Adhesive help please

[msatin]

Although I have seen improvement in my overall build skills, I have not been able to figure out how to successfully sheet larger areas such as fuselage or wings.
The problem is the relatively short drying time of typical wood glues (my preferred is Gorilla Wood glue). By the time I've applied glue to all the ribs, spars, formers etc, the area that I started at has already set up.
To save time, here are the things I've already looked at:
-In theory, gluing section by section can work, but for various reasons I can't seem to do it successfully.
-I have found there are "extended" PVA's such as Gorilla Wood Ultimate and Titebond Extended that provide up to 15 min of open time. Unfortunately for some reason no local retailer carries them, and shipping in cold weather is not a good idea.
-I have read conflicting info on diluting wood glue with water.
-There is a type of glue called "Old Hide". Although this potentially has the attributes I'm looking for, it apparently can be reversed by applying heat. Obviously this could occur while covering.
I diluted 15min epoxy with alcohol and it does work, but that requires a lot of epoxy! 

Any thoughts would be greatly appreciated.

Thanks very much

Mark S.

[msatin]

Quick update - After much more searching I finally found a local retailer & picked up a bottle of the TiteBond Extended.
I will give it a try tomorrow and post the result

[Andy Hoffer]

Hi @msatin,

Just hold a sheeting party (w/bbq hot dogs). Give every one two brushes and little cup of wood glue.  On your count, everyone applies glue to two ribs and gets out of the way. Then you immediately position and slap on the sheeting and apply a gazillion rubber bands around the wing to hold the sheeting in place. Foam pads under the bands help distribute the clamping pressure evenly and helps avoid the bands digging into the soft sheeting. Stretch bandage also works well and is easy to apply quickly and spreads the load.  There you go!!

Andy 😇

[JJerabek]

I've been playing with an epoxy with a long working time. It's sold through Amazon as "MagicResin", I use the 'arts & crafts' formula. It has a couple of hours working time but 24 hours full hardening time. It's $29.95 for 946ml. It's has a very low viscosity so it could be brushed into some joints. Just a thought.

[msatin]

Thanks John. I also like that it's a Canadian company.

I tried the Titebond Extend on a wing sheet, and it seemed to worked very well.
It certainly gave me a LOT more time to apply to all the surfaces. It does however take quite a bit more time to dry.
With this extended work time, I think I will simply coat the entire sheet rather than applying it to each individual rib, spar, etc.

[msatin]

Lesson learned
NEVER coat the entire sheet.
Immediately as I started applying glue to the sheet, it started curling, warping, and generally not cooperating in anyway.
Made a big mess, and did not come out well at all.
I went back to applying the Titebond on the structure and the sheet came out fine.
It does take at least an hour to dry, so I will have to be patient.
Overall - I think this will be useful for an application where extra set-up time will help.

[piker]

Hi Mark,

This probably isn't helpful for you, but I thought I'd tell you how I do it so you have another perspective.

I use medium CA.  in fact I ONLY build with medium CA, except for when I use thin CA on hinges.  I also never use epoxy, anywhere on my planes.

When doing large sheeted areas, I have to move pretty fast and it's a littke stressful, bit it always seems to work out well.  When sheeting the wing LE, for example, I'll glue the front of the sheeting on first, with about 1/2" of each rim covered with CA and the back of the wing LE where the sheeting edge will adhere.  this allows the sheeting to remain up off the curved ribs until step 2.  When that is cured (a few second) I apply the CA to all the ribs and main spare, then roll the sheeting down and move my hands from place to place, holding a few seconds as the sheeting adheres.  I've never had a problem with this method, and I can move ahrad with building without delay.

When I was applying the LE sheeting on my latest build, from a kit, the sheeting was quite stiff, being 3/32 balsa.  I sprayed windex to the outside surface to soften the wood a little.  I'm not sure, but I think Windex may have some amonia in it, which helps to temporarily weaked the woods cell structure (anyone help correct me if I'm full of poop here).  My point is, the CA works just as well, if not better on damp balsa.

Recently I bout some nice, little tip extenders for the CA bottle.  These really helped get the CA in under the sheeting as well as slowed the flow a bit for better control.  Yes, you want to move fast, but these helped with control so the process can be more purposful.  Not necessary as I've never used them before, but I nice thing to have.

Robert

[msatin]

Thanks for advice Rob.
Interesting that you only build with CA. I also use CA, but only when I when I need fast adhering, like sheeting to an LE.
I never thought of doing it front to back - only top to bottom. You're way provides a lot more "flex" in the sheeting.
Tunnel vision is a curse 
I still have some more sheeting on this build, so will give it a shot.
FYI - You can get the CA tips on Amazon. 300 for $13, and they fit every type of CA I've bought.
You're right about the amonia having the desired effect. Without it, it doesn't work nearly as well, if at all.

[piker]

Good to know about the CA tips.

Thanks Mark.

[davidk]

I use Zip Medium CA when I know things will go together fairly quickly.
But, I've found that on LW-PLA (and sometimes PLA) the Medium CA sets too fast.
So, for the last few builds I've used Zip's SLO-ZAP - a thick CA (Yellow bottle).  This gives me time to apply a large area.
Thick CA takes a bit more time to set once the parts are together, but a quick shot of accelerator hold things in place while the CA sets.

[msatin]

Rob - I did try your method, and it worked fairly well....sort of. 
This attempt is sheeting for the sides of of the fuse.
The first group of balsa/ply strips at the front of the fuse went fine.
However, as I worked my way backwards I still had trouble getting glue onto the strips.
The really good thing was that I could see immediately where I had missed, and redo it.
Dave - Thanks for your idea. I'm going to give that a try also.
I saw a video today that showed the builder applying thick CA to all the strips and then spraying a light coat of kicker on the sheet, then laying the sheet down.

Thanks for all the help - Much appreciated!

[piker]

Hey Mark,

That "glue the front first" only works on the LE sheeting where the ribs curve away from the sheeting.  Anywhere else, like the back half of the ribs or anywhere fairly flat like that, I just carefully check the fit of the sheet, then apply CA to the whole area (open framing like the wing rib... or even sheet on sheet type bonds) then add the sheeting and move my hands around to hold it in place while the CA set-up undernrith.  Yes, sometimes I'll spray kicker of the dry part before adding to the glued surface, but that's not usually necessary wth balsa on balsa.

Robert

[msatin]

The CA method using Slo-Zap is the winner hands down.
The sheeting here is 1/8" and quite curved.
I sprayed them with Windex last night and weighted them down overnight so they more or less had the shape.
Gave them another very light Windex spray this morning and then applied the Slo-Zap to the spars and formers.
Once I was happy with the position of the sheet, I hit the ends with kicker just to make sure there was no movement, then lightly pressed the rest of the sheet to to ensure contact everywhere.
Another benefit was I didn't need to use pins, tape or weights to hold it in place while it cured.
I was surprised how much time I had to coat everything with the CA, and am very happy with result.
Thanks David & Rob for your suggestions!

[davidk]

That looks really good... nicely done.