Teakle ASW 20 3.5/1

Let us all watch your new project progress.
Post Reply
Jolly Roger
Posts: 298
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Teakle ASW 20 3.5/1

Post by Jolly Roger » 19 Jun 2016, 22:05

For durability I would glass. It's a lot more work but as already said, the finish can take more knocks and if you do get a scratch it's easier to repair - with covering film you really need to recover the whole panel to avoid that naff "patched" look. It does add a little more weight, but you get the benefit of extra torsional strength too (especially if you can be bothered to lay the glass at 45 degrees, although I never have).

My PT 20 is 21 years old and still one of my faves! If I totalled mine, I'd buy another. I'm sure you'll love yours too.

Rog

P.S. Look - that glass finish is so tough you can even land it on wooden benches.
Attachments
P1120182(1).JPG

Martin Church
Posts: 75
Joined: 06 Oct 2015, 11:23
Location: Somerset edge of Mendips

Re: Teakle ASW 20 3.5/1

Post by Martin Church » 26 Jun 2016, 21:08

Had a chat about this subject at the SWSSA event at charter house. I am going to cut the flaps & ailerons off the wing (living hinged)
I will then glass the wing as I can't see a way to go it with flaps & ailerons in situ.
Martin

Martin Church
Posts: 75
Joined: 06 Oct 2015, 11:23
Location: Somerset edge of Mendips

Re: Teakle ASW 20 3.5/1

Post by Martin Church » 11 Jul 2016, 10:35

Both wings now finished Canopy finally glued on with impact adhesive. The horizontal tail panel seems to have enough torsional strength as it is so I will film cover that & the Rudder.
Now onto the horrible task of glassing the wings all 5 metres plus of them :(
I'm going to buy 25g sqm whing skinning cloth & a 1kg pack of EL20 slow setting epoxy from easy composites now before I order said skinning components is there anything else I will need from them?
Martin

User avatar
Peter Balcombe
Posts: 942
Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Teakle ASW 20 3.5/1

Post by Peter Balcombe » 11 Jul 2016, 16:12

Martin
It may be worth getting in some methylated spirits to use as an epoxy thinner/cleaning agent, latex or similar gloves to minimise skin contact with the epoxy in case you are allergic/become allergic to epoxy, plus measuring cups/scales and mixing containers.
You also need something to spread the mixed epoxy onto the wing/cloth & this is probably dependent on the mixed resin viscosity.
I could never get on with the usual more viscous resins using the "credit card spreader" application method as this ends to "grab" the cloth, making for an untidy/messy covering. I have tended to use the less viscous 24/36hour cure resins from Bucks Composites. These are quite runny and are easily spread with a 2" wide roller (either hard nylon, or the standard soft foam roller that I tend to use). The foam roller generates lots of air bubbles in the epoxy, but these quickly disperse due to the low resin viscosity. It is easy to see when the cloth has been wetted out as it changes from white to clear. The foam rollers are dscarded once used as the resin cannot be/is not worth being cleaned out.
Note that the idea is to use minimum resin to avoid weight gain, whilst ensuring full wetting out of the cloth/substrate material. I usually apply a 2nd cloth weave filling coat after sanding back all excess cloth/rough edges/cloth surface using 80-240 grit. I sand the final coat using Wet & Dry (used wet), working up to 600 grit.
Also note that you will need a sharp pair of scissors/scalpel blade to cut the cloth without snagging.
A good tip is to mix up a couple of smaller resin quantities for each wing as they will not start rapidly curing in the mixing pot to the extent that larger quantities do.
Good luck. :)

Martin Church
Posts: 75
Joined: 06 Oct 2015, 11:23
Location: Somerset edge of Mendips

Re: Teakle ASW 20 3.5/1

Post by Martin Church » 11 Jul 2016, 17:31

Cheers Pete you make it sound even worse than id imagined :(
I was even thinking of going the glosstex route?
I'm not overly worried on cost as I know it's expensive what I'm worried about is arseing up the glassing.
Martin

User avatar
Peter Balcombe
Posts: 942
Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Teakle ASW 20 3.5/1

Post by Peter Balcombe » 11 Jul 2016, 19:28

Martin,
Process probably sounds worse than it is in practice.
Have a look at the Bucks Composites web site as this contains a few "How to" guides including wing finishing. The guide covers both the "credit card" & "roller" techniques.
As you are close to me then I could always show you if reqd. (PM me if you like).
Peter

User avatar
B Sharp
Posts: 642
Joined: 19 Mar 2015, 17:18
Location: Perthshire

Re: Teakle ASW 20 3.5/1

Post by B Sharp » 11 Jul 2016, 19:34

Martin, it is not as difficult as it sounds. Think of it this way - you are gluing cloth to a wing with epoxy - simplesss.
Peter is spot-on with his sugestions so I have little to add there. I will advise you to cut a bit extra cloth all round the wing to give a good overlap. Spread the cloth on the wing and start by dribbling epoxy out the centre of the wing from root to tip. Then work outwards going from the centre to the LE and to the TE alternately. This will keep the glass from rucking up. Dont be frightened to put a fair amount of epoxy on to get a good wetting out of the cloth. Once it is all covered, wet and glossy, you can go over it with a credit card scraping off the excess, working chordwise from the centre line of the wing. Dont forget to wet well over the LE and TE.
Most important wear rubber gloved as epoxy gan get to you after a while.
Brian. :)

Martin Church
Posts: 75
Joined: 06 Oct 2015, 11:23
Location: Somerset edge of Mendips

Re: Teakle ASW 20 3.5/1

Post by Martin Church » 11 Jul 2016, 20:12

Ok I'm sold on it, those gorse bushes have teeth I guess. I will have a look on bucks composites website. How much cloth & resin for a 5 metre wing? Cloth's a metre wide as far as I know.

User avatar
Peter Balcombe
Posts: 942
Joined: 18 Mar 2015, 10:13
Location: Clevedon, North Somerset, U.K.

Re: Teakle ASW 20 3.5/1

Post by Peter Balcombe » 11 Jul 2016, 20:44

Martin,
I use the 25g cloth for skinning all my wings, including the ASW20. You only need a couple of inches overlap all round, so a 2m cloth pack may well be enough, although you would probably need a join (at tip end). A 3m pack would certainly be enough to use a single length for each wing panel.
I am pretty sure that I initially got one of the standard kit packs for my first attempts with the Bucks Composites materials & that was more than enough to do a complete wing/tailplane set on a 1/4 scale model, so will also do the '20.
You don't actually use as much resin as you might think.

Jolly Roger
Posts: 298
Joined: 30 May 2015, 20:35
Location: Sutton Bank, North Yorkshire

Re: Teakle ASW 20 3.5/1

Post by Jolly Roger » 12 Jul 2016, 23:43

Some great advice here on g/f wing skinning. If I could just add an important elf n' safety point...

Always use vinyl gloves with epoxy/polyester resins. Although latex gloves keep the sticky mess off your skin, they let the nasty chemicals straight through. So you feel safe from the carcinogens, but they've leaked right into you.

Easy Composites stock boxes of vinyl gloves for this reason.

Rog

Post Reply