Film covering for foam?

[Tim Wescott]

I have some styrofoam, with compound curves, that needs to get covered with film.

I have some SLC from Phil Cartier, but that stuff doesn't stretch much.

Does Nelson's go over styrofoam without melting it?  Are there other brands that folks can suggest -- preferably ones that can be had from the LHS?

[john e. holliday]

Econokote should do the trick.   I have used SLC with no problems on the Gotcha Streak by the Corehouse.

[Steven Kientz]

I've used Econokote on Corehouse Pyschos, actually worked pretty well. maybe  Phil will respond with some "tricks" for using SLC.

[Tim Wescott]

The only Econocoat I have is bright orange, and I've already decorated the wing with purple.  It is just an airframe that needs to fly but not be pretty, but still...

[Tim Wescott]

Here, I answered my own question.  This is a piece of foam with a much sharper curve than I need to cover, covered nicely with Nelson's black.  It turned out to be way easier than I thought it would be.

This was done with Nelsons, an old Monocoat iron turned low, and a Hanger 9 heat gun wielded with great care to not overheat anything.

I tried doing the other side with SLC.  It looks like SLC will do compound curves, but not at foam-compatible temperatures.  I was getting it to start going around the curve, but the foam was definitely melting underneath.

If you haven't used Nelson's, use care.  First, I don't think it's fuel proof.  Second, every skilled builder I know who's used it (including me) has a love/hate relationship with the stuff.  It's light and it looks wonderful when it's done right.  On the other hand, if you ever let the adhesive side touch itself, even at room temperature, it's permanently bonded.  The only thing to do when unauthorized touching has happened is to wad up that piece (it wads up Really Easily) and start over.

[Duke.Johnson]

I like Econokote and Ultra-kote parklite.  Ultra-kote cost more.

[Randy Powell]

And you're doing this why?

[Tim Wescott]

And you're doing this why?

TUT test pig #3.  #1 was lost to a software bug.  #2 was lost to a sticky control system (I didn't build it).  Hopefully #3 will be less ill-fated.

[Randy Powell]

OK. just curious. It will be easier if the plane flies decently. Paint it gold and call it the King Tut.

[Tim Wescott]

OK. just curious. It will be easier if the plane flies decently. Paint it gold and call it the King Tut.

Too late on the color scheme.  That tail looks teeny, but it's proportionally bigger and on a longer tail moment arm than a Flight Streak, so I expect that it won't be too bad (and it may grow a bit before the plane actually finds its way into the air).

Test pig #3 -- get it?  Snerk (as it were) snerk.

[Randy Powell]

Well, it's different. A timer-ESC on an IC engine?

[Tim Wescott]

Well, it's different. A timer-ESC on an IC engine?

Yes, for three reasons, in more or less descending order:

• Howard needed the TUT, and I'm flying slime
• I have an ambition to try my hand at inertial speed control, and see no reason to limit myself to electric power to do it
• Dave Trible has expressed interest in a timer for his IC-engined FAI planes

[phil c]

I tried doing the other side with SLC.  It looks like SLC will do compound curves, but not at foam-compatible temperatures.  I was getting it to start going around the curve, but the foam was definitely melting underneath.

Doing compound curves with SLC is not hard but takes some care.  The trick, if there is one, is to not do it all at once.  Start in the middle.  Heat and stretch the covering and pull it around some, the work forward and backward.  The iron should actually barely touch the foam.  The heat should be where you actually want to stretch the film, only briefly on the foam. You must let the covering cool before releasing it.  Going forward and then back helps keep from overheating a portion that was just stretched.  At some point you'll start to get wrinkles.  Try to heat and pull each one separately.

For correct temperature I use about 275degF on a black, Century 21 iron.  If you leave the iron in one place it will just start to melt the foam in 15-20 seconds.

[Steve Thornton]

I have some styrofoam, with compound curves, that needs to get covered with film.

I have some SLC from Phil Cartier, but that stuff doesn't stretch much.

Does Nelson's go over styrofoam without melting it?  Are there other brands that folks can suggest -- preferably ones that can be had from the LHS?

Bill Bischoff describes a great technique in the carrier part of the forum. He covers foam with silk span, using 50% Titebond that he squeegees out.  Then he covers the wing with econocote.  the econocote has a lower adhesive temp and shrinks nicely.  I used it on Bill's Wildcat design and another of my own &bit is tough and looks great.
hope this works for you...did for me!
steve