Sealing surface gaps
 

Hi folks,

I encountered two issues while trying to seal the surface gaps in my Big Stik 60 and I would appreciate some help:

1. I was going to use the transparent Ultracote that I had bought about a year ago to use for this, but to my surprise, when trying to apply the Ultracote I found out it didn't work, as though there was no adhesive on the film (I tried both low and high temps to no avail. I almost got the film to melt and it still wouldn't seal. And for the record, I was using the film and not the backing material.) Thinking that it was probably from a bad batch, I called the on-line retailer and they graciously sent me another role free of charge, but when I opened that one I got the exact same thing: it behaved as though there was no adhesive at all on the film. I then bought a roll of clear Monokote and it worked like a charm. Has anyone come across this problem?

2. After I sealed the gaps in the ailerons using the Monokote, I realized that it is now a lot harder to flex the ailerons, especially in the direction where the gaps are sealed. In other words, I applied the film in the aileron gap under the wing, and it is now rather hard to flex the ailerons down. I used Dubro nylon hinges, and the surfaces moved very freely before I applied the film. I took care to ensure the film (that was folded in a "V" shape) was deep in the gaps by using a thin ruler and pushing the "V" down in the gap before sealing it, but I am now wondering whether I pushed the "V" too deep in the gap. Any thoughts on how I can fix this? I haven't done the elevator and rudder gaps until I figure out what I am doing wrong.

Thanks!

RE: Sealing surface gaps
 

Blenderm is the easiest way to seal gaps. I usually flex the surface to its full throw and then seal. You may have warped the hinges a little if you laid the iron on it too long causing some binding.

RE: Sealing surface gaps
 

Was your plane flown before you tried to seal the gaps??

RE: Sealing surface gaps
 

sometimes it doesnt make a huge difference...it depends the speed of the airplane flyes and the total surface. in 20 years i have never did it.

RE: Sealing surface gaps
 

My question also.

Also, you may have attached the covering to the moving parts of the hinge

RE: Sealing surface gaps
 

KW - what is Blenderm, and would you let me know where to buy it?

All - Thanks for the replies. Sealing gaps is a decision I made some time ago, and of course whether or not it is needed is debatable. At this point however, I am trying to see how best to fix the issue. I don't believe I have distorted the hinges as I was careful not to leave the iron there too long.

RE: Sealing surface gaps
 

I was told that clear packing tape works well. It's thin and shouldn't interfere with the travel rate of the control surfaces. I still have not done this on my Big Stik 60 though.

RE: Sealing surface gaps
 

Every time I have used Monokote, it makes the hinging a little stiffer until it gets used a bit. I find it really helps the plane. Blenderm or micro plane hinge tape works; I even used scotch tape on a scale plane once.

RE: Sealing surface gaps
 

I looked up Blenderm, interesting application for a surgical tape! I take it if Blenderm is being recommended, then others have successfully used it with glow planes. With that said, I still have to ask the question: is it fuel proof?

Also a question on application: how easy is it to move it around once applied? In other words, if not placed correctly, can it easily be removed and replaced or will it take off the covering with it?

Thanks again everyone for your responses. I do think that the covering may be interfering with the movement of the hinges, so I will remove just enough covering above the hinges to see if it helps.

RE: Sealing surface gaps
 

Why would the Big Stik .60 even need this?

RE: Sealing surface gaps
 

The question is, did you fly this plane then decide to cover the gaps?? When I cover I my planes they are completely assembled and in the bones so I cover using one piece of covering and have no gaps top or bottom, this really helps with the clean up at the end of the day. I have used two inch wide scotch tape, packing tape and all types of covering and they worked just fine. Like OP mentioned, you don't notice a lot after sealing on a lot of planes. I wouldn't worry about it too much on any of the fun fly planes. I build and cover so anything I build has the gap sealed, when I assemble an ARF for people I don't bother with it unless it's requested by the owner. For effect you only need to cover the bottom of the plane but then that clean up thing rears it's ugly head. Oil gets into the covering and it peels over time.

RE: Sealing surface gaps
 

Graybeard & Opjose,

Fair enough, I certainly accept the argument that this may not be needed on all types of planes. With that said, the gap is already sealed so the question of why I did it to begin with (while it teaches me a thing or two about plane set ups) doesn't address my immediate problem ;).

At this point I have two options: either remove the seal it or fix it. Removing it would be somewhat problematic and probably the easiest way would be to cut at the bottom of the "V" along the surface gap. But in the spirit of learning for when/if I decide this is really needed and helpful, I ask that you and others who have been doing this much longer than I give me some advice on the proper procedure.

I am really intrigued by Graybeard's idea of covering everything with one piece! I will think about it for my 4*-Sixty kit. If I understand your process correctly, you assemble the plane completely (surfaces, hinges and everything), and then you cover with one piece. This indeed would inherently elimintate all the gaps, but in essence, the process would still involve covering the surface gaps; but instead of doing it on top of a layer of covering, you do it directly on the wood as part of the initial covering. If my understanding is correct, then can you please explain your process of sealing the gap when you cover the plane? This could help me understand what I am doing wrong.

Thanks again.

RE: Sealing surface gaps
 

Covering in one piece is a major pain! I used to seal all of my gaps, but when I started doing product reviews, I put so many planes together that I just don't bother anymore - and I have noticed NO difference.

Than being said, as far as your "stiff" elevator goes, how stiff is it? What many people feel is too stiff is really no problem at all. After all, even a freely-moving elevator is going to have an immense amount of air pressure on it when it's moving at 80mph. A "stiff" hinge is nothing by comparison.

RE: Sealing surface gaps
 

Minn - it's the perfectionist in me! To the point you and others made earlier if the difference after sealing is not noticeable to the experts, a newbie like me will probably not notice it either. My thought was, it's only a little more work so what could it hurt?

I have only sealed the ailerons on the bottom of the wing. When the plane is right side up, moving the ailerons up is not too bad, but moving them down needs more force and concern me a little. It's hard to describe stiffness, but let's say moving down is noticeably harder than it was before I sealed it.

RE: Sealing surface gaps
 

ppkk

You mentioned that there seemed to be "no adhesive" on the Ultracoat.

Not to overlook the obvious, but are you SURE you removed the bottom film on the Ultracoat?


I agree with MinnFlyer about the stiffness.

I assume the control surface moved freely before and now you feel some resistance.

As long as your servos are not fighting this resistance all the time, you should be fine.

Try deflecting the control surface and see if the servos go quite while holding the deflection. If so you should not have any problems.

RE: Sealing surface gaps
 

[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJGT1&P=ML]Benderm[/link] or hinge tape. Apply to a clean surface. It sticks very well and it is flexable and stretchy. But you don't want to stretch it when applying it. You can remove it without too much trouble, just peel. I cut it in about 1 ft. sections and appy with the control surface fully deflected open, without the control rods attached.

RE: Sealing surface gaps
 

Actually it is BLENDERM for Blend ( with ) "Dermis" (skin).

[link=http://www.3m.com/Product/information/Blenderm-Surgical-Tape.html]Blenderm[/link] is produced as surgical tape for use in medicine.

It is MUCH cheaper to purchase it in a pharmacy or through a medical supplier.

RE: Sealing surface gaps
 

opjose - I am positive about removing the bottom film. I have covered planes before and I know what to do. In this case, considering the Ultracote was transparent and to be absolutely sure (although obvious) I even tried to stick the backing film in case that was the real film and nothing!

I'll pick up some Blenderm at a pharmacy to check it out, sounds like an easy way to do this!

RE: Sealing surface gaps
 

I have many planes that I have not sealed the hinge gaps on. They fly just fine. As long as the gap is around 1/32 of an inch, it is not really a problem. I have flown planes were the gap was over 1/8th and it flew fine. About the only ones I seal every time are small foamies, not that hey need it, I just tape for the hinge.

It almost sounds like the thickness of the covering is binding the surface a little. Try this. Un-hook the linkage, us you hand and force it a little bit and see if it makes the movement better.



Dru.

P.S. I have to ask, are you sure you were using the covering correct side up? I have stuck the covering to my iron to many times now.

RE: Sealing surface gaps
 

So far I've checked a couple of pharmacies (walgreens, CVS) with no luck. I thought I would find it cheaper. Only place I can find it locally is the hobbytown usa. Good luck.

RE: Sealing surface gaps
 

Places that have and sell separate First Aid kit supplies tend to have it in stock as do medical supply houses.

e.g. places that also sell walkers and crutches.

At worst you can also order it on-line much cheaper than what HobbyTown sells it for.

RE: Sealing surface gaps
 

Check on Amazon, you can get one roll for $1.90 shipped for free. The catch is this is 1/2" wide tape which I think would only be useable on small planes. They have 1" width tape too, but only in cases of 6 or more.

RE: Sealing surface gaps
 

Big girl!!:) I don't bother with the gaps on ARFs unless the owner asks me to do it. I'm down to about one plane a year now so big whoop, the bit of effort it takes is nothing. When I was building a half dozen kits a year I still covered in one piece but by then it was second nature so I never gave it any thought. The only real trick to it is to bend the control surfaces as far as they will go when you start ironing the covering down. Ultracote makes the covering job a lot easier and I don't get wrinkles. I'm pretty good at hinging too so my gaps are always small, I really don't notice any difference when flying a plane with or without the hinges being sealed, I'm told by a lot better pilots then myself there is a difference but I'm not that good I guess. I just do it for the clean up and I'm in the habit of covering the way I do. I also fly on a dirty nasty dry lake bed and the clean up at the end of the day can be pretty nasty come late summer, I also don't get any oil in my gaps that can loosen the covering. It's just not a big deal to me one way or another, I just do it.

RE: Sealing surface gaps
 

Alright, I fixed the stiffness problem. The issue was that I had pushed the bottom of the "V" of the sealing covering too deep in the surface gap, actually below the level of the hinges. That meant that when moving the surface in one direction, the covering over the hinges would crumple over itself hence causing the resistance. To fix the problem I cut relief points in the sealing material just over the hinges and bingo, the surfaces move a lot easier now. It is still slightly stiffer than if was before I sealed it, but that is normal and expected.

One problem solved. As for the missing adhesive on both rolls of clear Ultracote, well...

RE: Sealing surface gaps
 

I used to hinge a lot of my planes with Coverite Iron On Gapless hinge material and even made up some using plain coverite cut in strips and sewed together back side to back side and it always worked very well if properly applied. It was almost invisable under the Monokote and took care of the gap sealing. I wonder if it is still available?