Vintage Model Co Se5a

Thanks Andrew it was a pleasure to meet you too. I thought I had read the rules build the model exactly to the plan. I think the only area I could have done better was the head rest, I couldn't get the paper to hold its curve.
I am hoping some time at an indoor meeting will give answers, re flight. I will get there

Hi John, sorry to hear you haven't been well, but relieved the procedure went well. Look forward to seeing you soon.
Cheers
Danny

Due to a glitch in the system, ie no email notifications, which Mike is working on, we have a new member on the forum which I wasnt aware of, so would like to welcome Andrew Darby to the site.
He did his first post yesterday, lets hope it isnt his last .
May I request that he does do another one in the "Introduce Yourself" thread, so we know who we are talking to.
Welcome Andrew from myself and the rest of the Admin team, glad to have you aboard my friend

Garry

Andrew Darby wrote: Glad you enjoyed the SE5a. you made a super job of the build, remember kit scale isn't that tight, read the rules if you decide to compete again. I build a lot of the Veron designs but wouldn't dream of using the tissue in the kit!

As an additional note, if I want more climb I tend to use a shorter motor first before going up a width. This has two effects, first the torque is increased, and also the model is marginally lighter. Of course you can't pack in as many winds but duration is not the issue here. Also your turn was tight, a tab on the inboard wing bent down would have opened up the circle and increased the climb....

It was nice to meet you, and I hope to do so again.

Cheers

Andrew

Welcome Andrew, nice to see you on here! Can I re-iterate Garry's request for you to put a post on the intro thread.

For the rest of you, you need to know that Andrew is an accomplished FF Scale modeller and designer of a number of models, including the VMC Me109 I recently built, Septic's SE5A and Graeme's Tiger Moth! He'll be a great asset to the forum, I'm sure!!

Hi John, sorry to hear you haven't been well, but relieved the procedure went well. Look forward to seeing you soon.
Cheers
Danny[/quote]
Apologies for the confusion Danny, it was the daughter in law who was in hospital.
I'm too far gone, they have given up all hope with me,LOL.
nah I'm good, fit as a butchers dog

Hello,
I know this topic is quite old, but since I'm currently building the same SE5a from VMC, I thought it may be a good place to ask my question about shrinking the paper.

I have just started the covering of the model. I am using the paper provided by VMC. As it is my first free flight model, I started with the small tail skid. I followed the indications and all went very well for the 1st step: sticking the paper to the part with a glue stick + diluted PVA around the edges. The paper was already well taut.
Nevertheless, I proceeded with shrinking the paper. Since I bought a bottle of "Eze Dope" to also "varnish" the model for outdoor use, I followed the indication from VMC for the shrinkage, i.e., I sprayed water with 5% of Eze Dope on the tail skid to shrink the paper.
Sadly, now that the part is well dried, there are actually more small wrinkles than before (mostly where the paper is above empty spaces). I tried to spray the mixture again, but it does not improve.

Did I make something wrong? Is there a way to correct the situation?
Should I rather spray only water for the other parts ?

Remark: I'm pretty sure my mixture of 5% Eze Dope, 95% water is accurate, since I used a graduated pipette. The room temperature is about 25°C, so I think it is not due to a quicker evaporation than it should be.

Thank you for your advice!
Thierry

This may be what you need "Stick and Tissue" group. There are other groups too

www.facebook.com/groups/59076733448/

I have used Eze Dope.
I suspect your problem is spraying it with a very weak solution of Eze Dope. the tissue sags because it gets wet but then the Eze Dope "fixes" the tissue before it has fully shrunk.
It is important to get the tissue as evenly taught as possible.
I used lightweight 'Model span' tissue which is water 'resistant' so has less tendency to disintegrate when it gets wet. I just used a light fine spray of water on the best evenly taught surface I could get. When dry a gentle brush coat of Eze Dope with the softest brush I could find. Some say dilute Eze dope 50% with water. I did not but then mine was a power model, actually a sub 250g twin EDF.
I had to use Eze Dope as the plane was not made of balsa but entirely Depron foam. Ordinary dope just eats foam.

It remained wrinkle free even when painted with a light coat of water based emulsion.

I hope this helps.
There is quite a bit of technique involved. Like most modelling the more you do the better you get.

Eric wrote: [...]as you may have noticed, there is almost no free-flight activity on here any more.
All I can suggest is you make a 'test piece' of scrap bits, and experiment until you find what works.

Oh OK, I had not noticed. But 4 answers is pretty good.
Thanks, I have tried as you said to understand what happened. The tests with 100% water and with 5% Eze Dope both lead to satisfying results on the scrap parts; and almost undistinguishable. The size of "window" where the paper is floating is also similar.
I suspect the issue is what Quorneng suggests, although I do not really understand why it did not occur with the test part.

Klipkopwildlife wrote: I don't know eazy dope. What springs to mind is that tissue has a 'grain', it shrinks one way better than the other, could this be part of the problem. A bit of advice, keep any tail parts as light as possible.

Since the "window" in the part with wrinkles is circular, I doubt the 'grain' orientation is the reason.
About the weight: yes, I've read this in this thread and I've tried to minimize weight downstream of the CoG. In particular, I've sanded the horizontal and vertical stabilizers a bit thinner + sanded (symmetric) leading and trailing edges. I hope not too thin either.

Flytilbroke wrote: This may be what you need "Stick and Tissue" group. There are other groups too
www.facebook.com/groups/59076733448/

Thanks! Unfortunately, I've no Facebook account and I do not plan to make one at the moment.

Quorneng wrote: I suspect your problem is spraying it with a very weak solution of Eze Dope. the tissue sags because it gets wet but then the Eze Dope "fixes" the tissue before it has fully shrunk.

That could well be the reason, although I applied the dilution suggested by VMC.
However, I would expect the same or even worse with a higher content of Eze Dope, as long as the solution is wet enough to make the tissue sag. Or am I missing something?

Quorneng wrote: It is important to get the tissue as evenly taught as possible.

What do you mean by evenly taught?
When I applied the tissue on the stabilizers, I do not see how I could make it more or less tight (before shrinking). I can imagine it will be a bit more difficult on curved surfaces...

Quorneng wrote: Some say dilute Eze dope 50% with water.

I'll have to make some tests for the sealing (varnishing) step. Because VMC suggests 30% Eze Dope and 70% water after the shrinking step. So, I fear the same or even worse wrinkles.

Just to be complete, here is the text about Eze Dope in VMC's booklet:

This is a modern replacement for cellulose dope, and being water based it is fine to
be shipped by post. This is thinned (30% Eze-Dope to 70% water) and then brushed on the tissue
after it has been shrunk. If you choose to use the Eze-Dope, then you should shrink the tissue with
a 5% solution of it (rather than plain water) and pin the model parts down each time you apply a
coat, as you do when you shrink them following the instructions overleaf.

Thierry
Wrinkles are usually the result of either the tissue being initially tighter in one direction then the other, or the structure 'giving' as the tissue shrinks or the wetting process has actually stretched the tissue more in one direction then the other or any combination!

There are of course several different types of tissue. Some virtually disintegrate when it gets wet and some do not shrink evenly depending on the direction of its fibres.

Using the semi water proof "Model span" tissue I have found it is possible to 'pre wet' the tissue by simply dragging a suitable area over the surface of some water. This limits its degree of 'wet' yet it remains strong enough to be handled. I use a thin bead of white PVA as a glue which allows a degree of 'manipulation' of the tissue to remove any wrinkles. The PVA sets before the tissue fully shrinks.
Done like this the big advantage is the wet tissue is taught before it starts to dry. Wrinkles are only likely if the frames work actually distorts as the tissue shrinks.

The difference is not that clear but the tissue on the right is Model Span. The one on the left is normal white tissue.

The white tissue feels crisp. The Model Span feels soft.
How does your tissue compare?
I hope this helps.

Another way to the Stick and Tissue forum. No Facebook involved.
www.stickandtissue.com/forum/cgi-bin/yabb2/YaBB.pl