I've decided, for a lot of reasons, to use UltraCote to cover my first build. Will UltraCote (or other coverings) work over sanding sealer or any other applied finishes? I haven't put any on yet, but am wondering if this would be helpful after final sanding and prior to attaching the covering. I realize that anything which seals the balsa will inhibit the absorption of air trapped between the wood and the covering. Also, is that "woodpecker" thing that Top Flite sells a good tool, and a good prep technique prior to covering? I gotta admit - the covering process has me a bit timid.

Just go for it... Don't be too discouraged with your first attempts. Just keep the covering pattern simple.

I can't comment on using sanding sealer, but my first inclination would be not to. I've had good covering success without it. I've tried to put covering over painted wood, and have had mixed results. Sometimes the iron melts the paint.

The best preperation that you can do for yourself after sanding is to thoroughly vacuum the sanding dust off from everything, then go over it with a tack rag for good measure. You can't cover dust. You'll be surprised how even the smallest imperfections will show through.

When you iron the covering down, 'burnish' it with a soft cloth to work the adhesive into the wood. Keep the cloth soft... the covering will scratch, though most people won't notice it - except you.

I'm not sure how far into modeling you've come, so pardon me if I'm repeating what you already know. Use a light colored pattern on the top of the wing, and something darker on the bottom. I usually put a spanwise pattern on one side of the wing, and a chordwise pattern on the other side. It doesn't mnatter which pattern goes where. I've also had good success with a checkerboard pattern on the wing bottom, but the checks should be about 3" or larger to be seen from the air.

I've got a woodpecker and have used it, but have to admit it doesn't do that much. If you've got one, use it. But I wouldn't go out and buy one. You might come across one at a R/C flea market for a buck or two.

Everyone develops their own techniques. I use the trim iron and heat gun - only use the large iron for large surfaces. Other guys won't touch the gun or the trim iron... you'll develop your own technique. Use what works best for you.

I'm sure that a lot of other guys will drop by and give you good advice here too.... and some not-so-good advice. Just remember, everyone's an expert here, including me :-D

Definition of an expert - someone who's been doing it for 15 minutes longer than you have....

Hope this helps.

Bob

One piece of advice would be to practice with some smaller covering pieces on some scrap to get the hang of how this stuff works at the different temperatures and such.

I did this before covering my first plane and it helped. I used Ultracote as well and was very pleased. The LHS dude recommended it and I'm happy I went with it(lotta good comments on RCU regarding it as well). Plan on using it on my current SSE build as well.

Gonna use monocote though for the graphics over the baselayer of ultracote. Everything I've read indicates it's much easier to use as a graphics material over the baselayer.

Good luck!

remeber that you will not be very good at covering at first. As you cover more you will get better at it. As for the woodpecker thing i would save your money. You could just poke the bubbles that you may get with a small T-pin or even with an exacto knife.

hey, sorry to butt in, but i was wondering which was the best covering for looks/ durability in cold weather?
as for covering models, i covered a little parkflyer and i learned that patience is a virtue

Why not start a thread asking this?

sorry, ive been on some forums (not rc ones) wher ppl got ticked at starting threads where questions could be answered in other threads
my bad!

It's all good on this board.

Jerry Nelson, who sells various modeling products, recommends spraying the woodwork with Aqua Net hair spray. He says it helps any covering, film or fabric, stick better. He says it has to be the old fashioned Aqua Net and not one of the modern desginer hair sprays, because Aqua Net apparently has some lacquer in it. That's why grandma's hair never moved even in gale force winds. I do not know how true this is but it might be worth trying.
http://www.nelsonhobby.com/covers.html scroll down to "Model Preparation"

Something I have used with great sucess is to dilute any water-soluable wood glue (Like Elmer's, or Titebond) with water. Not much glue is needed (Like 1 part glue to 5 or 6 parts water)

Brush it on, let it dry, sand it smooth.

Works great, and it seems to help the covering stick.

A tip for you to minimize/eliminate air bubbles over solid surfaces.

After you LIGHTLY tack the covering (I use 4 tacks ), start in the MIDDLE of the covering, release the tack on one end, and while holding the covering taut, iron from the middle toward the end and/or outside edges.

This takes a little practice, however once youget the hand of it, covering is easy and has few, if any bubbles in the end result.

You will like Ultracote. It goes on easily AND at a lower temperature than Monokote.

If you don't have a thermometer for the iron, I strongly suggest getting one. Coverite makes them and they run about $5.00 from Tower

http://www2.towerhobbies.com/cgi-bin...?&I=LXB352&P=7

It makes life substantially easier. I suggest starting with the temperature you need for tacking and once set, mark the setting on the top of the iron with a magic marker (Sharpie ). Repeat this for the ironing temperature and again for the shrinking temperature.

Remember this - all your coverings have a maximum amount of shrinkage and EVERY TIME you reshrink the covering you need to use a higher temperature thab you did before. So try to do your shrinking at the lowest possible temperature so you can reshrink it if/when wrinkles occur.

Hi!
Oracover or as it is known in the US Ultracote, is the best plastic film covering available, but it doesn't stick that good to sanding sealer (cellulose dope with filler material).
It's the same with all other plastic and tex films: they don't stick well to a cellulose doped surface.
A good filler material to use is polyester resin and brown microballons. Ultracote sticks to this as good as on balsa.

Regards!
Jan K
Sweden

I prefer the UltraCote over the other films as well.

As for any surface preparation, I'd try anything on a piece of scrap wood, then compare it to an untreated piece of wood. The scraps don't have to be big, maybe strips about 1" or 2" wide.

Just butting in...

Bob

Thanks, all, for your helpful advice. I'm not sure why I even asked about sanding sealer - guess I was just wondering if anything other than filling (ding repair) and sanding was required (or helpful) prior to covering. I definitely plan to practice on some scraps before I start in on the model.
I keep hearing about how important it is to cover "everything" - that is, to fuel proof the wood. Guess that's why I thought the sanding sealer (or something similar) might be a good consideration. How important is the fuel-proofing anyway? It seems that one way to correct for bubbles is to pin-***** then. Doesn't that break the integrity of the covering? Hinge cut-outs also seem like an "uncovered" area. And what about the aft end of the inside of the fuselage? It's pretty hard to do much of anything with it now that the top and bottom panels have been added.
Sorry for all of these questions - You veterans are probably have a good chuckle or two.
BTW, I attended my first swap meet this past weekend, and I have to say, the covering jobs I saw there were pretty wrinkly for the most part. Guess that attests to how hard covering can be, and why one (especially a beginner) should not expect perfection. My nature, however, kinda makes me want to strive for "a perfect job".

Absolutely not. You SHOULD strive for "a perfect job". Just remind yourself that it's going to take a bit of practice to get there. But if you "settle" for less then you won't challenge yourself to try and learn to do better jobs. The very first covering job I did lasted about 10 minutes. Meaning that 10 minutes after I finished I ripped it off and started over. I won't up doing that job 3 times until I would accept it. If you don't push yourself to do the best you can, then you won't get better.

Hope this helps

Ken

Covering isn't that difficult. It can be tedious at first, until you get the hang of it. Some guys just stop trying. Look at all tne nice covering jobs at your field and ask those guys if it was hard. It's not brain surgery. It's actually fun to watch this hunk of balsa become a thing of beauty before your very eyes. On, and a little bit of trim tape (3/32" or 1/8" wide) here and there goes a long way to sprucing up the job. Don't need much.

Fuel proofing is pretty important, but things such as pin *****s and hinge cutouts are probably pretty negligible.. just keep the covering as close as you can. If you're using CA type hinges, then the CA glue will also help to seal the area anyway.

As an aside, if you're wondering about the engine compartment and/or fuel tank area, don't try to cover these. Instead, either use dope, fuel proof spray paint, or that great old standby, epoxy. Just mix some epoxy and put a few drops of denatured alcohol in it... add more alcohol until you can get a consistancy that will paint on. It does a great fuel-proofing job in the engine-mount area.

And, as for those planes in at the Auction, yeah there are a lot of botchy jobs out there, but some would look a whole lot better if they just re-shrunk the film and cleaned it up.

I just thought of something... it's about heat guns. If you use a heat gun over an open area (i.e., no wood under the covering), you could burn a hole right through the film unless you keep that gun moving.

I went to a covering seminar at the WRAM show and heard Faye Stilley talk. He's won about every covering design award you can think of. His technique is to use the heat gun "...like a paintbrush". And, it works.