Semi-scale ASH25

[Jolly Roger]

Then I masked off the area and applied polyurethane glue, possibly the best glue ever invented except that (a) it foams as it dries and gets EVERYWHERE, (b) it is quite pricey, (c) it gives you cancer, as it admits on the label with remarkable honestly.

I'm using the Everbuild brand of polyurethane.

[Jolly Roger]

Then lots of slightly panicky rigging and jigging to check all the angles were true before the glue grips. Yep, all good.
(Also...an excuse for a sneaky bench-fly )

After lunch I’ll fit the deck above the wing roots and then I can actually start glassing the fuselage, which is good because if I leave it much longer it will be more dented than my car...

[Jolly Roger]

Front fuselage foam work now basically done, after adding foam fillets under the wing roots, then filling and final sanding. Polyfilla worked well - it sands about the same rate as the foam.
I used the shallow evening sunlight as it shows up every imperfection. And crikey the wing roots look rough! I’ll rework them with micro balloons after I’ve got the first layer of cloth on.

[Jolly Roger]

I’ve just parcel-taped the fuselage so I can mould the cockpit rim, and made a former for this too.

Was disappointed that the tape ended up with wrinkles (like you do when you try to get a flat material to take up a compound curve) but am hoping this won’t show through the glass cloth too badly.

May need a break now due to work, but hope to inch the project forwards whenever I can steal a minute.

[Elliot Howells]

Hey Rog, that's coming along lovely!

I presume you'll be removing the foam with solvent? Is the tape just stop excess epoxy soaking through to the foam then? Intriguing...

Hope it's as nice for you up there as it is down here.

Ell.

[RobbieB]

Rog,

I've always used parcel tape to protect my foam canopy plugs and it's fine - on a 'normal' canopy. When it came to the 100 plug, the acute compound curves were a nightmare - the tape actually lifting off in places after a little time.

I found a very good solution in giving the plug three coats of undiluted PVA, brushed on and allowed to dry thoroughly between coats and that completely protected the foam from polyester resin - and we all know what that does to foam.

It was only cheapo builders PVA that I used (or maybe my granddaughter's creative learning stuff - can't remember, but I will undoubtedly be found out in due course if it was the latter!).

[Jolly Roger]

Some useful tips gents - thanks. Yeah Ell, weather is glorious - but I'm stuck inside teaching!

Interested to hear your tape lifted, Robbie. I hoovered the foam with a brush fitting before taping it and found the tape stuck really well (such that when I tried to reposition it it tried to take a chunk out!)

I'm not worried about the polyester dissolving the foam...as I'm using epoxy. But I will forever remember that sick feeling when my dad and I tried to join the foam veneer wings of our first model, a Cambria Capstan, using polyester resin! It just ate it's way through the cores. Ugh. Upsetting.

So yes, the tape is just there to prevent the foam sucking up all my precious epoxy, which would then become a nightmare to remove. I'll chisel out most of it then use maybe petrol to wipe out the last bits. Will test first though as petrol is pretty aggressive stuff.

[Jolly Roger]

Cockpit surround moulded this evening.
Two layers of 200gsm glass (top one larger to reduce taper the strength) spot glued in place with cyano.

[Jolly Roger]

Then on to some proper glasswork at last!

The glass soaked out well and conformed amazingly to the tight curves around the wing root leading edge. I assumed I’d need to snip it here or there, but this twill weave really does take curves.

Then on with the waxed card to give a smooth finish to the cockpit ledge, then a layer of cling film, then masking tape to pull it all down tight.
Hoping for a reasonably sharp edge to the cockpit opening with no air bubbles.
Fun times!

[Jolly Roger]

So yesterday went well - removing the tape this evening revealed a beautiful crisp shiny cockpit rim, requiring almost no trimming. Check me out, master composite expert.

But then this evening I was back to my usual form - learning from mistakes!

The plan was to lay up 2 layers of 200gsm glass over the whole of the fuselage except the deck above the wing roots. However, it turns out those little wrinkles in the parcel tape not only show through the cloth, but seem exaggerated by it. So I only did one layer, and used the spare resin to glass the canopy plug.

When it’s cured I’ll have to sand out the bumps in the glass before I lay on the second layer. The fus should still be plenty strong as I hope to lay 200gsm Diolen inside after I’ve cleared out the foam.

You live and you learn, as my gran used to say.