash. Except the surface would need a minimum of filling so it would require less work...
I've been doing clam shell moldings of gear and props since the early 80's. It takes time to get experienced enough to make things strong and light. The whole gear set shown in the thread is a scant 4.3 ounces, with axles but without wheels. The mount in the fuse is about 1 ounce.Everything is plenty strong for an 11 pound model.....Good luck with your molding efforts and if I can help, email me