Ultracote over tape??

[Jason]

Just a thought...looking for any input;

I've read through most of the threads and I haven't seen this question asked....if I've missed it, I apologize and just point me to it, but my question is this...

I will be coating my Cub in ultracote (ultracoat?), and I've read alot about taping the plane to strengthen it. Has anyone ever applied coating over tape? Is that just redundant? Would it adhere? Would it make the coating look crappy?

Any experience/ideas here?

[ginginho]

Aug 20, 2009 15:26:31 GMT 1 Jason said:

Just a thought...looking for any input;

I've read through most of the threads and I haven't seen this question asked....if I've missed it, I apologize and just point me to it, but my question is this...

I will be coating my Cub in ultracote (ultracoat?), and I've read alot about taping the plane to strengthen it. Has anyone ever applied coating over tape? Is that just redundant? Would it adhere? Would it make the coating look crappy?

Any experience/ideas here?

Hello Jason and welcome. I've covered my SC with Profilm (similar stuff I believe) and had some fibreglass tape across the underside of the wing where I'd strengthened it with a carbon rod. It adheres well and is onlyt noticable if you look closely. The process of applying the film with a iron makes the adhesive on the tape work better.

Obviously any creases in the tape will be more obvious when covered in film.

[Jason]

Thanks for that quick reply!

In that case, I think I'll tape the plane before applying the ultracote. Better 'too much reinforced' than not enough

[ginginho]

Aug 20, 2009 16:09:35 GMT 1 Jason said:

Thanks for that quick reply!

In that case, I think I'll tape the plane before applying the ultracote. Better 'too much reinforced' than not enough

I'd suggest that you don't tape the curves on the wing ends as covering these areas is quite difficult as it is, and it's unlikely that you'll get the tape on without a few creases.

[Jason]

Yea...I see your point...I was thinking of a lot of short strips placed vertically instead of one long strip horizontally, maybe that way I can get the creases to be minimal. If that doesn't seem like it's going to work, I'll just tape the leading edge, the top and bottom of the wing, the wing saddle, and the fuselage....I know I can do those areas without creasing.

[duck9191]

depending on the tape the heat may losen the tape. econocoat shrinks at a lower temp and normally is a better idea for foam because there is less chane for damage with the lower heat. try a small peice of tape and put the coating over and see what happens when you shrink the coating.

[admiralev]

i would defintatley use econokote. covering planes is my favorite part of building and ive worked with many types of covering. ultracote is by far the best for balsa because of the multi-temp shrink charateristics but is much too hot for foam. monokote is too hot as well and IMO doesn't work as easily as ultracote. econokote (top flite) would be your best bet but if your not careful you can still put a mighty warp in the wing and mess up your dihedral.

if you want it to look good you're going to have to strengthen with something inside the wing...something other than tape. covering will look terrible over tape and will be impossible to do without wrinkling. put a carbon fiber rod in the wing and seal it with epoxy. sand the epoxy flush and cover over the flush surface. you could reinforce inside the fuse by just using CF rods glued to the inside of the pushrod bay, accessable by removing the section of foam that covers this bay with 3 holes. that should sufficiently strengthen the tail.

best tip when covering foam is to keep temp low and heat moving. if you were really ambitious you could sheet the wing with 1/16 balsa first and then wouldn't have to worry about heat as much. do some research before covering...it will make your first job much easier

admiral

[Jason]

Thanks for all this great advice....

It's a little frustrating, because I ordered the ultracote (online...no local hobby stores still in business in my area)...because I read another thread somewhere that the person said that ultracote was the best for foam, because it was slightly thicker and easier to work with than ekonocoat. He did not mention a heat issue. After spending the $20 for ultracote, I guess I have to try it now.

Sounds like the coating over tape is not a good idea...My question really is this; is more strenghtening really needed, or will the coating provide enough extra strength for the foam? Would it be overkill to do any more? I'm not familiar with just how well the coating will adhere and how much extra durability it will provide.

I hope I don't have a heat issue with the ultracote...this is my first coating experience.

[admiralev]

im not claiming to be a covering god but i can tell you that covering is something that looks better and better with experience. every plane you cover will look better than your last. chances are you wont be able to avoid wrinkles completley...especially on the cubs curved wingtips.

as for strengthening, the foam on the cub is great for what its meant to do: take off and land, softly and without incident. strengthening is directly related to crashing on this plane. you cant expect more from the foam than what it will give you, as foam is just foam. the covering will add some torsional stiffness, but like anything else, there is a way to destroy any type of strenthening work. my one frustration with covering on foam is that if you were to crash, the foam will flex under the covering and wrinkle the covering. you will have to go back and reshrink the covering many times if you crash a lot. if using ultracote, make sure when you shrink you start at the 300 degree onset point and only use more heat if necessary, as it will help by giving you more shrink at higher heat as will later be required.

if theres one thing i cant stress enough its keep the heat moving! if you hold your iron in one spot for more than a second or two you will have problems with melting, especially with ultracote. all being said, experiment and learn. it will get easier

good luck!

admiral

[Jason]

Thanks for all this great advise....what's frustrating is that I've already ordered the ultracote, and instead of throwing that away, I'll have to try that way.

One other question...can I install the servos and apply the coating on top of the wires that are inside a channel cut in the foam...or is that too much heat on the wires?

[flydiver]

Can we back up a bit?
This your first plane? Have you flown.....ever?

If you REALLY LIKE doing this, then go ahead.
If you are doing it to end up with a really pretty Cub AND it's your first plane you are likely to make a big pile of pretty foam and 'coat' in short order.

Learn to fly, THEN, learn to put on coat. Most 1st planes never make it though the learning experience.

FWIW, just because you bought it doesn't make it a good idea to use. A heat warped pretty plane is still warped and not worth flying > lots of effort wasted and ultimately ALL the money in the plane and the coat. Think on that. Admiral has done some coating and knows what he's talking about.

[admiralev]

if you do decide to cover cut thin channels for servo wires and lay them on their sides in the channels. the plastic servo case can also take limited heat as well...again just dont hold your iron on the casing for minutes on end. if you think about it, the average 30 watt soldering iron puts out about 500 degrees F of heat on a wire. your iron wont even get within 150 degrees of that temp with a sealing iron. i would worry less about the wires and more about the servo casing

admiral

p.s.: im about finished covering a four star forty right now and will post some pics that show certain covering techniques used on the plane in the coming week. check it out in the build threads

[Jason]

Thanks a bunch, admiral...that helps a lot. I've got the holes cut for the servos and the channels for the wires, I was trying to decide if the coating should cover over the wires, or if I should apply the coating and then make a cut in the coating to insert the wires afterward. It sounds like it would be better to apply the coating and then place the servos and the wires back in....I don't want to risk damaging the servo housing. It seems like it would be really tedious (if not impossible) to try coating and working around the servos with the iron.

I'll look for your posts on the covering techniques....again, thanks SOOO much!

BTW, flydiver, this is my seventh plane. You're right about the first plane to learn on, however, in my case, it took 3 planes. I am no expert at either flying or covering, which is why I like these forums where I can learn...

[flydiver]

Good enough! You only had a couple posts and your history/posts did not indicate your experience.

[Jason]

I've been reading this site awhile. A Supercub was my 2nd plane (and 3rd, after I lost the first one from a fly-away)...but this is the first time I've tried modifying anything, therefore, the first time I've really had need to ask any questions....The knowledge and helpful information here is awesome. I may be attempting too much for my first modification, but it's easy to get excited about this.