I have a gap in the TE what to do?
 

Sorry its TE....

When should I close it and how?
In the second picture we are looking at the gap itself, its between the TE sheeting and the TE, its about 1 mm wide and its too significant to ignore.
I need to cut off the excess sheeting to get to the TE then it would be more reviled.
Its glued with epoxy and the length of the gapped section is about 2 inches.
There should be a hinge in that place and I cannot just press it in tried that, there are epoxy drops there.

Thanks in advance
Alex

RE: I have a gap in the LE what to do?
 

Do you mean that TE?

RE: I have a gap in the LE what to do?
 

yes its TE sorry

RE: I have a gap in the TE what to do?
 

Use a hobby knife to clean out the drops of epoxy forcing the sheeting up. It's not going to be easy, but keep working at it until you can get the sheeting to sit down as it's supposed to. Then squirt carpenters wood glue into the gap and clamp it down (or weight it down) and let the glue dry.

Ken

RE: I have a gap in the TE what to do?
 

Will the epoxy soften if you hit it with a heat gun? I would try heating it with a heat gun while clamping it. If it does soften and close the gap, leave it clamped for several hours.

RE: I have a gap in the TE what to do?
 

Just block sand the TE, cap it with 1/8 balsa strips and sand.

Bob

RE: I have a gap in the TE what to do?
 

Thanks guys, just cleaned the epoxy drops from the gap with a hobby knife, no its not easy.
i see there is epoxy residue on both parts which means its gonna be old epoxy to old epoxy bond not wood to epoxy...
i'm lucky there is a ply wood wing tip to hold it.

i'll cut off the excess sheeting in few hours to get a clean place for sanding and will glue it again.

Thanks again
Alex

RE: I have a gap in the TE what to do?
 

Another approach would be to use a very hot iron , pick up one from the local thrift shop, or good will store,and heat the sheeting over a rib at a time. When the epoxy starts to break down, you can pry the sheeting off that rib. The covering iron just doesn't have enough heat to do this job, It gets hot enough, but it to localized to do much good. A heat gun may work, but you stand a good chance of scorching the wood before the epoxy starts to break down.

I would try RCKens method first, but I've never been very good at cutting epoxy that deep.

The last thing, and it may be the quickest in the long run is to sacrifice that sheeting. Cut it up and carve all the wood you can off the epoxy then the heat gun or iron can get directly at the epoxy. Peal it off while it's hot and then lay down a new sheet.

I've done just what your are showing, only on the LE. I used a bit of all methods untill I got a fairly good closure, then I filled in the gaps and sanded things smooth. I will not use epoxy for attaching sheating any longer because of this problem. I now use the carpenters glue and blue masking tape, I wrap the tape next to the ribs on both sides and then use some scrap balsa and clamps and clamp the TE about every three inches. Wood spring clothespins reversed work well for this.

Don

RE: I have a gap in the TE what to do?
 

I posted this in the beginners forum a few days ago.

http://www.rcuniverse.com/forum/m_8648894/tm.htm

Crank up the heat on your sealing iron and leave it on the stand.

After the iron is hot, place your hobby knife against the base of the iron for about 1 minute to get the blade hot. It may help to remove the blade about half way to keep the handle from sinking the heat from the blade.

Work gently on the epoxy, if it is puddles of epoxy the hot knife should slice right through it.

RE: I have a gap in the TE what to do?
 

That's the route I'd go, except I wouldn't bother taking the whole sheet off, I'd just cut out the part where there's a gap. Cut out from between two or three ribs, and about 1/4" ahead of the TE. You could glue a small piece of 3/32" balsa to the two ribs on each end of the cut to support the new piece. Wood glue on the TE and a little thin CA around the edges and done.

RE: I have a gap in the TE what to do?
 

Thanks everybody yes it looks like all of what you wrote is what im gonna do,
scraped the epoxy drops off when it was a bit soft.
now that im not in an emergency situation i'll probably cut that piece off and put a new one, its only one bay.

Thanks
Alex

RE: I have a gap in the TE what to do?
 

Sorry for deviating from the topic but doesn't it seem odd to be using epoxy on trailing edge sheeting?

Alex, life might be easier if you use aliphatic or CA in most of your future building. Trial fit the parts before gluing, then hold in place and apply CA or apply aliphatic and tape/clamp/weight in place.

Just a suggestion, David.

RE: I have a gap in the TE what to do?
 

David,

i used aliphatic titebond 2 on the first wing half and there is a phenomena i noticed, if i use aliphatic glue on a long surface its developing a curvature, the wider the surface the worse it gets.
on the first wing half it was 1/4" upwards curve.
the manual of the 4* calls for epoxy.
in general i prefer titebond and use it everywhere i can except for places i need it straight.
CA in these amounts is out of the question lungs wise...
thanks for the suggestion though.

Alex

RE: I have a gap in the TE what to do?
 

If you use Titebond, and notice that the plank bows, just weight it down and let it go for a couple of days. Balsa being a light and porous wood draws the moisture out of the glue. That is the main reason the glue sets up faster with balsa than pine or oak. Let it set for a couple of days and let the moisture escape the balsa.

RE: I have a gap in the TE what to do?
 

You can flatten out the curvature using a flat iron with the temperature set at "wool". For example, to straighten a sheeted trailing-edge that has curved, I: set the structure on a flat surface; add some small blocks to allow enough deflection that forms a slight counter-curve; press the hot iron against the sheeting and hold about 10 sec; work your way down the wing until you've applied heat to the entire length. Repeat the heating procedure on the sheeting that forms the opposite side of the trailing edge. The aliphatic glue will soften and plasticize to allow the structure to shift; when the glue cools it will reharden and hold the new, straightened shape. If you set the iron too hot, you can scorch the wood.