Tissue sealing issue

[AndyMech]

Hi,

New to the forum, but have tried to do a lot of reading. I'm partway through my first build ever (Thomas Morse Scout), and have covered the wings with the kit's stock tissue paper.

I covered using glue stick and shrunk with water, and achieved (after a couple of do-overs) a decent tight cover. Not as good as some of the photos I've seen, but acceptable to me.

Next step was to seal the tissue and I used a 50/50 glue/water mix and painted it on. The trouble is, the tissue on the wing got quite loose (which I expected), but when it dried there were a ton more wrinkles than before I applied the sealant.

Couple of questions:

1. When using glue/water as sealant, did I perhaps put way too much on, causing significant softening of the tissue? How thin should I be applying it?

2. Is there any way short of removing all the tissue from the wing (difficult) to fix these wrinkles? I tried spraying with water again and *gently* moving the tissue around so when it dried it would lie flat, but it didn't really work.

3. After applying the sealant, is it necessary to pin or weight down the wing to prevent warping? I did pin it down after the initial water shrinkage, but wasn't sure about after applying the glue/water mix.

4. When putting tissue on the wings, I did not apply any glue to ribs -- just the leading and trailing edges. Is this normal or should I have anchored the tissue to the ribs as well?

Thanks for any replies.

Andy.

[sissyboy]

what I found works well for me is I pre shrink the tissue with water before applying to plane.

when tissue is dry, I usually tack one end and then pin it down...then i will sparay it with krylon to seal it and pull it tight while its wet... it takes practice but works well.
I wouldnt recommend applying glue to ribs...just leading and trailing as you have done.

[cliffm]

When using white glue give the balsa surfaces coming in contact with fabric one coat of 50-50, let dry completely,you will now feel all the little stickers and rough spots that you need to sand smooth and apply another coat which should come out nice. Now take your pre-cut piece of fabric ,wet it completely, drag it over a towel to take off excess water, apply it to the surface pulling it tawt, not tight enough to distort the fabric, but take the wrinkles out. Now take your mix and coat the whole thing adjusting as you go keeping all contact surfaces moist enough to still be movable. Do not pull tissue so hard as to stretch it as you will lose the shrink affect. You will find small wrinkles and droops will disappear on drying. If you keep an eye on it while its drying you may be able to "doctor" on the problem spots, but be careful as this is a delicate procedure. This method has worked very well for me on large and small surfaces. I use an air brush from here on out and apply just enough to see the fabric start to sag and than let it dry again. If your fabric seems porous after the initial first coat you can give it another coating of 50-50 or I have found mixing my acrylics with some white glue and water to attain a viscosity compatible with the air-brush works extremely well. What kills the process is putting to much, too soon. Let each coat dry completely. I have used as many as 6 coats on darker colors to get rid of the translucence. Hope this helps, good luck.

[AndyMech]

To follow up:

Thanks for the replies -- since I had already attached the tissue using a "dry" method, I will try the wet methods described here perhaps for next time. It seems those techniques are using the glue/water mix as both the adhesive and the sealant?

To fix my problem, I repeatedly wet the wrinkled, sealed, tissue and moved it around with a small brush so when it dried it would not catch on the ribs. It took maybe 4-5 repetitions of this, but I finally got it about as smooth as I'm going to get it. This was on one half of the lower wing, as I hadn't sealed the other half or the upper wing yet.

When I sealed those, I used a lot less glue/water and went slow, and worked in non-adjacent sections, waiting for it to dry before moving on. Worked quite well, and I didn't have the overly wrinkly state I did with my first attempt.

When I go to paint (after assembling the wings, tail, etc), I plan on using an acrylic paint, and assume I'll have to apply a few thin coats as opposed to one thick coat? This is a display model, so I'm not worried about weight at all, but I don't want the tissue to loosen up too much and not dry properly. I assume it's also ok to apply regular acrylic paint over this sealed tissue? Is it necessary to thin the paint or not? I don't have an airbrush, so was going to just paint it on with a regular brush.

I'm pretty slow with the build, but I did manage to get both wings on last night -- I made a homemade jig out of cardboard to hold the upper wing in place (again, based off what I've read here), and the end result (with the wings anyway) looks great -- lined up properly, no skew that I can see visually. I think that should be the hardest part, next would be the landing gear.

Thanks again for your suggestions.

Andy.