Jump to content

DB Sport and Scale Auster J1 Autocrat


Danny Fenton

Recommended Posts

So while the fuselage dries, (used aliphatic for most of this).

 

131.thumb.JPG.ce9665dc70e0877094e4af4cc06183c8.JPG

 

 thought I would give a covering material a go that I have heard great things about, Ceconite.

 

132.thumb.JPG.29766fe852886386113c1cb536a4c9cd.JPG

 

This is a covering that is used on full size aircraft and is a polyester fabric that is heatshrunk.

 

I am very lucky that Dave Hopkin, friend and fellow balsa basher sent me an offcut to try, Dave did you know the offcut was 2 mtrs by 1 mtr??? What were you covering???

 

I am going to apply it with dope, lets' see how it goes.......

 

*****Spoiler alert*****

if you are a subscriber to the magazine, look away, as this will no doubt sneak into my column, and I don't want to spoil the surprise ?

 

Materials I am using first.....

 

133.thumb.JPG.1cbd81d74c06cccaba36c776ab6e28b6.JPG

 

The rudder has been sanded to shape, I like to taper the trailing edges, not necessary, but that's just me. A coat of 50/50 dope has been applied, and let dry before we start.

 

More later.

 

 

Link to comment
Share on other sites

So a very enjoyable few hours faffing about, with little to show for it. Anyway to cut a long story short even my "neat" LAS dope would not stick it to the airframe.

The official product for attaching Ceconite to metal, wood and itself is their "super seam cement" It is £25 a quart, and if I do order some Ceconite I may add some to the order.

 

136.JPG.50e49f98442b7de70fa9ed9d1aa66e6d.JPG

 

However, for now I am going to try Balsaloc. Makes you realise how good an idea it is to put the iron on adhesive on the back of the film.

However Ceconite has serious shrink, and doesn't sag, so maybe the hassle will be worth it.

 

134.thumb.JPG.9402c26d5f98928537df203edf954261.JPG

 

So a layer of Balsaloc on the rudder, once dry I will give it a go.

 

Cheers

Danny

Link to comment
Share on other sites

Well it goes on just like Solartex

 

137.thumb.JPG.67bb560e517ca920587481dfd97c34af.JPG

 

but because it doesn't have a coating of glue everywhere it is a bit lighter, probably not a lot in it however.

 

138.thumb.JPG.d554a5833c0c1ee6eddecfa7929a833c.JPG

 

3 meters (remember its nearly 2 meters wide) with VAT and shipping (£11.95) is £42, add to that you will need an adhesive, £25 but will probably be combined in the same shipment so courier works out better. It will need to be doped to seal it too.

 

An interesting exercise.

 

Cheers

Danny

 

Edited by Danny Fenton
Link to comment
Share on other sites

Not so sure, DD. I really struggled to get the Ceconite to stick to itself on the second side, even after two coats of balsaloc. This may of course be a short coming of Balsaloc, ie not meant for this task. But I am not sure I want to spend another £30 to try some of the correct adhesive.

 

Still food for thought.

Link to comment
Share on other sites

1 hour ago, Dwain Dibley. said:

I suspect if you are building models the size local boy (to me), Robbie Skipton does, then it's a different matter.

D.D.

Yes you are quite right, it suddenly ramps up in cost, and the angles you are trying to force the material to wrap around are bigger, just because of the scale. I have reverted back to a silk I got from Berrisfords. It was too heavy to go over tissue, but may work alone.

I really enjoy doping a covering.

Cheers

Danny

Link to comment
Share on other sites

Okay ripped that off as well, it was not tautening as much as i expected, both applied dry and wet, the weave was not filling well either, but knew that would probably be the case.

So I have gone back to what I know and love, tissue and dope. It does mean the model is susceptible to knocks, but I think its a price I will just have to pay.

140.thumb.JPG.d2821fa21a2d267519b9ba92aeb93bd3.JPG

 

Cheers

Danny

Edited by Danny Fenton
  • Like 2
Link to comment
Share on other sites

Thanks, Yes I have heard of this, I have never tried it. I was hoping to keep away from an iron on covering. The seams are so difficult to hide and the covering imparts very little strength compared to a doped down solution. Maybe I should get with the times.

Cheers

Danny

 

Link to comment
Share on other sites

1 hour ago, Danny Fenton said:

Thanks, Yes I have heard of this, I have never tried it. I was hoping to keep away from an iron on covering. The seams are so difficult to hide and the covering imparts very little strength compared to a doped down solution. Maybe I should get with the times.

Cheers

Danny

 

 

I think you maybe surprised with the strength of lam film Danny, even 38 micron is very puncture resistant, plus the seams can be sanded back so they are very nearly hidden, there's a joint seam in this wing from root to tip.

 

image.thumb.png.33e4e519839513ed3d2d38e8cb81b777.png

 

Link to comment
Share on other sites

Thanks Ron, it is something I should look at.

It isn't the strength of the film that is in question, no heat reactive film covering imparts the same sort of strength to the overall airframe (open structure) as tissue/nylon/silk and dope.

 

I have attached an interesting article by Alasdair Sutherland, though a bit dated now, he explored this subject, and I can certainly vouch for the rigidity of the tissue and dope wings on my Hawker Fury.

 

StructuresArticle1.thumb.JPG.484f1ae1524ff946aaafc736db3584fb.JPG

 

StructuresArticle2.thumb.JPG.414d6283ed30fdb22645b4e8300944b1.JPG

 

StructuresArticle3.thumb.JPG.87417eca915fd235f129e917a3f37608.JPG

 

StructuresArticle4.thumb.JPG.140f9b8ce070369eacb631591574702b.JPG

 

table.JPG.710e4d2b58de10725ddbf03c1c68666b.JPG

 

Cheers

Danny

 

 

Link to comment
Share on other sites

19 minutes ago, Danny Fenton said:

Thanks Ron, it is something I should look at.

It isn't the strength of the film that is in question, no heat reactive film covering imparts the same sort of strength to the overall airframe (open structure) as tissue/nylon/silk and dope.

 

 

Aint that the truth!

  • Like 1
Link to comment
Share on other sites

Well some progress. I tried silk over tissue and that got ripped off, this poor rudder has been through the wars, and took a fair bit of sanding to get it back to useable.

A quick chat with modelling chum Simon Lawson who uses Ceconite said he uses dope to stick it down. I told him i couldnt get it to stick. Anyway long story short, you have to put two good coats of dope on the airframe. Then lay the ceconite on the structure and use thinners through the Ceconite to soften the dope below. And what do you know, it works really well!

 

Pics when back at my pc later.

Cheers

Danny

Link to comment
Share on other sites

Okay pics as promised. I know I didn't really want a heat shrink film but this I am hoping is a happy compromise. I managed to get the Ceconite to work really well, and once you have figured it out (thanks for the leg up Simon) its a doddle.

 

There is a trick to doing compound curves, but I have been advised by my lawyer not to tell anybody ? so if you want to know you better PM me ?

146.thumb.JPG.200c16c5a2d07ce247a32c57bfd3fd08.JPG

 

147.thumb.JPG.9ee3050e5e897d85fc3a0e4ec5d6fa38.JPG

 

148.thumb.JPG.16217f2ce3ee04567523a1789313fc98.JPG

 

149.thumb.JPG.30cc14e3a24ecae95bd9d1a2a6dead06.JPG

 

I guess many will say why not just use Oratex, and you are right, it will be heavier but not by much, It will hopefully not sag like some others, what does it for me is the edges, they are much thinner and flatter against the structure. And of course Ceconite is a great deal cheaper.

 

I think I may place an order with LAS for enough to do the whole model.

 

Cheers

Danny

 

Edited by Danny Fenton
  • Like 1
Link to comment
Share on other sites

took a brief look at the fit of the two main bulkheads, 105 and 106. Alas they do not match the plan, and I have built the fus sides according to the plan sigh...... why do I build other peoples kits, double sigh.........

 

105

150.thumb.JPG.2dacee2dec3a410cf3b7a42c921f77ed.JPG

 

151.thumb.JPG.506461ff50a16624119bffa105439a60.JPG

 

106

152.thumb.JPG.fb945fa12cd32fc25eae3483b221fca3.JPG

 

153.thumb.JPG.bbe51f8cde9cad4c157895a3d504b8e3.JPG

 

I will assume the bulkheads are correct and remake the tops of the fus sides.

 

This of course may have a knock on effect on the wing incidence, I will need to check for that later on.

 

Cheers

Danny

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...